Purifi Audio by Bruno Putzeys and friends.

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6,5 midwoofer allows for 2way design and that's the whole point - to be able to design simple compact speaker with good quality. At the same time usability is quite low because of sensitivity - but again - they count to use them with their ampilifiers. On one hand I like the fact that they try to make things easy, on the other hand i don't like it that they leave us very little choice.
MTM with 2 PR and larger AMT from Mundorf seems like the way to go to max out the potential.
A two way configuration should still be possible with a 8", especially with a bigger AMT like an Heil AMT or an Airblade AMT which would enable lower crossovers. And a double 8" would probably kick *** on bass. Though I understand why Purifi started with a 6.5 incher... For smaller speakers it makes sense.

Fedde
 
A two way configuration should still be possible with a 8", especially with a bigger AMT like an Heil AMT or an Airblade AMT which would enable lower crossovers. And a double 8" would probably kick *** on bass. Though I understand why Purifi started with a 6.5 incher... For smaller speakers it makes sense.

Fedde


Over the years I've heard a number of speakers with different combinations of transducers and some solutions no matter what do not work. I don't know why but if difference in transducers in the crossover region is to big (heavy cone - light cone) then this never sound right no matter what you do. I'm generally fan of a 3 way solution where you've got small wideband mid (be it 4" or large dome), large woofer (light cone or you have to go 4way) and AMT tweeter (domes do not do it for me any longer against AMT in 2 top octaves).
 
Over the years I've heard a number of speakers with different combinations of transducers and some solutions no matter what do not work. I don't know why but if difference in transducers in the crossover region is to big (heavy cone - light cone) then this never sound right no matter what you do. I'm generally fan of a 3 way solution where you've got small wideband mid (be it 4" or large dome), large woofer (light cone or you have to go 4way) and AMT tweeter (domes do not do it for me any longer against AMT in 2 top octaves).
So do you think that the 6.5 incher is already too big to properly integrate with an AMT?

You will probably not like my current open baffle setup, where I combine a PAP 15" with Heil AMT. It actually works quite ok IMHO, though imaging wise I am not satisfied yet. The 15" speakers are far apart from the AMT (more than 0.5m) which also does not help. Next, I want to try to integrate my 8" Supravox Bicone as mid driver. But long term, I would like to try better options for mid (250-2500 Hz roughly). Could be Purifi, Satori or something else.

Fedde
 
Hi Mitch
Would it be possible to see an image of the F3 25 result.
I recall from you article that your room was very similar in size to mine, but that is one impressive result.

your indulgence is appreciated - Best James

Hi James, yes, this was in the context of testing Dirac Live 2.0 as I was evaluating the software using the Purifi SPK4 kit.

Attached is the preliminary sim response, which should match the REW measurement when I get to it. My "stereo" setup is offset of center in my room, so the left channel is more in the corner and the right channel is almost midway center along the long wall. Correspondingly, the left channel -3 dB point is about 22 Hz and the right channel is about 28 Hz and Dirac chose the median as 25 Hz which is the vertical divider you see in the chart.

I am still amazed at how much low frequency energy (i.e. sub range) these put out while the lower mids and midrange still sound crystal clear. I had to check on a few tunes that I had turned my F18 subs off. Songs like Awolnation, the Best has peak energy at 35 Hz and there is enough output to pressurize the room. Certainly not dual F18 levels to be sure, but ridiculous for a 6.5" woofer.
 

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Hi TimbreAudio, good question! i just checked - with the Purifi SPK4 measuring 95 dB SPL at the LP some 9ft away using the aforementioned track, the sub cones vibrate just a little. But nothing like when the subs are turned on at the same SPL. If I put my ear to the sub cone, I can't hear anything with them turned off. A bit hard to check though as those frequencies are omnidirectional. With the subs on, there is considerable cone movement and no question they are on. With the subs on, I measure a -3 dB point of 6 Hz in my room.

If there is any contribution from the sub cones with the power off, it would be at a very low level and could not approach the -3 dB point of 25 Hz at 83 dB SPL at the LP from the Purifi SPK4.

Edit. If I turn the subs on, but pass no signal to them, the sub cones don't vibrate at all in the above test scenario and I still hear the deep bass from the SPK4...
 
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Thanks for clarifying, i did remember reading somewhere that having a sub can add a few db to the mix.

Does everyone think these will mate best with proper tweeters?

I'm just thinking if a small array of BMR's or wideband drivers or even a compression driver horn loaded could provide a good top end, and allow driver spacing to remain small, and with high SPL possible, and flexible XO points.
 
So do you think that the 6.5 incher is already too big to properly integrate with an AMT?

You will probably not like my current open baffle setup, where I combine a PAP 15" with Heil AMT. It actually works quite ok IMHO, though imaging wise I am not satisfied yet. The 15" speakers are far apart from the AMT (more than 0.5m) which also does not help. Next, I want to try to integrate my 8" Supravox Bicone as mid driver. But long term, I would like to try better options for mid (250-2500 Hz roughly). Could be Purifi, Satori or something else.

Fedde

There is an evaluation build with a mundorf amt. Just google images and it'll pop up.
 
Dirac thoughts?

Hi James, yes, this was in the context of testing Dirac Live 2.0 as I was evaluating the software using the Purifi SPK4 kit.

Attached is the preliminary sim response, which should match the REW measurement when I get to it. My "stereo" setup is offset of center in my room, so the left channel is more in the corner and the right channel is almost midway center along the long wall. Correspondingly, the left channel -3 dB point is about 22 Hz and the right channel is about 28 Hz and Dirac chose the median as 25 Hz which is the vertical divider you see in the chart.

I am still amazed at how much low frequency energy (i.e. sub range) these put out while the lower mids and midrange still sound crystal clear. I had to check on a few tunes that I had turned my F18 subs off. Songs like Awolnation, the Best has peak energy at 35 Hz and there is enough output to pressurize the room. Certainly not dual F18 levels to be sure, but ridiculous for a 6.5" woofer.

Hi Mitch- very much appreciate your review of the SPK 5 I was wondering what you thought of Dirac? I know you’re comfortable with DSP so how did your results compare to Accourate or Audiolense? I ask because I’m toying with getting a Minidsp Studio because it would handle all convolutions with Dirac and my wife and kids wouldn’t have to know anything to play theIr stuff

Thanks!
Tim
 
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