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I read the manual it says " on the limit screen you may implement your own threshold, release, and hold settings using the built in limiters " Okay I can read but I do not understand can someone explain please?
 

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@notnyt

In your opinion do you believe the default values are good for subwoofer usage? I'm curious if the defaults are an all around safe setting or if they were chosen for full range applications and might not be the best values for a sub only setup especially for HT.
 

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attack is the time it takes to react to the signal crossing the threshold, hold is how long it will keep the signal limited, and release is how long it takes to restore the signal to full.

http://en.wikipedia.org/wiki/Noise_gate
What value do you use for attack/hold. I have used 5/20 ms? The I Nuke manual tells you that they are available but, it is hard to find source telling what value to use. I have used the 5/20 with the amps for around 3 years without any amp/driver damage.
 

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Discussion Starter · #5 ·
That was my point the manual for these amps is pretty much worthless other than just basic set-up. If the 5/20 has been working for Derrick for 3 years I will try it. If I am getting this somewhat correct the default settings must be more for full range, live music venue. I think the 5/20 would be better for HT applications with sustained low freq.'s.
 

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I have been wondering about this.......

I have the dsp software open right now and under the "configuration" tab, for the Peak Limiter there is "HOLD" and "RELEASE". The "HOLD" is default at 50.0ms, and the "RELEASE" is default at 100.0ms. I don't see a "ATTACK". Derrick when you say you have yours set to attack/hold 5/20, is that under the configuration tap? I only see attack in the DEQ tab.

I am curious what the recommended settings are for subs, and for me more specifically......Crowson's.

How popular these amps are for subs, I think it would come up more often.
 

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I have been wondering about this.......

I have the dsp software open right now and under the "configuration" tab, for the Peak Limiter there is "HOLD" and "RELEASE". The "HOLD" is default at 50.0ms, and the "RELEASE" is default at 100.0ms. I don't see a "ATTACK". Derrick when you say you have yours set to attack/hold 5/20, is that under the configuration tap? I only see attack in the DEQ tab.

I am curious what the recommended settings are for subs, and for me more specifically......Crowson's.

How popular these amps are for subs, I think it would come up more often.
the limiter on the "configuration" tab on the inuke is "zero attack".


the dynamic limiter on the other tab can be adjusted for attack.
 

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for a zero attack limiter how long it is "held" and for how long it takes "to scale" back are both irrelevant concepts. the zero attack limiter is a brick wall.

It's not a brick wall. It will scale the entire signal down to conform to the limit. Once the signal is below the limit, HOLD is how long it will remain limited for, and release is the duration of time it takes to scale the signal back to normal. They're quite relevant.
 

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I have been wondering about this.......

I have the dsp software open right now and under the "configuration" tab, for the Peak Limiter there is "HOLD" and "RELEASE". The "HOLD" is default at 50.0ms, and the "RELEASE" is default at 100.0ms. I don't see a "ATTACK". Derrick when you say you have yours set to attack/hold 5/20, is that under the configuration tap? I only see attack in the DEQ tab.

I am curious what the recommended settings are for subs, and for me more specifically......Crowson's.

How popular these amps are for subs, I think it would come up more often.
I'm running the default 50/100 Keep in mind, 50ms is 1 cycle at 20hz.
 

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As promised, without and with limiter.



Seems to have good control until until you push REALLY hard. It seems the limiter still functions at 0 as well, although that limit is a bit beyond the amps actual capability.

This was into an 8 ohm load.

limiter at -1.5
-15db input signal


-7db input signal

quoted
 

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re-read your thread and all i see is evidence for what i just said. the zero attack limiter is a brick wall.


here is how it normally looks in a limiter with other than zero attack. attack is to allow the first couple cycles to get through, so dynamics are preserved while setting thermal limits for protection.


the point of the "hold" and "release" functions are to set the window so the system knows how long to wait before allowing another "attack". with zero attack, there is never a reset of anything, so the functions serve no purpose.


 

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@LTD02 right, that's what I was getting at. The settings are still relative and have an effect. They're definitely a zero attack limiter, I wasn't saying they weren't, just saying it wasn't a brick wall like the clipped limiter. Hold is the minimum time it will keep the limit in place, and release is how long it takes to scale the signal back to normal.

The FP14000 have a hard/soft limit switch, I think it toggles between the two behaviors, I'll check it out at some point.
 

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when you say "Hold is the minimum time it will keep the limit in place..."


how does that apply? with a zero attack limiter, the limit is in place constantly.
Ok, so say you have a 10v limit, and send a signal that would output 20v. It then scales the signal down 50% to conform. The hold is the minimum amount of time it will keep it limited to 50%, resetting this "counter" any time it crosses the threshold again. Say you have a 1000ms hold timer. If you send a 20ms burst that exceeds the limit, followed by lower level signals, the signal will be limited for a full 1000ms, then it will scale back up to the unlimited level over the release window.
 

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with subs, hard clipping tends to give satisfactory results because most of the high order frequencies required to make the wave square get filtered out by the low pass filter and the waveform is restored to something that look almost like a soft clipping sine wave.


50hz signal with 3db of hard clipping:







same signal with 100hz 4th order low pass filter:





pfa, eh?


this sidebar is probably not very useful though because it assumes the high pass filter is after the point of clipping, which in the case of an amp doing the clipping won't be the case.
 

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Why would you want to hold the limit any amount of time beyond the length of the signal that caused it? As long as the limiter can keep up with the incoming signal it seems pointless to continue limiting afterwards.
 

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Why would you want to hold the limit any amount of time beyond the length of the signal that caused it? As long as the limiter can keep up with the incoming signal it seems pointless to continue limiting afterwards.
So you don't have drastic changes in output suddenly. You can control it with the settings. It's useful if you're limiting different frequency ranges as well.
 
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