Subwoofer limiter
Hello everyone,
I am new here and not familiar with DSP, but I found my way using the sigma studio,
I am building my own subwoofer using 18” woofer 1600w rms and I got the powersoft Digimod 2000HV witch is 1050w rms (mono in, phisically bridged out )
I am seeking help from experts on this forum, I used the template that comes with powersoft but I worried about setting up the limiter since the amp bridged is 2100w and the woofer 1600w so how can I setup the limiter? Or can I just leave it as is and lower the volume on sigmastudio template?
Can I Sum/Bridge the dsp instead of the hardware? What’s better?
Please advise and,
Thank you in advance.
Edit Notes
Can I Sum/Bridge the dsp instead of the hardware? What’s better?
[edited by: Mixondaw at 2:21 AM (GMT -5) on 16 Feb 2023]
Audio Signal Processors
software
4.7
sigmastudio
SigmaDSP Audio Processors
adau1701
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Hello Mixondaw,
This is a tricky problem since it is risky on your ears, the speakers and your neighbors to try to run the sub up to max!!
There are a few approaches you can take. I assume you are going out of the ADAU1701 analog? I am not sure what hardware you are using so I am not sure if there is any gain on the OpAmp filtering the DAC output?
Step one is to try to read the specs of the amplifiers to find the sensitivity of the amp input and what it takes to get it to full output power. Make note if it is a peak or RMS reading.
Then without the amplifiers connected, setup a program in the DSP to send an oscillator directly out of the DSP with no level change. The Oscillator in the DSP is 0dBFS so it is at MAX volume. Then measure the output level that would be going to the amplifier.
Once you have this data you will know if the DSP output is capable of driving the subwoofer to its max output or if it is not able to.
If it is able to then you can put in a volume pot to determine how much lower will it take to reach the max? 2dB? 10dB? Whatever it is then you know the MAX you can output from the DSP. Then setup the limiter for 1 or 2 dB below that point and you will not overdrive the sub.
If the DSP output cannot drive the amp to max output, then you can simply setup the limiter to limit around -2dBFS in the DSP to ensure the signal out of the DSP will not clip. I suppose you could modify the Opamp circuit to have some more gain but I am guessing you will not need it.
Once this is done then you can test your final SigmaStudio program with oscillators at high levels and watch the output on a scope to be certain you are not going too high. Then hook up the subwoofer and let her rip!
These are my first thoughts and other people might have other ways to do this that are better. Anyone else, feel free to chime in!
Dave T
Dave,
Thank you so much for your reply, I will try this method and get back to you,
the limiter on sigmastudio measuring Rms/v I guess it’s voltage not db, is there a way to change it?
thank you
You also need to simulate the excursion of the woofer to make sure you don't drive it past the safe limit and damage the suspension. This is particularly important with ported enclosures! The 1600W power rating will be an average figure, the odd short peak of 2100W likely won't matter - as long as it's infrequent and short!
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