Exploring Purifi Woofer Speaker Builds

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#2,305
JanRSmit said:
Several posts back a graph was posted showing the -technical- max spl of given size purifi drivers. Should give you an indication. Just calc the needed amplifier power and you have it.
Edit: could not find the post, but could find the image in my downloads, so here it is.
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This one is based on excursion only. Attached the same with power handling limit. The 10 inch will outperform the excursion graph but power handling is still TBD
 

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#2,306
They're still 2pi numbers. That makes them realistic for end-use, but it's always a pain to compare. A purifi sub that could handle midbass would be incredible. Since excursion is practically mandatory on a subwoofer, it makes a big difference having that surround for extended bass. Basically half the premise of the purifi stance on woofers. The 10" is exciting but it seems like the kind of thing they'll be using to target multiple markets, not a dedicated bass driver. Having a bass driver extend it's frequency in both directions is still a big deal for easy integration.
 
#2,307
Yes, 2pi number. It's a reference and allow comparison. If you want a simulation with baffle, vituixcad is your friend. Given excursion, power handling and your baffle size you can have a good approx of the driver spl capacity. Apart for the price, I believe the 10inch will be one of the best driver from 30hz to 1000hz. For a pure bass duty (<250hz) in home use, there are cheaper driver I guess.
 
#2,308
I do love me some VCAD. It's the surround from a subwoofer standpoint that really appeals to me. I'm staring at four SB29's right now trying to decide if they'll solve my main's low bass problem or not, and I'm seeing that I'll still have sub-bass deficiency in my sims. Like many people I see Purifi as a halo product to aspire to. A potentially very sound long-term investment in the most valuable, important part of a quality stereo system. Now they're branching outside of midwoofers and it's exciting.

EDIT: I'll put it to you another way. Room modes typically extend from 0-500hz. It would be cool if Purifi could target a driver to handle this in a large tower format or a sub box, designed to take DSP correction and handle a high PMAX.
 
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#2,313
hifijim said:
I appreciate the color/texture you used for rendering the image. It visually has a lot of contrast which clearly illustrates the shape.
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Thanks, I had to try quite a few materials and lighting options to find something that worked. This baffle is more 'slippery' than than the other one. There is quite a few profiles that form it.

Waveguide-Baffle-v2-copper-sketches.png


jcga said:
Very nice Duncan !
Wondering which dome you modelized ? one guess : Bliesma T34A ? another SB Acoustic SB26 ADC ?
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Thanks, T34A, I'm trying to concentrate on designs for the drivers I already have 🙂
This waveguide is too wide to work ideally with your M74B without putting a similar waveguide on it. The T34B works better in narrower ones that would fit better but be bigger than what you had before.

D1sco said:
Just remember to 3D print it in gold for a cool 1M a baffle @fluid
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I have been thinking about 3D printing a shell to fill with resin but I doubt it will be gold 😉. If I buy a fast printer maybe I will try.
 
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#2,315
fluid said:
Thanks, I had to try quite a few materials and lighting options to find something that worked. This baffle is more 'slippery' than than the other one. There is quite a few profiles that form it.

View attachment 1182136


Thanks, T34A, I'm trying to concentrate on designs for the drivers I already have 🙂
This waveguide is too wide to work ideally with your M74B without putting a similar waveguide on it. The T34B works better in narrower ones that would fit better but be bigger than what you had before.


I have been thinking about 3D printing a shell to fill with resin but I doubt it will be gold 😉. If I buy a fast printer maybe I will try.
Click to expand...
Get you a Bambu labs printer. Every maker needs one in their garage! I've printed like 20kg of front baffle / waveguide parts and it's never needed any tuning / changes. Stupid fast, too.
 
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#2,317
jcga said:
I know that I can't use it with the M74B but I'm thinking to a future (next year) project with the Purifi 8" and a T34 A or B waveguided ! The Fc would be around 1250 to 1500 Hz
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T34A needs to be really wide to work well in a waveguide and then making that go low gets big. The box does help quite a bit but the directivity can get less even quickly. The T34B can't get as wide in the top octave from the dome shape, but that makes it easier to maintain the directivity lower in a narrower waveguide. I've got a freespace simulation of mabat's Tritonia for the SB26 tweeter when I was considering a similar idea, that is solid down to 1K but the directivity is more smoothly narrowing with increasing frequency. Bliesma drivers can be wide without wavefront modification, SB's cannot so it depends on which directivity shape you want to target.
 
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#2,318
chargedcapacitor said:
Get you a Bambu labs printer. Every maker needs one in their garage! I've printed like 20kg of front baffle / waveguide parts and it's never needed any tuning / changes. Stupid fast, too.
Click to expand...
I probably will get an X1 Carbon with AMS because I do not need another project, but something in me feels like there is something wrong with that 🙂

hifijim said:
... What is your plan for fabrication? Outsource to a CNC shop and have it carved out of MDF?
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It would be quicker to outsource it but my own CNC machine might get jealous 🙂 Either CNC MDF or 3D printed outer layer filled with resin. Unfortunately there is too much real life stuff to make either likely to happen very soon. Rendering and simulation is easier to fit in with the spare time I have.
 
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#2,319
@lrisbo

The updated website looks great!

Here's a screenshot for datasheet on the 10" woofer:

1687418455306.png


Zoomed in:

1687417887702.png



I think we all appreciate manufacturers releasing FRD and impedance data for direct download:

https://ptt.purifi-audio.com/shop/p...,6022,6023,6024,6025,6026,6027,6028,6029,6030

When I imported into a viewer- here's what is shown:

1687417725994.png



The sensitivity for the Frequency Response Data for the PTT10.0X04 zip file for download on the website seems too low:
This difference also exists for the PTT8.0X datasheet. (not shown)

For people unable to take their own measurements, this may be a little confusing. Can you please advise?
 
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