Connecting REL sub to a 2 channel (Mono blocks) using High Level connection

[Davey Willo]

Hi

I'm hoping that someone can help if they have had experience with connecting a REL sub via the high level connection to a pair of 'mono blocks'

 

I know that with a single amp the connection is 'Red to right positive speaker post' 'Yellow to left positive speaker post' and the black appears from my understanding and depending on amp 'type' can be anything from 'Floating i.e. not connected at all' or 'to the right negative speaker post' or to 'a ground'

 

However, I can't find much if anything at all in regard to using mono blocks. I don't use a pre-amp, my streamer feeds my DAC which has volume control, and the DAC feeds my mono blocks, all of which are plugged into an Oyaide Power strip, so I 'think' that they share a common ground, but then I don't have a clue about this stuff, I'm just guessing

 

Any help appreciated, so thank you in advance.

regards

Dave

[SonicArt]

What sort of amps? if class D then you would not connect the black to anything initially,  test with red and yellow,  then if you had hum you would look to connect the black to a chassis earth,  I would suggest emailing Rel they are quite helpful with this stuff.

[thimmy118]

We have a REL thread on SNA. Perhaps you can also post your question on that thread.

 

Cheers

 

Thim

[almikel]

On 07/02/2025 at 12:53 PM, Davey Willo said:

I'm hoping that someone can help if they have had experience with connecting a REL sub via the high level connection to a pair of 'mono blocks'

With a high level/speaker level connection, you can only connect the sub to one speaker channel.

 

On 11/02/2025 at 4:41 PM, SonicArt said:

What sort of amps? if class D then you would not connect the black to anything initially,  test with red and yellow,  then if you had hum you would look to connect the black to a chassis earth,  I would suggest emailing Rel they are quite helpful with this stuff.

As per Mark's post - class D and bridged output stage amps (ie where the -ve speaker terminal is not earthed) can cause issues with Rel high level connections.

 

You could also run a splitter cable (low level/RCA) from one of the outputs from your DAC to both your Rel sub and one of your mono-blocks.

 

You still won't have stereo "sub" information, only 1 channel, but there's very little "stereo" information in the signal at sub frequencies - you likely won't hear any difference swapping the sub between the DAC channels.

 

You would have to buy another sub, and connect each to either side if you wanted to ensure no sub frequencies were lost.

 

Do not, under any circumstances, try and "join"/combine signals with splitter cables - they're "splitter" cables, not "joiner" cables! 

If you did that you could easily overload the output of your DAC, and maybe let out the magic smoke, which has been proven to be extraordinarily hard to put back in again!

 

Mike