What's a semi-objective way to evaluate a live audio setup for a small-medium sized acoustic band?

Question

So I'm hoping this is "answerable" :) We are a small band (two vocals, two acoustics, keys, sometimes an electric guitar, sometimes drums). Stopping by a Guitar Center there was a lot to look at, but it was hard to get an objective measure to evaluate against cost.

For example, is there a rule of thumb for speaker size for musical style? How many watts should we be looking at (i.e., is it based on size of audience)?

We are thinking:

1. Two powered mains
2. Two powered monitors
3. A mixing board with a good number of inputs (say 10)

I'd love to hear recommendations of what equipment people love, but we also really just need some metrics to judge speakers against apart from just listening to them.

Thanks!

EDIT: Here's some more helpful info:

• Budget - Roughly $2,000-$2,500
• Venues - Currently of the large coffee-house variety, but would like something versatile enough to take to maybe a small-medium sized concert hall or even a small outdoor thing (maybe 100-150 people)
• Style - somewhere in between folk, rock and blues

Answer 1

The good thing is that style of music is not necessarily that important. Generally (and this is a generalisation) you want your PA to provide amplification without affecting the sound, with EQ to carry out tweaks to compensate for the frequency response of the venue. Any effects on instruments or vocals should be carried out using processors separate to these, so you can define your sound once no matter where you play. Admittedly, for loud club beats, you need something that can cope with driving bass cabs with some power.

That said, I have run rock, metal and blues bands through everything from a 300Watt PA to a 12kW system and I would say the important thing is to look at your biggest expected gig and budget for a PA that will not need to be turned up above 6 or so.

For a coffee shop you could be just fine with a 100 Watt PA with >6 inputs - you would want your keys and electric guitar to go through it, plus vocals, but acoustic guitars and drums will be loud enough on their own.

For a bigger venue you will probably want to mic your acoustic guitars (or add piezo pickups), and maybe some of your drums/cymbals so you might more inputs, and something like a 300 watt PA should have headroom for the sizes of gigs you are talking about.

Budget for a mixing desk/EQ so you can cut feedback frequencies and tweak response.

For speakers, get a set with a separate bass from the mids and highs for clarity - if you don't the bass response can impact higher frequencies quite badly.