GR Neo3 back-cup ideas!

Hobbsmeerkat · « **Reply #40 on:** 31 Jul 2020, 08:18 pm »

Quote from: hawkeyejw on 29 Jul 2020, 04:05 pm

This is fun to watch, I'm looking forward to seeing Danny's testing results on all of this. Nice work Hobbs.

Thanks! Its been a fun project. I've been working on a sealed servo sub base for the NX Studio as well as an MTM/center version of the Studios. but that'll be a different thread going forward

Just got confirmation that everything printed well and will be mailed out this weekend.

Danny will get the 2nd model of the cup & spacer along with 5 of the round over bars for the front face of the Neo3.
And I'll be getting the first spacer/cup and the remaining 5 rods.

Im excited to do some of my own testing with these soon! And see how they compare with Danny's results of his cutom neo 3
Ill probably strip the stock cup off. Cant be any harder than delidding Intel i5 & i7 desktop CPUs when that was common back in 2013-2018

Hobbsmeerkat · « **Reply #41 on:** 6 Aug 2020, 02:38 pm »

I got the tracking number for Danny's package,
Says It should arrive ~~Saturday~~ today

Checked the tracking again and its already out for delivery!

Danny Richie · « **Reply #42 on:** 7 Aug 2020, 04:22 pm »

Quote from: Hobbsmeerkat on 6 Aug 2020, 02:38 pm

I got the tracking number for Danny's package,
Says It should arrive ~~Saturday~~ today

Checked the tracking again and its already out for delivery!

Got it.

Hobbsmeerkat · « **Reply #43 on:** 7 Aug 2020, 04:59 pm »

Quote from: Danny Richie on 7 Aug 2020, 04:22 pm

Got it.

Sweet! Mine will be here Tomorrow

Hobbsmeerkat · « **Reply #44 on:** 8 Aug 2020, 09:31 pm »

Looks like my prototype has been delayed.
Hopefully it'll be here Monday.

Hobbsmeerkat · « **Reply #45 on:** 11 Aug 2020, 02:10 am »

Okay, I got my 3D printed cups & bars in the mail today! I also went ahead a ripped off the original back cup, & I'm happy to say they fit really nicely, a little tight, but within tolerances.

Rear face with spacer and hand cut rubber gasket.
A silicon sealant should work well too:

The curved walls in the stock cup are doubled from the base to the first inch. The felt stuffing is glued in and incredibly soft. Not far off from the feeling of cotton balls, and should make for a fair substitute within the custom cups. It is also glued into place, so i imagine any cotton balls used probably should be glued into place as well.

The printed cup is pretty resonant, so lining the inside with a dense product like butyl based liners, or no-rez on the outside surfaces is probably a good idea.

If/when I make any further adjustments/prototypes, I'll probably use thicker walls to reduce the structural resonance, but will probably still recommend such a lining, unless using a dense glue with the cotton that can achieve a similar effect.

Now for the face plate rods:

They aren't quite as smooth as i hoped they'd be, but i imagine some coats of paint and a some gentle sanding should help smoothen them out. Tho I think I also want to make variants that are taller with a gentle curve until it gets close to the tip, I suspect it might be more beneficial to the response than just a simple half-circle option. With a waveguide or faceplate, only 3 rods are needed per Neo tweeter.

Danny Richie · « **Reply #46 on:** 11 Aug 2020, 11:09 pm »

I may be able to take some measurements on these tomorrow.

Hobbsmeerkat · « **Reply #47 on:** 11 Aug 2020, 11:18 pm »

Quote from: Danny Richie on 11 Aug 2020, 11:09 pm

I may be able to take some measurements on these tomorrow.

Awesome! Im excited to see your results!

Hobbsmeerkat · « **Reply #48 on:** 12 Aug 2020, 02:48 am »

~~Hooray for accidentally deleting my whole post by hitting the back button when i wasn't looking!~~

Okay! I cut myself a better gasket that fits the shape of the cup half of the mod, & got some nice results and was able to mount it to the flush mount i got with it.

I also have some thermal tape on hand and it made for a pretty effecient way to mount the rods to the face of the Neo3, tho I definitely want to try some taller options once i can also get my hands on my own 3D printer. (Probably in the $300-500ish range?)

That said, i did come across a similar thread to the one i have linked here, but som users there did some testing and they seem to think their tests were done right next to the Neo 3, rather than 1 metre away as Danny's tests are done. And considering that a headphone company did something similar but by rounding the magnets instead to achieve a similar response. (I wanna say it was Hifiman??)

But I definitely want to test if taller "micro-wave guide" rods help in long distance response curves, or if by the time they get to 1M return to standard normal response curve.

Hobbsmeerkat · « **Reply #49 on:** 17 Aug 2020, 02:23 am »

While working on my other speaker design thread, i had the idea for a separate mounted wave guide plate. I think this is a little too big currently as its design would interfere with the mounting of the M-165NQ drivers, but once i can get more accurate measurements of the actual waveguide i should be able to make something that allows it it to be mounted in vertical or horizontal orientations for uses in center speakers, so expect design changes going forward.

Hobbsmeerkat · « **Reply #50 on:** 18 Aug 2020, 12:50 am »

Ordered myself a 3D printer so I can do some more rapid prototyping and, hopefully soon, some testing.

Hobbsmeerkat · « **Reply #51 on:** 19 Aug 2020, 07:03 pm »

I've updated the design of the waveguide to better match the design of the NX waveguide, & was able to shrink the face enough to make them fit within the space needed, esp for vertical MTM options, where the wave guide is taller, and still be rotated 90° for horizontal center channel use.

Danny Richie · « **Reply #52 on:** 20 Aug 2020, 04:26 pm »

I added the three bars on the front side a few days ago when measuring some NX Studio Monitor front baffles. It did not make an improvement in any way.

I will try it again with a different face plate and see what it does.

Hobbsmeerkat · « **Reply #53 on:** 20 Aug 2020, 04:49 pm »

Quote from: Danny Richie on 20 Aug 2020, 04:26 pm

I added the three bars on the front side a few days ago when measuring some NX Studio Monitor front baffles. It did not make an improvement in any way.

I will try it again with a different face plate and see what it does.

Well that's a bummer, the hear but im not entirely surprised either.

I read another thread by the same user in a different forum that they think than the difference is down to the driver being tested with the mic right up close to the driver, rather than at the standard 1M distance.

I will be printing some taller versions and doing my own testing next week once i get my 3D printer up and running to see if a more gradual slope helps, or if it also leads to the same results.

Hobbsmeerkat · « **Reply #54 on:** 22 Aug 2020, 02:16 pm »

Progress!

Got my 3D printer in! (Creality Ender 3) and after running some small test prints I went right into printing the waveguide, and it turned out pretty good! Some small issues near the inside edges and the outer screw mounts. But it fits the Neo 3 perfectly, as do the screwholes, and the deep cup also fits nicely!

Probably gunna work on making a baffle out of cardboard and getting some measurements over the next couple days.

RonP · « **Reply #55 on:** 22 Aug 2020, 04:18 pm »

that's pretty damn cool dude

Hobbsmeerkat · « **Reply #56 on:** 22 Aug 2020, 11:11 pm »

Quote from: RonP on 22 Aug 2020, 04:18 pm

that's pretty damn cool dude

Thanks, it's been a lot of fun!

Okay make myself a quick & dirty test baffle for the waveguide.
Not perfect, about 9" wide before it slopes off to the sides. But itll do. The back is currently in the standard NX open baffle setup, & the little face rods have remained attached to the front.

I did some really quick tests out on my back porch before the humidity drove me back inside.

Tests were done roughly 3 feet away using my tiny Dayton Audio measurement mic.
I'm using REW & running a tone sweep from 500Hz to 20,000Hz.
Using a 1/24 smoothing on the graph, but otherwise a surprisingly decent result..

I currently have some taller rods on the printer, as well as a modified back cup, and I'll share info/pics on those once its all completed.

I also plan to do several different tests to see what sorts of results i can get, including the back cups, and felt/cotton for back cup stuffing

Hobbsmeerkat · « **Reply #57 on:** 22 Aug 2020, 11:44 pm »

Well that was great timing! The prints are finished, so time to share the updates!

The new back cup design with two different versions of the faceplate rods:

The new cup should be closer to the same internal dimensions as the stock cup, and also a little more rigid thanks to some thicker walls.

Close ups of the new rods (Center & Right) vs the original round over. (Left)

Hobbsmeerkat · « **Reply #58 on:** 6 Sep 2020, 08:21 pm »

As "coool" as the cardboard baffle is, it's not a great or accurate platform for this testing. So I designed & printed a test baffle.
I also had to update the waveguide cuz it was apparently too deep. (About 1.65" instead of 1.5")

So here's the fruits of my "labour"

Hobbsmeerkat · « **Reply #59 on:** 22 Mar 2021, 11:29 pm »

Okay, this thread has beed dead for a while.. but without a proper Neo3 for testing, along with the GRS thread, (where I killed them both...) It was hard to do some proper testing
Read more here:
https://www.audiocircle.com/index.php?topic=172523.0

But I finally got my hands on some more BG Neo3 for a decent price.

A pair of Neo3W & a pair of Neo3 PDRW, all with shallow cups.

Having these on hand again, I want to start doing more testing again, and working towards a usable replacement for the deep-back cup.

I've already finished the design for the spacer that will fit all Neo3 versions, including the GRS clone & Danny's Neo3.
But I also want to develop a simpler version that can be "glued" on like the original, BG model.

I also want to do some more testing with the original flush-mount faceplate as well as with waveguides.
So be on the lookout for more in the coming week or two~