REL speakon connection to amp vs speakers

@macg19 you are right and Franks version is awesome.

Frank at Signal Cables makes an aftermarket version of the REL speakon cables, he does not make the cable supplied by REL.

I have tried it both ways, connected to the the amp outputs and the RCA out from my preamp going to my S812. I do prefer the RCA out to sub, it just seems a bit more dynamic and deeper bass. It's a much easier hookup also, especially if you are using mono blocs amps.  I had to make a extention cable when I rolled out my monos. Besides, I don't really want the sub to have the flavor of the main amp, I prefer it having the flavor closest to the source. 

"For stereo set up, the manual is actually pretty poorly written. p18 1.a refers you back to pages 11 & 12 where there is nothing mentioned about stereo set up."

Agreed.

*To correct my poor grammar, Frank at Signal Cables makes an aftermarket version of the REL speakon cables, he does not make the cable supplied by REL.

OP, sorry for going off topic.

@ross6860 Thanks for the clarification - there is no mention of this in the manual but it makes sense (it’s the same). Connecting to the speakers could be more convenient and maybe help reducing hum (if any) by reducing the length of the supplied cables - which are 60Hz antennas. It would not work for me as I’m using my mains for both stereo and a/v (by manually switching speaker cables).

@tony1954 I think we are both saying the same thing, or close. refer to page 15 in the manual. The black wire in the speakon cable is a ground and referred to as negative and ground in the manual. Differential and Class D amps use the same method.

My REL dealer said I should "float the ground" if there was a hum in my system, which there was (Initially the amp was a Line Magnetic, no pre or sub-outs, not differential). Floating the ground/black wire helped but trimming the 30ft cables also helped a lot but didn’t cure the issue 100% in one of the RELs. Re-configuring the red and yellow connections in the speakon connector itself eliminated the hum completely (I called REL and talked to Frank at Signal Cable who makes the speakon subwoofer cables and both agreed it was safe to try prior to doing this).

For stereo set up, the manual is actually pretty poorly written. p18 1.a refers you back to pages 11 & 12 where there is nothing mentioned about stereo set up.

In fact stereo set up is really the same as the mono-block instructions on page 16 except L & R terminals are on the same amp, and again, in my case floating the ground/black wire worked best.

I did experience the high gain issue mentioned on p16 btw.

When I bought the Raven amp, I discussed wiring the subs with Raven and James strongly recommended using the RCA connections. I again called REL to get their opinion and they said use whatever method sounds best.

@macg19 

"@tony1954 for balanced amps you just need to "float" (not use) the ground for the supplied  speakon cables. The "issue" is 60Hz hum. Doesn't apply to either RCA inputs."

The issue is not hum. The issue is that with balanced amplifiers BOTH speaker terminals are HOT. Unlike typical amplifiers, where the red terminal is hot and the black terminal is the ground, both terminals are hot with the negative being 180 degrees out of phase with the positive terminal.

If you hook up to both terminals you are actually shorting the circuit. "Floating the ground does nothing.

@macg19 

"@tony1954 for balanced amps you just need to "float" (not use) the ground for the supplied  speakon cables. The "issue" is 60Hz hum. Doesn't apply to either RCA inputs."

I am not sure you are correct with this. Below is the response I received from Rel regarding hookup to my MF integrated.

"Your Musical Fidelity M6si is a balanced differential amplifier, if you're hooking up a pair of T/7i's, don't hook it up to the negative speaker terminal with our SpeakOn cable.  Instead hook it up to the phono ground terminal and twist the red & yellow wires together and wire into the positive on each channel. 

If you only have one T/7i, then wire it from the preout to the low level input on the back of our sub. The low level uses the same exact audio filters as the high level. "

I believe the OP was going to use the speaker-level connection.  His question was if there was a difference connecting at the amp vs the speaker.

Electrically, they are the same.  The REL input is "reading" the signal just like a volt meter and is a very high resistance device.

It should not make any difference.

Currently using two T/9x with Magnepans.

 I am wondering if there is any audible difference between connecting them to the amp or to the speakers directly and am guessing somebody here has tried it.

Honestly I was confused by this question, and because others had chimed in with advice I thought I'd add my 2 cents.

@tony1954 for balanced amps you just need to "float" (not use) the ground for the supplied  speakon cables. The "issue" is 60Hz hum. Doesn't apply to either RCA inputs.

@andrewkelley +1 definitely call REL that's what I did 

I have done both. On my old setup my fancy speaker cables were terminated in banana at my amp end and spade at the speaker end. I had some custom rel spec cables from an even earlier setup that were terminated in banana so I just piggybacked them off the speakers. It worked fine. 

whenever I upgraded to my current system, and my new speakers, cables, and Rels I made sure to order spades for my main speaker cables so i could piggyback the banana rel cables off the amp. 
 

i suggest calling rel and just asking what they think! 

Connecting to the speaker outlets is the recommended method, but be careful.

With balanced amplifiers Rel recommends a different way of connecting subs, so do some research or there might be "issues".

Interesting approach I will have to try. My original question was connecting at the speaker or amp end.

But using the sub out does indeed mean I can use the m33 for signal processing (cross over frequency) but the reason for my question was actually I was thinking about upgrading the sub cable and I have 10 plus feet between the amp and the subs and the cost is way higher running the cable back to the amp.

PS. I know this wasn’t your question but it took me a while to figure this out so FWIW...

IMO integrating the subs with the mains works best with the subs on either side of the mains, phase set to 0.

Start with the crossover set roughly 5-10 hz below your speakers bass response or at the min for full range speakers. Gain maybe 10-15 clicks. Adjust from there. You should not hear the subs when they are set up correctly (or "see" them with your eyes closed) but miss them when you turn them off:)

I have also have pair of T/9x's and contrary to the above, I use the sub-out connections from my integrated tube amp to the RELs, RCA to RCA (low input not LFE .1)

I've done it both ways and prefer using RCA interconnects for stereo.

I also have a Yamaha A/V. My main speakers double as fronts, and the RELs are connected using the LFE input / RCA subwoofer cables so I use the RELs in dual mode (5.1 and true stereo) seamlessly.

The M33 has pre-out and sub-out connections that you can use for the RELs - if you use the pre-out, the REL crossover will handle more of the bass management so in your case either should work if you decided to go this route.

REL pushes the speakon connection partly because it's easier from a support perspective - everyone can use the speakon method.

If they didn't want you to use the pre or sub outs, why provide the extra RCA input?

I've spoken with REL support and both work, it's a matter of personal choice.

If you stay with the speakon connection, trim the cables!

I agree with the above advice and REL's recommendation.  You arguably get the amps flavor coming through with this method,  

definitely use the REL Speakon connectors from amp to sub...

@pbomberg you definitely want to connect your T/9's using the Speakon connector and connect to your amps speaker output that your speaker cables are on, for several reasons which REL explains in their videos. https://rel.net/blog/2018-01-04/how-to/how-to-connect-my-rel/

REL claims that by hooking to your amp it gives the subs the 'flavor' of your amp.