Dave the Pub muso wrote
Firstly, My power amp (made by phonic) has a switch that switches between "floating" and "grounded". What does this mean?
That disconnects (AKA "floats" or "lifts") the grounding to the mains plug. Sound systems are usually set up so only one item (usually the mixer) to avoid ground loops between equipment. The one grounded item then grounds all the other connected gear via the audio cables.
Secondly, there's another switch which switches between "stereo" (obvious enough) and "Series". Whats the series thing all about?
That's for using both channels together, so the amp is mono (usually called "bridging") - used when you need more power and add in another amp so each handles one channel. So if you have a 200W per channel stereo amp, it will give you 400W as a mono. The minimum impedance also adds together, so if your amp has a 4Ohm minimum on each channel in stereo, it will have an 8 Ohm minimum in bridged mode.
and lastly, Can I run different speakers (different watts) for left and right? I now have two speakers which are both 8ohms, but one is 150watt and the other is 300watt. Assuming that it's a 150 watt amp, can I use both of these speakers?
That's fine - the impedance is the most important thing as long as the speaker is rated to handle the amps full power (at least), it doesn't matter if the speaker's power rating is higher.
I'm asking this because I once destroyed an amp by inadvertantly having a 4ohm speaker on the one side and an 8ohm speaker on the other.
Most PA amps should handle down to 4 Ohms (it's kind of a standard), in fact they will usually only get their full rated power output at the minimum impedance. Was it a mono amp? Then the speakers would have been paralleled and the total impedance would have been 2.6 Ohm and the amp would have tried to feed them too much power (almost double it's rated power) and then it would overheat or blow.
