Well.. i see that you are kind of in the dark here.. I am testing the Purifi 4 inchers from the very beginning, and i can only say that i am absolutelly in love with them.
In some way their wow factor, and the surprise of their great sound and depth of bass are (believe it or not) much bigger than the PTT 6.5 range, at least for me.
Those are little gems, in my book absolutely incomparable to anyting else on the market.
Here a few early prototype builds for your inspiration 🙂
And I don't have usage for an 8". Wouldn't the world be boring if we all wanted the same thing 🙂
FYI! https://purifi-audio.com/ptt5-25x04-nfa-01/
@lrisbo I thought the 5,25 was supposed to be high sensitivity midrange? Did I dream this or is a M version coming too? And what are the USPs for the 5,25 or is it simply "only" another size option?
@lrisbo I thought the 5,25 was supposed to be high sensitivity midrange? Did I dream this or is a M version coming too? And what are the USPs for the 5,25 or is it simply "only" another size option?
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so the Vas of the 5.25" is twice that of the 4" and the 6.25" is twice again. Anyone would think you designed it that way...🙂
Interesting trade offs (for those of us with small rooms) between the 3.
Interesting trade offs (for those of us with small rooms) between the 3.
re Vas: scales with Sd^2/Kms so it kind of follows the frame size unless you make extreme changes to Kms
Quick modelling of the 5.5 looks like its another woofer that needs PR's , I could be wrong though, would make a killer compact 2 way.
Laws of physics dictate that low F3 from a small passive box reuslts in low sensitivity and high Mms (Hofmann's Iron law following from Thiele and Smalls analysis from the early 70'ies). A high Mms/Sd results in a long port. So getting low F3 from small passive boxes goes towards PR - no driver in the world can change that - you need a different gas than our current atmosphere. This is why it is claaed an 'Iron Law'. The alternative solution is to do active EQ on a small sealed box and get the wanted F3 andsuch compact long stroker with a very strong motor is very well suited for that (need a strong motor to compress the iar in a smalll box)
The 5.25 uses essentially the same motor as the 6.5 with a slightly lower BL. Is the same motor sufficient for an 8" cone?
could work for a light 8" but the coming 8" has a bigger 52mm coil motor for higher power handling and more strength for a sub woofer version
Yes I have miniDSP 2x4HD and 2x4 plain. Also have Hypex Amp modules. I need to explore nice compact bookshelf once that is done a good Soundbar for my TV and lastly a BoomBox. I am bored with my Marshall Wuburn and Bose S1Pro. I am zero in understanding software to design box. Just can't understand the world there so looking for this forum to help me
Hofmann's Iron Law was confirmed by Thiele and Small with exact equations over 50 years ago and seems far forgotten today. Box Volume grows,for constant sensitivity, inversely with F3 cubed!!! Getting one octave more costs 8x in volume. Volume scales with sensitivity squared. Once you have chosen a point in the graph then the moving mass is given for a given area Sd. So pick F3 and volume and everything else is pretty much set in stone (iron). Sealed box requires even bigger volume for the same F3 and sensitivity (but then roll off is only 12dB/octave).
Doing low F3 in a small box reuires high Mms and sensitivity will be low. Nothing can change that except using active EQ or using another athmospheric gas. It has nothing to do with the driver - it just needs to have a suitable Qt for the application whilst Mms and motor strength and Mms is fixated by the choice of volume and F3. All of this was actually a little bot of a surprise to me until recently so glad that I got it refreshed.
Doing low F3 in a small box reuires high Mms and sensitivity will be low. Nothing can change that except using active EQ or using another athmospheric gas. It has nothing to do with the driver - it just needs to have a suitable Qt for the application whilst Mms and motor strength and Mms is fixated by the choice of volume and F3. All of this was actually a little bot of a surprise to me until recently so glad that I got it refreshed.
Makes me wonder how Klipsch managed to claim 102dB/W/M at 34Hz for the Cornwall. Doesn't look much more than 150L for that box.