DPLII & DPLIIx

[xiaoyu]

Hi,

I currently own a Denon receiver with DPLII which I love it and, I am using it almost 30 % of the time (My setup has 7 speakers). Can you hear a difference between II and IIx?

Xiaoyu,

[filecat13]

Yes, PLIIx is an improvement, especially in that it gives you 7.1 instead of 5.1 reproduction.

[xiaoyu]

Originally posted by filecat13
Yes, PLIIx is an improvement, especially in that it gives you 7.1 instead of 5.1 reproduction.

Are you sure that DPLII produces only 5.1 channels?

[rjsquirrel]

on a different note

See article in AV ultimate about 5.1 vs 7.1. The one or 2 extra channel may not be needed They say that 5.1 maybe better in smaller rooms. June 2004 issue I think.

[Philip Brandes]

Originally posted by rjsquirrel
on a different note

See article in AV ultimate about 5.1 vs 7.1. The one or 2 extra channel may not be needed They say that 5.1 maybe better in smaller rooms. June 2004 issue I think.
They are dead wrong, unfortunately. There is no way that 5.1 could ever be better than 7.1. There is no way to achieve a seamless enveloping soundfield with only a single pair of surrounds--there will always be a hole somewhere. If you have one pair of surrounds directly to the sides and another in the rear you get complete envelopment; the psychoacoustic research establishing this is quite definitive. Depending on your room and your listening position, you may achieve greater or fewer benefits from an additional pair of surrounds (fewer if your listening position is too close to the rear wall), but there will always be some benefit.

Cheers,
Philip

[spha]

Originally posted by Philip Brandes
They are dead wrong, unfortunately. There is no way that 5.1 could ever be better than 7.1. There is no way to achieve a seamless enveloping soundfield with only a single pair of surrounds--there will always be a hole somewhere. If you have one pair of surrounds directly to the sides and another in the rear you get complete envelopment; the psychoacoustic research establishing this is quite definitive. Depending on your room and your listening position, you may achieve greater or fewer benefits from an additional pair of surrounds (fewer if your listening position is too close to the rear wall), but there will always be some benefit.

Cheers,
Philip
No sir, he is not dead wrong. I have set up multiple smaller systems involving 5.1 and 7.1 setups and can tell you flat out that 7.1 setups in some rooms detract from the experience of DD or DTS. In a small room a properly set-up system with surrounds that have decent imaging, will trump the "pound me in the back of the head with effects" sensation that 7.1 can have.

-spence

[Philip Brandes]

Originally posted by spha
No sir, he is not dead wrong. I have set up multiple smaller systems involving 5.1 and 7.1 setups and can tell you flat out that 7.1 setups in some rooms detract from the experience of DD or DTS. In a small room a properly set-up system with surrounds that have decent imaging, will trump the "pound me in the back of the head with effects" sensation that 7.1 can have.

-spence
If you got poorer results setting up 7.1 system than a 5.1 system, then you set it up wrong. If you're getting a "pound me in the back of the head with effects" sensation" from 7.1 then you're most certainly setting it up wrong. A properly set-up 7.1 system will improve on a properly set-up 5.1 system every time. This is why Meridian and Lexicon and Fosgate have designed their cutting-edge pre-pros around 7.1 speaker setups for over a decade, and why Dolby, THX, and DTS have all followed their lead. It's also why none of them claim 5.1 to be superior under any circumstances. Nor will you find any published research to support your claim, although there is extensive research supporting the improvements of a second set of surround speakers.

This sour grapes argument that 7 speakers are unnecessary has been perpetuated in one form or another since the roll out of Surround EX as a home theater standard. The fact remains that the reason for using two pairs of rear surrounds is grounded in a solid body of psychoacoustical research that clearly establishes why a 5.1 speaker configuration is inadequate when attempting to create a seamlessly immersive soundfield. This has been well-known in audio engineering since the definitive work by Theile and Plenge, as reported in their paper “Lateralization of Phantom Sound Sources,” published in the Journal of the Audio Engineering Society, April 1977. Their tests into side panning and phantom imaging effects showed quite conclusively that due to differences in the way we hear sounds originating from the side vs. the front, if we attempt to create phantom images at the sides using only front and rear speakers, the images are highly unstable. Their conclusion is that: “in the search for a loudspeaker arrangement that allows for ‘all round effect,’ the directions right and left on the lateral (90 degrees) must be represented through real sources.” In other words, stable side imaging *requires* a *real* pair of speakers placed directly to each side of the listener.

It is easy enough to demonstrate this fact for yourself in any system or room. Sit or stand in the sweet spot, and play a mono source through your two front L&R speakers--you’ll hear a typical stable phantom center image. Now turn 90 degrees, so that one ear is pointed towards that phantom center--rather than remaining locked to a fixed location, the “image” will break apart. Hence the reason why a pair of physical speaker is needed directly to the sides of the listening position.

Of course, placing the side speakers at 90 degrees inevitably leaves a huge gap in the rear soundfield. That is why many 5.1 speaker setups have the surrounds positioned farther behind the listening position. The popular speaker placement at 110-degrees is a compromise that narrows (but does NOT eliminate) the rear hole, but this partial improvement comes at the expense of seriously weakened side imaging, because of the problem described above. Thus, there is no way to achieve a seamless soundfield using only one set of surrounds. Dr. Robert E. Greene wrote a very cogent article explaining the inherent limitations in attempting to create surround with only 5 speakers in “The Perfect Vision,” Issue 30. May/June 2000.

Adding a second pair of surrounds for a 7-speaker setup solves this problem handily. The sides can be placed at 90 degrees for stable side imaging, the rears can be placed at 150 degrees to close the rear gap, and voila!--seamless, smooth envelopment.

This is why home surround processors from manufacturers with expertise in psychoacoustics (Lexicon, Meridian, and PL II developer Jim Fosgate) have been building their technologies around 7-speaker configurations for many years. This is also why in developing the Surround EX format, THX and its Pro-Logic II partner Dolby Labs adopted a 7-speaker configuration for an immersive soundfield.

There may be some rare atypical rooms unable to benefit from an extra set of surrounds (I haven’t heard any, but I’m willing to concede the remote theoretical possibility), but that is no logical justification for a blanket assertion that a 5.1 system is preferable in small rooms. Once you know what to listen for, the ambient envelopment which makes up 99% of a film soundtrack (rain, wind, traffic, crowd noises, etc.) will never sound realistic because of the soundfield gaps that cannot be solved with only 5 speakers. And of course you use the intended directionality of EX and ES rear channel effects that are specifically encoded to be extracted and reproduced from the rears. That isn’t opinion, it is simply long-established scientific fact.

Cheers,
Philip Brandes

[Jesse S]

Spence would be right in a small room where the sofa or chairs are against the back wall. The only place to mount the rear surrounds is the back corners or a few feet above the sofa. Neither works so 5.1 is sufficient, and most suited to such a setup.

But, any room with 2' or more behind the sofa/chairs will benefit from a 7.1 setup. People often refer to the scene in Dragonheart where Drago(?) flys around Dennis Quaid. It never sounds right with only 2 surrounds.

[NightHawk]

xiaoyu,
I just had my Denon receiver upgraded tp PLIIx and it was a nice improvment. Both the cinema and music modes have an improved surround effect and I considered it worth the effort, even in my 22 by 15 foot room.

[BruceOmega]

Referring to the orginal subject, can DPLIIx generate 7.1 outputs from 2.0 and 5.1 and 6.1 sources?

My understanding is that DPLII could only generate 5.1 outputs from 2.0 sources, and I'm not sure it could be applied to 5.1 or 6.1 sources.

Thanks
Bruce

[sdurani]

Bruce, Referring to the orginal subject, can DPLIIx generate 7.1 outputs from 2.0 and 5.1 and 6.1 sources?Yes, PLIIx can generate 6.1 or 7.1 outputs from 2-channel and 5.1-channel material. With 6.1 sources it ignores the discrete surround-back channel and treats the material as a 5.1-channel EX/ES encoded soundtrack. No sound is lost because the entire contents of the discrete surround-back channel are duplicated in the Left & Right surround channels. PLIIx can extract the surround-back information and steer it amongst the two rear speakers. My understanding is that DPLII could only generate 5.1 outputs from 2.0 sources, and I'm not sure it could be applied to 5.1 or 6.1 sources.Your understanding is correct: PLII outputs five channels maximum (the .1 channel is simply a subwoofer output that your receiver/processor creates via bass management). Therefore PLII can't be applied to 5.1 or 6.1 sources. I mean, what would it do: convert a 5.1 source to ...5.1? ;)

Best,
Sanjay

[BruceOmega]

Sanjay,

Thank you for clarification. Sounds like Logic 7's capabilities- 7.1 outputs from any source.

The last part of my post was poorly worded, sorry. Dates back to more than a year ago when I was looking into alternatives to Logic 7 and wondering if DLPII could in any way expand 5.1 to 7.1; e.g., when a PrePro had DPLII but not THX Ultra II. Appreciate you keeping me straight.

Thanks
Bruce

[Philip Brandes]

Originally posted by Jesse S
Spence would be right in a small room where the sofa or chairs are against the back wall. The only place to mount the rear surrounds is the back corners or a few feet above the sofa. Neither works so 5.1 is sufficient, and most suited to such a setup.

But, any room with 2' or more behind the sofa/chairs will benefit from a 7.1 setup. People often refer to the scene in Dragonheart where Drago(?) flys around Dennis Quaid. It never sounds right with only 2 surrounds.
As I mentioned in my first post above, having the seating position close to the rear wall will lessen the advantages of 7.1, but not eliminate them. There are several ways to make this work, by using small rear speakers firing up from behind the couch or down from high on the rear wall (Gallo Acoustics lend themselves very well to such applications), and moving the side speakers slightly forward (1 foot or less). It isn't ideal, but it will still improve over 5.1. I have gotten good results mounting rears high above the sofa, with tweeters aimed at a slightly deflected angle away from the listener.

As you point out, moving the seating even a little bit into the room will make a much more significant improvement. But it is not accurate to say that 5.1 is most suited to even that setup. 7.1 can work with a little ingenuity.

Cheers,
Philip Brandes

[sdurani]

Bruce, Sounds like Logic 7's capabilities- 7.1 outputs from any source.Functionally they're very similar, though there are a couple of minor differences. PLIIx gives you the flexibility of having 6.1 outputs whereas L7 does not (Lexicon is dead set against a single rear speaker, it's not even an option on their processors). And with DTS ES Discrete 6.1 soundtracks, L7 works a little differently than PLIIx in that the discrete surround-back channel is not ignored but simply steered between the two rear speakers (this may seem like a big deal but the difference in sound is negligible).

Best,
Sanjay

[sdurani]

Originally posted by Philip Brandes
It isn't ideal, but it will still improve over 5.1.It may not be ideal but it is important to point out that it allows the various surround channels to be individually localizable. Even if the rear speakers are behind the couch pointing up, listeners off to the sides will be still able to localize surround-back content as being separate and distinct from surround Left & Right content. No fancy processing involved, just speakers at the side of the room vs speakers at the rear of the room (makes it difficult for those sounds to appear from the wrong direction). This kind of imaging stability in the surround field, especially for listeners out of the sweet spot, is simply not possible when using only 2 surround speakers.

Best,
Sanjay

[rtype]

Originally posted by Philip Brandes
As I mentioned in my first post above, having the seating position close to the rear wall will lessen the advantages of 7.1, but not eliminate them. There are several ways to make this work, by using small rear speakers firing up from behind the couch or down from high on the rear wall (Gallo Acoustics lend themselves very well to such applications), and moving the side speakers slightly forward (1 foot or less). It isn't ideal, but it will still improve over 5.1. I have gotten good results mounting rears high above the sofa, with tweeters aimed at a slightly deflected angle away from the listener.

Philip

Your posts in this thread have been awesome. Thanks a lot. I'm fleshing out my system to 7.1 soon (speakers have just arrived) and my seating is pretty close to the rear wall. My main (L & R) speakers are floorstanding and I'm planning to wall mount all five of the others. Because I have a projection screen, the center channel will be mounted high and angled down to the seating area. I'm planning to mount the other four speakers at this same height, side left angled down to target the rightmost listener's head, right angled down to target the leftmost listener's head. Since the seating position is close to the rear speakers, how should I angle them?

[xiaoyu]

Hi,

Somehow I thought that DPLII could produce 6.1 from 2 channel Dolby signal, which the back surround channel is mono and came from two surround channel like the DPL do for center channel. Am I wrong? BTW, I read a review (Sound & Vision) long time ago when DPLIIx just came out. The reviewer said the differencs between DPLII and DPLIIx are very small for him.

Xiaoyu,

[sdurani]

Hi Xiaoyu, Somehow I thought that DPLII could produce 6.1 from 2 channel Dolby signal, which the back surround channel is mono and came from two surround channel like the DPL do for center channel. Am I wrong?Yes. As mentioned earlier, PLII outputs a maximum of 5 channels. If you want 6.1 or 7.1 from a 2-channel source you'll have to use PLIIx. BTW, I read a review (Sound & Vision) long time ago when DPLIIx just came out. The reviewer said the differencs between DPLII and DPLIIx are very small for him.That's entirely possible, especially if the reviewer's speaker set-up couldn't take full advantage of the difference between PLII and PLIIx.

Source material can also make the difference more noticeable or less. I've heard some 2-channel material that really highlighted the rear vs side imaging of PLIIx. I've heard other 2-channel sources where the surround field was just a sonic blur; it wouldn't have made much difference if you were listening with PLII or PLIIx.

Best,
Sanjay

[jbjbjbjb]

Spence would be right in a small room where the sofa or chairs are against the back wall. The only place to mount the rear surrounds is the back corners or a few feet above the sofa. Neither works so 5.1 is sufficient, and most suited to such a setup.

With my sofa directly against the back wall I have a pair of JBL N24's facing downward from about 7 feet high. For me this works perfectly, especially with flyovers, it sounds like helicopters or spaceships directly from above as it should be. This PLIIx system blows away my old 5.1 system. Its not even close.

[mn_hokie]

I was in a similar situation when setting up my room. I wanted to go 7.1, but my rear wall is only about 8 feed wide, so I decided to mount a speaker in the center for 6.1 instead. My seating is fairly close to the wall, so I decided to put my side surrounds in the ceiling and the rear channel in the wall. All three are Klipsch speakers, so I was able adjust the tweeter to aim toward the viewing area. Not perfect, but I feel like I'm able to get better sound in my situation than wall mounts would have provided me with.

[xiaoyu]

Hi,

Why do I hear the sound coming from two back speakers when I set my Denon 3802 to DPLII with Dolby stereo sonrce?

Xiaoyu,

[sdurani]

Xiaoyu, Why do I hear the sound coming from two back speakers when I set my Denon 3802 to DPLII with Dolby stereo sonrce?Because the Denon doesn't want two of the speakers to go silent when you're listening to 5-channel material. My processor does the same thing with 7.1-speaker set-ups: the side and rear speakers are run in parallel when I use PLII. The Left surround channel is reproduced by the Left rear and side speakers; ditto the Right surround channel. With PLIIx you would actually get unique content in each of the 4 surround speakers.

Best,
Sanjay

[filecat13]

If you guys would have just written, "Yes, he's right" after my initial reply, think of all the time and energy you would have saved. I'll bet you all drive SUVs with big chrome wheels, leave your lights and TV on all night, use the water hose to "sweep" your driveway, and hold the refrigerator door open for hours while you drink out the milk carton and look for something to eat. :p

[rtype]

Originally posted by filecat13
If you guys would have just written, "Yes, he's right" after my initial reply, think of all the time and energy you would have saved. I'll bet you all drive SUVs with big chrome wheels, leave your lights and TV on all night, use the water hose to "sweep" your driveway, and hold the refrigerator door open for hours while you drink out the milk carton and look for something to eat. :p
If you lived in Texas, you'd be looking for any excuse to leave the fridge door open or turn on the hose, too. Regardless, I thought some interesting and more detailed responses came after yours so I'm glad they happened even if most of us did agree with your post just as a matter of common sense. :)

[joerod]

I just had my 5803 upgraded with DplIIx and with Directv broadcast it is MOST definitely an IMPROVEMENT! It is hands down better than PLII. It gives DTS-NEO6 a run for the money. It may be better but I need more time to decide that. X box games sound 100% better. I can't wait to watch NFL games and feel the difference...

[filecat13]

Originally posted by rtype
If you lived in Texas, you'd be looking for any excuse to leave the fridge door open or turn on the hose, too. Regardless, I thought some interesting and more detailed responses came after yours so I'm glad they happened even if most of us did agree with your post just as a matter of common sense. :)

You're right, of course, on both counts. I spent some time in Dallas. My smart-a** analysis:

Winter: Yikes! It's freezing rain.
Spring: Two beautiful days.
Summer: Yikes! It's an extreme sauna all day, every day.
Fall: Two beautiful days.

However, I enjoyed watching the Burn play in the Cotton Bowl, and I enjoyed the discussion in this thread. ;)

[sdurani]

Originally posted by filecat13
Winter: Yikes! It's freezing rain.
Spring: Two beautiful days.
Summer: Yikes! It's an extreme sauna all day, every day.
Fall: Two beautiful days.Well at least they have four seasons. Here in Los Angeles we only have two: Hot and Hotter.

Sanjay

[rtype]

Originally posted by sdurani
Well at least they have four seasons. Here in Los Angeles we only have two: Hot and Hotter.

Sanjay
Right, and LA is hotter than Dallas, huh? :rolleyes:

[BruceOmega]

Sanjay,

Didn't realize you were in LA. I was associating Monterey Park with Monterey, CA!

Thanks
Bruce

[sdurani]

Originally posted by rtype
Right, and LA is hotter than Dallas, huh? :rolleyes: There are times when it can be, especially if you're inland and away from the ocean breeze. Nothing mild about the oven-like weather of the San Fernando Valley in August. The only saving grace is the relatively dry air. When it comes to humidity, yes - Dallas wins.

Best,
Sanjay

[sdurani]

Bruce,

Yeah, people confuse those two cities all the time. Monterey is a nice coastal city north of me. Monterey Park is a predominantly Chinese neighbourhood (yes - pretty women, great food) just east of Downtown LA.

Best,
Sanjay

[keenan]

Originally posted by rtype
Right, and LA is hotter than Dallas, huh? :rolleyes:


How many times have you been water skiing or to the beach on Christmas? I lived there for over 30 yrs and when it rains people look toward the sky like it's some sort of alien attack:D

Jim

[rtype]

Originally posted by sdurani
There are times when it can be, especially if you're inland and away from the ocean breeze. Nothing mild about the oven-like weather of the San Fernando Valley in August.
There are times when Toronto is hotter too, but it's pretty rare. The average temperature of Dallas is higher than LA and the extremes are more severe. In my visits to LA, I'm always amused by people saying "how hot it is" when it's only 80.

LA http://www.weatherbase.com/weather/weather.php3?s=159227&refer=
Dallas http://www.weatherbase.com/weather/weather.php3?s=095227&refer=

[rtype]

Originally posted by keenan
How many times have you been water skiing or to the beach on Christmas? I lived there for over 30 yrs and when it rains people look toward the sky like it's some sort of alien attack:D
I'm not into water skiing, but people do go to the lake here year round. We get 90s in January sometimes. I'll give you that it rains more here, but it's definitely not cooler.

[bluesjam]

Hi, new here, been doing a lot of reading the last couple of weeks, great info!

Just purchased some new Polk speakers and have H/K 630 on the way, should be here today. I'm excited! :)

I've had a Sony 5.1 HTIB for a couple of years now (I know, what was I thinking) and thought I was going to stick with 5.1 but this thread got my attention and now I think I want a 7.1 system! See what you guys do to me! I could use some help/advice.

Here's my setup for now:
Fronts: RTi8
Center: CSi5
Surround: FXi3

Surround are placed in rear corners right now, center is on top of Sammy DLP. I have about 2-3 feet between the wall and where I sit. If I want to add the back speakers which ones should I get? Should I just use the small Sony from my HTIB or get something to match my Polks?
What height should the surround be at if I move them to the sides?
What height should I mount the back speakers and should they be facing downward or upward? I prefer to mount them on the wall so that they're not in the way behind the couch, there's a door to the backyard there.

I read that the 630 doesn't support DPLIIx right now but will with an update soon, am I right?

Thanks for any help!

Jamal

BTW, speaking of heat, I'm in Florida, we know all about heat and humidity! But, we got it made in the winter! :)

[hvn4179]

Didn't see discussion on using PLIIx w/ 6.1 speakers configuration, what do you think of it merit versus the 7.1? I plan to buy a new receiver that could be the Panasonic XR-70 or the Kenwood VSR-7100 but they only come w/ 6.1.

[scolumbo]

Originally posted by hvn4179
Didn't see discussion on using PLIIx w/ 6.1 speakers configuration, what do you think of it merit versus the 7.1? I plan to buy a new receiver that could be the Panasonic XR-70 or the Kenwood VSR-7100 but they only come w/ 6.1.

I expect Sanjay will jump in here to give the full explanation, but the short version is *don't* go with a 6.1 speaker configuration. Use a 7.1 speaker configuration even if the receiver only does 6.1.

My question is, with all the new receivers coming out with 7.1, why would you buy a 6.1 receiver?

All you guys talking about the heat in Dallas and LA, I laugh at you here in Jax, Florida.

[mn_hokie]

I have a 7.1 receiver with a 6.1 speaker setup. Simply put, an additional speaker on my back wall would be no more than 12-18" away from the center speaker there now, since the back wall is so short.

I can't justify any improvement in sound by having a speaker that close to the one already there, especially considering the additional cost of a speaker and the fact that the sound generated currently is identical to the effect being heard from the single center rear one.

Maybe my opinion will change on my next home, which will have a larger back wall. Hopefully 7.1 titles will actually be in production at that point :)

I agree with not advising someone to purchase a 6.1 receiver these days. You don't want to be kicking yourself in the head when 7.1 becomes the preferred choice and you're one input too short :)

[hvn4179]

Many new low/mid range digital receiver only come out w/ 6.1 channel only. Either w/ the 7th speaker in use, it must connect either in parallel or in series w/ the 6th (sharing the surround back channel). So if DPLIIx promises to deliver a separate content for the back pair then how it be done in the 6.1 configuration?

[sdurani]

Originally posted by scolumbo
I expect Sanjay will jump in here to give the full explanationYou rang? ;) I'll give my usual speil:

The problem with 6.1-speaker set-ups is that having a single rear speaker behind the listener can be problematic. It's an old and well documented phenomenon called back-to-front reversals, where sounds along the listener's centre line can momentarily appear to come from the opposite direction. Remember that when we hear sounds equally loud in both ears, our ear/brain mechanism tell us that the sound is directly in the middle but can sometimes be confused about whether it's directly in front or directly behind.

Now, this isn't normally a problem for a single centre speaker up front because our hearing acuity is at its best in the frontal hemisphere. However, our hearing is not so hot behind our heads and this is usually where reversals can be a problem. The solution to this problem couldn't be easier: instead of a single rear speaker, simply use two and space them well away (at least 30 degrees away) from the centre line.

This is one of the primary reasons that Dolby and DTS and THX all recommend using two rear speakers when decoding EX/ES encoded soundtracks (even though the surround-back channel is mono). You'll notice that this is the only channel where it is recommended that two speakers be used for playback. As Philip mentioned earlier, companies that have been at the leading edge of surround processing (Fosgate, Meridian, Lexicon) have all historically built their proprietary technologies around a 7-speaker set-up. There's a reason none of them went with 6 speakers. My question is, with all the new receivers coming out with 7.1, why would you buy a 6.1 receiver?Indeed. I think 6.1 was a cheat on the part of manufacturers; it allowed them a way to feature EX/ES decoding without having to scare consumers away with the prospect of buying two additional speakers. But it seems people are actually embracing 7.1 rather than being overwhelmed by it. So hopefully 6.1 will go away eventually. All you guys talking about the heat in Dallas and LA, I laugh at you here in Jax, Florida. Show off!

Best,
Sanjay

[sdurani]

Originally posted by hvn4179
So if DPLIIx promises to deliver a separate content for the back pair then how it be done in the 6.1 configuration? Obviously, it can't. I mean, how can you get stereo from one speaker?

If you haven't purchased a receiver yet, then I would strongly urge you to consider a 7.1 model with PLIIx processing rather than go 6.1.

Good Luck,
Sanjay

[Gables]

Originally posted by scolumbo
All you guys talking about the heat in Dallas and LA, I laugh at you here in Jax, Florida.

Try living in South Florida this time of year. It's an absolute sauna. You can't walk 10 feet without perspiring. How much longer until fall?

[hvn4179]

Thx guys for answers. Both mentioned receivers, Pana SR70 and Kenwood 7100, are the latest as they have DPLIIx but only provides 6.1 channel output. I don't know how do they be DPLIIx certified w/ 6.1 versus 7.1.

[sdurani]

Originally posted by hvn4179
I don't know how do they be DPLIIx certified w/ 6.1 versus 7.1.PLIIx can be on 6.1 or 7.1 channel receivers. However, the only way to take full advantage of it's capabilities is with 7 channels.

Best,
Sanjay

[mboy]

Originally posted by jbjbjbjb
With my sofa directly against the back wall I have a pair of JBL N24's facing downward from about 7 feet high. For me this works perfectly, especially with flyovers, it sounds like helicopters or spaceships directly from above as it should be. This PLIIx system blows away my old 5.1 system. Its not even close.

I have similar situation.

Couch is 1.5' from rear wall, have a pair of N24's firing up towards ceiling.

Orderred my Pio 1014tx today to replace my 811. VERY excited to hear how 7.1 sounds with this setup.

E10's as side surrounds are 6" or so towards front (depends if I lean back on couch or sit upright. had no choice as that is only palce I could put them due to lack of right sidewall in that area (wall has door size opening to kitchen there).
Can not wait!

[akm3]

So, is the DPLIIx more of an ambience extraction present in the original signal, or a fake DSP creation?

=D

LOGIC7 or DEATH.

-Allen

[cwood]

Originally posted by akm3
So, is the DPLIIx more of an ambience extraction present in the original signal, or a fake DSP creation?

=D

LOGIC7 or DEATH.

-Allen

DPL IIx is directly comparable to Logic 7 in terms of what it achieves but the steering signals are generated in a far different manner. Both systems derive the additional channels based on the content of source program material as opposed to DSP generated soundfields.

Charles Wood
Fosgate Audionics
RHG

[akm3]

Sorry this was a smart-ass reference to a previous thread and shouldn't be discussed seriously :)

I know DPLIIx and Logic7 do basically the same thing just based on different calculations.

-Allen

[bubbawilly]

Does L7 affect/alter the presentation of the main L/R channels like PLIIx does?

In my processor, I feel like PLIIx alters the main channels too much in many cases, at the expense of quite a bit of detail, whereas Neo 6 does not alter the main L/R channels at all. Where does Logic7 fall?

[akm3]

It is my understanding both L7 and DPLIIx leave the frost channels alone or essentially alone. Almost all the processing is steering things to the rear array.

I don't actually know any of this (after all I am a "zealot" not an "Expert") so I hope someone more knowledgable then me comments. (Particularly about DPLIIx because I derailed this thread on accident)

-Allen

[bubbawilly]

Originally posted by akm3
It is my understanding both L7 and DPLIIx leave the frost channels alone or essentially alone.
-Allen
I think (hope) that is true for 5.1 sources, but I can readily discern that PLIIx Music is altering my main L/R on 2.0 sources, or it sure seems to.

Someone here will know for sure.

BTW, does Logic7 require that the mains be set to Small in order to provide redirected bass to the sub like PLIIx does? I'm a bit confused that since the surrounds in DPLIIx are supposed to be full range, why does setting them to small not redirect some bass to the sub?

[gwsat]

I don't know personally whether PLIIx affects the front channels but I think I remember Sanjay saying in one of his posts that PLIIx matrixed the surround channels but left the front channels alone.

I, too, make no claim to "Expert" status. In fact I have heard "Expert" defined as a guy from out of town who carries a briefcase and talks all the time. :)

[Philip Brandes]

Originally posted by akm3
It is my understanding both L7 and DPLIIx leave the frost channels alone or essentially alone. Almost all the processing is steering things to the rear array.

Not exactly. This is true for 5.1 sources, but when applied to 2-channel sources (including Dolby Surround-encoded content), steering takes place across the front L-C-R array as well. However, the frontal steering in both PL II and Logic 7 is designed to honor the intended phantom imaging in the mix--e.g., vocals mixed equally into the left and right channels that would normally form a phantom center image in 2-channel would be steered to the physical center speaker instead.

Contrary to bubbawilly's post below, I've found in my experience that both PL IIx and Logic 7 honor the inetended front channel imaging without the inherent drawbacks of using only two speakers. The benefits are a reduction in comb filtering artifacts, more stable center imaging, and the ability to lock center content in place even for off-axis listeners. it's nice when serious music listening can be a social experience. Of course, this requires a center speaker of equal quality with the front L & R; otherwise, you may very well find that center steering compromises your front soundfield (but then, that's a hardware issue, not processing-related). With Neo:6, I hear so many anomalies that I find it unlistenable, but to each his own. There's a good discussion comparing these modes' respective approaches to ambience extraction processing here:
http://www.hometheaterhifi.com/volume_8_1/dolby-prologic2-3-2001.html
The article is dated, and both Logic 7 and PL II have been improved since it was written, but its explanations and descriptions about their objectives and approaches are still helpful.

Cheers,
Philip Brandes

[spider_bill_2003]

Originally posted by bubbawilly
I think (hope) that is true for 5.1 sources, but I can readily discern that PLIIx Music is altering my main L/R on 2.0 sources, or it sure seems to.

Someone here will know for sure.

BTW, does Logic7 require that the mains be set to Small in order to provide redirected bass to the sub like PLIIx does? I'm a bit confused that since the surrounds in DPLIIx are supposed to be full range, why does setting them to small not redirect some bass to the sub?



This thread was closed a short time back over that very discussion.

The discussion on that matter was deleted from this thread, and now the tread is open.

I agree that PL-2 Music alters the sound from the mains FOR THE WORSE.

To me, it sounds like the soundstage collapses, and details are lost from the main speakers. Sort of a back to mono sound up front - YUK!


The Lexicon crowd will dispute this OBSERVATION, but I do not care what they CLAIM!


PL-2 Movie is great for television and VHS tapes!


--Bill

[keenan]

Originally posted by gwsat
I don't know personally whether PLIIx affects the front channels but I think I remember Sanjay saying in one of his posts that PLIIx matrixed the surround channels but left the front channels alone.



I would like to believe this as well, but in my practical use with 2ch sources, there is definitely some altering on the the 2 main channels, or, the addition of material from the other channels has colored or altered what I hear from the mains to the extent that I personally don't like the result. For me the imaging gets all twisted up. Plus it seems to add far too much content in the rears for my taste. It great for 5.1 sources such as movies though.

[bubbawilly]

I wasn't aware that this thread once covered that topic, and that it got out of hand. That's too bad.

All that I'm trying to do is determine whether DPLIIx has been correctly implemented in my processor. I 'expected' DPLIIx to simply act as an "extension" of DPLII (adding stereo back surrounds), much like Dolby's site describes it. However, on my processor it muddies the detail in the front soundstage to the point that I cannot 'correct' it with a boost in EQ. Real detail is so lacking that I can adjust the bass and treble EQ's to either extreme with no affect what-so-ever. There is a significant change in presentation (forget about the back surrounds for now) when I toggle between DPLII and IIx, so I'm wondering if it's my Sherwood. There is at least one acknowledged anomaly with the IIx implementation in the Sherwood in that the redirected bass is low by approximately 7dB, so I'm wondering if there aren't more problems.

My center channel speaker is of equal quality as my mains, but my problem is not with center imaging, it is with the muddied detail, flattened response and a bit too aggressive surround steering. I realize that the latter may just be a personal preference, but the former is real.

[tbhugh]

That is not why the thread was closed.

[Philip Brandes]

Bubbawilly, have you checked to see if the adjustable parameters are set differently in PL II and PL IIx music modes? It is certainly strange that you'd be hearing that big of a difference. Is the same difference just as noticeable in the (non-adjustable) movie modes? It seems unlikely that Sherwood could have implemented PL IIx incorrectly, since they're probably using the same chip as everyone else, but anything is possible. Please keep us posted on any further results of your investigation.

Good luck,
Philip Brandes

[bubbawilly]

Originally posted by Philip Brandes
Bubbawilly, have you checked to see if the adjustable parameters are set differently in PL II and PL IIx music modes? It is certainly strange that you'd be hearing that big of a difference. Is the same difference just as noticeable in the (non-adjustable) movie modes? It seems unlikely that Sherwood could have implemented PL IIx incorrectly, since they're probably using the same chip as everyone else, but anything is possible. Please keep us posted on any further results of your investigation.

Good luck,
Philip Brandes

Sounds like I may not be the only one with this problem.

My comparisons between II and IIx were with the parameters in their default positions, so no differences there. I've adjusted DPLIIx's "Dimension" parameter to move vocals from the rear, back to the front where they belong, but nothing more. The rear soundstage was much too hot at the default setting. I've tinkered with all of the settings, but none have solved my problem. I have no problem with PLII Music or Movie, but I need to do some checking on IIx Movie with 2.0 sources.

I'm with you on the IIx implementation. Actually, it would be Cirrus, not Sherwood necessarily, and I would think that there would have been some sort of Dolby certification process on the Cirrus code. However, somehow they let units get onto the streets with a problem in redirected bass under IIx. IIx's redirected bass measures 7dB less than DPLII. How this could happen I haven't a clue. There is a problem in layering PLIIx Music over DTS 5.1 Music sources as well. The result is a highly altered and strange rear soundfield, but I don't know if this can be attributed to the Cirrus/Sherwood implementation, or if it is an incompatibility between IIx and DTS.

[spider_bill_2003]

Originally posted by bubbawilly
I wasn't aware that this thread once covered that topic, and that it got out of hand. That's too bad.

There is at least one acknowledged anomaly with the IIx implementation in the Sherwood in that the redirected bass is low by approximately 7dB, so I'm wondering if there aren't more problems.

My center channel speaker is of equal quality as my mains, but my problem is not with center imaging, it is with the muddied detail, flattened response and a bit too aggressive surround steering. I realize that the latter may just be a personal preference, but the former is real.


If you want to try something interesting, make a stereo (Center) test tone CD from 20HZ up to 100HZ. I have large mains, so my subwoofer is optional.

Measure the bass output of the various frequencies in the following modes:

2-channel (no subwoofer - large mains)

automatic (subwoofer plus large mains, or subwoofer plus small mains)

PL

PL-2 Movie

PL-2 Music

You will see different bass levels in each mode.


What is your speaker setup? I have large mains, small center, and small surrounds plus a subwoofer (L, S, S, plus SW).

--Bill

[sdurani]

Originally posted by bubbawilly
I 'expected' DPLIIx to simply act as an "extension" of DPLII (adding stereo back surrounds), much like Dolby's site describes it....There is a significant change in presentation (forget about the back surrounds for now) when I toggle between DPLII and IIx, so I'm wondering if it's my Sherwood.Indeed, PLIIx is simply a functional eXtension of PLII. When applied to 2-channel material, there's no difference in surround processing quality (same algorithms, just expanded to more surround channels). If you're hearing a difference (significant or otherwise) between PLII and PLIIx, then something is wrong with the implementation.

I've never heard soundstage collapse with the PLII Music mode. In fact, quite the opposite: whenever I turn on PLII Music, the front soundstage seems to stretch outside my front left & Right speakers. Raising the volume of the side speakers can increase this effect. Like Philip, the only sounds I hear move towards the centre are sounds that would have imaged there anyway. PLII/PLIIx doesn't steer stereo information to the centre; that stuff is left front Left & Right speakers, since circuitry only extracts correlated mono info for centre channel placement.

If your local A/V store has any H/K receivers, you may want to try PLIIx and LOGIC7 on some material you're familiar with to see if you hear the same problems. I'll also echo Philip's comments about Neo:6; steering anomalies and other artifacts keep me from using it.

Best,
Sanjay

[bubbawilly]

Bill,
I've done most of what you describe (all but measuring bass response without the sub). I get a variance of no more than about 2dB between modes, which isn't bad, with the exception of IIx. It is down about 8dB from DPLII and Stereo, and down at least 6dB from 'reference' (DPLII is slightly higher than reference). I first noticed the problem when DPLIIx wouldn't even trigger my sub in Music mode, yet the system was in balance for everything else.

I run all 7 of my speakers small, crossed over at 60Hz to the sub (all of my speakers perform down to at least 50Hz). I get a little flatter bass response in my room at that setting than I do with the crossover set to 80Hz. I'd prefer to run my mains as large, but as long as I use PLIIx, I cannot do that and get any sub reinforcement.

[bubbawilly]

Sanjay,
I 've heard logic7 in my system, and I loved it (unfortunately, I had problems with its host AVR 630). I hoped PLIIx would be close, but it is not, at least not with the Sherwood. Something just doesn't seem right, although at least two others in this thread are hearing the same thing that I am with PLIIx.

I'll try to find some 7.1 demo setups featuring any PLIIx gear. It won't likely be H/K, but I will get a better reference for how PLIIx performs on other platforms.

[Roger Dressler]

bubbawilly wrote:
>>I'm a bit confused that since the surrounds in DPLIIx are supposed to be full range, why does setting them to small not redirect some bass to the sub?<<

The bass in the surrounds of a matrix decoder operating on 2-ch music is redundant with that of the fronts--after all, there's only 2 channels of bass to start with. Spreading it to 5 outputs only to recombine it to mono does not seem essential. Therefore there is no need to collect bass from the surrounds for the subwoofer, even if the rear speakers are set to small. The exception is when very hard steered content is directed to the surrounds, like a space ship in a video game, and now you see why there is a Game mode in PLIIx.


>>However, on my processor it muddies the detail in the front soundstage to the point that I cannot 'correct' it with a boost in EQ. Real detail is so lacking that I can adjust the bass and treble EQ's to either extreme with no affect what-so-ever.<<

I'd like to suggest an experiment. In PLII Music mode, set Dimension back to default (middle) position, and Center Width to full L/R (no output from center speaker). How does it sound in terms of L/R quality? Stereo image?

One further test would be to set up same as above, but disconnect all the surround speakers. Just L/R will remain active. With music recordings, how different is it from stereo mode? (Note there will be a possible gain difference of a few dB between stereo and PLII modes, so you may want to trim the volume accordingly.)

[bubbawilly]

Thanks Roger.

I will perform these tests and report back.

[Disclord]

The best stereo-to-surround synthesis I've ever heard is still the Surround mode setting on the Fosgate Tate-II DES 101A decoder. Yes, it has some audible decoding artifacts from the DES IC's, but the surround synthesis is so discrete, and non-phasey, that I like it better than any other. And the 180 horseshoe wrap-around is totally unique. PL-II and other matrix systems have wrap-around modes, but the Tate's is much better, at least in my opinion. It sounds more like four discrete channels than any other synthesis I've heard, including PL-II, Logic-7, CS, etc...

[ss9001]

Originally posted by Disclord
The best stereo-to-surround synthesis I've ever heard is still the Surround mode setting on the Fosgate Tate-II DES 101A decoder. It sounds more like four discrete channels than any other synthesis I've heard, including PL-II, Logic-7, CS, etc...

I'll second that, but don't forget Sansui's QS Variomatrix QS matrix decoder.

I have both from the quad days. Although I do not have Logic7, I can say the both the Tate and Sansui have a more discrete-sounding and robust surround field with 2 channel than the same recordings run thru DPLIIx so far. The differences can be striking, with both quad decoders being more satisfying to my ears. DPIIx has less engaging surround use. And I've tried the all the adjustments. The QS and SQ matrix formats were Dolby's predecessors, and Sansui's QS-Variomatrix and Tate's SQ decoders were the best implementations of each.

All processors are powered by same amps with the same speakers so the differences are due to the way the decoders extract out-of-phase information.

ss9001

[Disclord]

>>I'll second that, but don't forget Sansui's QS Variomatrix QS matrix decoder.<<

I've never liked the way Vario-Matrix sounded, even the 3-band QSD-1 - it's better than non-logic, of course, but the QS systems need for side-to-side separation enhancement and the Vario-Matrix design of re-distributing non-dominant sounds around the soundfield really gets fatiguing to listen to, at least for me. SQ's requirement of only front-to-back enhancement and the Tate DES' ability to keep non-dominant sounds in their properly decoded locations makes for a less phasey-sounding and less fatiguing listening experience. The wrap-around QS Surround Synthesis mode just seems "unfocused" to me - and I've heard it on many different decoders/systems, including Sansui's last, Japan only, QS Vario-Matrix decoder, the model number of which escapes me at the moment.

[neoprufrok]

Mr. Brandes,

I just have 2 questions for you -

1. Do you prefer DPLII/x over straight 2 channel stereo for solo listening?
2. What psychoacoustic studies are you referring to?

This would help me clarify your position on the matter further.

Thanks,
Rich

[ss9001]

Originally posted by Disclord
>>I've heard it on many different decoders/systems, including Sansui's last, Japan only, QS Vario-Matrix decoder, the model number of which escapes me at the moment.

I believe the Japan only decoder was the QSD-1000.

ss9001

[Disclord]

QSD-1000 - that's it! I think about 20 were imported by one of the quad newsletters in the early 80's. I heard it in my system and was not impressed - its basic fidelity was fantastic, but the decoding was still the phasey-sounding Vario-Matrix I had heard before. The 3-band QSD-1 was the best Vario-Matrix decoder. I'm not sure which model QS Decoder Ioan Allen used in the first Dolby Stereo decoders for theaters (before they switched to the Tate DES chips).

[Philip Brandes]

Hi Rich,

To answer your questions:

Originally posted by neoprufrok
Mr. Brandes,

I just have 2 questions for you -

1. Do you prefer DPLII/x over straight 2 channel stereo for solo listening?

Speaking for myself and were based on my listening priorities, I do prefer well-designed matrix decoding to straight 2-channel listening, even for 2-channel recordings. In my case, I generally use Logic 7, but I also like PL II--both do an excellent job of creating a more believable experience. Nowhere in the real world do we hear all sound emanating from two point sources in front of us.

My priorities have always been music first and foremost. Since the 1970s, I had been a 2-channel purist (Win Labs turntable, B&W DM7 speakers, etc.)--actually, a vinyl purist, with all the associated biases against digital. In fact, I didn’t even own a CD player until 1995. At that time, I finally got on board because of the HT bandwagon, but music remained my top priority. I broke down and bought a Denon receiver, but found it was a step down for music.

It wasn’t until I heard well-implemented surround processing (Logic 7 on a Lexicon DC-1), that I had a change of heart regarding digital--and DSP surround processing in particular. Until then, all the surround processing I’d heard had been junky ambient synthesis modes with horrible unnatural reverb. But when I heard 2-channel music enhanced by Logic 7 on the DC-1, it got my attention--it was the first DSP I’d heard that sounded like real music played in a real space. Even more unsettling to me at the time was the fact that when I switched from Logic 7 back to my beloved 2-channel, the sound collapsed to the front of the room and I became very conscious of how artificial the 2-channel paradigm really is. There was a lot of cognitive dissonance about this for me--I’d grown up with 2-channel, and because it was familiar I accepted it as the “natural paradigm” for home audio playback, but I had to admit that Logic 7-enhanced CDs sounded more like the sound of live performance, which I was also familiar with. It wasn’t until I acknowledged the fact that all music reproduction is an artificial construct that I could accept the idea that there was no “right” paradigm even for playback--that freed me to pursue whatever gave me the most convincing and involving illusion.

I did some research into what made Logic 7 so different from other DSP processing I’d heard. I learned that unlike other surround modes that synthesize ambience according to crude pre-set algorithms and imposing it on whatever happens to be on the recording, Logic 7 and PL II actually extract ambience from cues in the recording itself. This is critical to why they sound so much more natural. It’s no coincidence that the designers of these respective decoding processes--David Griesinger (Logic 7) and Jim Fosgate (PL II)--are music lovers first. In my opinion, both of their efforts have done wonders to overcome the limitations of the delivery medium. Keep in mind that 2-channel is a constraint, not an ideal.

Let me stress again that these are my listening priorities. Others with different priorities may very well prefer two-channel listening and that is absolutely their choice to make. I am not trying to say that my preference is the right choice for anyone else. But I would encourage readers to consider that there are different paradigms for reproducing a musical event, and a knee-jerk allegiance to two-channel playback can unnecessarily limit your options.


2. What psychoacoustic studies are you referring to?

See my post on page 1 of this threat.

Cheers,
Philip Brandes

[M Code]

Originally posted by Disclord
QSD-1000 - that's it! I think about 20 were imported by one of the quad newsletters in the early 80's. I heard it in my system and was not impressed - its basic fidelity was fantastic, but the decoding was still the phasey-sounding Vario-Matrix I had heard before. The 3-band QSD-1 was the best Vario-Matrix decoder. I'm not sure which model QS Decoder Ioan Allen used in the first Dolby Stereo decoders for theaters (before they switched to the Tate DES chips).

The best quad matrix decoder was in fact based on the Sansui QS Variomatrix system but was actually built by Marantz. This advanced version of the QS decoder of which only 3 units were built were never released to the market as Sansui was fearful of the heavy litigation and class idemnification being threatened by the Peter Schrieber (Electro Voice) group.

Since the QS system worked by phase relationship rather than level such as the SQ/Tate system, QS did not have the channel pumping. I had a close friend who had one of the Marantz QS decoders, and it sounded great for its day... I am told that these decoder cards are worth about $2000 today due to their scarcity..

[neoprufrok]

Mr. Brandes,

I appreciate your comments, particularly your description of your love for 2 channel purity. It helps me understand, and in my eyes, provides a stronger validation of your statements that you've come from a 2 channel audiophile background.

I also am a 2 channel purist first - although I started out in the digital realm. I've been highly resistant to the multichannel craze up until recently, when I was able to demo the system I ended up buying - a Cary Cinema 6 Pre/Pro and Cinema 5 Amp. Listening to this system was a revelation for me. I've heard great surround sound from pre/pro/amp sytems at this price range before - but never heard 2 channel music and all analog SACD/DVDA done as well as the Cary - just amazing transparency, detail, and soundstaging for a pre/pro.

In any case, I wanted to see the difference between DPLII/x vs 2 channel straight analog via the bypass. I run an Arcam CD93t via MIT analog ICs to the Pre/Pro and also an MIT Digital Coax to teh Pre/pro. Switching between the two - I've noticed one good and one bad thing about DPLII/x. The great thing is the sense of ambience and air that the surround channels bring - and I can only assume its further enhanced by a 7 channel system (I have only 5 - but am comfortable with that at this point). Live recordings are electrifying. The bad thing relates to the nature of the pre/pro decoding itself. I feel that it artificially introduced some level of upper range emphasis and also sounded a little bright, while overly emphasizing the center image. Just my thoughts - and my ears.

Either way, I'll have to do more listening to finally decide which I think is better. I still do prefer the 2 channel analog at this moment, but I can see the benefits of DPLII.

[gwsat]

Originally posted by Philip Brandes
. . .
. . . It wasn’t until I acknowledged the fact that all music reproduction is an artificial construct that I could accept the idea that there was no “right” paradigm even for playback--that freed me to pursue whatever gave me the most convincing and involving illusion.
. . .


Indeed! I think the most important thing to keep in mind in evaluating the sound of any home audio setup is to keep in mind that what we hear can be only an approximation of a real performance -- no matter how hard we try to make it "authentic." Once I accepted that recorded music is, as Philip put it, an "illusion," albeit a convincing one at its best, I learned to relax and have enjoyed recorded music even more ever since.

Last night I got out my old Stereophile Test CD #2 and played some low frequency test tones while trying to tame an errant subwoofer. While I had the disk in the machine I played several of the two channel test tracks with PLIIx engaged and was very pleased with the results. The addition of PLIIx made for a more enjoyable listening experience -- to my ears, at least -- than straight two channel did. The difference was subtle, which is good, but I thought it made for a more pleasing sound.

[sdurani]

Originally posted by neoprufrok
I feel that it artificially introduced some level of upper range emphasis and also sounded a little bright, while overly emphasizing the center image.I don't know if you're aware of it but PLII Music mode has a parameter that allow you to control how much information is steered from the front Left & Right channels to the centre. It's called Centre Width, and it can be adjusted in gradual steps from a MIN setting (all correlated mono info is moved to the centre speaker) to a MAX setting (no info sent to centre speaker). Start at MIN and adjust the Width till you feel the centre isn't overly emphasized and all three front speakers are in balance. This may vary with different recordings, so experiment a bit.

Best,
Sanjay

[Randybes]

Originally posted by sdurani
I don't know if you're aware of it but PLII Music mode has a parameter that allow you to control how much information is steered from the front Left & Right channels to the centre. It's called Centre Width, and it can be adjusted in gradual steps from a MIN setting (all correlated mono info is moved to the centre speaker) to a MAX setting (no info sent to centre speaker). Start at MIN and adjust the Width till you feel the centre isn't overly emphasized and all three front speakers are in balance. This may vary with different recordings, so experiment a bit.

Best,
Sanjay

This may have been covered, but what does Panorama do on DP2x?

Thanks,

Randy

[M Code]

Originally posted by Randybes
This may have been covered, but what does Panorama do on DP2x?

Thanks,

Randy

Panorama control was also available in Pro Logic 2 but not every brand made this control available. Basically it provides to the user the option of extending the front L/R stereo imaging to include the L/R side surround speakers (5.1). This makes the sound field almost like a complete circle or wrap- around the listener. For DPL2x, Dolby took it one step further by adjusting certain frequency filters to extend this image in the L/R back surrounds (7.1)..

Dolby has provided some exceptional controls in Pro Logic and DPL2x with Center, Width and Panorama for which the listener now has many adjustments to optimize to his/hers personal tastes...

[Legairre]

So do most of you guys leave panorama on or off? Also do any of you use the DPL IIx music mode for movies or just for music?

Thanks
Legairre

[neoprufrok]

Originally posted by sdurani
I don't know if you're aware of it but PLII Music mode has a parameter that allow you to control how much information is steered from the front Left & Right channels to the centre. It's called Centre Width, and it can be adjusted in gradual steps from a MIN setting (all correlated mono info is moved to the centre speaker) to a MAX setting (no info sent to centre speaker). Start at MIN and adjust the Width till you feel the centre isn't overly emphasized and all three front speakers are in balance. This may vary with different recordings, so experiment a bit.

Best,
Sanjay

I'll look into it, but I'm pretty sure my Pre/Pro doesn't have it. Thanks.

[Randybes]

Originally posted by M Code
Panorama control was also available in Pro Logic 2 but not every brand made this control available. Basically it provides to the user the option of extending the front L/R stereo imaging to include the L/R side surround speakers (5.1). This makes the sound field almost like a complete circle or wrap- around the listener. For DPL2x, Dolby took it one step further by adjusting certain frequency filters to extend this image in the L/R back surrounds (7.1)..

Dolby has provided some exceptional controls in Pro Logic and DPL2x with Center, Width and Panorama for which the listener now has many adjustments to optimize to his/hers personal tastes...

Thanks, M Code. This has been helpful as I find some of the explanations in the manuals of various processors leave a lot to be desired.

[sdurani]

Randy, This may have been covered, but what does Panorama do on DP2x?One of the things that makes matrix decoders have better separation between channels is "logic steering", which basically boosts the sounds sent to a particular channel while suppressing sounds from other channels. For example: centre channel information is suppressed in other channels using a cancellation signal so that you don't hear dialogue leaking from all around you. Likewise, sound from the front Left & Right channels are cancelled from the surround channels so that front soundstage stays up front and doesn't wrap around the front hemisphere.

However, this wrap-around effect can sometimes be pretty exciting (especially with studio/pop music). So one of the options that the PLII Music mode includes is Panorama. Turning this parameter ON turns off the cancellation signal from the front channels to the surrounds, which allows the front soundstage to be pulled out beyond the front speakers and along the side walls into the surrounds. For classical or acoustic/live music, I tend not to use it; for pop music, I always have it on. It doesn't sound as gimicky as you may think and can be downright subtle on some recordings.

Since surround application for music is usually more subtle than for movies, PLII Music mode engages a filter that rolls off the high frequencies in the surround channels to keep them from being too distracting. This roll-off filter is off in PLII Movie mode. When Dolby introduced PLIIx, they used the opportunity to make a small change: the roll-off filter now turns off when Panorama is engaged. The goal of Panorama is to wrap the front channel cues around the sides, and this helps make the effect more audible. Since this change is now part of the code, it applies not just to PLIIx but to PLII also.

Best,
Sanjay

[Randybes]

Thanks, Sanjay, fascinating and also very helpful. I appreciate it.

[Dave W]

For what it's worth, I just switched from a Lexicon DC-1 driving Adcom amps to a Pioneer Elite 56txi. At least in my particular setup, I never found Logic 7 that convincing for music. I used it exclusively for movie watching, but I almost never used it for serious music listening. Whereas it could sometimes create a convincing 3 dimensional soundfield, I found that it blurred the imaging too much, so that I always was happy to return to stereo. The soundstage collapsed to the front, but the imaging improvement was more important to me. I'm a LONG time Lexicon fan and supporter (I started with a CP-1+ back in 93, then got a CP-3+, and finally a DC-1), so I was very hesitant to venture into non-Lexicon territory, but I have to say, I am really quite impressed with PLII. It seems to offer as good or better of a soundfield as Logic 7, but it still retains excellent imaging, at least to my ears. Now I feel like I might actually listen to some 2 channel music in surround mode (probably on a case by case basis), while I never really found myself reaching for the remote to switch from stereo to Logic 7 for music.

Dave

[ss9001]

Originally posted by sdurani
Since surround application for music is usually more subtle than for movies, PLII Music mode engages a filter that rolls off the high frequencies in the surround channels to keep them from being too distracting. This roll-off filter is off in PLII Movie mode. When Dolby introduced PLIIx, they used the opportunity to make a small change: the roll-off filter now turns off when Panorama is engaged. The goal of Panorama is to wrap the front channel cues around the sides, and this helps make the effect more audible. Since this change is now part of the code, it applies not just to PLIIx but to PLII also.

Best,
Sanjay

Sanjay,
One of the things I find interesting in these discussions is overall, how poorly the manufacturers have documented and explained these formats, features and adjustments. I include in this list Pioneer Elite (my own brand), Denon, Anthem, Parasound, Rotel, and even Lexicon to an extent.

None have taken the time or pages to really explain in detail how these
adjustments really work or the intended effect nearly as well as you and others, such as Philip Brandes. Certainly they explain the mechanics of making the adjustment or activating a particular format, but do not describe the effects very well. I for one would appreciate knowing these details (hello, manufacturer, are u listening?) For instance, I would never have known about the cancellation or filtering you just described without reading this thread. Certainly this stuff isn't a Dolby trade secret!

The Japanese brands are the worse, even with their flagship receivers. I've picked up extra info from reading manuals by some of the premium prepros, with Lex and Anthem being the best. But still, they all could take a few lessons from you guys.

It would only take several extra pages to do what you & others have eloquently done in these forums. Maybe you should take up technical writing. Do these manufacturers think no one cares to understand what these features do or that we are not smart enough to figure it out. While I am a vigourous fan of my Pio Elite 59TXi, Pioneer's descriptions of the various surround formats and these features is pathetic IMO. Denon's may be a bit better in some areas, but still inadequate.

Thanks for all your advice and expertise.

ss9001

[gwsat]

I agree that receiver documentation leaves a LOT to be desired. I got a Yamaha RX-V2400 last year and quickly saw that the owner's maual was pitiful -- it doesn't even have an index. Had it not been for Sanjay and several other patient and generous posters to this Forum I might never have learned how to use many of its more useful features. I love it but accessing its features is about as intuitive as nuclear physics. I assume that Yamaha knows this, too, but you would never know it from reading it's owner's manual.

[dtc]

I pretty much understand what happens in home theater, but am not as clear about movie theaters. What signal drives the rear speakers in a movie theater? Are most movies encoded in 5.1 for the theater? Are the rears matrixed or just not used unless the movied is EX/ES encoded? If a movie is 6.1 encoded, do theaters matrix the back or is it just a mono signal in back? If money, why don't you get the front/back flipflop that 6.1 can create? Thanks for any insight.

[sdurani]

Originally posted by dtc
What signal drives the rear speakers in a movie theater?If it's a 5.1 movie, then the rears are driven by the left & right surround channels. The rear speaker array is split in two: the left half is a continuation of the left side speakers (think of it as an L shaped array of speakers). Ditto the right side. So the left and right surround channels wrap around behind the listeners instead of just being at their sides.

If the soundtrack is EX encoded, then the rear speaker array is driven by the surround-back channel. Are most movies encoded in 5.1 for the theater?Yes. Are the rears matrixed or just not used unless the movied is EX/ES encoded?The rears are always used, whether the soundtrack has a surround-back channel or not (see above). If a movie is 6.1 encoded, do theaters matrix the back or is it just a mono signal in back?Well, both: the surround-back channel is matrix derived and it is mono.

The surround-back channel is always matrix because there is no DTS ES Discrete 6.1 format for commercial theatres; ES 6.1 is a consumer/home format only. Likewise, even though the rear speaker array can be split in two, the surround-back info is always played back in mono because there is no Pro Logic IIx type post-processing for commercial theatres that generates stereo rears; PLIIx is a consumer/home technology only. If money, why don't you get the front/back flipflop that 6.1 can create?Money? You mean mono? You don't get the back-to-front reversal problem because you're listening to an array of speakers spread out along the back wall (in commercial theatres) as opposed to listening with a single speaker directly behind your head (at home). Using 2 rear speakers at home alleviates the reversal problem and also mimics another aspect of the rear array: the surround-back information images behind you in general, not specifically from the middle of the back wall.

Best,
Sanjay

[dtc]

Sanjay - sorry for the bad typing - I did mean mono. That is pretty much what I thought - 5.1 only in theaters and the rears are the same as the corresponding sides. But can you clarify one thing - you say "the surround-back channel is matrix derived and is mono" - that only applies at home right? Not in the theater. Theaters always wrap the sides to the back. Do I understand that correctly? Thanks.

[sdurani]

Originally posted by dtc
But can you clarify one thing - you say "the surround-back channel is matrix derived and is mono" - that only applies at home right? Not in the theater. Theaters always wrap the sides to the back. Do I understand that correctly?Theatres wrap the sides to the back only for standard 5.1 movies. For EX encoded films, the rear speaker array is used to reproduce the surround-back channel. So, for example, back in 1999 if you watched 'Star Wars: Episode 1' in a properly equipped movie theatre, you heard three surround channels: surround-left, surround-right and surround-back.

For a clearer idea of what I'm talking about, see the bottom two drawings on this page (http://www.dolby.com/professional/motion_picture/technologies2.html); pay particularly close attention to how the surround speakers are connected.

For home playback, you can listen via EX/ES decoding to reproduce the theatrical effect or use PLIIx (or LOGIC7) processing to take it a step further. Those technologies will steer surround-back information between the two rear speakers. So if a particular sound is zipping from front to back along the left side of the room, it will disappear over your left shoulder rather than generally behind you. While this is not how it was mixed nor how it was heard theatrically, I personally think it sounds more natural with stereo rears.

Best,
Sanjay

[dtc]

Ok - I am getting closer - there is a DD EX 6.1 decoder for theaters but no DTS ES 6.1 decoder for theaters. Right? Is the bitrate in theaters the same as on DVDs?

[sdurani]

Originally posted by dtc
Ok - I am getting closer - there is a DD EX 6.1 decoder for theaters but no DTS ES 6.1 decoder for theaters. Right?Close. For us consumers at home, there are three formats that include a surround-back channel: DD EX, DTS ES and DTS ES Discrete 6.1 (yes, that long thing is the actual name of the format). The first two have a matrixed surround-back channel while the third one has a discrete surround-back channel.

When used in the context of source material, the X.x nomenclature describes the number of discrete channels. Therefore, DD EX and DTS ES are 5.1 formats (since their surround-back channel is not discrete). There is no "DD EX 6.1" format. The only 6.1 format is DTS ES Discrete 6.1, but it's not used in commercial theatres since it's a consumer-only format.

When you see a movie in a theatre, the soundtrack has no more than 2 discrete surround channels. If the soundtrack has a surround-back channel, it will always be matrix (irrespective of whether it is DD or DTS). Is the bitrate in theaters the same as on DVDs? No, the commercial versions of DD and DTS are different from their consumer versions.

Best,
Sanjay

[Disclord]

>>Is the bitrate in theaters the same as on DVDs? <<

Theatrical Dolby Digital AC-3 runs at 320kbp/s, and is a slightly different version of the AC-3 code - the biggest difference between it and the home version is that Dolby can update the theatrical decoder on the fly with data embedded in the AC-3 signal on the print. This has been used in the past to give better performance in handling splices, etc...

DTS-6 for theaters is an entirely different encode/decode system from the home DTS Coherent Acoustics coder. Theatrical DTS uses the APT-X100 4:1 ADPCM encoder/decoder and is stored on a CD-ROM synchronized to timecode embedded on the print. Home DTS has MUCH higher sound quality and flexibility as compared to the theatrical system.

[dtc]

Sanjay - thanks for the clarification. I understand the discrete vs matrix formats but am very sloppy at using the correct terminology. Your explanation is very precise - as always. Thanks.

If a theater is set up for surround-back (vs. "wrap-around") what does it do with a standard Dolby Digital 5.1 source (not EX encoded? Is the speaker wiring flexible enough to switch between surround-back and "wrap-around" mode? Or does it somehow create a single surround-back signal from the sides? Or do they only show EX encoded movies in theaters with surround-back setups? Showing EX encoded movies in "wrap-around" setups should be trivial - just ignore the encoding.

As I now undertand it consumer AC-3 runs at 384 kpb/s, so at a slightly higher rate than in theaters. With DD Plus, that rate can go to to 3Mpbs (or 6 Mpbs depending on which Dolby release I read) and will be a 7.1 discete source. Any plans to put this is place in theaters? Seems like it would require a much different format on the tape, a different projector to read it, and potentially different wiring. The other issue is whether discrete rear channels would be an improvement in a large theater or not. Or is Plus just a consumer format for now? Also, are soundtracks typically produced such that going to the higher bitrate of DD Plus will be easy - or will that require significant re-tooling of the process?

Thanks for the help.

[sdurani]

Originally posted by dtc
Is the speaker wiring flexible enough to switch between surround-back and "wrap-around" mode?Obviously it must be. Remember that it has to be flexible enough to accomodate three surround channels (for EX/ES) or two surround channels (for standard 5.1) or even a single/mono surround channel (if the system has to fall back on the 2-channel Dolby Stereo encoded optical track, all the surrounds will be playing the same signal).

Best,
Sanjay

[bubbawilly]

Originally posted by Roger Dressler
bubbawilly wrote:
>>However, on my processor it muddies the detail in the front soundstage to the point that I cannot 'correct' it with a boost in EQ. Real detail is so lacking that I can adjust the bass and treble EQ's to either extreme with no affect what-so-ever.<<

I'd like to suggest an experiment. In PLII Music mode, set Dimension back to default (middle) position, and Center Width to full L/R (no output from center speaker). How does it sound in terms of L/R quality? Stereo image?

One further test would be to set up same as above, but disconnect all the surround speakers. Just L/R will remain active. With music recordings, how different is it from stereo mode? (Note there will be a possible gain difference of a few dB between stereo and PLII modes, so you may want to trim the volume accordingly.)

Thanks Roger. I figured out what was going on, thanks to your recommendations. I disconnected the surrounds, and I used PLIIx with just the front three speakers connected. I compared straight Stereo to PLIIx with center width set to max. There was little, if any difference, with the exception of weak bass when in PLIIx mode, so I compensated by resetting the sub level between modes. I believe that is a problem with my Sherwood processor, not PLIIx. PLII on the Sherwood is fine, but when IIx is used, the redirected bass level drops by about 7dB.

I isolated the problem to the surrounds. IOW, when listening to just the front speakers, I was not experiencing the loss of detail and 'smearing' that I experienced when the surrounds were connected. Then, I thought of something. I'd always left the 'auto' distance settings that the the Sherwood's auto speaker setup routine determined, even though they were as much as 3' off with some speakers. I figured that a computer processor certainly knew what it was doing better than me and a tape measure. :rolleyes: Well, was I wrong (as wrong as the Sherwood). Once I set the actual distances the old fashioned way (as close a Sherwood's crude 1' settings would allow), the front image cleared up entirely, and the back surrounds were no longer overwhelming.

The processor was setting the back surrounds (and sides) several feet further than they actually are, so the sound from those speakers was arriving at my ear before the sound from the fronts, causing some cancellation and smearing as far as I can tell. Moving the distance settings back to the values that the Sherwood had determined muddied the image again and confirmed my findings.

Wow! I take all of my complaints about PLIIx back. I really like it now that I've found the source of my problem and have things dialed in correctly. With the exception of the Sherwood bass anomaly, I think that I like it better than Logic7. :D

Thanks again Roger!!

[filecat13]

Great post. I admire a man (or woman) who takes the time to report back on a problem, identifies his mistake, cleans up the loose ends, and publicly changes his mind. We all learn from that.

Way to go bubbawilly, you are the man! :D I totally respect your integrity here.

[Roger Dressler]

Bubbawilly, I have to echo filecat's comments. You did your homework. I'm very glad it was worth the effort.