Subwoofer size and connectivity

No need to worry, plenty of folks run M700s with high level sub connections. Just requires a little bit of fancy footwork on how you connect it.

I’ll use a REL’s high level Neutrik connection as the example, though this should translate to other subs using high level as well. It’s got red and yellow for left and right and black for ground.

You would connect the red and yellow leads as normal and then float the black.

To ground the sub, you’ll want to hook up an RCA cable from the sub to an unused RCA jack on your amp or Gain Cell.

And that’s it. Everything should be hunky dory after that.

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As Scott says, no need to worry with REL and M700s. Just this week I installed a REL S/5 SHO high level to my M700s with the supplied Nertrik/Speakon cable. As Scott says, the red and yellow wires go to each red/plus speaker terminal on each M700, and for me, I crimped a spade lug on the black wire and slipped it under a handy screw head on the back of one of the M700s. It is chassis ground and the REL is silent unless driven by music.

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@scotte1 - very nicely done and love the black. What was the sonic improvement if there was improvement and does that REL have a passive radiator firing downward? Just ordered (2) sets of SVS isolation feet (SAT) and painted one spacer gloss black; looks OK… rest waiting for the SVS feet. I should have this all up and running w/ pics I’ll send you by SUN evening. Thanks for your help.

For flexibility in sub placement, REL sells the HT-Air, a wireless low-level sub driver. I’ll be using them with my new Velodyne subs.

I’ll probably be getting the Rythmiks though… what then?

Should be the exact same. I don’t know the exact cable they use for their high level connection, but the principle remains the same. The important thing is you can’t ground the ground cable to the speaker binding post. You either need go for the method I outlined, or the one @calord outlined.

The just have speaker cable connectors on the sub

Have not been able to listen at levels to discern any impact on sound quality…

This model has a single, down-firing (8”) driver.

Has a 125 watt, Class A/B amplifier…

Mfgr. rates it @ -6dB/32 Hz in room FR.
Regards.

Definitely check with Rhythmik to get the best info possible.

With that said, I spoke with Darren (the one who designed the Stellar amps), and it should work out okay if you hook up the left and right red wires as normal and ground the black wires to the Stellar chassis. You’d ground it like how calord mentioned - just unscrew one of the back panel screws on the M700 a bit and wrap the black wire around it. Then screw it back down.

Definitely check with Rhythmik though to make sure that will work. We’ve not used their subs here so they might do things differently than expected or there might be some info we’re missing.

I heartily agree with your chice of Rythmik SWs. I have FOUR in my c. 3000CF room… I use two F15HPs in front, driven with the stereo signals… I keep these at relatively low level and set the low-pass filter at 25Hz so they’re really subwoofers… They merely add some bottom-octave info to my Quad '2905s.

I also have a pair of F18s against the rear wall… These are driven by the preamp’s two ‘.1’ outputs and are activated only for movies.

Both pairs produce HIGH-quality bass and were quite affordable, but Rythmik doesn’t ask us to pay our hard-earned money for fancy looks. :smirk:

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Wow, other than me, no one else has mentioned anything about JL subs…

Anyway, I have my M700’s connected to my SGCD via balanced outputs, and the subs connected via the single ended outputs. All running stereo.

https://pmc-speakers.com/products/professional/subwoofers/xb3

flat down to 20 Hz (17Hz)

though even 1 of them may be too powerful for most home systems…also works with low powered amps because design is ultra efficient

sound waves are 13’ long/developed as they leave the speaker…

@scotte1- I got the SVS isolation feet in yesterday and mounted them this morning.



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Ok, Rythmik recommended just RCA out from my preamp. Good enough for bass?

The question is: A 400 W 12" or 600 W 15"??

F12’s for music only. I have a pair in both systems one pair connected line level and in the Main system connected speaker level to the BHK 250.

I’m glad you wrote Brian.
Re: 12" vs 15" - I think it depends on how much room and tolerance you have for giant, heavy cabinets. I have pair of 15" CIs due to arrive from Rythmik later this week that will be going in my own cabinetry. These will be followed by a pair of 8" Rythmiks with custom amps.

This might give you enough low end :slight_smile:

I’m leaning towards the 12, but I have an 18x18x14 listening area that extends way back. So the room size is essentially that of my entire apt. Just worried about output.

The two in my Family Room are in a room larger than that with a large opening at the rear that opens into the Kitchen and Breakfast Room area. More than enough impact for music even in the Kitchen.

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Subwoofer challenges:

1.) Having multiple subs (3 or 4) to help even out in-room bass peaks/dips;
2.) Proper placement (NOT side by side, especially not beside main speakers, read Floyd Toole’s “Sound Reproduction” - he recommends staggered corner placements);
3.) Convincing others that multiple small subs is so much better than one big one;
4.) Going low enough (many smaller “subs” are only rated down to 30-40 Hz).