Following on from here:
Does anyone have a zoomed impedance response (or log scale) between 500-2KHz
Does anyone know if the rear cup can be removed?
Hats off to @silverD for his waveguide. Now I have a suspicion (but no evidence yet) that the midrange amplitude response and harmonic distortion could be further improved with a modified rear cup.
Cursory look indicates the rear cup is glued.
This is the 7600, but it is the same driver it just has a more of a waveguide faceplate.
A bit of hot air gun later…
do tell!
I’m happy to share the waveguide STL, but I’m in no way an expert. I have yet to make progress on the build with the DM-7500.
If I am not mistaken I think Thanh is trying to get one of us to heat gun our DM7500’s to remove the cup - too cold here and don’t have a heat gun . . .
To be clear, I’m not trying to talk anyone else into doing it. I’m trying to talk myself out of the being the first idiot to try it. I’ll only even consider it once mine arrives and I can inspect the glue line properly.
I found a pair for a reasonable price from a trusted distributor…
Guys, Don’t waste your time and money on the DM7500 - Go with the DM7600 instead!!
I just replaced the DM7500’s in my mid field 3 way monitor mini towers tonight and the DM7600’s are much warmer and detailed XO’d from 600 Hz @ BW-48db/oct to 3500 Hz LR-48db/oct - exact same XO settings as the DM7500 - (DM7600’s are right out of the box though - no burn-in done yet). The directivity problems I was blaming on the tweeter (HiVi RT1.3) are mostly gone now in my weird basement room.
Off axis is MUCH smoother and even as I walk back and forth - vertical dispersion is MUCH better too!! DM7500’s are too trebly - DM7600’s have the missing depth/guts that were previously missing.
Hi-hats and snare have far more guts now - from 6 ~ 8 ft away standing in the sweet spot . . . .
Anyone want these DM7500’S ??
1/2 price plus shipping via Paypal . . .
Thanks for the report. Now I’m happier that I’ve got a new pair of DM7600s on the shelf.
Where did you find a DM7600? They’ve been out of stock on hivi’s website every time I went to look for them. I’m looking at some JR from a different forum linked on Aliexpress… kinda nervous and weighing them against Part’s Express’ Morel CAM 558 (MDM 55 with a round faceplate, parts express exclusive) … It’s a 2 inch dome, but its a 2 inch dome that dome aficionados seem to respect. The difference is 20 bucks and not being able to return the Hivi’s to the seller if/when I find out they’re production rejects being resold. >.<
You found the link I suspect but this is where I bought the DM7600’s –> https://www.aliexpress.us/item/3256806560872392.html?spm=a2g0o.order_list.order_list_main.5.6a6318024UT67Q&gatewayAdapt=glo2usa
Mind you that I am using DSP so I don’t pay much attention to impedance mismatches as I can adjust FR to my ears/space.
It was a good transaction for me.
Let us know what you do or don’t and how it turns out or not, Mr. Dichotomist !
Hey, silverD - how is your DM7500 in a printed wave-guide going?
Care to elaborate?
Bet it is just as good as the DM7600 . . .
Hi Steve,
I haven’t done anything more since my post. I’ll share the STL in a few minutes, but I’m also willing to ship out my prints to someone with DM-7500 who can take better measurements than I.
DM-7500 Waveguide final.txt (1.8 MB)
Change from .txt to .stl
Thanks for the feedback and gracious distribution of your efforts silver-dude!
If you’ve already made good 3D prints, I’m happy to accept them.
But might costs a small fortune to ship anything Down Under (Australia- post/zip code 3000) no thanks to recent world events.
I’m setup to take good polar measurements (eg. higher SPL handling microphones with low self noise/distortion) for high sensitivity/larger Sd drivers. My main limitation is time; due to recent home renovations priorities.
An alternative if you share your trusted print material/settings and online 3D printer and I could give it a go…
