Crown XTi 4000 needs a compressor - dbx ???

[metaverse]

Hello all,

Was just wondering if anyone out there had any recommendations for a good quality compressor to slap in between my traktor S4 and my crown xti AMP.

Brent Evans recommended a dbx 266. Just looking for a second opinion because i've never used a compressor before.

thanks and merry Xmas!



EDIT:

Originally i was searching for a 2nd mixer to place between my Digital DJ mixer and the Crown xti.

I was searching for a mixer because last week I had another DJ plug in his controller/mixer and basically clip my amp until it nearly shut off to protect itself. In other words : The boy didn't understand gain structure at all and pushed everything into the RED on his mixer. This is going to happen again and again and therefore I need to have protection to prevent further damage to my speakers.

I have the limiter and crossovers already set. I just wanted an extra layer of protection to protect my sound system.

Someone then mentioned using a dbx compressor instead of a mixer stating that it would not only protect my speakers but also let the music breath a bit more than just running the built in DSP limiter.

[Bas Gooiker]

Do you need a compressor? Or just a general DSP for limiting etc. etc.

The DCX2496 by Behringer is an alternative for the 260.

[gzc_stageTech]

I have a dbx 166, also a great compressor. I use it for a vocal input to control screamers.

And I use an Alesis 3630 as a 'final' compressor which would be like you've described your use. It is like a soft knee limit although I don't use it to "brick wall".

The Alesis is around $100 and the dbx is twice that.

Incidently, compressors reduce output gain to input gain with an adjustable threshold point. As a result, you can turn up the input without overdriving you amps.

Chris

[mr.lussier]

In fact, the built-in limiter in your xti amp is a hard compressor. Compressors are invaluable for vocals, instruments and such. But if you mostly DJ with cd's, maybe a compressor is not really needed. Today's cds are already so much compressed (especially on a lot of electronic music records) that IMO there's not a lot to be gained without beginning to tradeoff some sound quality for a few more db. A string instrument can perform over a range of several tens of db, whereas, IIRC, a typical cd has less than 10 db of dynamic range, sometimes more like 6 db. Also, don't forget that when you compress and pump up the volume, you also raise the average power your amp produces. So in the end your speakers will still deal with more power and more heat, even if the voltage limit remains the same.

I'll let others chime in, because I'm not really a professional DJ. Just my 2 cents, for what it's worth...

[Bruce Weldy]

In fact, the built-in limiter in your xti amp is a hard compressor. Compressors are invaluable for vocals, instruments and such. But if you mostly DJ with cd's, maybe a compressor is not really needed. Today's cds are already so much compressed (especially on a lot of electronic music records) that IMO there's not a lot to be gained without beginning to tradeoff some sound quality for a few more db. A string instrument can perform over a range of several tens of db, whereas, IIRC, a typical cd has less than 10 db of dynamic range, sometimes more like 6 db. Also, don't forget that when you compress and pump up the volume, you also raise the average power your amp produces. So in the end your speakers will still deal with more power and more heat, even if the voltage limit remains the same.

I'll let others chime in, because I'm not really a professional DJ. Just my 2 cents, for what it's worth...

You are absolutely correct. Today's music is already squashed like a bug - putting more compression on it just takes it's already limited dynamic range and makes it disappear.

I can't hardly listen to anything new. The softest parts of the song and the loudest parts of the song are damn near the same.

Compression is the most overused and least understood tool in the studio.

[metaverse]

Originally i was searching for a 2nd mixer to place between my Digital DJ mixer and the Crown xti.

I was searching for a mixer because last week I had another DJ plug in his controller/mixer and basically clip my amp until it nearly shut off to protect itself. In other words : The boy didn't understand gain structure at all and pushed everything into the RED on his mixer. This is going to happen again and again and therefore I need to have protection to prevent further damage to my speakers.

I have the limiter and crossovers already set. I just wanted an extra layer of protection to protect my sound system.

Someone then mentioned using a dbx compressor instead of a mixer stating that it would not only protect my speakers but also let the music breath a bit more than just running the built in DSP limiter.

[Bruce Weldy]

Originally i was searching for a 2nd mixer to place between my Digital DJ mixer and the Crown xti.

I was searching for a mixer because last week I had another DJ plug in his controller/mixer and basically clip my amp until it nearly shut off to protect itself. In other words : The boy didn't understand gain structure at all and pushed everything into the RED on his mixer. This is going to happen again and again and therefore I need to have protection to prevent further damage to my speakers.

I have the limiter and crossovers already set. I just wanted an extra layer of protection to protect my sound system.

Someone then mentioned using a dbx compressor instead of a mixer stating that it would not only protect my speakers but also let the music breath a bit more than just running the built in DSP limiter.

A compressor doesn't necessarily make the loud parts softer....depending on how you set the gain makeup - it might just make the soft parts louder.

The limiter is the only protection.

And a compressor would make the music breathe less - if by breathe you mean dynamics.

[gzc_stageTech]

If the deejah is clipping his controller, it's gonna sound like she-ite anyway. The brick wall should save your drivers though if they're properly set. The compressor in his signal chain would let him think he was getting louder 'gracefully'.

Like Bruce said , it'd further squash the softer parts to the louder parts, but if that's the way he (the deejah) thinks it sounds better. . . there you go.

Still, I think the deejah needs to put some money on the table to insure the rest of the system, in light of his ignorance.

You're much more patient than I would be with my pa. I'd pull the gain down to the point he'd just leave.
Sorry, I've got too many $$$ to let some punk ass kid blow up my rig.

Chris

[DJPhatman]

If the deejah is clipping his controller, it's gonna sound like sheite anyway. The brick wall should save your drivers though if they're properly set. The compressor in his signal chain would let him think he was getting louder 'gracefully'.

Still, I think the deejah needs to put some money on the table to insure the rest of the system, in light of his ignorance.

You're much more patient than I would be with my pa. I'd pull the gain down to the point he'd just leave.
Sorry, I've got too many $$$ to let some punk ass kid blow up my rig.

Chris

+1,000,000! No one else plugs in to my system without a signed contract putting all liability on the end user, even if I am at the controls. I would even go so far as to shut such a so-called "DJ" completely down, and inform him/her that said show is over for "abuse of system components" clause in all of my contracts. Since payment is always up-front, and there are no refunds, I am out nothing by stopping.

[mr.lussier]

If the guy that plugs in your rig clips his own mixer, then there's nothing you can do to fix the sound after that.


There's a lot of folks out there that will tell you to limit 3 db above the rms rating of your cabs (so-called music program, 3db crest factor). However, this is counting on the fact that the 3db pulses are onl pulses, and not machinegun clipping. If in doubt, don't do that. If there's substantial doubt, limit 3db BELOW rms voltage rating. That's what I'd do.

[gzc_stageTech]

Excellant point Mr.Lussier.

Sometimes you've got to take matters in your own hand.

Walkon deejahs don't always know what makes the sound, just that they want to control it. With little capital investment, they have little to lose when the system goes silent. They can simply walk on to the next gig. As an owner, we've got the rights and responsibility to stay in control.

I think all builders would want to protect their labor as well as the $$$ invested.

[metaverse]

OK ... so to sum it up:

Just make sure my limiter is in check and my rig will stay protected ??

- 3db or -6db on the crown dsp limiter? right now its set to -3 and he was able to make it clip a couple of times.

[mr.lussier]

Do you mean -3db relative to the voltage limit of your cabs, or 3db below the amps full rated power ? Common practice here is if for instance the plans call for a max voltage of 50 volts, you set the limiter so the amp never produce more than 50 volts. You can verify that with a voltmeter. If your system has a lot of headroom you can as well limit to 35-40 volts for added safety.

That being said, my t39 is hooked up to a crown xls1000. The built in limiter is fixed to 75 volts, which is more than what is recommended IIRC. On occasions I drove it hard for 5 hours with that occasional clipping light. It never gave up (until now, at least). I think a hard Highpass may be at least as important as the correct limiter setting.

Regarding your clipping light... I may be wrong, but I'd guess if you have an amp with a built-in limiter, the red light must indicate the limiter licking in, and not the output stage clipping. You should verify this in the manual.

[Grant Bunter]

OK ... so to sum it up:

Just make sure my limiter is in check and my rig will stay protected ??

- 3db or -6db on the crown dsp limiter? right now its set to -3 and he was able to make it clip a couple of times.

It pays to be cautious but it is easy to be overly so at the expense of max output when you want that.
Having said that, when you set up limiting in the amp, you want to see the clip light come on, but only very briefly, and not on every bass drum hit. If the clip light does come on with every bass drum hit, or, when clipping, the light does not fade rapidly, then, there is not enough limiting.
If the "other" DJ was getting occasssional short duration clips a couple of times only, you probably have it set correctly already...

If his sound was distorted (due to being pushed into the red on his deck), that's doesn't necessarily mean that your cabs were being pushed to the point of distorting as well, it could well mean your cabs were simply faithfully reproducing the distorted content being provided to them. There is a difference. You wouldn't worry about hearing distorted reproduction of sounds from a guitar cab, so you need to be able to distinguish the two.

At shared gigs, you need to tell other DJ's that it's your rig, and if they wish to push to the red all the time, you will adjust the attenuators and no argument will be entered into. Play by the rules, or they don't work that night. Simple.

[metaverse]

When he had the channel fader jacked to 100% and was showing red in his meter : it sounded like the amp stuttered on and off , a couple of times, for a couple of seconds. It was short but painful sounding. It wasn't just a constant distortion buzzing through the sound.