REL subs with Rowland Amplifiers


I'm having issues connecting my REL Carbon limited subwoofer to my Jeff Rowland 625 S2 amplifier via the high-level input. I connected my sub according to REL's instructions...yellow lead to positive on one channel, red lead to positive on the other channel, and floating the black wire(ground). I get minimum output when connected according to the instructions. When I use the low level input, the output is sufficient and the sub sounds great. Per my conversation with Jeff Rowland I need to ground the black wire by loosening a screw on the amplifier and connecting the black wire, but if it isn't properly grounded I may damage my amplifier. Is there anyone that owns a REL with Jeff Rowland 625 S2 amplifier or other balanced differential amplifier? If so, how do you connect your REL via the high-level input. Is there an easier way to ground the wire than unscrewing the screw on my amplifier. I just don't want to unscrew the screw and prefer another method of grounding the sub.   
ricred1
calvinj,

My thoughts comparing the JL Audio F112 v2 to the REL Carbon Limited in my system/room. This has nothing to do with sound, but the JL Audio F112 v2 is built like a tank and is packaged significantly better than the REL.  My initial thoughts on REL vs JL Audio, comparing a single Carbon Limited to a single JL Audio F112 v2. The REL has more affect on the mids and highs than JL Audio. The mids and highs have more detail with the REL. I think JL goes a little deeper, but doesn't allow you to hear the different shades of low level information like REL. You can feel the JL a little more, but it doesn't provide the nuance of the REL. The REL totally disappears, but no matter what I did with the JL Audio I could tell it was there. I choose the JL Audio F112 v2 for a HT only system. For music only I choose the REL Carbon Limited. My system is a combination of 2-channel and HT. I listen to music 80% of the time, so I prefer the REL for my situation. If it was 50/50 or 80% HT I prefer JL Audio, because it has more bass impact. For now the REL is located in the same spot as the JL Audio was. I'll pickup my 2nd REL from FedEx today and start the process of dialing in both subs.
@ricred1  Richard, what made you pick the Carbon Limited vs one of the other REL Subs. The new S series seems to be where they are concentrating their line. The Carbon series isn't even on their web page, unless you do a specific search. Seems like they don't want to push that model.
@ricred1  BTW, replacing the stock power cord and better still, the stock connecting cable with a REL Signal cable is a BIG step up in SQ for these subs. I highly recommend the Signal cable that they will supply with the yellow and red cables summed for your mono subs.
daveyf,

"What made you pick the Carbon Limited?" I was originally looking at a single No. 25 or dual S5s. After a long conversation with the dealer about my main speakers, the fact that I had a single JL Audio F112 v2, and I listened to music the majority of the time he recommended the Carbon Limited. If it didn’t work in my system I had the opportunity to return it. I was purchasing right at the time that REL was discontinuing the S3 and S5, so I eliminated the S5. I talked to REL and a few other people that convinced me that dual Carbon Limited subs were a better fit than a single No. 25. I’m extremely satisfied with my choice.

I'm ordering the Signal Cables today:)