7.1 Speaker Set-up with the Onkyo 770 6.1 System?

[millerwill]

I bought the Onkyo 770 system ~6 months ago, and have recently replaced the center, L/R fronts, and L/R surrounds with Infinity Primus'. I am still using the Onkyo 520 (6.1) AVR and subwoofer, and for the surround back I have been using the 770's center speaker.

I am thinking, though, of using 2 of the old Onkyo surrounds hooked in parallel to the surround back terminal of the 520 AVR. Since the Onkyo center has two 4" drivers, and the Onkyo surrounds have one 4" driver, it seems like two Onkyo surrounds = one Onkyo center, connected to the 520 AVR surround back terminal. Does this seem reasonable? The idea is to spread out the surround back, thus having a 7.1 speaker set-up connected to the 6.1 AVR.

I would appreciate any thoughts about the advisability of this.

[Mr2Spyder]

In a true 7.1 system the same information is being sent to the two back speakers. Is that correct? I guess it should work in diffusing the sound. Let us know how it sounds. I have some extra speakers to play with.

[millerwill]

Originally posted by Mr2Spyder
In a true 7.1 system the same information is being sent to the two back speakers. Is that correct? I guess it should work in diffusing the sound. Let us know how it sounds. I have some extra speakers to play with.

My impression is that there are very few true 7-channel sources, and that even with Dolby Digital Ex, etc., the same signal is being sent to both surround-backs in a 7.1 system. So the answer to your question is 'yes, i.e., it is really a 6.1 signal, with the surround back being split into two speakers. (Some of the more knowledgeable of you please correct me where I'm wrong!).

Anyway, I have proceeded to carry out the plan described in my entry above: I have used TWO of the original Onkyo surrounds from the 770 system as the surround-back, thus having a 7.1 speaker set-up. I simply twisted the two + and the two - ends of the speaker wires together and connected them to the surround-back terminal of the 520 AVR. It all works fine, and sounds fine. It is a subtle effect of course (as most of these things are), but I do believe that it leads to a fuller surround experience by splitting the surround-back into two speakers this way.

Question for the pros: do I risk over-extending the AVR in this way? (My room is not enormous, 17'x15', 8.5' ceiling; and I don't turn the sound up to the pain threshhold.) If I ruin the 520 AVR, then I suppose I would replace it, e.g., with the Pioneer 1014 that people seem to like so much.

[Bellamy]

Your configuration will work, but you are dropping the impedance for the rear center from 8ohms to 4 by adding another speaker. Just because a speaker has two drivers does not mean you can put two speakers with one driver in its place. With the original center there are resistors to keep the ohms at 8. But your receiver should be able to handle the load fine, after all it's just the rear channel which does'nt get taxed that much.

[JohnR_IN_LA]

Originally posted by millerwill

Question for the pros: do I risk over-extending the AVR in this way? (My room is not enormous, 17'x15', 8.5' ceiling; and I don't turn the sound up to the pain threshhold.) If I ruin the 520 AVR, then I suppose I would replace it, e.g., with the Pioneer 1014 that people seem to like so much.

Yes, but you will probably not "ruin" your receiver, it just will impact the sound quality while the 7 speakers are hooked up. It also may go into "protection mode", where the receiver temporarily shuts down.

Remove all the Onkyo speakers for better timber matching and clarity.
Run 5.1, and focus on improving your 5.1 system, rather than dividing your power to more speakers.


You have a good base system.
If you feel the need to upgrade, then I would consider:
Subwoofer
Center Channel
Receiver

[Mr2Spyder]

Originally posted by JohnR_IN_LA


You have a good base system.
If you feel the need to upgrade, then I would consider:
Subwoofer
Center Channel
Receiver

Boy you really don't like Onkyo. I have had a sony, aiwa and pioneer dolby receivers and the Onkyo blew them all away in features and sound quality/power.

[millerwill]

Originally posted by Bellamy
Your configuration will work, but you are dropping the impedance for the rear center from 8ohms to 4 by adding another speaker. Just because a speaker has two drivers does not mean you can put two speakers with one driver in its place. With the original center there are resistors to keep the ohms at 8. But your receiver should be able to handle the load fine, after all it's just the rear channel which does'nt get taxed that much.

Thanks for the reply and comments. What about adjusting the sound level with this screwy set-up of mine. Should I just proceed as before, and adjust the levels of the center, fronts, surrounds, and surround-back to be about the same, or since my surround-back is now two speakers, should I increase the level from the surround-back channel?

[JohnR_IN_LA]

Originally posted by Mr2Spyder
Boy you really don't like Onkyo. I have had a sony, aiwa and pioneer dolby receivers and the Onkyo blew them all away in features and sound quality/power.

I stated his system was a pretty good base system, didnt I ? Those upgrades were just that, optional upgrades :)

One of the most necessary upgrades I did on my setup was to replacy my HTIB Onkyo receiver. I bought some nice, but inefficient speakers, and the Onkyo HT-500 just choked.

However I wouldn't of hesistated to go to a heavier Onkyo 600 or 700 series receiver, they are pretty awesome.

[millerwill]

The Onkyo 520 AVR (the one with the 770 system) seems to be a substantial cut above the 500 that John mentions. Though I'm sure it's not up to the 602 and beyond, it is rated at 130 wts/ch; and even if this is inflated, I think it still is quite a good entry-level AVR.

But I will certainly testify that the sound improved immensely when I replace the Onkyo center with the Primus C25. This motivated me to replace the L/R fronts with Primus 160's, and that also led to a very noticeable improvement (though not as dramatic as when the center was replaced).

[Mr2Spyder]

I will say the Onkyo receiver that comes with the 770 should be fine with most 8 ohm speakers. There is no doubt the sound can be improved with better more expensive speakers. In a few years Ill upgrade my Onkyo home theater and get a some aperion speakers.

Did you hook up the two back rears? Im assuming you will have to readjust the speaker levels using a sound pressure level.

[millerwill]

Yes, I did connect two old Onkyo surrounds in parallel to the surround-back terminal of the 520 AVR. Sounds quite good, better (I believe) than just one surround-back speaker (it spreads out the surround-back sound for a fuller surround experience). And yes, I have the RS spl meter to set the sound levels. I'm quite pleased with the set-up (at least for now--one is never TOTALLY content!).

[solderguy]

I kinda like 6.1, it's fun watching horror movies with a single rear speaker directly behind you, can really make you jump. :)

[usace]

While the setup you have probably works and sounds ok, I'm wondering how much this is taxing the AVR. As was mentioned earlier, if you take two 8ohm loads and wire them in parallel you now have a 4 ohm load on that channel. When you drop the resistance on this channel you are going to be putting more of a strain on it. An alternative might be to wire the speakers in series instead, producing a 16ohm load and putting less strain on this channel. As a result, this might drop the volume level of this channel, but you may be able to bring it back up with the individual volume controls for each of the channels. Someone did mention above that this is the rear center channel and won't see a lot of action, so it may not even matter. All I'm saying is that this channel is now working a little harder then it may have been designed to... hard enough to damage it? Tough to say. It all depends on how robust Onkyo made this thing. Does the manual say anything about speaker resistances on each channel? There may be some kind of warning that says something about not using less than an 8 ohm load.

[solderguy]

Heh, keep the two 8 ohm speakers in parallel (4 ohms) then add another parallel pair in series. 4 + 4 = 8ohms for a 9.1 setup :)