Exploring Purifi Woofer Speaker Builds

oh crap. maybe we need a warning sticker to keep a minimum safe distance.

We can send you a spare dustcap?
Yeah, If I’d have been 10mm further away. Heck I will be moving forward. Massive excursion.

Yes please you legends! Pm me. I’m happy to pay for and attempt a dust cap replacement. Is it difficult?

For now I was going to attempt to heat the dust cap with a heat gun, then apply vacuum to it, to at least try and get it to pop out, will probably still look like a crushed can but should perform better.
 
The reason why i measure my accuton midrange with grille still mounted.

I had similar incident with measuring my scanspeak 8" woofers, luckily the amplifier switched off instantly so no physical harm done to woofers. But makes me very cautious with measuring. First turn mute on then do changes to set up.

@mainframe99 , is your mic still ok?
 
Yeah, If I’d have been 10mm further away. Heck I will be moving forward. Massive excursion.

Yes please you legends! Pm me. I’m happy to pay for and attempt a dust cap replacement. Is it difficult?

For now I was going to attempt to heat the dust cap with a heat gun, then apply vacuum to it, to at least try and get it to pop out, will probably still look like a crushed can but should perform better.
Got some feedback from my partner Carsten: The alu-alu glueing using our super heat resistant glue is virtually impossible to disassemble without damage. The glue is stable to 160C or more. He is therefore not recommending a change of dustcap :-(
 
not recommending a change of dustcap
Will the caps nest? One way to restore the visual integrity would be to remove the damaged cap by cutting it off near the base and bonding the new one to the base (where cone meets cap). Unless they won't nest. Just to see how hard it would be to cut an Al cone I tried it with a smashed B&W driver and it was like cutting a beer can. Cone thickness measures 0.33mm (0.013") is that comparable to the PTT?

alCuts.png
 
This is one way to do the cap surgery with reasonable precision. Use the driver's suspension to apply mild pressure. The annular cutter is just a solid continuous edge with a heavy grit lapping compound applied to it. Probably best done at a 90 degree angle to keep the debris from entering the VC upon penetration. This method would get the cut close enough to the base that nesting is not a factor; plus the danger of piercing the cone with a blade is mitigated. Probably about fifty bucks worth of parts (bearings, wood, etc.) and another fifty for lapping compound and Hysol structural adhesive. This would be overkill probably for most people. But if you can't stand having the visible damage on such a fine driver it could make sense.

repairFixture.PNG
 
Last edited:
My body has never been more ready
That's the o'l college spirit ! :cheers:

I hope that's a render and you haven't really taken apart the /US$400 Purifi?

I take it you've seen our state of the art midrange coaxial using off the shelf parts?
That's an IRL operating table with both patients in stable condition. If these can't be worked on that's what I'd consider a call to action for getting my hands dirty. "FarmBosssTM dirty"

As to your coax project, no I haven't seen that yet. Looks awesome! It's quite a detailed writeup so I haven't had a chance to get into the meat of the details. Are you thinking it would work on this application? This is something I was tinkering around on in 2019 and that's when I tore into the Dayton RST28 to see if it could be repurposed. I even had the custom magnet T frame partially machined and ready to go. Now that the PTT is opened up I can see some better ways to proceed. Let me know if you want some dimensions of the de-capped internals, maybe they'll translate over well to your custom project-
 
  • Like
Reactions: Zvu
I agree that dealing with the travel disparity is problematic. There's about a half dozen other problems I can think of and I'm not even a speaker guy. I'll let you in on a little secret...I don't even know how properly to measure the performance, but don't tell anyone m'kay 😉

But then again, boyz with cheap toys don't have much incentive to salvage the dents now do they? Was it the bailing wire and shoe glue that gave the FarmBossTM hustle away?
 
  • Like
Reactions: Boden