"Tuning" a PA system to be flat -- how-to??

[bduersch]

I recently picked up a PA system to use for DJ-ing and small band gigs. When I play CD's through the system, I've noticed that there's an upper-midrange honk that gets annoying pretty quickly. So I did a little adjustment to the mixer EQ, and while it sounds better, I'm curious to see how flat of a response I can get out of the PA system (mixer, power amp, & speakers). Ideally, when not being used for gigs, I'd like to use the PA at home for large studio monitors... When I'm done mixing on small monitors I like to blast the mix through larger ones just to see if any new artifacts appear.

Based on a little reading earlier this afternoon, it seems like I need a microphone, a spectral analyzer, and a graphic EQ to pull this off... Use the spectral analyzer to generate pink noise, monitor the frequencies on the analyzer using the microphone, and adjust the EQ accordingly. Then repeat for the 2nd channel.

So far I've seen several used analyers (DOD, Rane, Alto) and mics (dbx, Behringer) out there, but don't know if any are drastically better than the others. For the EQ, I'll probably pick up an Alesis MEQ-230, since it's got two 31-band EQ's in a single rack space.

Does this sound like the right process? Does anybody who's tried this before have any gear or proecess recommendations? Any help, as always, would be appreciated.

--B

[JESTER700]

That's the idea, but it's not an exact science. For one thing, the room is a BIG part of the equation, and you will only ever be able to get it "flat" in one listening position. But this can be a cool learning tool.

Also, I wouldn't use PA speakers as monitors. Accuracy is usually a secondary concern, and the generally low crossover point to a compression driver/horn assembly doesn't help.

[bduersch]

Originally Posted by JESTER700

For one thing, the room is a BIG part of the equation, and you will only ever be able to get it "flat" in one listening position. But this can be a cool learning tool.

Also, I wouldn't use PA speakers as monitors. Accuracy is usually a secondary concern, and the generally low crossover point to a compression driver/horn assembly doesn't help.

Yeah, my original plan was to buy a used analyzer, get the EQ set up for monitoring, then sell the analyzer, but then I realized that the EQ will vary based on location (and will probably vary considerably in the studio as gear & people get shuffled around), so it's really more of a long-term investment if I decide to go through with it.

For reference, in my home studio after mixing I listen to everything on 4 sets of monitors (studio headphones, small Carvin desktop monitors, Sony 3-way stereo speakers, and the aforementioned PA cabs). If the recording passes the test on all of those speakers, then I burn a CD to listen to in the car and on a boombox. I do the majority of work on the desktop monitors and headphones, but like to review new tunes on as many setups as possible to listen for differences. For example, one song I recorded last year had this "drone" note that was barely detectable on the desktop monitors & headphones, but was really obnoxious on larger speakers. A little EQ in the mix made it more palatable across the board.

Back to the task at hand... I just discovered the Phonic PAA2, which is a handheld analyzer with a built-in mic. That could actually come in handy to take to gigs to help tweak EQ of sound systems in different clubs. Even if I can't fix a lot of the sound issues in clubs, it'd be a great learning tool. One feature I like... it allows you to save up to 10 readings from around the room then generate an average EQ curve. I know it wouldn't be perfect, but it'd likely be better than relying upon my already poor hearing!

--B