6 ohms + 8 ohms on 7.1 biwired

dan98svt

I have an onkyo tx sr806 currently running two 6 ohm sda srs 1.2s bi-wired to front main and back surround. I also have three 8 ohm technics spkrs wired normally to center and l/r surround. The sub is running itself off the sub pre out. Are the differing ohms hurting the amp? It gets pretty warm, and there is also a sticker on the top of the amp that says it'll get pretty warm. ..
I would like to use some 6 ohm spkrs as the l/r surrounds. Would that be bad for the amp?
The manual doesn't really get that detailed.

deronb1

The ohm difference isnt as much of a deal as the total load you are trying to drive with an avr. As long as you are not playing at crazy loud levels, you should be fine, but an external amp for the sda would improve the overall sound of your system and reduce the load on your avr.

I have an axial fan sitting on top of my onk. I plugged it into the avr so it only runs when the avr is on. Runs very cool now and imo will extend its life.

F1nut

What you are attempting is not bi-wiring, it's called ghetto bi-amping because it is not bi-amping at all. Furthermore, the more channels you use, the less wpc you get. Bottom line, that or any AVR is not capable of driving SDA SRS 1.2 speakers as they should be.

Polkie2009

+1000 This ghetto wiring sounds like a disaster waiting to happen.

dan98svt

Being where I am, it's either AVR or half fried 30 year old Kenwood amp and pre-amp. The amps I want are too heavy to be shipped to me (70lbs max) (APO).
The Onkyo has a much better sound than the Kenwood (way too harsh). I hooked them up according to the instructions in the Onkyo manual "or bi-amped to provide separate tweeter and woofer feeds for a pair of front speakers that support bi-amping, providing improved bass and treble performance."
They sound good and I didn't seem to lose too many wpc, as I listen at about 75 and it gets about as loud as the SDA1cs did when I had them hooked up normal (not bi-amped). The Onkyo says 180 wpc @ 6 ohms 2 channels driven. If this turned out to be 4 x 90 wpc (bi-amped), I'm not really hearing the difference at my usual listening level. The big dog leaves at about 65 and the little one runs out at 70. No change there either.
I was just wondering if mixing 6 ohm and 8 ohm speakers for the surrounds would be too hard on the amp with 6 ohm fronts.
Dan

tonyb

The answer to your question is....no, shouldn't make that big a difference. Your overall load on the receiver will or should be more of a concern. That's what the guys are trying to convey to you.

The 1.2's thrive on current, something most any receiver lacks. Taking that off your receivers hands by adding an amp would greatly enhance your listening experience and the life of your AVR.

Under powering speakers is about the worst thing you can do, which also maybe the reason your in need of tweeters too. Just sayin'...

dan98svt

Lol, just got the 1.2s on Sat. Swapped some MWs from SDA1Cs and hooked them up yesterday. As for the tweeters, it wern't me...

tonyb

dan98svt wrote: »

Lol, just got the 1.2s on Sat. Swapped some MWs from SDA1Cs and hooked them up yesterday. As for the tweeters, it wern't me...

LOL...cool man. We are just sayin'...if you don't want that to be you in the future, think twice about feeding those 1.2's enough juice.

F1nut

The Onkyo says 180 wpc @ 6 ohms 2 channels driven. If this turned out to be 4 x 90 wpc (bi-amped), I'm not really hearing the difference at my usual listening level.

Key words, 2 channels driven. Drops quickly from there when all are driven, so maybe 120 wpc with 5 driven and maybe 90 wpc with 7 driven. Ok, so 90 going up top and 90 going to the bottom. The top might use 5 watts, the rest is wasted. If using only 5 channels say the top gets 5 and bottom gets 115. That would net 25 more watts to bottom where that little bit of extra power would help.

Besides all that, bi-amping requires separate amps, each with its own power supply as opposed to the shared one in an AVR and very important, the use of active crossovers.