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

[Roland68]

@Roland68 is correct that these speakers are small enough to print in one go if you get the right printer. Printers that big are far less common but not hard to get if you want one. In that case, it can look pretty decent straight off the printer when things go right. Removing supports from the interior would be kind of a pain, but the removable back would help with that.

Therefore, I would largely forgo a dedicated support structure, instead utilizing the internal framework for the insulation material and optimizing the transition from there to the front panel.

 

[Kaladin]

Yes, of course, it’s my ability to glue and seal the cabinet that is in question. I hadn’t realised that there was a standard kit version cabinet (in MDF or ply) of the SPK16. Can you provide a link?

You’re no doubt right about the manufacturer’s cost

Purifi doesn’t offer one yet but I believe they plan to offer a plywood kit in the future as well as a a limited run of composite speaker cabinets with matching stands.

It’s outside my realm of expertise but we have a lot of different industrial scale printers around that mostly get used for prototyping. The material costs are pretty mind-blowing when you’re coming from a hobbyist perspective that was just looking to save $8 per roll. I’m guessing Onyx would be around $800 USD per cabinet in just materials and Ultem double that.

 

[kemmler3D]

Therefore, I would largely forgo a dedicated support structure, instead utilizing the internal framework for the insulation material and optimizing the transition from there to the front panel.

I'm thinking that the bracing as it exists in the original design would need to be printed with supports due to large bridges / overhangs. But it sounds like you're suggesting that the bracing just be removed and use infill (gyroid) for the whole interior?

I think that would print fine, but I am personally not ready to change the functional parameters of the speaker!

 

[Roland68]

I'm thinking that the bracing as it exists in the original design would need to be printed with supports due to large bridges / overhangs. But it sounds like you're suggesting that the bracing just be removed and use infill (gyroid) for the whole interior?

I think that would print fine, but I am personally not ready to change the functional parameters of the speaker!

No, you’ve completely misunderstood me there.
I’m only talking about modifying the transitions on the interior side of the front—where it meets the internal bracing—in such a way that little to no support structures are required.

 

[Roland68]

Purifi doesn’t offer one yet but I believe they plan to offer a plywood kit in the future as well as a a limited run of composite speaker cabinets with matching stands.

It’s outside my realm of expertise but we have a lot of different industrial scale printers around that mostly get used for prototyping. The material costs are pretty mind-blowing when you’re coming from a hobbyist perspective that was just looking to save $8 per roll. I’m guessing Onyx would be around $800 USD per cabinet in just materials and Ultem double that.

The biggest issue with these industrial printers is the extremely high hourly rates. When using a service provider, this cost is even higher than that of the filament itself.

The filament market has evolved tremendously over the last two years, and there are now excellent, affordable alternatives to Onyx and Ultem that can be printed flawlessly on many standard 3D printers—materials such as PP-GF and CF, PPS-GF and CF, PAHT/PA12-CF, and others. Siraya Tech offers several interesting and affordable products in its lineup; their Fibreheart PPA-CF Core Black—a PPA nylon with a 25% concentration of carbon fiber in its core—comes very close to replicating the results of printing with continuous carbon fiber.
For loudspeaker enclosures, I consider pure PC—whether reinforced with glass fiber (GF) or carbon fiber (CF)—to be the absolute ideal material.

 

[Reddoc]

pure PC—whether reinforced with glass fiber (GF) or carbon fiber (CF)—to be the absolute ideal material.

Measurement of the cabinet resonance with each material would make for interesting reading!
Also:
Thanks for everyone's contributions to this thread- I'm learning a lot

 

[kemmler3D]

I'm thinking that the bracing as it exists in the original design would need to be printed with supports due to large bridges / overhangs. But it sounds like you're suggesting that the bracing just be removed and use infill (gyroid) for the whole interior?

I think that would print fine, but I am personally not ready to change the functional parameters of the speaker!

I see, that makes more sense. Because there are large flat overhangs no matter how you orient it, (unless you print it sitting on a corner with support on the outside?) I feel like you can't get away from supports with this one... So I'm keen to see what you come up with!

 

[Kaladin]

The biggest issue with these industrial printers is the extremely high hourly rates. When using a service provider, this cost is even higher than that of the filament itself.

The filament market has evolved tremendously over the last two years, and there are now excellent, affordable alternatives to Onyx and Ultem that can be printed flawlessly on many standard 3D printers—materials such as PP-GF and CF, PPS-GF and CF, PAHT/PA12-CF, and others. Siraya Tech offers several interesting and affordable products in its lineup; their Fibreheart PPA-CF Core Black—a PPA nylon with a 25% concentration of carbon fiber in its core—comes very close to replicating the results of printing with continuous carbon fiber.
For loudspeaker enclosures, I consider pure PC—whether reinforced with glass fiber (GF) or carbon fiber (CF)—to be the absolute ideal material.

Yeah, the difficulty is that you need a fairly high-temperature heated chamber to combat warp. My Bambu H2D only goes up to 65c and it's not enough for large objects with that much surface area on the build plate.

 

[Luvchampagne]

Back to the thread title instead of 3d printing of a speaker cabinet. Please open new thread on that.

Who has bought and built this kit?
How does it compare to comparable Purifi driver speakers such as Marcg, Ascilab s6b or others?

 

[JohnnyNG]

That's a good idea to save some money. Your prices look better but in the US it's about $8 less per roll for the cardboard rolls.



I've attached a couple pictures plus a few older ones. The pieces are just stacked together for now. I'm not going to glue them up until after they've been filled.

Very cool!

 

[Kravi4ka]

I don't think any kits have been shipped, at least my three kits are expected in June...

 

[Kaladin]

Back to the thread title instead of 3d printing of a speaker cabinet. Please open new thread on that.

Who has bought and built this kit?
How does it compare to comparable Purifi driver speakers such as Marcg, Ascilab s6b or others?

Last I saw I’m the only person to share a cabinet build. If there’s an issue get a moderator.

 

[WerT]

I just did a very rough quick test to see if a one-piece design with internal structure is an option.
It should work.

View attachment 518963View attachment 518964View attachment 518965View attachment 518967View attachment 518968

Very cool, what printer are you using to do all this on? I have printed myself some horns which worked and attempted to do an entire large speaker but my printer isnt accurate enough to get the pieces to fit together with enough tolerance. The better quality printers tend to be on the small size which is frustrating but an elegoo max isnt really good enough even if it is large enough.

 

[kemmler3D]

Very cool, what printer are you using to do all this on? I have printed myself some horns which worked and attempted to do an entire large speaker but my printer isnt accurate enough to get the pieces to fit together with enough tolerance. The better quality printers tend to be on the small size which is frustrating but an elegoo max isnt really good enough even if it is large enough.

Not to turn this entire thread into a 3D printing thread, but this is probably due to warping, which can be mitigated with a sealed / heated chamber. Something that you can DIY in very basic fashion for printers that don't come with them. Supposedly some folks get improved (if not perfect) results just by popping a cardboard box over the printer.

 

[WerT]

Not to turn this entire thread into a 3D printing thread, but this is probably due to warping, which can be mitigated with a sealed / heated chamber. Something that you can DIY in very basic fashion for printers that don't come with them. Supposedly some folks get improved (if not perfect) results just by popping a cardboard box over the printer.

yeah it is something i have been meaning to try - but now i find you can't get plastic and my speaker was 10kg of it

 

[Matias]

Purifi tweeter reviewed as a "top contender".

Test Bench: Purifi Audio’s PTT1.3T04-HAG-01 WG104 1.3” Aluminum Dome Home Audio Tweeter

Vance Dickason had the privilege to try out and measure the new Purifi Audio PTT1.3T04-HAG-01 WG104 1.3” aluminum dome home audio tweeter with its 104mm waveguide. This is Purifi’s first tweeter design, and it appears to have been well worth the wait. What immediately gets our attention is the...

audioxpress.com

 

[WerT]

Oh nice i've been hanging out for them to measure this

Purifi tweeter reviewed as a "top contender".

Test Bench: Purifi Audio’s PTT1.3T04-HAG-01 WG104 1.3” Aluminum Dome Home Audio Tweeter

Vance Dickason had the privilege to try out and measure the new Purifi Audio PTT1.3T04-HAG-01 WG104 1.3” aluminum dome home audio tweeter with its 104mm waveguide. This is Purifi’s first tweeter design, and it appears to have been well worth the wait. What immediately gets our attention is the...

audioxpress.com

 

[AudioJester]

Purifi tweeter reviewed as a "top contender".

Test Bench: Purifi Audio’s PTT1.3T04-HAG-01 WG104 1.3” Aluminum Dome Home Audio Tweeter

Vance Dickason had the privilege to try out and measure the new Purifi Audio PTT1.3T04-HAG-01 WG104 1.3” aluminum dome home audio tweeter with its 104mm waveguide. This is Purifi’s first tweeter design, and it appears to have been well worth the wait. What immediately gets our attention is the...

audioxpress.com

Thanks!

Heard them in the new March Audio all Purifi floorstander at a recent audio show. Went back several times.

Best sound of show for me.

 

[illusonic]

Purifi tweeter reviewed as a "top contender".

Test Bench: Purifi Audio’s PTT1.3T04-HAG-01 WG104 1.3” Aluminum Dome Home Audio Tweeter

Vance Dickason had the privilege to try out and measure the new Purifi Audio PTT1.3T04-HAG-01 WG104 1.3” aluminum dome home audio tweeter with its 104mm waveguide. This is Purifi’s first tweeter design, and it appears to have been well worth the wait. What immediately gets our attention is the...

audioxpress.com

Purifi speaker datasheet(s) look fatastic. But nothing is see in this review would make me consider buying these tweeters for their asking price. Some measurements don't match the datasheet.

Directivity looks quite average for a small waveguide. Issues may at least partly be caused by the test baffle (15”×8”), also depending on the unknown position on the baffle. Given the width of the baffle, I would expect the bunching just below 3kHz to be caused by baffle edge diffraction, while above 3kHz we may see the actual tweeter directivity.

Figure 4: Purifi Audio PTT1.3T04-HAG-01 WG104 horizontal on and off-axis frequency response (0°=black; 15°=blue; 30°=green; 45°=purple).
Figure 5: Purifi Audio PTT1.3T04-HAG-01 WG104 normalized on and off-axis frequency response (0°=black; 15°=blue; 30°=green; 45°=purple).

Given that the datasheet shows off-axis measurements referenced to the listening window, these are hard to compare.

More than 1% H2 at 2kHz / 3.3V (means about 95dB SPL) while the datasheet shows <-54dB (0.2%) at 94dB SPL at 2.83V and -46dB (0.5%) at 105dB SPL.

Purifi datasheet:

 

[Paul7777x]

Thanks!

Heard them in the new March Audio all Purifi floorstander at a recent audio show. Went back several times.

Best sound of show for me.

What show were they at? Not the UK I suppose, I’d have loved to hear them.

Did you by chance hear if they are out for a test anywhere?