How do I cable my sub?

Firegod

Firegod

Firegod

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Location
Newcastle, UK
Hey all, silly question but I'm getting my new sub delivered on Monday and I just wanted to check that I'll be cabling it correctly. REL say if the sub has stereo RCA low level inputs then connect those to the left and right low level outputs on the Amp. I've been using (with my old sub) the Left/Right Line Out connectors. I have no idea if that is/was correct? The REL HT/1003 has stereo low level inputs - like my old sub. Am I OK to continue to use the Line Out Left/Right outputs? REL say that to use the Subwoofer Pre-Out on the Amp if the REL sub only has a single low level input. Which the HT/1003 does not.

Back of my Amp currently:

Amp-Rear.jpg


Excerpts from the Pioneer SX-N30 instruction manual below. It doesn't state to use Line Out for a subwoofer, just a recording device. So am I OK in using Left/Right Line Out or should I use the one marked for the Subwoofer on the Amp? And therefore, what do I do about the REL sub which has Left/Right low level inputs and not a single. I just don't want to damage it by hooking it up wrong.

Amp-Connections.jpg

Amp-Info.jpg

Amp-Output.jpg


Thanks.
 
Ignore what rel say

But typically AV system, use bass management in your avr, set to small 80hz, disable the subwoofers own crossover, run calibration, change to small 80hz if avr changed it by itself.

In stereo system use RCA or high level to sub, enable subs own crossover, dial in just by listening to music adjusting crossover and volume to blend in
 
Cool. I guess I'll just pick left or right in sub, and see what happens. I don't think either are labelled as mono... but I'll see on Monday. Probs try left first. Seems to be the most common when looking on Google.
 
Yeah it is suspended floor. I'll try and grab a cheap granite chopping board. Interestingly just read this on a forums (this sub is connected to a stereo amp not an av receiver) :


"IF you have a 2-channel setup, i.e. a "stereo", Then you would typically want to use 2 RCA--RCA wires from the preamp outs to both the sub inputs; then you have the stereo summing taking place inside the sub which gives you mono bass while preserving the stereo signal separation going into the main amps."

But I don't have preamp outs. Just line outs. Stick with subwoofer pre out?
 
Pre outs are variable level that change relative to the master volume outputs. These can be stereo or multi channel. They're used for power amplifiers and subwoofers with line level inputs.

Line outs are fixed level used for recording onto tape, or when using a external headphone amplifier that has its own volume control.

Sub out is sum of signals stereo is downmixed to mono, multi channel is downmixed to mono.


You only use stereo RCA to a sub if your have a stereo amplifier that has stereo pre outs and not a downmixed sub out.

As for sub crossover adjust it to roughly your speakers roll off but you may want to go either side by 10hz depending on bass boom or bass suck out.

You may need to adjust phase, to do this in a hifi is more difficult.
 
Check your manual as some sub outs could be low passed, I doubt it as it's a stereo amp however I have seen some that are. You want a full range signal sent to the sub then adjust sub own low pass.

If the stereo amp has a low pass that is say 100hz this may too high, you'll also be applying a low pass on the sub, you don't want cascading low pass. Also you want the filter frequency to be around your speakers not massively low or higher than your speakers

You can check if it's full range or filtered by outputting the sub out into a active portable speaker, if it sounds normal then it's full range but if you can't hear any high frequencies then the signal is filtered.
 
Firegod said:
Interestingly just read this on a forums (this sub is connected to a stereo amp not an av receiver) :


"IF you have a 2-channel setup, i.e. a "stereo", Then you would typically want to use 2 RCA--RCA wires from the preamp outs to both the sub inputs; then you have the stereo summing taking place inside the sub which gives you mono bass while preserving the stereo signal separation going into the main amps."

But I don't have preamp outs. Just line outs. Stick with subwoofer pre out?
Click to expand...

The stereo pre-out advice applies to pre-amps and integrated stereo amps that do not have a mono sub output.

Your SX-N30 has a mono subwoofer output, and so the advice on another forum doesn't relate directly to your gear. Ignore it.

Your SX-N30 sums the bass output of the left and right channels into a mono signal. Connect a single RCA-to-RCA cable.

Usually with subs with a stereo input, on of the two RCA sockets is marked up as 'mono'. However, if your REL is different then follow the manufacturer's instruction.

Since yours is a stereo network receiver, then my guess is that you'll need to set the crossover frequency (blend point), phase (in-time / out-of-time with the main speakers) and level (how loud or quiet in relation to the main speakers) manually to dovetail sound from the sub with the speakers.
 
Thanks both. Appreciate all the help.

Yeah last time I had to set the crossover and level on the old sub to blend. The stereo amp doesn't have anything to alter that. So it's a case of just using my ears. I know the Bowers and Wilkins have a response range down to 33hz so I was gonna aim for 40hz on the sub and see how that feels as a starter.

I have my burn in tracks selected up in Spotify ready to go as well. Some 90s hip hop with good low repetitive bass lines. :)

@lucid yeah the REL video I watched for cabling was useless. It didn't cover what to do if using a single sub pre out to a REL sub with stereo low level inputs. Didn't cover it. Lol.
 
Aye you are right sorry I gave the wrong figure earlier. 33 wasn't the Hz that was the kHz value. I was at the wrong end of he scale lol.

-6dB at 40Hz and 33kHz

I'll go for 50Hz first as you say.
 
You'll have room gain that effects bass response of the speaker as does Placement

Don't use -6db native response will be one octave higher 50hz. You can tell as look at the high frequency, it won't be 33khz flat , hf is normally 20khz

B&w speakers are a bit bright so true using treble - a few dB if your amp has it.

You'll need to get your sub phase time aligned, i don't know how you do this in hifi.
 
Woop. It turned up today. :D

Love it. Just following the break in procedure for it, and it's sounding real good so far. So I moved the RCA to sub out as discussed. The sub does have an RCA input labelled for LFE so I plonked it into that. Opened up the Crossover all the way so the sub is playing the full range. Ran it gentle for first 15 mintues now it is just past half way and I'll keep it like that for a few hours. Might crank it to 3/4.

Thanks for all the help!

Amp-Rear.jpg


REL-Rear.jpg


REL-Front2.jpg


REL-Front.jpg
 
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