Exploring Purifi Woofer Speaker Builds

kimmosto, wow those look great. Are those white beauties a commercial offering or advanced (very advanced) DIY?

Interesting as this thread's discussion is spending time on midranges and subwoofing the kimmosto posts these 2-ways + PRs that IMO perfectly illustrate where the capabilities of the Purifi 6.5 lead.

Clearly, this type of design uses the PTT6.5 exceedingly well. However, it wouldn't really meet my design goals, especially the goal of cleanly reproducing occasional, fairly loud, sub-40 Hz signals - mostly pipe organ - while keeping composure. I think it all depends on one's design goals (and budget).
 
Clearly, this type of design uses the PTT6.5 exceedingly well. However, it wouldn't really meet my design goals, especially the goal of cleanly reproducing occasional, fairly loud, sub-40 Hz signals - mostly pipe organ - while keeping composure. I think it all depends on one's design goals (and budget).
Have you considered TLs for the bottom end? Paul Kittinger (AKA pkitt AKA Paul K.) has a number of highly-regarded designs out there where an MLTL or tapered TL provides substantial reinforcement via rear wave where the enclosure volume might not be large enough to allow port resonance to stay above passband.
 
Thanks Jasdiy. When you say 'roll off naturally' are you meaning at the top? Or do you mean at the bottom after your equalisation is applied?

Also have you measured it to see that there is no hole in the 50-80hz area?

Sounds like a good implementation. It would be interesting to hear more about your project. What tweeter and crossover at the top and how it integrates with the Peerless sub.

WE have Scanspeak Illuminator D3004/6640-00 1" Tweeter Beryllium Dome and the ETon 3-400 mid, every thing is done in dsp
by role off I mean at the bottom.
Cheers
 
Thanks Jasdiy, I am not wanting g to implement another driver for midrange but looking at bringing the Purifi up to about 1800 -2000. I am going to try the KE 25 SC with waveguide to go down to that level with 4th order electronic crossover. I will then see how I feel about the sub 40hz region and decide if I need to supplement with subs or not. Maybe HT and Music can have options to only switch subs on for HT.
 
"This is a second review and detailed measurements of Purifi woofer reference design implementation by Celuaris called SPK5. The original sample had some enclosure leakage issues which have been resolved in this unit due to collaboration between our DIY expert, @Rick Sykora, and builder, @sgoldwin.

I am going to borrow the picture from the last review since nothing is changed in that regard:
Celuaris SPK5 Purifi Review (speaker) | Audio Science Review (ASR) Forum
 
I have a feeling amir has a monstrous listening room and no neighbours so can play at reference levels in his listening tests, hence bottoming out the drivers easily and no boundary gain from the bookshelf speaker. He has Salon 2’s ffs as his standard and those things need a great room. That SPK5 crossover is likely not taking into account full -6db baffle step loss in order to improve sensitivity slightly, maybe in the hopes boundary gain will compensate for the remainder in more common 20sqm rooms? Just spitballin’ anyway.

Slightly off topic - I have those AMTs (got em cheap too) and although they do measure “wiggly” it’s not something I noticed, in fact the AMT while not having stellar polars does seem to be the “easiest on the ear” to me of any HF driver I have, at any level. Great at “disappearing” I suppose. Ultra smooth. I’ve swapped them back into my current purifi 3 way and am enjoying them crossed at 4K, much more then I did in the earlier 2 way. It’s also nice to know there’s no Breakup mode.
 
I have a feeling amir has a monstrous listening room and no neighbours so can play at reference levels in his listening tests, hence bottoming out the drivers easily and no boundary gain from the bookshelf speaker. He has Salon 2’s ffs as his standard and those things need a great room..... Just spitballin’ anyway.
Here's a picture


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mainframe99,

IIRC xrk971 has done a tapered TL design? I requested another respected TL / MLTL designer to have a look at the PTT6.5, and he said that he didn't get great results trying to model a transmission line with the driver.

The more satisfactory designs look like the ones using the passive radiators? Both the HifiCompass and Selah Audio Purezza designs utilize passive radiators.