# REW for live sound



## webhatter (Aug 24, 2014)

Hi everybody!

I'm a live sound guy, new to REW. I read some guides on the forum and I watched the tutorials on YouTube.

But now I would like to know if and how REW could help me to tune my system before a concert.
Basically I have to do subs to tops alignment and loudspeakers equalization to obtain a flat response.

I already own a PC, a Focusrite Saffire 6 USB audio interface, a Behringer ECM8000 microphone and a ‎dbx DriveRack PA2 DSP.

Which is the best step-by-step workflow to do that?

Thank you in advance!


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## gazoink (Apr 17, 2013)

webhatter said:


> Hi everybody!
> 
> I'm a live sound guy, new to REW. I read some guides on the forum and I watched the tutorials on YouTube.
> 
> ...


To be honest, I haven't been very successful with REW for live sound for one simple reason: I don't have the time. I need to get answers quickly and respond with EQ, and hardly every have even an hour to mess with things. Especially in live sound, you need to look at response over a fairly large area, you should never try to EQ with a single mic position. With REW that means set the mic, take a measurement, move the mic, take another...etc. Then average them, adjust EQ and start over. Simply no time to do it. I often end up with like 30 minutes to play, simply can't do FOH and stage monitors with REW in that time, not even close.

My live sound technique involves the basic THX spatial/temporal average idea. You can use either 4 mics arranged in a large square in the main audience area, or use a single mic that you move over an area while integrating the measurement over time, like 30 seconds or so. The software I use is WinRTA which has an integration timer that helps you do this, but it's expensive. Anyway, that's what I use. 

The RTA in REW can also be used this way, sort of. Set the RTA for 1/12 octave, average "forever", FFT length 8192 or 16384. Get someone to help. Start your pink noise, then start your RTA when you're in the house, while it's averaging, move the mic around over a path that covers the target area, letting REW average as you go. Careful not to bump the mic or induce any cable or handling noise. Then stop the RTA and look at the result, eq, repeat. The main difference between this and WinRTA is that WinRTA has a timer that starts the RTA, runs for a preset time, then stops both the RTA and pink noise. 

I know you don't see the time domain that way, but if you need the big answers quickly, it's the way to go, and doesn't involve subjecting people working in the venue to repeated chirps for hours.


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