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XLS 602 + JBL JRX 125


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#16 Bud Bolf

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Posted 04 June 2006 - 07:09 AM

QUOTE(Clubber @ Jun 3 2006, 01:08 PM)
Thanks for the advice.

But I've got a question: When the amp clips than it masures that the speakers are overloaded or the amp?
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Hi Clubber,
When your Amp Clip lights light up then it means that the Amp's Input is being overloaded which you can correct by either turning the Amps gain knobs down a bit or turn down the Source Input, the Behringer.
The way to know which should be turned down, the Amp or the Behringer is all about "Gain Structure" see below....
An occasional clip light is not terrible but I prefer to never see it at all.

You can set up your Gain Structure for your System by connecting your Source Input to the Behringer and then the Outputs of the Behringer to the Crown XLS 602's Inputs.
Do not connect your speakers yet, or if they are disconnect them.

Turn the power ON  to your Source (CD player etc..) the Behringer and the Crown Power amp, leave the front Channel knobs on the Crown all the way down.
On the Behringer wether you are using Inputs 2/3 or 4/5 I would leave the Level for the channels at "0"
I would leave the "Main Mix" knob at "0" straight up also.
Now turn up your Input source to the Behringer until you just see the Red Clip LED's light up for your L&R Outputs.
If your Input source such as a CD player, does not have a volume control and instead has just a fixed output, then adjust the Channel Level knob until you see the Red Clip Led's light up at the L&R LED Meters.
Red lights should just Flicker and not be Solid on!
Now on the Crown XLS602 Power Amp turn up the front Channel 1 and Channel 2 Gain knobs until you just start to see the RED Clip lights start to flicker.
Once the Clip lights start to flicker on the Crown turn the Channel Gain knobs down just a bit until you do not see any RED Clip lights.
I would rather set the System so when the Red lights on the Behringer flicker, the Clip lights on the Amp still will not!
Now if the Behringer happens to hit Red the Crown will not and you will not Clip the Amp.
Your System's "Gain Structure" is now safely set.

Some will set up their System more on the edge to tweak every ounce of Power that they can!
They set the System Gain Structure so that when the Red Clip LED's light on the Mixer, they are also lighting at the Power amp, then they know if they see Red at the Mixer they know the Clip lights are also lighting up on on the Amp.
You then need to be quick on the Levels to pull down what is Clipping the Mixer.
I and many others take a more conservative approach that I'd rather be Safer than Sorry.
If I see an Occasional Red Clip at my Mixer, then I still know that my Amp is not Clipping and my Speakers are OK.
You can set these two whatever way you want, just so you know when the Amp's is Clipping!
My Subs are getting 2800 watts each from a CE4000 and at the higher wattage, Clipping can send a lot of heat to my voice coil and cause damage a bit quicker.
I also have more headroom and can back off on the Amp's gain a bit more to guarantee no clipping.
Clipping is one of a major cause of Speaker failures today.

The only better way to set "Gain Structure" would be to use a solid test tone but Source Material is acceptable, many put on a CD and set the Gain.
Now just watch the Behringer L&R LED's and from the method that you used to set the Gain Structure you know when the Amp is clipping.
I have also seen that some CD's are mixed hotter than others, so when you change the Input Source (different CD) make sure that the Behringer red clip lights do not light up or do so rarely.
If your System is plenty loud then leave your Mixer in the Green and then if a hotter Input is used you have some headroom.
I also always leave my Main fader or in your case Main Mix Knob at "0" Unity!
If you need to turn down the Behringer, use the Channel Level knob or turn down the Source.

At this point if your System cannot get loud enough for your taste, then you need a bigger Amp or Speakers because your System is running at or pretty close to it's max.

Good luck,
      Bud

#17 Bud Bolf

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Posted 04 June 2006 - 08:24 AM

Hi again,
Clubber, since you do not have a Crossover or anything to cut Frequencies per your Speaker's spec's, you are now running your speakers from 20Hz to 20kHz.
If you really crank them, then you may run them into frequencies that they were not designed to reproduce.
The Lower frequencies concern me more than the higher freq's.
Just an FYI.

QUOTE
Specifications:
System Type: Dual 15" 2-way, sound reinforcement speaker
Frequency Range (-10 dB):2 35 Hz - 16 kHz
Frequency Response (3 dB):2 45 Hz - 12 kHz

Sensitivity (1w/1m): 100 dB SPL
Nominal Impedance: 4 
Power Capacity:1 500 watts
Peak Power Capacity:1 2000 watts
Recommended Amplifier
Power: 500-1000 watts @ 4 
Maximum SPL: 133 dB
Nominal Dispersion: 90 x 50
Crossover Frequency: 2 kHz


Later,
   Bud

#18 Clubber

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Posted 04 June 2006 - 12:28 PM

Thanks for your advice. smile.gif

My source is the PC yet. I`ve tested an mp3 (before you where giving me this adivce) called a test from 20 hz to 20khz.
It plays a signal beetween these HZs.
And than it can damage the speakers even if the volume is low?? As you where saying neither those HZ the speaker can not support.

#19 Bud Bolf

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Posted 04 June 2006 - 04:08 PM

QUOTE(Clubber @ Jun 4 2006, 01:28 PM)
Thanks for your advice. smile.gif

My source is the PC yet. I`ve tested an mp3 (before you where giving me this adivce) called a test from 20 hz to 20khz.
It plays a signal beetween these HZs.
And than it can damage the speakers even if the volume is low?? As you where saying neither those HZ the speaker can not support.
View Post


Hi Clubber,
  No not at low volume, probably really not a problem at medium to medium high volume.
I said that
QUOTE
If you really crank them (very high SPL's) then you may run them into frequencies that they were not designed to reproduce.


If you have an EQ just do not boost frequencies below 50Hz.
You should know if the speakers sound like they are being over exerted.

Later,
   Bud

#20 Clubber

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Posted 05 June 2006 - 03:11 PM

Hello
Well I have an EQ beacuse I bought the UB-802 version of the mixer:


And even the amp clips sooner if i turn the low to +5dB.
So i better stay at 0dB. smile.gif

#21 Bud Bolf

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Posted 05 June 2006 - 09:44 PM

QUOTE(Clubber @ Jun 5 2006, 04:11 PM)
Hello
Well I have an EQ beacuse I bought the UB-802 version of the mixer:


And even the amp clips sooner if i turn the low to +5dB.
So i better stay at 0dB. smile.gif
View Post


Hi Clubber,
That's  because when you boost the EQ it actually makes your Channel strip hotter.
If you want to be able to use the EQ to it's full path then when you adjust your EQ
to the plus side and if your amp wants to clip but your mixer is not, then just turn
down your Amp's gain until the clip light goes out.

When I was talking about removing EQ below 50Hz it was if you used a
31 band EQ or Dual 31 or even a Dual 15 EQ with sliders.
Some EQ's even have a variable Low pass adjustable filter.

That Low EQ on the Behringer is one that I caution turning up while really cranking your speakers, because it will definately Add possibly more low end than your speakers want.

Like I said before, you should be able to tell from the sound of your speakers if they are being pushed past their limits.

Good luck,
     Bud

#22 Clubber

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Posted 06 June 2006 - 01:51 PM

QUOTE(Bud Bolf @ Jun 4 2006, 07:09 AM)
QUOTE(Clubber @ Jun 3 2006, 01:08 PM)
Thanks for the advice.

But I've got  a question: When the amp clips than it masures that the speakers are overloaded or the amp?
View Post


Hi Clubber,
When your Amp Clip lights light up then it means that the Amp's Input is being overloaded which you can correct by either turning the Amps gain knobs down a bit or turn down the Source Input, the Behringer.
The way to know which should be turned down, the Amp or the Behringer is all about "Gain Structure" see below....
An occasional clip light is not terrible but I prefer to never see it at all.

You can set up your Gain Structure for your System by connecting your Source Input to the Behringer and then the Outputs of the Behringer to the Crown XLS 602's Inputs.
Do not connect your speakers yet, or if they are disconnect them.

Turn the power ON  to your Source (CD player etc..) the Behringer and the Crown Power amp, leave the front Channel knobs on the Crown all the way down.
On the Behringer wether you are using Inputs 2/3 or 4/5 I would leave the Level for the channels at "0"
I would leave the "Main Mix" knob at "0" straight up also.
Now turn up your Input source to the Behringer until you just see the Red Clip LED's light up for your L&R Outputs.
If your Input source such as a CD player, does not have a volume control and instead has just a fixed output, then adjust the Channel Level knob until you see the Red Clip Led's light up at the L&R LED Meters.
Red lights should just Flicker and not be Solid on!
Now on the Crown XLS602 Power Amp turn up the front Channel 1 and Channel 2 Gain knobs until you just start to see the RED Clip lights start to flicker.
Once the Clip lights start to flicker on the Crown turn the Channel Gain knobs down just a bit until you do not see any RED Clip lights.
I would rather set the System so when the Red lights on the Behringer flicker, the Clip lights on the Amp still will not!
Now if the Behringer happens to hit Red the Crown will not and you will not Clip the Amp.
Your System's "Gain Structure" is now safely set.

Some will set up their System more on the edge to tweak every ounce of Power that they can!
They set the System Gain Structure so that when the Red Clip LED's light on the Mixer, they are also lighting at the Power amp, then they know if they see Red at the Mixer they know the Clip lights are also lighting up on on the Amp.
You then need to be quick on the Levels to pull down what is Clipping the Mixer.
I and many others take a more conservative approach that I'd rather be Safer than Sorry.
If I see an Occasional Red Clip at my Mixer, then I still know that my Amp is not Clipping and my Speakers are OK.
You can set these two whatever way you want, just so you know when the Amp's is Clipping!
My Subs are getting 2800 watts each from a CE4000 and at the higher wattage, Clipping can send a lot of heat to my voice coil and cause damage a bit quicker.
I also have more headroom and can back off on the Amp's gain a bit more to guarantee no clipping.
Clipping is one of a major cause of Speaker failures today.

The only better way to set "Gain Structure" would be to use a solid test tone but Source Material is acceptable, many put on a CD and set the Gain.
Now just watch the Behringer L&R LED's and from the method that you used to set the Gain Structure you know when the Amp is clipping.
I have also seen that some CD's are mixed hotter than others, so when you change the Input Source (different CD) make sure that the Behringer red clip lights do not light up or do so rarely.
If your System is plenty loud then leave your Mixer in the Green and then if a hotter Input is used you have some headroom.
I also always leave my Main fader or in your case Main Mix Knob at "0" Unity!
If you need to turn down the Behringer, use the Channel Level knob or turn down the Source.

At this point if your System cannot get loud enough for your taste, then you need a bigger Amp or Speakers because your System is running at or pretty close to it's max.

Good luck,
      Bud
View Post



Hello again smile.gif

I've tried this, yes it really works and it's a good idea, but as you where saying some  songs are more powerfull than others and those may clip your amp. So I should  be cearfull. cool.gif