GR Research NX-Otica and Servo OB Subs


I am amazed that these speakers (and other models from GR Research) have not garnered more attention on Audiogon. For about $6K, and 40-50 hours of work, I now have a set of speakers that is, by far, the best speakers I've ever owned. And I have owned some fairly good speakers including Tympani IVs with Entec servo subs, Duntech Sovereigns, Revel Ultima Gems with dual Revel Ultima Subs, Revel Studios, among others.

The NX-Otica, along with GR Research's other speaker designs, are DIY designs. I know that scares a lot of people off, but they are really not difficult to build. For the NX-Otica and stereo triple 12" open baffle servo subs that I built, GR Research has teamed up with a woodworking company to produce MDF flatpacks which just need to be glued up to create extremely robust and well constructed cabinets. GR Research provides everything else.

The NX-Otica is an open baffle design with a narrow (~8 inch) front baffle and side wings to reduce dipole cancellation. The driver complement is a planar magnetic NEO 3 tweeter (in a wave guide), two 6 inch midrange drivers with phase plugs in an MTM array. The wave guide allows the tweeter to cross over fairly low, while the midrange phase plugs allow the driver radiation pattern to more closely match the tweeter at the crossover point. Four 6" woofers complete each tower.

The NX-Otica by itself only reaches down to 40-70Hz depending on the room, and are designed to be used with the servo open-baffle subs. I finished the NX-Oticas a couple weeks before the subs, and in my room they didn't really sound that bass shy on most recordings, but the subs really complete the package.

The crossover components supplied by GR Research are stellar quality with a mix of heavy gauge copper coil inductors, copper foil inductors, sonicaps, miflex copper bypass caps. In other words, these crossovers put most crossovers you'd find in sub $20K speakers to shame.

I've never built a DIY speaker before, and I think I jumped into the deep end with these speakers. The large number of drivers and fairly complex crossover make this a somewhat more challenging project than many kit speakers, but they really weren't that hard to build and Danny Ritchie from GR as well as numerous other builders on Audio Circle, are there to help.

There are obvious downsides to this system: You have to spend some time to build them unless you pay someone else to do it for you which ups the cost. Their complex front baffle shape makes them hard to veneer although some builders have veneered the side panels. I decided to just paint the whole speaker. This was by far the most time consuming part. I don't have great painting skills and have never painted anything like this, but they came out fairly nice. I think if you had another couple $K to invest, you could take the built cabinets to a cabinet shop or auto-body shop and have them professional sprayed and could get a much more professional finish.

Open baffle speakers aren't for everyone. They need a fairly large room. I have mine in a 17' x 27' room, with the front of the baffle about 6 1/2' from the front (17') wall. The two cabinet per channel design takes up a lot of space.

And probably the biggest downside is resale. Even if more people knew how good these speakers sound, finish quality is an unknown, so it's unlikely a buyer would be willing to buy them sight unseen.

But the upsides are huge. For a relatively modest investment in time and money, you get a speaker system that sounds amazing. They have the open, airy sound of magnepans with more precise imaging due to the narrow baffle. They have thunderous, fast bass that doesn't energize lateral room modes and transmits a lot less of the bass energy through the walls. They are efficient (93db/w), easy to drive, and very dynamic, with a beautifully smooth and detailed midrange and high end. Vocals - both male and female - sound amazing.

Sorry for the very lengthy post, but it's hard to stop gushing about these speakers. I've only heard a few other speakers that sounded all-around as good to me as these, and they were ~10 times the cost.
Ag insider logo xs@2xjaytor
To answer your second question, I haven’t personally tried my system in a room like this, but others have indicated that open baffle speakers, particular OB subs, have worked much better than traditional speakers in this kind of environment. 
I suggest you post your questions in the AudioCircle GR Research forum. There are a lot of participants in that forum that have a lot of experience with Danny’s various designs. 

Magic44ken;

If you can find some B&G Neo 10's i would strongly recommend the Super Mini's over the MTM Ottica's as, to my ears anyways they image quite a bit better due to the very narrow baffle,  both benefit greatly from having a lower driver compliment however, we have sent the prototype to Danny for the lower section but believe it or not, he's been extremely busy lately and hasn't found the time to test them yet.

Jaytor;

How was your session last week??

Don

Don - I had five people come over last weekend for a listening session. Everyone seemed to be very impressed with the sound from the NX-Oticas and subs. A couple of them commented that they had never heard bass that sounded so natural, and everyone commented how well the sound fills the room such that you can be well out of the sweet spot and still get decent imaging and great tonal balance.

That's great to hear, your system looks fantastic, and for my money OB bass is very hard to beat, and they are so adjustable which people tend to overlook.

Cheers,

Hi Jay

I was one of those five people that was lucky enough to hear your Ottica's - I can without hesitation double down on everything Jay said about these speakers and will be building the Ottica's myself... I have already built the dual twelve OB subs from scratch and now have to figure out how to finish them, then on to the Ottica's.........Thanks again Jay for your hospitality your system is very impressive.  Steve