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PA EQ'ing tips.

Posted: Sun Nov 13, 2005 5:35 pm
by VelvetGeorge
A few pointers for getting the pa "dialed in".


#1 don't EQ at all. Don't start by grabbing frequencies on the graph. Wait until you have the crossover dialed in. My suggestion:

power up and make sure everthing works, put in a CD you're familiar with and play it through the system with no EQ on the channel or graphic EQ. If everything works and sounds in phase (the speakers seem to couple the sound together, not cancel each other out) mute or turn off the power amps for highs and lows. This is for a 3 way system. In a 2 way setup, just turn off the sub.

With only the mids (and highs in 2 way) playing, set the crossover for the recommended frequencies. It should sound fairly normal, but missing kick drums and cymbals.
Listen at different volumes, in different places around the room. If it sounds kinda honky, cut a few dbs at 500 or 630. If the mid speakers fart out in the lows at high volume, try raising the cutoff frequency on the crossover.

The mids should sound as natural as possible. You should not have to cut any frequency by more than 3db. Except in extreme situations.

With the mids adjusted, unmute the highs and bring their level up on the crossover. They will typically need only 1/4 to 1/2 the level of the mids to be in proportion. Many people add too much.

With the mids and highs working in tandem you can cut any trouble frequencies. Typically rooms with low ceilings, tile floors, mirrors on the wall ect will need a cut or two between 2-8k.

The sound should now be full and even. The CD should sound natural and familiar. And speaking into a mic should sound natural as well. Not overly sibilant or nasally.

Finally, bring up the level for the subs. They should require the most level from the crossover with properly matched poweramps and speakers. As the level goes up, kick drums and bass guitar should become clear but not overbearing. Many low frequency speakers need a cut around 100-150Hz.


Overall, EQing should be in small doses and only for cuts. Typically not more than 3db's. If you feel like you need to cut more than 3db, try cutting a little from 2 or 3 frequencies rather than a deep cut on one particular band.

A well EQ'ed PA will allow you to have a powerful sounding mix that isn't painful to listen too. Go easy on the 2.5k it hurts.


George

Posted: Sun Nov 13, 2005 11:41 pm
by Flames1950
I think you're avoiding the subject of an eight-input JTM100 PA head clone, with vertical clone PA cabs. Just admit it. :wink:

Posted: Mon Nov 14, 2005 12:54 pm
by VelvetGeorge
You really want one of these don't you???

And you know I'd do it.

How cool would it be to walk into a bar and see a band playing with a circa' 68 setup?


George

Posted: Mon Nov 14, 2005 1:45 pm
by dosmun
You forgot the part about making the smiley face on the EQ :lol:

Posted: Mon Nov 14, 2005 2:26 pm
by MacGaden
Flames1950 wrote:I think you're avoiding the subject of an eight-input JTM100 PA head clone, with vertical clone PA cabs. Just admit it. :wink:
Have anybody actually heard one used for PA ? I can´t imagine what it must have sounded like back in the ´60s..

It would look really cool, and would often be enough for some jobs.

Posted: Mon Nov 14, 2005 4:45 pm
by Flames1950
VelvetGeorge wrote:You really want one of these don't you???

And you know I'd do it.

How cool would it be to walk into a bar and see a band playing with a circa' 68 setup?


George
I think it would be freakin' sweet for that REAL late 60's sound....... :D :D :D