Purifi Audio SPK5 Measurements | SoundStage/NRC

[Ilkless]

I listened to and measured the Purifi SPK4 eval kit: https://audiophilestyle.com/ca/revi...and-1et400a-amplifier-technology-review-r866/

From the SPK4 application note:

"SPK4 is intended as demonstration platform for the PTT6.5W04-01A transducer.The design is deliberately kept very simple: a small ported wooden box, traditionally shaped with no particular management of edge diffraction, and a passive cross over at ~2.5kHz. Although extremely simple, with
numerous possibilities for enhancement by the skilled speaker designer, the SPK4 design very successfully demonstrates the tremendous improvements in sound quality which is possible to achieve when using the longstroke ultra-low-distortion PTT6.5W04 woofer from PURIFI Transducer Technology."

Having listened to them quite a bit, I think they were pretty successful as a demonstration platform for the PTT6.5.
The lack of distortion and outstanding low frequency extension (32 Hz) from this 6.5” (sub)(mid)woofer sets a new standard to these ears. The clarity is stunning. PTT6.5 does not break up like a regular driver. Long past the point of where my Kef LS50's have given up, the PTT6.5 keeps going without a hint of distortion until it physically bottoms out. If you back it off a bit, crystal clear. I have not heard any other transducer like that.

There are a number of diyAudio Purifi builds: https://www.diyaudio.com/forums/multi-way/352063-exploring-purifi-woofer-speaker-builds.html

What I am surprised about is there does not seem to be a cardioid/DSP build like the 8c or Kii THREE... These PTT6.5 drivers would make a perfect candidate for a loudspeaker like that.

I can't see Kii not using the Purifi for their next gen. The same guy is involved with both, and the R&D story is similar: pushing the envelope based on existing theory applied in unintuitive ways.