GR Neo3 back-cup ideas!

Hobbsmeerkat · « **Reply #60 on:** 29 Mar 2021, 02:48 am »

Made some design updates to the deep cup. I made the base thicker to increase its rigidity and clamping pressure, i also tweaked the faceplate spacer to fit all Neo3 variants/clones.

Here's how it looks placed together with a printed waveguide.

Here's a failed/unfinished sample mounted to a BG faceplate. With stuffing in place.

Tho if you look, you can see the issue using this mod when used with this type of faceplate... Notches would need to be cut/filed out in order to fit them. But I also want to design one thats more similar to the BG design that will just be applied using a silicon adhesive. It'll be much cheaper & faster to make/assemble, tbh.

Hobbsmeerkat · « **Reply #61 on:** 31 Mar 2021, 12:35 pm »

First pass at the glue-mounted mod looks pretty good!
Did my best to match the original geometry and managed to get pretty close.

Tho I'm getting a curling issue at the base since I switched to a glass printing surface, so this unit isnt viable for future testing. Thankfully, I do have a few options to fix that in the next pass after I make a couple small changes.

Danny Richie · « **Reply #62 on:** 3 Apr 2021, 01:57 pm »

Dang those look good.

Shives · « **Reply #63 on:** 3 Apr 2021, 02:27 pm »

You over-achiever!! Lolol dude, awesome work! You’re awesome!! Inspiring people to get motivated and build!
You must have had a smile ear to ear when that printer arrived!!!
It’s amazing what you can do with some 3D printing. I have a laser, engraver CNC machine that is being setup. Engrave those cups with HOBBS! Lol

So, I know your coming up with ideas.. Can I ask what you plan to do with these?

Hobbsmeerkat · « **Reply #64 on:** 3 Apr 2021, 09:50 pm »

Quote from: Danny Richie on 3 Apr 2021, 01:57 pm

Dang those look good.

Thanks Danny! I'm pretty happy with the results, but I'll be happier once I get the curling problem sorted.

Once I do my own testing I'll be sure to send you a pair to test their viability yourself.

Quote from: Shives on 3 Apr 2021, 02:27 pm

You over-achiever!! Lolol dude, awesome work! You’re awesome!! Inspiring people to get motivated and build!
You must have had a smile ear to ear when that printer arrived!!!
It’s amazing what you can do with some 3D printing. I have a laser, engraver CNC machine that is being setup. Engrave those cups with HOBBS! Lol

So, I know your coming up with ideas.. Can I ask what you plan to do with these?

I try!

I did! Ive had it for a few months now! Its made prototyping these ideas really easy. Tho not necessarily "fast" since some of them can take up to 30 hours at times. lol
Its been a great purchase.

I could technically just put my initials into the cup or even the GR logo so it becomes part of the print.

The idea for these is to possibly make for a return of the old N-series product that used a BG Neo 3 PDRW with a deep back cup, that is no longer being produced. (A Neo3 W with deep cups are still be sold, but aren't very common) Or at the least a similar line based on Danny's GR Neo3, but with a deep cup that can be screwed or glued on. Next will be designing a flush mount faceplate to replace the BG ones. Theyll need to be sanded & painted to smooth out the layers lines, but should be pretty doable

Here's a N3 & N1 for reference:

Hobbsmeerkat · « **Reply #65 on:** 4 Apr 2021, 05:42 pm »

Quick update on the glued deep cup!

Turns out I just needed some Elmer glue sticks to prevent the curling issue!

The base is now perfectly flat, so hopefully, I can do some testing in the near future!

Shives · « **Reply #66 on:** 4 Apr 2021, 07:28 pm »

Completely understand. Sorry, showed up a bit late to the game, but appreciate you giving me the 1-2! Looks awesome!! Hey, I know that second Speaker and location!! 😎😎.

I have a really really good 2 part ABS plastic glue. (Have the gun as well) I’ve used to to make plate brackets and mounts for motorcycles that still are in use some years later. I’m not going to date myself. Again drill it, cut it sand it. It’s hard like ABS. And it’s very quick setting with a good work time.

Most people I’ve mentioned are like ya ya.. till they use it. It’s also black in color. Anyways, if you think it might help at some point drop me a message or call. Happy to help!

Good work man! Really! Keep pushing the level higher!!

Hobbsmeerkat · « **Reply #67 on:** 5 Apr 2021, 01:47 am »

Yeah! I took that pic back of Danny's N-1X in October! It sounds great even just playing random music off YouTube.

The original BG models use a black silicone type adhesive, and I've got some clear silicone sealer i can use, but if this mod is viable, I'm sure there will be a few different options people can use to get good results. Be it epoxy, silicone, gorilla glue, super glue elmers school glue, etc. lol

Thats pretty interesting, I had no idea there was a specific ABS based glue, I'll definitely keep that in mind! I am using PLA tho, so I'm not sure how compatible they are together..

Shives · « **Reply #68 on:** 5 Apr 2021, 03:32 pm »

I’ve used it to smooth out 3D printed items to give it that smoothness rather then using bondo or trying to build up paint and sand. I found when trying to sand down a printed item, due to how’s its construed if found spots would get thin.

No worries! Figure I would share some insight to see if it could help ya!

Awesome stuff man! Yea I just got back from said location.. Went down for a visit. Possibly moving towards his direction. And yes, they sounded great just playing random music.... Sadly the saying is very very true... If you want the phone to ring, play music! I don’t think in 3 days I heard one song play all the way through!! Ha!!

Hobbsmeerkat · « **Reply #69 on:** 6 Apr 2021, 02:55 am »

A fair point! I'm sure getting a good finish would definitely time consuming & plastics don't sand all that well, unless they're a very regular, & consistent shape.

I appreciate it!

Oh hell yeah! I'm sure you had a great time! Danny was definitely on the phone or answering emails all day. And it ended up being launch day for the new site & I remember Ron calling a few times to help work out some of the kinks as it got rolling.

Took the shallow backs off of one of my Neo3 PDRW & Neo3W, should help verify the results that the mod works with PDR as well as re-verify the standard models with the yarn mod.

Hopefully I can get some time to run the tests soon.

pinkfloyd4ever · « **Reply #70 on:** 6 Apr 2021, 04:29 pm »

Following with anxious anticipation.

I'd love to be able to build a pair of N3s.

jeffh · « **Reply #71 on:** 7 Apr 2021, 01:16 am »

Quote from: pinkfloyd4ever on 6 Apr 2021, 04:29 pm

Following with anxious anticipation. I'd love to be able to build a pair of N3s.

Same here. I would like to build a pair of N3’s. I don’t have room for open baffle speakers.

corndog71 · « **Reply #72 on:** 7 Apr 2021, 03:03 am »

I got to audition the N1 and it was my first time hearing the Neo tweeters. They were more resolving than my X-series speakers and just super smooth. I wanted the N3 monitors but waited too long. I still wouldn’t mind a pair but already have too many speakers.

Hobbsmeerkat · « **Reply #73 on:** 7 Apr 2021, 04:19 am »

Glad there's at least a few people that are interested in this project!

I've currently got it set up for testing using a faceplate that more closely resembles the BG, but is larger to accommodate my current waveguide test baffle. Plus it's also large enough to fit the screw mounted back cup.

Hoping I can do the testing sometime tomorrow!

Hobbsmeerkat · « **Reply #74 on:** 8 Apr 2021, 04:38 am »

A bit later than i wanted, but I finally got the measurements.

This is a graph showing the Neo3 PDRW response curve for with and without the deep cup attached. (1/6th smoothing)

Red: Deep Cup Green: Open Back

% THD graph

Aside from the peak at 1.7K Hz, the mod's response is actually quite smooth, esp from 2K-20K Hz.

Open-backed, I'm a bit surprised by the 2dB dip in the response around 2-4K Hz, but it gets some pretty good extension, easily down to 600Hz

I'm actually the most surprised by the rise in THD, esp above 5K Hz..

But I'll see how the standard Neo3 fares, as well as testing the GRS-3, since it will be a more direct comparison to the PDRW model I have currently

Next time I get to do some testing, it will be with the standard Neo3.
It will also be a little more involved, since I'll need to mod it with both the cup, but also some thick yarn, to be the closest approxiation to Danny's GR Neo 3.

Hobbsmeerkat · « **Reply #75 on:** 10 Apr 2021, 12:55 pm »

Nother update since I had some time alone this morning!

I started with the GRS 3" PDRW clone:

Purple: Deep Cup Teal: Open Back

% THD

The cup mod does a great job, tho the hump in distortion below 2K range is rather pretty apparent, should make for a solid choice crossing over to a mid driver around 2.5K tho, esp for the price..

Next is the Standard Neo3 W without yarn.

Magenta: Deep Cup Tan: Open Back

% THD

Here's the most promising results by far. The Neo3W with the cup mod gives a fantastic response in both frequency and THD..
Can easily crossover at 1.5K

(The rise in THD above 5K Hz is incredibly consistent across all drivers & tests I'm guessing its a software/hardware bug with how consistent it appears...)

All that's left is to use the yarn mod once I figure out where I left it...

Cheers!

Danny Richie · « **Reply #76 on:** 15 Apr 2021, 01:03 pm »

Try shooting THD with the tweeter not playing at all. Just to see what the room noise is doing to the measurement.

Also, how far away are you and what power level are you using?

Hobbsmeerkat · « **Reply #77 on:** 15 Apr 2021, 01:33 pm »

Quote from: Danny Richie on 15 Apr 2021, 01:03 pm

Try shooting THD with the tweeter not playing at all. Just to see what the room noise is doing to the measurement.

Also, how far away are you and what power level are you using?

Ill have to check that, thanks for the tip.

Im measuring from 1M away.
As for power level, I'm not sure how to measure it, since my Sprout only has a dial and I don't want to risk blowing them out.

Hobbsmeerkat · « **Reply #78 on:** 17 Apr 2021, 12:48 am »

I took some measurements of the room with no sounds other than the laptop and fridge, but distortion was really clean across the board. I didnt save the graphs cuz i didnt see anything that looked relevant to the issue.

There was a steady 15dB rise in the noise floor SPL measurements starting at 3.6KHz, but it continued up to 18k Hz when the THD graphs see their rise from 5K to roughly 8.5K Hz.

Not really sure what to make of the issue.. esp since it wasn't an issue the the past...

Only guess is i had something off in the settings or configuration that caused it, i might be missing.

durwood · « **Reply #79 on:** 5 Apr 2024, 05:21 am »

Hey Hobbs I have an old set of the BG neo 3w without the back cups, was curious if you ever posted the stl 3d print files for your cups?