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Nice BG knockoffs! Decent price too, 8" model at 1/4 the cost of a BG Neo8!
I really wish they would design a nice decorative plate for them to cover up the flange, those take a little more work to make them look pretty in a baffle. And mounting for that matter with screw nuts poking out the back. The screws are maybe slightly better than the rivets in the original BG though
WOW - the squiggles on the spec sheet looks pretty good for a $35 Neo3 clone. Wonder if they actually live up to the specs and the tolerances are good enough to get decently matched pair?
I might have to revisit Cabrini. $35 is a nice price.
The 8 looks pretty good. FR is a bit different than the BG, so there's something not quite the same. Not bad looking by any means, especially for the price.
Meniscus audio sells face plates for the original BG drivers. I looked at the dimensions for the GRS neo3 and it looks identical to the BG original. So I'm hoping they'll work. They're not cheap, but I think they're worth it for appearance and labor involved.
Round Neo3 face plate: https://meniscusaudio.com/product/bg-neo-3-face-plate-r/
Rectangular Neo3 face plate: https://meniscusaudio.com/product/bg-neo-3-face-plate-s/
Neo 8 faceplate: https://meniscusaudio.com/product/bg-neo-8-face-plate/
I bought some of those Mensicus rectangular faceplates for a Neo3 build. Well worth the price, IMHO.
re: GRS planars. WOW. what a knockoff of the B&Gs. Gotta get Erin to test some of them.
That 3.5" looks really flat from 2k up.
How would you deal with the 10" rising response and huge hump around 9k.?
Crossover at 2.5-3kHz to the 3.5".
Does anyone in Canada sell GRS? I would like to try these but shipping/taxes/duty is a bit much sometimes and I can't go to my US mail box.
Group buy on the GRS?
@squamishdroc Not that I know of, though the only Canadian driver distributors I know of are Solen and QComponents.
If you buy enough things from the US there are some reshipping services where you have all your items shipped to a single US location, where they put together and reship to you in a single package to save on costs. I also know of a few people who used this service for large items https://myusaddress.ca/
8 of the pt6816 slim per side then what ...
I was a little surprised that a search on the PE site for "Bohlender" pulled up a number of the GRS drivers. I wonder how BG feels about one of their distributors selling obvious knock-offs.
If they perform well and consistently, I'm happy about it...
Sehlin Sound Solutions
The 3.5 with the back cup is fairly flat. The open back version peaks up around 9k, similar to the Neo3W that I am using in my Radiusaurus speakers. I flattened out the huge hump around 9k with a series notch filter (see 3 pane attached). This peaking changes quite a bit when you change baffle shape, but the Radiusaurus baffle with 5.75" roundovers is similar to an IEC baffle at the higher frequencies. (EDIT: 15k peak, not 9k, on the Neo3W).
My bad. Correction. The 3.5 open back version is not even close to my Neo3W open back peaking. My peaking is much higher, around 15k or so. Also, I am crossing over very low, 1.8kHz, which may be why I am experiencing sound quality problems with I try to use them with open backs. I'll have to try moving the xover up to the 2.5kHz region to see what happens.
I never had any luck when notching the peak on the 3's or 8's. It just killed the presence they have. It looks much worse than it sounds.
Eric, I agree. My pair are the non-PDR version of the Neo3, which require significant notching of the HF peak. I noticed that they sounded kind of "dull" when we played my version of the Matrix Revolutions in Dakota. Scott used the Neo3 PDR version in his Matrix Revolutions and they seemed to have much more "sparkle" or "presence" when they were played at the Harris Center. When I look at the spec sheets for the GRS PT2522-4 3.5" open back and the GRS PT2522C-8 3.5" with back cup, they seem to have much less HF peaking compared to the Neo3 or Neo3 PDR (especially the Neo3, which has a giant peak). In fact, the 8 ohm version with the back cup is fairly flat and might not need a notch filter at all.
Kornbread, sorry, I misinterpreted your comment about the 9k peak. I thought you were talking about the tweeter.
I agree with dcibel and would cross the 10" at about 3k or so, which would bring the peak down with an approx 18dB/octave electrical filter plus a notch. In addition, I would attempt to fill in the depression in the 350-1kHz region by experimenting with various sizes of back chamber. The right size back chamber would move the 200Hz bump to a slightly higher frequency. I'd then cross to a woofer at about 400Hz.
I was looking over the spec sheet for PT6816-8 8" and noticed that only the inner two columns appear to be open. The horizontal polar response appears to be very consistent. On my Neo8 PDR's, all of the slots appear to be open.
I wonder if PE will just drop the BG divers after a while and then increase the price of the GRS divers.
That is where my money is at.
Only on the back side if you look at the product photos. Can't tell if the back side is blocked off or if its felt. It looks like felt to me.
Would something like Newform be possible?
I know this is an old thread, but I'm curious if anyone did distortion testing on these?
Thanks!
Jim
Hi everybody. Some comments on GRS/BG planars. Igor Levitsky (BG and Radian planars designer ) tested all GRS models. His founds: 3" models are the best of bunch. 8"models are OK. 10" are the worst -they measured OK on low power, but that's it. 10" GRS is lacking corrugation on diaphragm (patent is still valid) that is used on BG Neo10 and Radian LM10 .Radian LM10 will be available soon. All new construction (flat front and back plates), stronger magnets grade, bolted plates (solved unit to unit consistency -biggest problem with BG10) .In general all Radian Ribbons are superior to BG and GRS (of course ).I used LT3 for 3-way and LT6 for line array. I'm waiting for LM10 witch should be ready for sale in April (according to Igor). My cost on LM10 -$175 (I'm Radian and Faital Pro dealer). If anybody is interested to get new Radians please send me e-mail at jerzy53@sbcglobal.net .I ordered 14 LM10 ,but it is still possible to add some extra units. Measurements on LT6 and LT2 was done in Voice Coil (new replacement for LT2 will be available soon). PS audio is using Radian LT2 and BG10 in their latest $25 000 speakers.
Thanks for the info. Radian looks very nice! Do you have any test measurements for the GRS 3" drivers? I'm curious how they compare to the Radian LT2 and LT3's?
Jim
I will ask Igor for test measurements for 3" GRS and Radian LT3 after he will be back from Manila.
Thank you! I appreciate it!
Jim
I just stumbled onto this old thread. I measured the PT6816 last fall. I tested it with a number of 3D printed back cup shapes, as well:
Back cups from smallest to largest are red, brown, black. Cyan is open back, firing into a 12L sealed cab.
Distortion wasn't great, even at modest drive levels. The middle-sized back cup was used in this image.
They're on the shelf, awaiting something, I dunno, less-than-critical.
I was very proud of the mounting bezel & rubber seal I crafted. Wish they hadn't been so...average.
