CurtPalme.com Home Theater Forum

[Curt Palme]

Guys, I just got a couple of QSC power amps in on trade. They are 70 volt amps designed for commercial use, but they are powerful enough to drive an 8 ohm load directly. Something like 400 watts a side, go figure.

The question is, do the rear surrounds and front surrounds, the 6.1 and 7.1 speakers use a mono feed from the processor? If so, that would allow me to only use one 2 channel amp, one channel for the two rear speakers, and one channel for the front surrounds. If however the signal info is different between the left and right surrounds, then I'll use two 2 channels amps.

Thanks!

[Curt Palme]

Guys, I just got a couple of QSC power amps in on trade. They are 70 volt amps designed for commercial use, but they are powerful enough to drive an 8 ohm load directly. Something like 400 watts a side, go figure.

The question is, do the rear surrounds and front surrounds, the 6.1 and 7.1 speakers use a mono feed from the processor? If so, that would allow me to only use one 2 channel amp, one channel for the two rear speakers, and one channel for the front surrounds. If however the signal info is different between the left and right surrounds, then I'll use two 2 channels amps.

Thanks!

[Nashou66]

I think 6.1 is mono 7.1 discrete.

Nashou

[ecrabb]

If you're referring to the source content, with Blu-ray at least, most big-budget action or thriller movies are mixed in 7.1 and encoded on the disc in TrueHD or DTS-MA 7.1, i.e. 8 discrete channels. In a 6.1 playback system, the surround-back channels are down-mixed to a single surround-back, and in a 5.1 system, the surround-back channels are down-mixed with the other two surround-outs.

Regardless of whether the content is newer discrete BD, or whether you're talking about older DTS-ES, the surround processors still treats the outputs as separate channels and steers 5.1 to the rears if your decoder is set up for it. You could tell the processor you're only using a single surround-back, and it would down-mix the two surround-backs to one channel which you could then feed a mono amp to drive the two surround back speakers, but not only would you lose the discrete surround-back content on the big-budget stuff, you'd also lose the capability to set levels and EQ on those two speakers discretely.

Personally, I'd use two 2-channel amps. Anything else is a compromise. It's not like you can't scrounge up an amplifier or two, Curt.

SC

[Curt Palme]

You're right, I inherited 3 of the QSC amps in mint shape.

[Curt Palme]

You're right, I inherited 3 of the QSC amps in mint shape.