GR Research NX-Extreme


Looks like a helluva lot of speaker for the money, even if you need to put it together which sounds kinds fun. Anyone built a pair of these or heard them? 
mofojo

m-a, I didn’t mention it, but the Rythmik A370 plate amp (the amp that is included in the GR Research/Rythmik OB/Dipole Sub kit includes a continuously-variable Phase/Delay control, providing phase rotation from 0 degrees to 180 degrees (0-16 ms). That phase rotation creates a time delay exactly the same as physically moving the sub further from the wall!

In fact, that phase control is found on all the Rythmik plate amps, including those installed in sealed and ported models. I would not buy or own a sub without it. While I myself like the GRR/Rythmik OB/Dipole Sub, a few found it to sound too unlike what they think a sub should sound like ("thicker", "plumper", with more "weight") . One who feels that way is the owner/designer of Rythmik, Brian Ding! For those people, Rythmik offers many sealed and ported subs, including the F12 (a single 12" driver in a 1.5cu.ft. enclosure with a 600w amp) and F15 (a 15" in a 2cu.ft. box, same amp).

Lots of info---including unusually technical---available on the Rythmik website. For discussions about the OB/Dipole sub, take a look in the GR Research section of the AudioCircle Forums. 

As a note, Jay runs the GR Super 7's which is an OB speaker based on the GR Neo 3's, and the B&G Neo 10's, with 2 servo subs in the lower part of the speaker, a unique design that takes up a smaller footprint. His speakers used House of Kolor paint, Tangerine Candy with 5 coats of Show Clear on top, beautiful, but not cheap!!


Don

It does take a decent size room I think, but I found it took less effort to get them (the NX-Otica with triple-stack OB servo subs in my case) to sound quite good compared to conventional box speakers I've owned.

I have a fairly big room (17' x 29') that is reasonably symmetrical, so I have plenty of space to get them out into the room. I set them up about 7' from the back wall and 4' from the side walls and they sounded great. I tried moving them around a bit, but other than some toe-in tweaks, they are pretty much right where I set them up initially. 

I have used Room EQ Wizard to set up the sub amps, which makes it MUCH easier to get them dialed in. But again, I haven't found the need to move the subs around to get good sound. The servo amps provide lots of flexibility in controlling level and phase and also include a single frequency parametric equalizer which I used for one channel to smooth out the bass a bit. The other channel didn't need it. 

I do have a well treated room which helps, but I initially set them up before I had any treatments and they still sounded awfully good. The treatments sharpened the image and smoothed out the bass response a bit, but I think I would have been happy with the sound without most of the treatments. The tube traps in the corners behind the speakers were the first thing I added and made the biggest difference.