That waveguide was designed by Lars Risbo for Purifar's new 8" demo. It used Mundorf AMT tweeters and was optimized using COMSOL. I don't know if this will be a public design like the SPK5,8, but it hasn't been released yet.
I was the one who visited Purifi. I considered posting here, but they are already very busy. I didn't want them to get a bunch of mails because of my post, so I decided not to post it. Instead, you can ask me and I'll explain it to the best of my knowledge.
Thanks for replies! Now I have to learn ATH... Is this really running on CMD?
I'm just preparative DIY user and engineering student who want to learn about acoustics.. It's for my curiosity!
Oh, 3,5rd harmonic distortion peak due to hysteresis peak in on axis could be tame by DSP? I didn't know that. As I study, making high impedance by passive series notch filter in that curve is only solution.
Exactly.
Super YES
Can I ask what graph is this? Might be average crestfactor?
Thanks for new suggestion and simulations! I might not play over 86dbspl at most, 96dbspl for max target spl which use in measurements, +12db headroom is enough I think?(I don't know well)
As I saw in Hificompass review, he said breakup made by hysteresis in voicecoil which is 15khz in M74b only could be tamed by passive notch filter. Is he wrong?
My most important part of this design is low distortion and nice design. I thought using 8" instead of 6" will give lower IMD and extend internal volume for side woofer. Thanks for advices, I have to rethink about using 8".
Also I saw SB26, designed nice, but I can't find klippel measurements...
I don't want to use separate subwoofer. Also I'm using passive crossover in T/M because tame to big breakup in middome and in low passive crossover, it cost a lot. Also I prefer sealed enclosure no port, no PR.