There is a GR Research subforum on Audiocircle you may want to check out.
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The NX-Oticas are a pretty amazing value if you're willing to put in a little time to put them together. They produce a deep spacious sound stage with excellent clarity and detail and fantastic dynamics. They are very easy to drive with over 93db/watt efficiency. Downsides - they need to be several feet into the room to sound their best (mine are set up with the front of the battle about 6.5 ft from the front wall); they really need subs to be truly full range (they go down to 45 or 50 hz on their own, but matched with stereo OB servo subs, they are incredible); and, you have to put them together and finish them yourself (or pay someone to do it) I really enjoyed the process of building them and am thrilled with the sound. I think these are the most satisfying speakers I've ever owned after 45 years in this hobby (and over a dozen speaker systems, many costing several times the cost of the NX-Oticas with subs). If you've got high enough ceilings, I expect the NX-Extremes would be a nice step up, From what I've heard, they have a bit more punch in the mid bass and a little more height to the imaging. My ceiling is just under 8' which I don't think is high enough to allow these speakers to sound their best. |
I built the OB subs with three 12" drivers for each channel. Danny's design can be built with 1, 2, 3, 4, or 6 drivers per sub, and flat packed are available for all configurations. The more drivers you have, the less each driver has to work and the faster they will settle when the signal goes away. The servo control makes them settle very quickly anyway, but with three drivers (6 for both channels), the bass is extremely fast and articulate. If you've ever heard Magneplanars, particularly larger ones, the bass has a similar quality except the GR subs go considerably deeper and are a bit more dynamic. The bass doesn't pressurize the room quite like a sealed box sub, since you are moving air from one part of the room to the other. So musical instruments sound more natural, but movie sound effects such as explosions don't have as much of a shock wave feel. If your primary use is home theater and you like movies with exploding helicopters, I'd probably stick with more conventional sealed box powered subs, but for music, the OB servo subs can't be beat. I would expect the OB subs to integrate much easier with the OB speakers compared to a traditional sealed box sub. It's kind of the same issue with trying to integrate subs with Maggie's. But I haven't tried so I don't know for sure. I would post your question on AudioCircle in the GR Research forum to see if anyone else has experience. I live in Portland, OR so quite a trek from Michigan. It took me about 50 hours to build both the NX-Oticas and subs. Probably 30 for just the NX-Oticas. Most of that was painting. Building the cabinets was very easy - probably a couple hours total. The crossovers and wiring up the drivers took about 8 hours. And cutting and installing the NoRez for speakers and subs took another few hours. |
There are a couple of You Tube videos documenting how the GR Research loudspeaker flat packs (precut MDF panels you glue together and finish) are assembled. You don't need any woodshop tools except for some wood clamps (and glue, of course). The flat packs are very easy to put together, made with alignment dowels (just like IKEA furniture) and "biscuits". I love that you can finish them (or have it done for you, as in an automotive body shop for a Wilson Audio-quality paint job, or cabinet shop if you want a genuine wood veneer finish) any way you want. Build threads are also posted on the Audiocircle GR Research Forum website. Join the fun! Once you get used to the idea, you realize it can take your hi-fi involvement to a new level, like super-charging your car's engine with a bolt-on blower kit. Ultra-high performance for the price of mass-produced mediocrity. Danny Richie designed and has manufactured his own drivers (including the NEO3 planar-magnetic tweeter), and his cross-overs are the best in the business. Don't wait for a review of a GR Research product in Stereophile, it ain't gonna happen. But lots of speaker companies pay Danny to design the x/o's for their loudspeakers, He is a leader in the open baffle DIY market, highly respected by his peers, of which there are few. Um, does this make me a fanboy (I hate that term)? |
Hello. While I have not heard Danny's speakers yet (soon) I have heard some of his work. I have a pair of Emerald Physics EP 2.7 open baffle speakers that he build new crossovers for and they sound amazing! They use much higher quality parts than the original crossovers. I have the frequency response and waterfall graphs before and after and they are quite a bit better that stock. In fact I was told by Danny and one of EP's designers that they are likely the best sounding pair of EP speakers on the planet. That said I am just starting to build Danny's latest speaker design, the new NX Studio monitor kit. Just received the kit and all the MDF, cherry veneer and grill cloth and stuff over last week and will start the build this weekend. Very excited about this. See it here: https://www.audiocircle.com/index.php?topic=160647.0 Also see this as to why you can build better speakers than you can buy in most cases: https://www.youtube.com/watch?v=7yozUh8xBfk&list=PLUFNGRKZZWXzCt2Syx4yjR4Oy7V-uiePB&index=19 I recommend subscribing to that channel and watching all the videos. Very educational. Cheers. |
I guess it depends on what you are looking for. I find the bass to sound very natural sounding and extremely dynamic, as if you were listening to acoustic instruments in the room. You can still feel the bass, but it's probably a bit closer to what you'd get from a high quality open back headphone (e.g. more sound than pressure). Hope that helps. |
There is a pretty noticeable difference between the Ottica's and Xtreme's and it's not just with the WAF as they stand 86 inches!! There is an added fullness to the sound from the additional 8 drivers that seems to be greater than the sum of 4 extra drivers, the fact that they barely break a sweat during large musical passages really helps define the inner detail that can sometimes get lost during increased spl's. There is also a deeper sound stage that also comes with having more drivers that can be quite addictive if you have the room to support them and in this regard the Ottica's are far easier to place within your average room. I own the first pair built, and my partner Jay and I build almost all of the flat packs sold, I run mine with a 4 stack of 12 inch GR subs and the combination will absolutely shock you with well recorded music. To give you another perspective, and i'm trying not to be too biased, I recently attended the Toronto Audio show, which I thought was excellent and the speakers that I felt had the closest signature to the Xtreme's, meaning with scale and size of presentation were from Grandinote, they were OBish line arrays and I believe that they cost 60K. Hope that also helps, Don |
Count me in on purchasing the nxtreme . Later this summer I will be buying . Along with a pair of the triple subs . One owner compared them to King sound King electrostatic speaker , with better bass . Crossing my fingers they will meet my expectations . With the high sensitivity it will allow me to try any amp on the market which will be a first for me . Anyone who owns them or are building a set please fill us in on them ! |
@maplegrovemusic , here are a couple of pointers about building a GR Research kit: Glue: I recommend Titebond III Ultimate. It gives you longer "open" time before starting to harden than do Titebond Original and II. Use more glue than you think necessary; the MDF that the flat pack enclosures are made of soaks up glue. Use a small paint brush to spread the glue evenly (you can get a bag of small aluminum-handle brushes at Harbor Freight). After you tighten the clamps, wipe off the glue "squeeze out" with a damp sponge. Clamps: I really like the Jorgensen Heavy Duty (1,000 lb.) clamps. Lowe’s has the best price I found: $21 for the 36" online (Lowe’s doesn’t stock them, but their shipping is free and fast). You’ll need at least four, more is better. If you want to spend less, Harbor Freight has some okay clamps that are really cheap. Before gluing, do a "dry fit": assemble the enclosure, using masking tape to keep all the panels together. Looking at it assembled will help you think in an organized fashion. Once you apply the glue, a feeling of panic may overtake you! Prepare, think ahead, and remain calm. If this knucklehead can do it, so can you ;-) . Read through as many "build" threads on the AudioCircle GR Research Forum as you can. You will learn how other guys went about their builds, the mistakes they made, and what they advise. You can ask them questions; Danny’s customers are a really great group of fellas! As for finish, check out the black spray paint John Deere makes and markets (yeah, the tractor company!). It’s sheen is what’s called "Hot Rod Black" in the custom car world. Really cool, chicks dig it ;-) . |
I have GRs OB doubles but bought drivers for a third one. I wished I would have gotten the 8 ohm versions, for doubles. Then the 370 watt amp would have a little more push 370 @ 4, and half that at 8. So pick your drivers too. If you go trips, I think you have to use th 16 ohm drivers. Doubles you use to have an option, 16 8 or 4, use to be anyways.. As for building them, just a snap, great workmanship and QC is outstanding.. Everything was dry fitted and marked.. Jays a great guy..., The whole bunch had a LOT of patience, I ASK QUESTIONS, always a speedy response, very professional.. I had a pair of LS6s, man did they need breathing room. lots of room.. 6-8 feet from back wall, no wall behind you worked the best, ampa style sure a different speaker, the way they work, pretty picky, pretty cool if you get it right. lots and lots of room treatment..Same with most speakers.. I got them second hand, and the builder did a great job. I'd love a pair of LS9s oh yea...Much better tweeter section. I'd love to hear a pair...I think Danny uses a pair for reference in his builds.. Alu, frame. The new ones are HDF or MDF Regards.. |
Good point about the two different versions of the woofer @oldhvymec. Knowing I was going to build doubles (the 2-woofer version), I got myself the 8 ohm woofers rather than the 16 (the woofers actually measure 14 ohms and 7, I believe). Putting two of the "8" ohm woofers on the plate amp creates a little more output from the plate amp than do two of the 16 ohm (the plate amp behaving as do almost all solid state designs). Three of the 8 ohm woofers can NOT be used on one amp, as their combined impedance is too low. |
Oh, I neglected to comment on the 4 ohm version of the GR Research woofer. GR Research offers a 4 ohm woofer, but not for use in open baffle applications, only sealed and ported. The non-ob version has not been optimized for ob use, and the two are not interchangeable. So the non-ob woofer is available in 4 ohms only, the ob woofer in both 8 and 16 ohms, but not 4. Another point: the GR Research 4 ohm woofer is exactly the same as the 12" woofer found in the Rythmik F12, except the GRR has a paper cone, the Rythmik an aluminum. Rythmik sells the F12 in a version with the paper cone woofer, model F12G. GR Research, being a company aimed at DIYers, offers the F12G as a kit only. You get the woofer and the Rythmik plate amp, and build the enclosure yourself. Or buy the version Jim Salk offers, with the F12 kit installed in an incredible box of Jim’s design and build. His enclosure has the best bracing I have ever seen! Is everyone now thoroughly confused? ;-) |
bdp246,377 posts03-15-2020 11:40pm Oh, I neglected to comment on the 4 ohm version of the GR Research woofer. GR Research offers a 4 ohm woofer, Yup there was an option or two. 8 or 16 ohm drivers 8 ohm drivers are louder, hows that? Also a sand filled DIY, too. There are some guys that will build the kits, finnish is always the spendy part. Emron, was a great paint, just the lead content was through the roof..and no breathing it at all.We called it drop dead gorgeous, paint... Jay the box and kit builder guy with GR, has the speakers the OP is referencing, (I think). he just loves um. Ask him, good guy.. Quality work from that guy... Regards |
I heard the NX-Treme speakers at the Lone Star Audio Fest in May 2019. The sound was more three dimensional and holographic than anything I have ever heard before. It felt as though I could get up and walk completely around each individual performer as they were positioned on the stage. The system was very dynamic and presented fine detail in a smooth, relaxed, non fatiguing way. Bass was deep and powerful, but sounded different from the deep bass of other systems I have experienced. It sounded less like a reproduction and more like bass heard in a live performance. I was quite surprised to learn the price of the speaker system. Granted, you would have to invest the time to build them yourself, or additional money to have someone else build them, but I have heard several speakers in the $50,000-$100,000 range that did not engage me in the music like these did. Based on the hour and 20 minutes or so I spent listening to them, I would highly recommend anyone in the market for new speakers this large to find a way to give them an audition. |
Sure @martin-andersen, as with all dipoles, any of the GRR open baffle loudspeakers and subs can be placed as close as 3’ from the wall behind them (you call it the back wall, but if you’re facing it, it’s the front wall ;-) . 4’ feet is even better, 5’ better yet. Sound travels at around 1’ per millisecond, and what we want to achieve is a 10 millisecond difference at the listening position between the direct sound from the front of the speakers/subs and that coming from the rear after being reflected off the "front" wall. A minimum of 10 ms is what is required for the sound of two acoustic events to appear to be separate from one another. 5’ spacing automatically creates that 10 ms delay (5’/ms from the rear of the speaker/sub to the wall, 5’/ms back to the speaker/sub), That 5 ms difference makes the rear wave sound like an acoustic event separate from that coming from the front of the loudspeaker, rather than part of the direct sound, a "smearing" of the latter. By the way, Danny Richie recommends the use of diffusion rather than absorption on the wall behind dipole loudspeakers. I concur. As subs handle frequencies with very long wavelengths, the 10ms difference is not nearly as important for subs as it is for the shorter wavelengths/higher frequencies handled by the loudspeakers. Far more important is the phase relationship between the front and rear waves produced by each sub. The front and rear waves are in opposite polarity (180 degrees apart) relative to one another, and as the long wavelength bass frequencies "wrap around" the sub OB baffle, they meet on the two end sides of that baffle and cancelled out (one of the reasons dipole subs don’t energize as many room modes as do non-OB subs); + 5 added to - 5 = 0. The rear wave also of course travels to the wall behind the sub, is reflected back towards the sub, and when that rear wave meets up with the front wave can create an either in-phase addition or an out-of-phase subtraction of lower frequencies. OB/dipole sub users need to experiment with sub placement to optimize the phase interaction between the front and rear waves. That might sound like a daunting task, but when you hear a good OB/dipole sub you understand why it’s worth it! |
@bdp24 this forum really needs a like button!Thanks for an excellent explanation. So 4' is okay and the subs has time-delay so I can maybe place them 6' away from the wall.I have the Tekton DI, have you heard them? I really like them but I want to try something new.Also with the subs I can better integrate the bass in my room.I have a very well treated room, that has a WAF lower than the absolute minus (: Again thanks |
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 takes a lot work and the right treated room to get this kind of speaker to sound really good ! https://www.youtube.com/watch?v=iFQKGaxfIJk |
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. |
