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Avid Contributor I
May 30, 2025
Answered

Sonos Amp settings with third party sub amp

I have a home theater setting with front in wall speakers powered by a sonos amp and rear ceiling speakers powered by a second sonos amp.  I also have a Definitive Technologies in wall subwoofer powered by a Definitive Technologies SubAmp 600 getting it’s signal from the Sonos Amp.  The SubAmp 600 has knobs to control volume, crossover frequency, and phase.  The Sonos app has controls to control volume, crossover frequency, and phase.  My question is, which one of these should I be use to set these parameters?  What should the other one be set at it?  

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Stanley_4
Stanley_4Answer
Grand Maestro
May 31, 2025

Lost a long response, short one…

Does the sub amp have a direct input, no controls? Use it. 

Or

Set the sub Amp filter as high as possible, phase 0 and volume about 3/4. If the Sonos Amp volume setting is very low or high tweak the sub amp volume to get both to near mid-range.

5 replies

Stanley_4
Stanley_4Answer
Grand Maestro
May 31, 2025

Lost a long response, short one…

Does the sub amp have a direct input, no controls? Use it. 

Or

Set the sub Amp filter as high as possible, phase 0 and volume about 3/4. If the Sonos Amp volume setting is very low or high tweak the sub amp volume to get both to near mid-range.

Avid Contributor I
May 31, 2025

In my mind, it seems like it could be problematic if you set the subamp crossover lower than the crossover setting in the app.

 

ie. if you set the app crossover at 120 all frequencies less than 120 get sent to the subamp and all frequencies above 120 get sent to the main speakers.  If you were then to set the subamp to 80, the frequencies between 80 and 120 would be lost.

However, if you did it the other way around, set the crossover frequency on the subamp as high as possible, then it would play whatever frequencies it is sent from the app and the mains would play anything higher than the setting in the amp.

 

I have no idea what happens with the phase adjustments.  If you set the subamp at -90 and the app at +90, do they cancel each other out?

Stanley_4
Grand Maestro
June 1, 2025

In my mind, it seems like it could be problematic if you set the subamp crossover lower than the crossover setting in the app.

Which is why I suggested what I did for the sub crossover.

 

I have no idea what happens with the phase adjustments.  If you set the subamp at -90 and the app at +90, do they cancel each other out?

You have a 90 setting, not 180? Use one or the other, not both.

 

Avid Contributor I
June 1, 2025

Subamp has a knob for zero to 180. 

Stanley_4
Grand Maestro
June 1, 2025

Subamp has a knob for zero to 180. 

Zero to 180 - or - zero or 180?

Can't imagine how the first would work, the second is what I have seen.