The dials on the back of the REL are for the high-pass inputs from your amp speaker connections; they help with true sub-bass and bass blending for normal 2-channel listening. Is the single-RCA connection you are talking about the LFE output from your surround pre-amp/proc?
No, Zephyr, it's running out of a preamp output (this is a 2 channel rig, no surround). When I had a Velodyne DD sub in the system, of course I would use the internal crossover etc etc and I had it crossed over pretty low, probably around 40 Hz or so (I've got Avalon Eidolon Visions, no monitors) so they didn't overlap with the lower bass of the Eidolons. I was just surprised that on the absolute lowest setting on the REL crossover, I was still getting quite a lot of sound at the higher frequencies. I'm not a REL expert by any means, and I know that their crossovers/integration is different, thus my original question. I did have a old REL storm in my old home....I tried the neutrik connection and the low level connection and compared. I'm sure the REL engineers are smarter than I am, but man I sure did get quite a lot cleaner bass out of the low level connections than using their preferred way.
I have owned several REL subwoofers and still own a pair of REL Storm III's for my 2-ch setup. There is no situation (IMO) where you would have the setting at "A" "1" for hi-pass, ever. I think mine are set to "B" "4" or so in a 16' x 20' room with 10' ceilings.
Hi Audiofreak.....mine are running low pass RCAs....a single for the left and single for the right sub.....I don't have the Neutrik connectors yet but I wanted to get them up and running.
I believe that the REL subwoofer has one input for low pass RCA input and another identical looking input for LFE input that is crossed over at 80 Hz. If I remember correctly I had to take my left and right channel subwoofer output and use a Y connector and plug the Y connector into the single low pass input. It was an older REL subwoofer, but that may be the reason why you are getting 80 Hz output even though you have the crossover set at the A1 position. Take a look at the back of the subwoofer and see if you may have one your cables connected to the LFE input. Hope that this helps.
Drew: I think you are right....
Neutrik Speakon plugs are ridiculously easy to install on a proper cable (any decent 4 wire speaker cable should work fine using 3 of the wires of course), and I've found that method seems to work best with my groovy old REL.
I agree with you Wolf, but some amplifiers, differential balanced amplifiers in particular, will not allow this connection to work properly. Not exactly sure why that is the case, but I am sure one of our more technical friends can spell it out.
Hey Zephyr: I hope that you were able to fix the issue. I only know about the LFE input because I did the exact same thing you may have done when I hooked up my first REL. I just got an R505 delivered yesterday and am looking forward to hooking it up later tonight.
I had to talk to the ARC tech support about the hook-up with my REL T5 and my ARC D70Mk2. The ARC' s of this vintage and possibly later, use the 4ohm tap as a ground and therefore hooking up the REL was not obvious. I was told to hook up the left and right cable from the REL to the left and right 8ohm tap of the amp and the ground cable to the 4ohm tap. The speaker cables are hooked up to the 4ohm taps and the 0 ohm taps....Haven't tried this yet, but will report back after I have hooked up in this manner.
Good discussion on this........after talking to someone who is more of a REL expert than I was, turns out their crossovers are indeed different. When you set it on the lower settings, apparently the frequencies somewhat higher are not totally filtered out which is how they manage integration with your speakers rather than a steep cutoff such as in a system with mini monitors etc. Obviously it was much more complicated than that, but that was the main idea. The Britannia B2 has setting specifically for LFE from a HT processor so that you can use their bass management if you choose. I still haven't decided to order the Neutrik connectors for them...I'm sure the manufacturer/engineers are much smarter than I am, but in the past I sure did get deeper cleaner sound from the low pass inputs. They seem to integrate just fine, but I guess I would have to compare.
Drew: What is the thought behind the neutriks not working with a differential balanced amplifiers....I believe by MC 402 is one of those.
It is my understanding that the neutrik connection works with most amplifiers and because the output signal matches exactly with the amplifier, not the preamplifier output signal, a more exact output match is created. What I have found, I think you did as well, is that the output signal is stronger when taken directly from the preamplifier so you require less volume to get more bass output. Over time, however, it has been my experience that when properly mated to the amplifier via the neutrik connector the bass response is more realistic and creates the illusion that there is no subwoofer at all because of the better integration. Long term the REL subwoofers with the neutrik connection in my systems, I am a subwoofer addict and have had many different brands/connections in various systems, have been the best subwoofer integration experiences.
Not sure why the neutrik connection does not work with differential balanced amplifiers. I beleive that it has to do with negative feedback and that differential balanced amplifiers either do not offer it or offer too much. Someone technical would be able to offer a better explanation. Either way in one of my systems when using a neutrik connector the Storm III, great subwoofer, would emit a loud pop that would scare the hell out of me. I cannot remember which amp it was, but I was advised by someone at that time to use the preamp output connection.
This may sound simplistic (and might actually be wrong) but somebody at a "boutique" hifi place told me that when hooking up the REL to a Class D amp you connect the 3rd wire to ground on the amp chassis (the other 2 to left and right positive speaker plugs).
It is a ground issue with some 'D' series amps. REL addresses this in the operators manual of their newer models.
The Neutrik connectors from the amp assume a common ground plane, that's why there are only 3 wires (R+, L+, either -) and not 4. A balanced amp does not have a common ground plane. So you can only get one channel into the sub with the Neutrik, at best. You need to connect the sub to the preamp via RCA's if you have a balanced amp, or get 2 subs.
I think in the case of a balanced amp, you would need to connect the ground wire to a ground lug or screw on the the preamp, which should give you a common ground for each channel. This is not entirely clear in the manual for my B2, but it has worked fine for me (I have a BAT balanced amp and preamp). The manual shows this connection configuration for mono amps, and also mentions (albeit not very clearly) this configuration for a differentially balanced stereo amp also.
Hooked up the system as suggested by the ARC tech and all seems to work fine.
The REL T5 is a great match to my speakers and room, highly recommended for the small room music only system.