Guitars? I have that completely covered. P/As? - All I know is that ours sounds terrible. Here's the setup: I play with my band in our 20' x 12' rehearsal space every week. We gig maybe a couple of times a year. Mostly, we just play for ourselves. The singer is consistently lost in the mix, the P/A just plain sounds bad, and our mics feedback like crazy if the volume gets too high. Our current signal chain for the vocals: Shure SM58 --> Mackie CR1604-VLZ mixer --> QSC USA900 amp --> Shure Model 702 floor monitors One thing I noticed right away. The amp is 450 Watts per channel and those pathetic floor monitors are 50 Watts. I don't know what you need to do to get 450 Watts out of that amp, but I'm pretty sure those monitors are being overwhelmed. I'm also fairly certain that the floor monitors are low quality to begin with (not to mention old and probably terribly inefficient). What I would like: 1) More volume out of the P/A 2) More clarity 3) No feedback My questions: 1) I assume I need new floor monitors or P/A speakers. Which one is preferred for my application? If new floor monitors are required, I have a budget of $600 for two new ones. I have an opportunity to get two SM12Vs for $250 each, but I'm not sure if that's a recommended model. Any other suggestions on models would be appreciated. 2) How do you regulate the power out of the amp? Since you are driving it externally, how would you even get 450 Watts out of it (i.e., max power)? (I noticed there are pots on the amp input that look like they attenuate the input signal). 3) Do I need a better mic? The salesperson at the local music store said that an AKG D-5 would be better overall, especially the anti-feedback technology.