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How to connect monoblocks to a single REL sub with ONE RCA input

I just purchased two Quicksilver 60w Monoblock amplifiers and a LineStage Preamp by QS.
To connect this REL 328, normally one uses connect their Speakon cable (Red, Yellow, Black ends that connect to Right+, Left+, and Ground) or a SINGLE "low-level" RCA in. But this preamp doesn’t have a single sub out.

REL’s advice is to buy a second sub and attach one sub to each monoblock. Well, maybe I’ll do that, but in the meantime, I’d like to be able to hook up what I have.

Should I orient the amps so that the speaker terminals are close enough together to attach the strands of the Speakon cables? I have been warned by REL not to hook up high level to monoblocks because it will create a ground problem.

An alternative is that I get a Y cable that will bring two RCA outputs from my Preamp into the single RCA input on the REL?

Or is there another alternative?

Advice appreciated. (But please try not to tell me to just buy a second sub.)
128x128hilde45
ieales's avatar
ieales
1,201 posts
 

NEVER use high level outputs to drive a subwoofer. It's a Band-Aid that should be banned.

According to the REL S/812 manual, it has two low level inputs. You can simply Y off the main pre out if there are not two sets of outputs

Ideally, you should roll the lows out the mains with a passive HP filter. Doing so will tighten up the low end and effectively double the apparent power of the PLs

That being said, you should flog the REL and get a pair of subs with real controls. IMO, REL markets bling, not good bass and are not serious about proper system integration due to their dearth of controls making them impossible to integrate properly. e.g. 180° phase inversion is equivalent to moving the sub about 25 feet @ 40Hz. Fixed XO slope will only integrate properly in a tiny subset of rooms and systems. 

Martin-Logan X series and JL Audio are excellent offering full control.

 

 

linndec's avatar
linndec
8 posts
 

Sorry but more than one sub in one room seems overkill.Can also lead to standing waves and cancellation not only not doubling bass ability but cancelling each other out in some frequencies.. All seems a bit of a problem really.

hilde45's avatar
hilde45 OP
4,974 posts
 

@linndec Don't be sorry if that's the way it seems to you. You're mistaken. At least for my room. And you understand that generalizing about this is pointless, since the room's particular dimensions are critical to the number of subs. 

I've googled it for you, just to get you past reflexive opining.

https://mehlau.net/audio/multisub_geddes/

https://www.svsound.com/blogs/subwoofer-setup-and-tuning/75040195-why-go-dual

https://www.audioholics.com/subwoofer-setup/two-subs

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