Purifi PTT6.5W04-01A 6.5" midwoofer

[briskly]

Purifi 6.5 for dedicated midrange duty announced. PTT6.5M04-NFA, the result of putting overweight woofers on the Dr. Risbo diet. Directivity and various large-signal parameters TBD.

https://purifi-audio.com/ptt6-5m04-nfa-01/

 

[McFly]

Nice sensitivity! However IMO while not a true midrange in the traditional sense, it looks like the breakup is starting after 3khz and I wouldn't cross it any higher than 2-2.5khz, where you'd still need a waveguide of some sort if directivity matching with your HF driver was your goal. Distortion specs look extraordinary between 100hz and 2khz. ATC mid dome levels. Couple 8" (sub)woofers crossed 100-150hz to this driver with a waveguided tweeter could make on hell of a floorstander.

If they bring out a midrange 4" with similar performance, we could be looking at the new possible leader in the traditional "midrange" band (300hz to 3-4khz)

 

[tktran303]

Well there’s a lot of ways to skin a cat.

Some would say that wouldn’t use a midrange smaller than 5 inches.

A pair of 12–15” woofers goes well with a 6.5” midrange crossed to a waveguided compression driver…

 

[AnalogSteph]

I'm a bit surprised that such a major change in fs (from 33 to 52 Hz) hasn't resulted in a greater increase in sensitivity - the voice coil may have been put on a diet for the better highs extension seen? (Compared to a traditional high sensitivity wideband driver like a Visaton BG17, that one adds about another 3 dB to efficiency but needs fs of over 100 Hz to pull that off, with a response that is substantially more lumpy though still more extended on top. The 6.5M04 looks exceptionally flat from 200 Hz up to about 3 kHz.) I always thought fs should have a major effect on efficiency as it appears cubed. Looks like the factor that actually matters is (Bl/Mms)².

In any case this driver should be more BR-friendly in its parameters. It's still very much a midwoofer that can easily be crossed over at 150-ish Hz, so that's neat.

 

[briskly]

I'm a bit surprised that such a major change in fs (from 33 to 52 Hz) hasn't resulted in a greater increase in sensitivity

Stiffness has nothing to do with efficiency in the mass-controlled region well above Fs. In the passband expression, the stiffness terms in Qes^-1, Vas, and Fs^3 cancel out. It remains in the damping-controlled region and below.

 

[Digital_Thor]

anyone tried the dedicate midrange yet?

 

[Dennis Murphy]

anyone tried the dedicate midrange yet?

I used it in Jim Salk's new flagship speaker (along with the new Purifi 8" woofer and a Satori Be tweet. Not much to say other than it measures beautifully in terms of frequency response and distortion. It's kind of large for a midrange, though. I prefer something with wider dispersion, although this wasn't a major issue with a cross at 1900 Hz.

 

[Digital_Thor]

I used it in Jim Salk's new flagship speaker (along with the new Purifi 8" woofer and a Satori Be tweet. Not much to say other than it measures beautifully in terms of frequency response and distortion. It's kind of large for a midrange, though. I prefer something with wider dispersion, although this wasn't a major issue with a cross at 1900 Hz.

Thank you.
I cross a Satori MW13TX at 2000Hz with a 5" waveguided SB26ADC, which I find very smooth. And I also think that the Purifi is just a bit to large for optimum dispersion and mating with a waveguide. Maybe I will be fine, by simply printing a 6" waveguide instead and cross a bit lower
Though... the small Satori really makes the speaker disappear by being narrow in design - I believe. Or maybe that is the wider dispersion "talking"..?

 

[killitmore]

Any thought on purify woofer (6.5 inch or 8 inch) compare with jbl 4367 driver?

 

[mk1classic]

Any thought on purify woofer (6.5 inch or 8 inch) compare with jbl 4367 driver?

Comparing a 6.5" or 8" with the 15" driver of the JBL? Or the horn / CD combo?

 

[killitmore]

Comparing a 6.5" or 8" with the 15" driver of the JBL? Or the horn / CD combo?

I meant Comparing a 6.5" or 8" with the 15" driver of the JBL

 

[mk1classic]

I meant Comparing a 6.5" or 8" with the 15" driver of the JBL

Two different beasts - JBL has a lot more of all. You will need multiple Purifi 6.5 or 8" to even get close on capacity. But when you get enough small woofer capacity, then the JBL will loose out on finesse. But there's still something with the sound from speakers with large woofers.

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