Connecting passive subwoofer to amp without speaker-level sub outs

curious14

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Jan 7, 2017
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I'm trying to cobble together a 5.1 out of an old Denon AVR-3802 and Denon DSW-60 passive sub I have lying around. I want 5.1 but obviously I'm not worried about ultimate sound quality.

The 3802 has only a line-level output for an active sub (or external sub amp). But it has lots of power and can handle additional satellite or multi-room speakers that I'm not using.

Can I connect the 3802's sub pre-out back into one of the 3802's other source inputs (e.g. Aux) and then set the multi-room speakers to play that source to the sub? Theoretically that source would only be receiving and amplifying the sub signal, so the sub would get the signal it needs, no? Why won't this work?

I assume I can't just connect the sub to the extra speaker outputs because then the sub would be getting a full-frequency signal (I assume the sub has no crossover but I don't know how to check - I can't find it online).

I don't want to test and risk damaging the amp.

Thanks
 
Solution
This only would work if you use the 3802 as a straight amplifier, can't use its built-in codecs, can't use its radio.

i.e.: The back of your PC outputs all 5.1 channels, hook these up directly to the EXT IN, use SBR for your passive sub.

Your PC is doing the dolby decoding and crossover, so you needn't worry about the sub getting the full range.
This only would work if you use the 3802 as a straight amplifier, can't use its built-in codecs, can't use its radio.

i.e.: The back of your PC outputs all 5.1 channels, hook these up directly to the EXT IN, use SBR for your passive sub.

Your PC is doing the dolby decoding and crossover, so you needn't worry about the sub getting the full range.
 
Solution

curious14

Commendable
Jan 7, 2017
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1,510

Thank you but the only source is a TV (not a PC), so there is no crossover and the sub will get the full range.

I was hoping that by feeding the low-level sub pre-out back into the 3802, it would provide the crossover (the 3802 pre-out has configurable low-pass filter). The low-level pre-out is the only subwoofer output on the 3802.

Can that work or will connecting the pre-out back into the amp cause some sort of feedback loop that will suck my house through a space-time vortex?

 

curious14

Commendable
Jan 7, 2017
3
0
1,510


Oh well - I know I can connect the pre-out to an external sub amp, so I hoped I could use a spare channel on the 3802 as the sub amp.

Thank you for the replies.