REL speakon connection to amp vs speakers

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.

@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. "

@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.

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.

*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.