Audio Systems/What watt @ ohms power amp to get?
I have a Yamaha CW118V 18" Club Concert Series Subwoofer(600W program, 8ohms nominal impedance) and two Yamaha S115IV 15" 2-way System passive speakers(500W program, 8ohms nominal impedance each). I would like to run the CW118V on one channel with a bass line out, then run the two S115IVs on another channel in parallel for my highs/mids. What would be the correct watt @ ohms power amp to run this setup? Here is a link to a power amp that I was wondering if it was powerful enough - http://www.pyleaudio.com/sku/PQA3100/19-Rack-Mount-3100-Watts-Professional-Power
The cabinet wattage is fine for the amp you're looking at. If the speaker rating exceed the wattage of the amp, you're typically in the clear. One thing to remember is that amplifier wattage rating are measured at full blast, volume up all the way to "11". Usually, people don't run them all out, but if you did, your speakers would handle it (I don't recommend it for your ears sake).
The main issue is with impedance (ohms) of the 2 x 15" subs. If each is 8 ohms, tying them together in parallel would effectively make the load 4 ohms, which could blow the amp. If they were in series, you'd get 16 ohms which would probably still work, but would only be pushing maybe 190 watts.
I would contact Pyle Audio about using this specific amp in this type of arrangement to be certain, but the rule of thumb is to NEVER hook a lower impedance speaker (or speaker combination) to an amp with a higher impedance output (8 ohm output to a 4 ohm cabinet can/will damage your amp).