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CE2000 Pops in Bridge mode


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#1 PSIPHON

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Posted 16 August 2005 - 04:23 PM

I have a Yamaha SW218V (cont 1200 / peak 2400 W) that im tying to run on my CE2000 in bridge mode.

I set the amp to bridge and i repinned the cable to +1 +2 on the amp side. normaly if i accedentilay flicker the clip light no big deal you dont really hear anythign and i know to pull back, which doesnt susulay  happen any way becuase i have everything set at level. But in bridge mode if the clip light flickers i get a nasty pop noise out the speaker and im really concerned. Do you know what is going on? When i run the subs off one channel it can handel the full 660 no problem even if the clip light flicks, and the whole system is fine.

Whats going on here?

#2 KWhitehead

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Posted 17 August 2005 - 03:10 PM

You stated that you run your "sub's" off of one channel in stereo mode and it works fine. Do you have 2 subs? If you do you can only hook up one sub to the amplifier when running in bridge mode. The Yamaha's are rated at 4 Ohms and you can only go down to 4 Ohms in bridge for 1950W. If you are hooking up 2 of these subs in bridge mode that would be a 2 Ohm load which is below the amps ratings and the amplifier may be current limiting.

Kip Whitehead
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#3 PSIPHON

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Posted 19 August 2005 - 09:43 PM

Im sorry for my poor termonology, I have one (1) of these dual 18" cabs taht i am running the amp into in bridge mode at 4 ohms. Im not sure why the amp makes popping noises. Everything is wired correctly.

+1 +2 Amp Channel 1, Switch set to Bridge Mode

+1 -1 To speaker (single box) with 4ohm rating.

Signal to amp is going through a crossover @ rouglky 120 Hz.

If clip light flicks in bridge mode nasty pop noise comes out speaker; but in normal mode (660w @4ohm single line to cab +/-1 to +/-1) nothing major the light just flicks.

#4 1001US

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Posted 06 November 2005 - 10:17 PM

This is my guestimate... I am not a crown technician:

Well your sub is 1200 watts RMS, probably 1600 continous operation, and 2400 peak... so when your amplifier clips, your sub is recieving 2000 watts (on it's way to peak) of a wav form it cannot reproduce. Essentially when you clip an amplifier at that much power, the speaker is forced to whatever transient it's given (+ or -) at a full 2000 watts and it stays there momentarily. Therefore it's no longer an AC, it's a DC current momentarily. Of course that would make a popping noise, just like turning appliances on inside of your signal chain.

Now, if you're driving it at 660 watts (One stereo channel, 4 ohms), the force of the speaker being slammed out to it's full transient (+ or -) isn't nearly as powerful, and therefore wouldn't cause a pop. It's still bad for your speaker, however, it's a significantly more minor pop.

Thats my guess. It seems like your amplifier and subs are running fine, they're just being driven too hard. You should perhaps consider the use of a limiter as a solution to avoiding such pops.

#5 Bud Bolf

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Posted 07 November 2005 - 08:18 PM

Howdy,
Just a thought here but why are you clipping your Amp on a regular and constant
Basis?
If you set your Gain Structure correctly, you should NEVER see your Amp's clip light.
Also, if your amp is clipping, is the entire signal chain clipping, from the Mixer Inputs all the way to your Speakers?
Were you taught that the only way to reach your Amp's maximum
Input to Output scenario, was to completely go past it and overdrive the Amp's Inputs.
Have you ever been to a Professional Concert Tour and spied the Amp Racks and EVER see a flicker of a Clip light? I have not! Even the Sub Amp racks.
I am surprised that a Crown rep did not jump on this more.
If you are clipping, even if it's short and instataneous, then your Gain Structure is Incorrect.

I'd recommend that a better answer would be to not run your Power Amps to Clipping. Proper Gain structure should be enough, but if you do need help, you can put a Limiter on the Signal chain or on an offending channel insert, in the case of a Kick drum. Also Gate the Kick.
Better processing such as a DriveRack would help as well.

But, you CAN get a Clean, Safe, Un-distorted, non Harmful, FULL GAIN from your Power amps, without seeing any Red flicking Clip lights!
Do yourself and your speakers a favor, run your System correctly and Don't CLIP!
Plus, you will never hear a POP, Bridged or not!

I feel like someone saying, ya know, everytime I do this, it hurts,
Crowd response is, Then don't do that!

  Good Luck,
        Bud

#6 1001US

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Posted 07 November 2005 - 09:00 PM

In a nutshell, he took what I had and pulled the nice out.

A limiter will do the trick. If your program has alternating volumes from 15db or so, and you only want to deliver 110-115db or so (115 being peak), than just run a 3:1 compression ration. Keep in mind thats a crash course and overly simplified way to approach compression.

As for the pop, it probably is just the result of DC power delivery at that high of a voltage to your speaker.