In need of a builder...

[kemmler3D]

PEEK or PC may be my best bet

Overkill if you ask me, unless you are dead set on the highest density. You can always get it printed in PETG and fill the pieces with something heavier like plaster if you are concerned about vibration.

Those materials are good for durability and mechanical strength, but IMO all you really need is a bit of mass to hold things in place...

 

[BKr0n]

Overkill if you ask me, unless you are dead set on the highest density. You can always get it printed in PETG and fill the pieces with something heavier like plaster if you are concerned about vibration.

Those materials are good for durability and mechanical strength, but IMO all you really need is a bit of mass to hold things in place...

Main reason I chose those was mainly for vibration etc. If I use a denser material then I won't have to worry nearly as much. Now, I am also lining the inside pretty heavily so that may be enough, but I am not sure.

 

[kemmler3D]

Main reason I chose those was mainly for vibration etc. If I use a denser material then I won't have to worry nearly as much. Now, I am also lining the inside pretty heavily so that may be enough, but I am not sure.

PEEK density is 1.32 g/cm3, ABS median density according to Wikipedia is median, 1.07 g/cm3, and the humble PLA is 1.2 - 1.4... so you're gaining a tiny bit of density over the most basic filament, but both are denser than MDF (about 0.7), and cement is denser than any of those. So if you wanted to max out density I would suggest A) just don't worry about it and do a 100% infill PLA print, or B) go crazy and fill a hollow PLA / ABS print with concrete.

I guess my point is you don't need to use high-end 3D printing materials to get a dense-enough baffle. You will end up paying a lot more for the specialty printing without getting much more mass into the baffle.

Using the expensive stuff not be a problem, but if the first design doesn't work and you need to go back and get more prints, it could get expensive and tedious.

Personally I would definitely use the cheaper / easier material, because I would say 9/10 times when I design and print something with hardware fittings, I have to redo it to get the fit right. Printing tolerances vary a fraction of a millimeter which can prevent a decent fit and require you to go back and add the tolerance to the design.

If you do decide to go with the expensive stuff anyway, I would highly recommend getting a test batch printed, where you print several versions of the holes / fittings that you need to fit hardware into with different tolerances, so you can use the correct one in the final design. For my QRD diffuser I tested 0.1 - 0.4mm tolerances for the tab fittings in 0.1mm steps to find the right one.

But still, I think the PEEK and PC and even nylon filaments are only when you need really good mechanical properties for structures or moving parts, if you're not worried about it breaking then it's kind of a waste of time and money.

 

[BKr0n]

PEEK density is 1.32 g/cm3, ABS median density according to Wikipedia is median, 1.07 g/cm3, and the humble PLA is 1.2 - 1.4... so you're gaining a tiny bit of density over the most basic filament, but both are denser than MDF (about 0.7), and cement is denser than any of those. So if you wanted to max out density I would suggest A) just don't worry about it and do a 100% infill PLA print, or B) go crazy and fill a hollow PLA / ABS print with concrete.

Density usually provides that greater rigidity. In this specific instance, I just need a material that will allow me to make a small structure that will be bale to bear any forces acted upon it like the subwoofers one cavity over. If i really wanted to get anal retentive about it I could always find a conversion table of decibels to pounds per square inch

Personally I would definitely use the cheaper / easier material, because I would say 9/10 times when I design and print something with hardware fittings, I have to redo it to get the fit right. Printing tolerances vary a fraction of a millimeter which can prevent a decent fit and require you to go back and add the tolerance to the design.

Now THAT is a terrific point. Not only that, but a change in hardware could also mean a change in overall design.

But still, I think the PEEK and PC and even nylon filaments are only when you need really good mechanical properties for structures or moving parts, if you're not worried about it breaking then it's kind of a waste of time and money.

I mean, this would all probably be a lot easier if I had a 3d printer myself, but I'm not sure what else I would use it for. That would also be en entirely new rabbit hole I would be jumping down after I just came back from another lol

 

[kemmler3D]

Density usually provides that greater rigidity. In this specific instance, I just need a material that will allow me to make a small structure that will be bale to bear any forces acted upon it like the subwoofers one cavity over. If i really wanted to get anal retentive about it I could always find a conversion table of decibels to pounds per square inch
\

At this point we are getting into stiffness vs. strength and stuff which I am aware of, but only to the extent that I don't know how it applies here. I will just point out that PLA is about as dense as PEEK but nowhere near as strong, it's much more brittle, etc. If you want a good compromise between mechanical robustness, cost, and difficulty of printing, most people go with PETG these days. I'm making some PETG wheels for the lazy susan in my kitchen... they're going to have to hold up about 50lb+ worth of oils and vingegars and whatnot... YMMV...

Now THAT is a terrific point. Not only that, but a change in hardware could also mean a change in overall design.

I mean, this would all probably be a lot easier if I had a 3d printer myself, but I'm not sure what else I would use it for. That would also be en entirely new rabbit hole I would be jumping down after I just came back from another lol

It's not that hard to find people with 3D printers looking for something to print for a few bucks. A good 3D printer these days costs about $600, from what I have seen the Bambu Labs ones keep their resale value pretty well and they are about as turnkey as you could hope for, so it wouldn't be stupid to buy one for this project and then sell it later.

If not, I think you can probably get someone to print this for you no problem, but definitely do a series of fit test prints BEFORE the full print so you know everything will fit properly. Make sure you use the same printer and filament for that as the final print.

 

[terryforsythe]

@BKr0n - FYI, apparently Purifi's new tweeter is almost ready to ship.

PURIFI finally did a fully purified passive speaker design! The SPK 16 prototype is here - with a PTT tweeter

You can always make your own coax with the tweeter of your choice.. I guess you can ultimately make anything "yourself" if you have the dough, but in practice it's not that simple considering you'd ideally match the cone curvature to the tweeter specifically and so on

audiosciencereview.com

PURIFI finally did a fully purified passive speaker design! The SPK 16 prototype is here - with a PTT tweeter

The Belgian-Danish source of audio greatness in Roskilde / Denmark have achieved to provide something to the community that many DIY speaker enthusiasts were hoping for.: A PTT tweeter !!! They've put that little thingy called PTT 33 tweeter - which Lars Risbo describes as: "33mm alu hard dome...

audiosciencereview.com

 

[terryforsythe]

Here is the white paper on the reference design:

SPK16 Reference Design

White Paper

purifi-audio.com

 

[BKr0n]

If not, I think you can probably get someone to print this for you no problem, but definitely do a series of fit test prints BEFORE the full print so you know everything will fit properly. Make sure you use the same printer and filament for that as the final print.

Guess I need to build a box then first before I build the MTM enclosure.

@BKr0n - FYI, apparently Purifi's new tweeter is almost ready to ship.

Almost only counts in horse shoes and hand grenades Jk. Spec sheet out in the wild yet?

 

[terryforsythe]

Spec sheet out in the wild yet?

Not that I have seen. Hopefully soon.

The dispersion pattern looks terrific. I read somewhere (I don't remember if it was in the white paper or the thread for the tweeter) that the tweeter is designed to have very low distortion and compression. If we use what Purifi has accomplished with their woofers as a guide as to their design ability, I expect the new tweeter will be a phenomenal performer, though not cheap.

 

[BKr0n]

Not that I have seen. Hopefully soon.

The dispersion pattern looks terrific. I read somewhere (I don't remember if it was in the white paper or the thread for the tweeter) that the tweeter is designed to have very low distortion and compression. If we use what Purifi has accomplished with their woofers as a guide as to their design ability, I expect the new tweeter will be a phenomenal performer, though not cheap.

No decision will be made without a spec sheet. Did they give a time frame? Or just Soon(tm)?

 

[terryforsythe]

No decision will be made without a spec sheet. Did they give a time frame? Or just Soon(tm)?

This below post was the one to which I linked above. If that post is correct, I would expect a spec sheet to be coming very soon.

We just heard from Purifi today stating that the tweeter is almost ready to ship.