Will new Purifi woofer be just right?

[Rick Sykora]

Purifi now offers multiple versions of its groundbreaking 6.5 woofer along with the 4 inch one.

Does a 5.25 hit just the right compromise between their other offerings?

No pricing as yet, but here is the preview of the 5.25: https://purifi-audio.com/ptt5-25x04-nfa-01/

Could post a pic, but looks just like the 6.5!

So here is a quick look at the specs…

As you might expect, it is flatter out to 5 kHz than the 6.5. Off-axis looks more promising too, but the posted graphs are too tiny to really know for sure.

 

[AudioJester]

Only one (expensive) way to find out!

 

[alex-z]

Seems to be an extremely nice option. A 3.3 liter box + 43Hz port tune provides 80 watts of power handling with a 2nd order high-pass at 30Hz.

Puts -3dB at 53.7Hz (including loss from HP filter) and -10dB at 39Hz. That 80 watts of power allows it to output 98.6dB at F3, which is a solid 2dB higher than any other 5.25" woofer I have seen.

 

[hex168]

Superbly executed, but I still don't get optimizing a speaker for bass when it will need a sub anyway. I bet it could be significantly more sensitive if it were designed to give up a half octave or so on the low end.

 

[thulle]

Does a 5.25 hit just the right compromise between their other offerings?

I've been looking at purifi woofers for making two sealed speakers for my desktop, with a goal of ≤0.1% distortion above 80 Hz where I cross over to subwoofers. Just looking at specsheets the PTT6.5X08-NAA-08 manages this except for a 2nd harmonic peak @ 90 Hz where it's -55 dB. But the 6.5" is pretty large to squeeze in below my monitor with a tweeter.

The 4" PTT4.0X08-NFC-01 is easier to fit, but distortion is only -50dB @ 80 Hz due to rising harmonics and falling sensitivity.

This 5.25" manages the 0.1% down to 100 Hz, but then sensitivity drops off and we end up with -55dB @ 80 Hz. The difference from the 6.5" is that it's the 3rd harmonic that's climbing, whereas with the 6.5" the third harmonic starts increasing at even lower frequencies. An 8Ω 5.25" aluminium cone version might be able to do what I want, but for now the 6.5" and some excessive 2nd harmonics seems to be the best solution in that regard.

 

[MSP0416]

It could be that the upcoming 8" is going to be the real surprise. A tiny bit of discussion has been happing over on DIYA.

 

[Somafunk]

I’d like a small 3 way active (like my lyd48’s) with purifi woofer, purifi mid range driver and purifi tweeter, someone please take my money for such a thing

 

[Rick Sykora]

I’d like a small 3 way active (like my lyd48’s) with purifi woofer, purifi mid range driver and purifi tweeter, someone please take my money for such a thing

I would if the tweeter existed. It was rumored a while ago, but looks as though it was just a rumor.

 

[thulle]

It could be that the upcoming 8" is going to be the real surprise. A tiny bit of discussion has been happing over on DIYA.

Lars even dropped part of the specsheet currently underoing approval: (EDIT: Extra clarification ,this is for the 8" driver, not the 5.25")

For my use case there's no improvement 80-100Hz, but without having looked at too many specsheets, that third harmonic seems low! For people piling woofers in their floorstanders, mounting every 2nd in reverse to neutralize the 2nd harmonic (and assuming we manage to do this fully) gives us a worst-case of 20-90= -70dB harmonic distortion between 100 Hz and 3 kHz. 0.03%? Too bad i don't need floorstanders right now.

Edit2: Actually thinking this through, it becomes impossible at higher frequencies. For a 8 inch element, we have at least 8" center<->center, and assuming we lose the ability to counteract 2nd harmonic above a fifth of the wavelength, that gives a max of 8*5 = 40"/1m wavelength, or a 2nd harmonic at 340 Hz, or a fundamental at 170Hz.

 

[Rick Sykora]

Btw, Purifi was also working on an SPK6 design using their passive radiators. It has not surfaced either but knew which tweeter they planned to use and it was from another vendor. Pretty much how I knew the tweeter rumor was a bum steer.

 

[boXem]

Btw, Purifi was also working on an SPK6 design using their passive radiators. It has not surfaced either but knew which tweeter they planned to use and it was from another vendor. Pretty much how I knew the tweeter rumor was a bum steer.

Since they position themselves as "problem solvers", I see much less solved problems waiting to be sold for tweeters than woofers. Just my 2 €c.