That's unnecessary, your receiver will give the miniDSP much lower RMS voltage after level matching. Going from 12 V to 3 V is only 6 dB down, your amplifier after the miniDSP will make up for that. Your receiver will never hit those voltages under normal circumstances
How did you measure the 12 V rms? Did you input a 0 dB signal with the receiver at 0 dB? In that scenario if the voltage is 12 V RMS, then after level matching the LFE, if it's set to say -6 dB, then the max signal the LFE pre-out will do is 3V RMS. If you want to run above reference, you can get the additional output from either additional subs/amps, or turning the gain up on the external amp. As long as the miniDSP has the output voltage to drive your sub amp, then the AVR will never be the limiting factor, the signal just has to be turned down.
Yes I measured 60Hz sine at 0dbfs on a multimeter to approximate rms voltage all trims maxxed and avr at "0"
I get what your saying but dont the A/D converters on the minidsp input clip at like 2.2Vrms or something crazy low?
I basically wanted to set it where the middle of the signal chain didn't clip before the amp... When doing this with just the AVR controls with the BFD I found I had to use extreme cuts to trims -12db on the related outputs to keep from clipping the inputs on the BFD. Also when using extreme cuts like this I found the dynamic range to be compressed and or the signal to be very "on-off."
Using an attenuation circuit is worse than turning down the trims, because your receiver will put out more distortion with a higher voltage, and less distortion with a lower voltage. It should have zero effect on dynamic range. You should aim for - 6 dB trim, if it wants -12 dB, turn the amps down a bit.
What Bassment said: No reason to rig up a voltage divider when you have a sub level control that you can dial down. It’s all the same in the end, as far as getting the voltage cut you need goes. The only issue you might have is if your amp requires more than 2 volts to drive it to max. If that’s the case you’ll have to ditch the mini for a more suitable equalizer.
Originally Posted by NicksHitachi
I basically wanted to set it where the middle of the signal chain didn't clip before the amp... When doing this with just the AVR controls with the BFD I found I had to use extreme cuts to trims -12db on the related outputs to keep from clipping the inputs on the BFD.
Are you saying that with the BFD set for +4, your receiver would still drive it into clipping??
Is there a problem with the attenuation circuit?
What attenuation circuit, the one for the receiver’s sub output?