As requested a group buy thread was created by me for the DFM-2535R00-08 compression driver:
https://www.diyaudio.com/community/threads/group-buy-peerless-by-tympahny-dfm-2535r00-08.415988/
https://www.diyaudio.com/community/threads/group-buy-peerless-by-tympahny-dfm-2535r00-08.415988/
You would not expect much more than a reduction in the SPL level with measurements like that ones you posted. You need time domain measurements to see if you have knocked down any harmonics. So you need a Waterfall plot before and after to indicate any positive effects. Have you listened before and after? Mics are good, and very powerful tools. But our ears are as well! At least when you have trained them a little.
Sources? I would like to read a bit if that is possible. All I have right now is intuition. It may be correct. And it will not hurt I am sure. But knowing a little bit of the physics behind the stiffening ribs would be awesome.
Sure. I've found this document most helpful in providing some practical guidelines for support structures in the model - mainly pages 25-31. Some of the concepts are specific to plastic injection molding (flow/ejection/cooling/etc.) and can be ignored in 3D printing, but the structural aspects around feature thickness/height/geometry are what's useful.
https://kompozit.org.tr/wp-content/uploads/2021/11/A_Design_Guide_Part_and_Mold_Design_Engi.pdf
There are some more guidelines about halfway down this page showing placements and effects on rigidity.
https://www.envalior.com/en-us/serv...guidelines/corrugations-ribs-and-gussets.html
I've yet to find any useful documentation in the context of reducing resonances in horns/waveguides specifically, so like you I'm basing my design process off of the intuition that increasing the rigidity & mass of the part should minimize unwanted resonance.
I've looked at the FR plots for this very interesting driver.
Would it reach down to 800 or 900Hz with some meaningful output?
I'd like to use a 1st order XO.
I'm guessing that the XO wouldn't actually be doing anything set that low.
Will only be hifi, upto 85dB listening. So don't need full PA output🙂
it's relatively small diaphragm, so might be pushing it. Use good big constant directivity waveguide, perhaps with the throat extension to help some, and you can use very small high pass capacitor, all the way up to 10kHz or something 😉 Waveguide mouth size about 800hz wavelength or so. Test in simulator to see whether it works and with which size woofer.
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Thanks for the detailed reply.
It would be used on an SH50, conical. No throat extension.
Has to meet the 5" mid range drivers and I've found that compression drivers that can reach down to 800Hz do well.
The 1.4" Eminence N314T could be a goer low end wise - 'For a few dollars more'.
But looks like that runs out of puff higher up too soon though... Compromises comprises🙂
Glued together and put on the first layer of polyester putty on the front face. Did a bit of sanding too!
Attachments
I am tempted to join, but to pull the trigger I would need the comfort of an existing design that incorporates those and an ATH4 based horn. Their frequency range would probably mean that they should be part of a 3-way (horn, mid bass subs; or MEH). Would anybody be aware of such a design?
Thanks, but this is "so 2020". ;-) ATH4 has come a long way since then. And it seems they use a different driver than the DFM-2535R00-08 for which the group Buy is open?
I was thinking of a 3-way that can be combined with one of Mabat's Gen 2 horns, or a MEH along the lines of what vineethkumar01 is doing here (without his constraints of using the dual 15inch woofer module that he already has).
I was thinking of a 3-way that can be combined with one of Mabat's Gen 2 horns, or a MEH along the lines of what vineethkumar01 is doing here (without his constraints of using the dual 15inch woofer module that he already has).
I'm quite convinced that the DFM-2535 can handle 800 Hz when used in A460 or A520 Gen2 waveguides, even with the standard (short) adapter: https://at-horns.eu/gen2m.html#2535 (which reminds me I wanted to add an adpater matching the exit angle perfectly).
So there's really no reason for a 3-way, IMO. Of course it depends on your SPL requirement, but it would have to be extreme for the driver to really suffer (but probably still less than your ears).
So there's really no reason for a 3-way, IMO. Of course it depends on your SPL requirement, but it would have to be extreme for the driver to really suffer (but probably still less than your ears).
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Don't expect much improvement over what's shown above, though.
There must have been a considerable amount of luck in that combination 🙂
There must have been a considerable amount of luck in that combination 🙂
Thanks Mabat! Really eager to try this, and I wonder if there is a design out there that I could combine with the horn.
Use case is home audio, so only reasonable SPLs. Speaker would be against the back wall, placed to the left and right of a USM shelf in the centre (75cm high, front 45cm away from back wall), so back-firing isn't an option.
Designing one myself is a bit over my head.
Use case is home audio, so only reasonable SPLs. Speaker would be against the back wall, placed to the left and right of a USM shelf in the centre (75cm high, front 45cm away from back wall), so back-firing isn't an option.
Designing one myself is a bit over my head.
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That system is a purely experimental one.. 🙂
The only objective in that build is to experiment with a bit wider horizontal polars (close to 90degrees) above 1kHz than the Gen2 waveguides. Another "side purpose" was to try and understand a little bit more about MEH design.. 🙂
I have had direct radiating 3-way speakers with dual Satori WO24P drivers per side with wide enough (larger than 90degrees horizontal beamwidth) polars.. But so far I have preferred the sound of EXAR400 + dual woofer system over all the other combinations that I have tried out..
So I don't even know if that entire build will serve any ultimate purpose except maybe a bit more dynamics capability in my echo chamber of a listening room..
But let's wait and see.. 🙂
Probably not the one I would choose - it has a very light, not well damped diaphragm. I don't like that, it's a pain to work with. But maybe with DSP it's easier nowadays. See the FTR15-3070C.
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Based on this drawing, does everyone agree that the exit angle of DFM-2535 is 22 deg?
(Which is right between the current STD-1 and STD-2 adapters.)