Thanks Terrance. I don’t see these types of connectors on the REL’s so I was confused. I have a Dynaudio Sub so I’m trying to put the pieces together.
Jensen makes a transformer that does the job. Here’s the one you need.
Cool little gizmo. Since I will be connecting a single sub to a par of M1200’s it looks like the ISO-Max Mono may be the best fit
Yes but many of us find a matching pair of subs is well worth the money. It’s fine to use just one side and add another at a later date.
Agreed a pair of subs would bring more life to the music but I have limited power outlets in this 1917 San Francisco apartment and am pushing the edge now but that’s for a future post titled “You Think You Have Power Issues”
Thanks for the advice I truly appreciate it.
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What I shows in my post above is from my JL Audio D110.
REL uses different connector for high level input. See the pic (mark in red cycle) grabbed from REL website.
When I was looking for a pair of sub years ago, I was looking for sub with highlevel input. At that time, I was very interested in Dynaudio sub (build in Denmark, I think). If I remember correctly, Dynaudio sub does not have high level input, So I picked JL Audio (build in FL and crutchfield.com carries them)
I’m a firm believer in having my stereo subs integrated into my system the same way Paul prefers them, running speaker outs from the main amp to the high-level (speaker) inputs on the subs as well as running the main amp directly to the main loudspeakers, allowing them to play fullrange.
For convenience reasons, I currently have the subs connected to the binding posts on my loudspeakers instead of directly to the amp, but it’s the same thing either way. I’m also using my older pair of Wireworld Oasis 7 bi-wire cables for the signal cables for the subs, injecting the signal into both inputs on each sub.
I find that running the subs/loudspeakers this way offers the best integration, not to mention the subs simply sound much better being fed the high-level signal rather than from low-level. With the high-level inputs, the subs have better dynamics, more extension, and a cleaner top end at the crossover point.
These are the same results I had when I was running my JL e110 subs, which reminds me, I need to box up and get ready to sell.
In short, I’ll never go back to low-level inputs for subs.
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I swapped my sub’s input from RCA to high level input from BHK 300 amp yesterday. Night and day difference! So far, just one sub… but one day I can see myself sneaking in another. Playing the BHK Pre at 52, DSD Mk1 @ 92, plus sub is rocking! (SuperNova sub, about 16 yrs old). Can’t wait for my DSD Mk2 to arrive
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To achieve a totally seamlessly blend with my stand monitors, I finally took Paul’s philosophy to heart and sent the high pass signals directly from my power amp to the single subs’ high-level inputs and set the stand monitors’ full range. This change has furthered enhanced tonality, transients, speed, and resolution of the bottom 2 octaves, as the sub signal receives the same sonic signatures of the main power amp! Additionally, soundstaging, imaging and holographic presentation have also been improved within the full bandwidth system/listening room response of 18Hz to 28kHZ!! 
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Hi - Looking to connect the speaker level inputs of a ML800x subwoofer to a differential/balanced power amp. I believe the BHK Amps are also balanced Amps. I can’t find any info on this other than REL subs float the ground cable on the balanced amp’s speaker outputs. Anyone have any experience with this? Wondering if any know if Martin Logan Subs do the same? thx
Any time you try to connect subwoofers speaker level to either a Class D amp or a differentially balanced amp you have to find an alternative grounding spot for the negative speaker terminal from the sub to the amp as the amp’s negative terminal is not ground. Do you have another device with a grounding post? Also what termination is on the cables you want to use to connect the subs?
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Hey - Thanks for getting back… Right now I’m using the ML Sub with a regular speaker cable from my old balanced amp’s speaker outputs to the sub - left/right positive/negative binding posts. I don’t have the new amp yet but it’s an Orchard Audio Starkrimson DMC 2 which is a fully differential output amplifier. Thinking I can find a ground. Would I need the ground only if there is hum or do you think I need to ground both left and right channel negative connections from the Sub? thx again
Ground it to the chassis of the amp/s.
Have used a single REL T9 with a M1200s with the black high level REL wire not connected. Works great when playing and no ground loop. However, last week a new problem emerged. When I turn the M1200s to standy by there is now a hum from the REL.
Considering connecting the black REL wire to one of the amp grounding terminals or I could just turn off the REL when the M1200s are on standby.
Connect it to the grounding terminal.
You need to ground them both and there will be hum. If Leo hasn’t built your amp yet have him include a ground terminal either on the case’s rear or in place of one of the back case screws.
thanks - yea the amp is a Demo… So I got in touch with ML today and they said…
“The speakers level inputs on the Dynamo 800x are fully balanced, so you’ll be able to connect them (following the instructions from the manual) without any issue.”
Leo says the chassis is connected to ground, and the amplifier outputs are not grounded and both outputs are hot. So the fact that the ML is balanced - would that mean I can hook this up the traditional way? Not 100% confident with ML support. thx again
I wouldn’t try it. I would find someplace else to ground other than through ML’s method. Easiest way to do it is if the cables from the sub to the amp are bare wire on the amp end. That way you can tie the two negative ends together and use an extension piece to go to a ground point if you can’t get one of the Starkrimson chassis screws to work. From looking at the back of the case it looks like you can use the two back corner screws on the left hand side though you may have to buy slightly longer screws to fit bare wire or even a spade underneath. So ask Leo the thread size of those screws which you should be able to get at Ace.
ok - any downside to trying it this way? So you’re thinking the fact that both positive and negative speaker outputs are hot it’d be better to connect both the 2 negative speaker connections from the amp side to chassis ground? Worst case I guess I could use the extra preamp outs to the L/R line level rca inputs… thx again