A lens will not eliminate any IM caused by the breakup as far as I understand.
Another thought. Much has been said and demonstrated about conductive vs non formers. Why a former? When I was in industry and we needed super low mass armatures, we used air core armatures. Basically just glue. A lot of force, far more than a speaker. We were driving a beryllium capstan wheel about 2 inches in diameter. It could be going at a edge speed of 200 IPS. Stop, stabilize, and be stable in the opposite direction in 6/10ths of an inch edge. Used 90V in a power H. Inertia was so high, a magnesium wheel would explode at that acceleration.
There are coatings that improve the radiation or absorption of a surface. Could these be used to improve VC cooling?
So many parameters. Again, glad I just use them and not design them.
Another thought. Much has been said and demonstrated about conductive vs non formers. Why a former? When I was in industry and we needed super low mass armatures, we used air core armatures. Basically just glue. A lot of force, far more than a speaker. We were driving a beryllium capstan wheel about 2 inches in diameter. It could be going at a edge speed of 200 IPS. Stop, stabilize, and be stable in the opposite direction in 6/10ths of an inch edge. Used 90V in a power H. Inertia was so high, a magnesium wheel would explode at that acceleration.
There are coatings that improve the radiation or absorption of a surface. Could these be used to improve VC cooling?
So many parameters. Again, glad I just use them and not design them.
Indeed they are. In many instances I can't stand the things, and I'm far from alone in that. While a well-implemented example can improve the off-axis HF response, you'd be better off with a better designed tweeter.
It must be a mightily impressive 'rod' if it only affects a specific narrow frequency and has zero impact on anything else. 5KHz is sufficiently high that some diffraction effects, ruining all the effort that went into making the driver pistonic up to that point, are almost guaranteed. When you put that effort into optimising a particular aspect of performance, compromising it doesn't seem a good idea. And equally pertinently, as has been noted, it will do nothing to address the resonant-amplified HD which is what we are talking about here, and the main point of notching out a high Q breakup mode.
No, a bottomless / high Q notch is by definition very narrow band / precise, and here we are dealing with a driver that has the primary (I assume bell) mode concentrated very effectively, so it should be relatively easy to put a notch in there to kill the HD lower down.
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I am really looking forward to the PTT6.5M04-NFA-01, the midrange driver with higher sensitivity, higher Fs, and reduced Xmax.
I guess you would still need that 51 ohms in series from Lars' crossover to appear somewhere.
yes, an active EQ will be just as effective at reducing distortion at the peak frequency. However, only the passive notch increasing the inpedance seems by the driver at the notch will reduce the subharmonic 3rd harmonic peak at fpeak/3. luckily this peak is very low to begin with for the PURIFI driver
a filter with a notch has a minimum order of two. You are absolutely right that one does not necessarily have to cut sharply as long as the peaks are properly handled. see the example I posted earlier.
Thanks a bunch! I was not clear in my question, it was the fpeak/3 I meant to address
I have a couple of Purifi driver questions:
Where can I find and order a pair of 8 inch woofers?
I see that the PTT6.5M08-NFA-01 is called a midrange on the data sheet.
Is there an issue using it as a mid-woofer?
Thanks DT
Where can I find and order a pair of 8 inch woofers?
I see that the PTT6.5M08-NFA-01 is called a midrange on the data sheet.
Is there an issue using it as a mid-woofer?
Thanks DT
Hello,
Thanks that driver was not listed with the others, but it was listed under the shop tab.
It sis a small small world after all. In 6 weeks ish they will be at my door.
Thanks DT
Here:
https://www.diyaudio.com/community/...ifi-woofer-speaker-builds.352063/post-7085572
Basically it works in the same box as the 4 ohm version.
Mine arrived this week…
https://www.diyaudio.com/community/...ifi-woofer-speaker-builds.352063/post-7085572
Basically it works in the same box as the 4 ohm version.
Mine arrived this week…
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Please see above post:
Click the link and download the datasheet for TSP...
Otherwise I will attach it here. Courtesy of Lars @ Purifi
The PTT8.0X-08-NAB (8Alu-8) looks ripe for waveguided 2 way. Or use in pairs. Or converted to a state of the art co-incident/co-axial driver.
Now, who’s brave enough to remove that dust cap… @5th element
Now, who’s brave enough to remove that dust cap… @5th element
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Use a hairdryer or heat gun and gently heat the dustcap until the glue softens. The only drivers that happen to use heat resistant (non thermoplast) glue are the alu coned Dayton Long stroke subwoofers. For others resistance was futile..But Lars can certainly tell us if the glue applied is thermoplast or not.
The 8" drivers are very tempting. My current speakers each have 2x Seas H1252-08 (8" aluminium cone), which are pretty good. They're a 2.5-way design, and a 18Sound NSD1095N takes over at 1kHz.
I'm happy with the sound, but I do wonder if the Purifi drivers would be a big improvement in sound. At approx £600 per driver (ie, £2400 to upgrade my speakers), I think it'll have to wait until I'm considerably more wealthy.
Chris
I'm happy with the sound, but I do wonder if the Purifi drivers would be a big improvement in sound. At approx £600 per driver (ie, £2400 to upgrade my speakers), I think it'll have to wait until I'm considerably more wealthy.
Chris
should be possible but we could also sell you one with the dustcap on the side 😎 . Have done that for a company that mounted an accelerometer for MFB.