Power Amp/speaker connection?

[Carrot22]

Completely new to PA/live sound so i could use some help here....

I plan on purchasing the QSC GX5 power amp and 2 Electro Voice ELX 112 speakers for my PA. what is the best way to configure the set up? I'm confused with the ohmage and exactly how a power amplifier works. The QSC GX5 says it can run stereo at 8 ohms or 4 ohms per channel at different wattage but is this due to how I set up my circuit (parallel or series) or do i configure these settings on the actual power amp itself?

So with 2x 8 ohm speakers how should I set them up to get their maximum potential? Thanks for any help

[carl h.]

Do you want stereo or maximum sound?

[3506string]

If you have a left and right coming from your board run them to both inputs on the power amp. If not then run the output from the board into channel 1 and use a 1/4" to jumper from channel 1 to channel 2 on the power amps input.(this is in the manual) Then run 1 speaker per channel. Also leave the amp in full range.

[Carrot22]

my speakers peak is 1000w (250 continuous) so whatever I can do to get the maximum potential out of them without fear of damaging them. If i go stereo I either have a choice of 500w at 8ohm or 700w at 4ohm correct? However, am i right to say that If I drive one channel I can daisy chain both speakers at 600w?

QSC gx5 specs here to save you the time- QSC GX5 Stereo Power Amplifier: Shop Pro Audio & Other Musical Instruments | Musician's Friend

[WayneP]

Originally Posted by Carrot22

my speakers peak is 1000w (250 continuous) so whatever I can do to get the maximum potential out of them without fear of damaging them. If i go stereo I either have a choice of 500w at 8ohm or 700w at 4ohm correct? However, am i right to say that If I drive one channel I can daisy chain both speakers at 600w?

Sure you can daisy-chain the speakers, which will get a 4-ohm load on one channel of the amp, but do the math.

The GX-5 will deliver 850 watts @ 4 ohms when only channel is driven. That will be divided between the two speakers – i.e. 425 watts per speaker.

However, the amp will deliver 500 watts @ 8 ohms with both channels driven. That’s what you’d get with one speaker connected to each channel.

So - if you daisy chain you’re losing 75 watts per speaker, plus you’re driving the amp harder. Lose, lose.

Regards,
Wayne A. Pflughaupt

[4Mal]

True. But that 75 watts isn't a real big deal and going mono on one channel of the amp leaves the other channel available for floor monitors, or a sub ...