DIY Open Back Subwoofer

Testing of my open back subs. 3 12in woofers in an open back H- frame, servo driven. Still need paint and damping material. These are the same drivers and servo amp used by Clayton Shaw of Spatial Audio in his new Lumina speakers. These play extremely flat 20-200Hz. More to follow!


Chapeau…! Very, very nice…!!! Can you elaborate on the “servo driven” part…? Is there an extra set of servo wires going to the feedback of your amp…?
P.S. Interesting paint on the walls… :star_struck:

Yes the speakers have driver and servo coils providing amplifier feedback and controlling cone movement. Allows for very tight bass- the cleanest I have heard. I am working on getting my mains cabinets done now. Will be a MTMWWWW configuration using a planar mag tweet. Check out the GR Research forum on Audiocircle- Danny puts together some great designs.

Oh man MTMWWWW sounds like so much fun. If you take any pictures during the build process, I (and I’m sure others on the forum) would love to see them!

Hated to post the subs unfinished but I couldn’t stand it any longer- Hard to look at drivers and amps and not throw the juice to the monster- “It’s ALIVE, mwahaha!” I will post as the project comes together.


Here are pics of the mains cabinets and completed crossovers. Slow progress but moving along!


Better pic-sorry

Sweet project! Are those paper drivers? I would love to hear your Rythmik servos in open baffle.
I have the Rythmik 12" aluminum drivers in bulletproof boxes and they sound great.

They are the paper drivers- servo is the way to go for crisp bass- hope to get these finished soon but I will miss them now that I have them dialed in!

Awesome! Paper drivers are super fast and responsive due to extremely low mass… When low E resonates with every string vibration we’re onto really good bass!!

Finally making some progress-


If these work out in my room like I suspect they will, my Spatial M3 Turbo S pair may have to find a new home- they will be tough to beat

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Wow. Those look fantastic. Very nicely done.