the real problem of a 4 inch or 3inch compression driver is not the breal up or the response is not the driver it's the Horn , to go to 400 500 HZ you need a horn with a maximum of 250 / 300HZ cut off this will be a big horn and will not be good with the HF dispersion . even if Tad with the 4003 has made one of the best compression driver they still sell ET703 tweeter to come with for a reason ..
I think I'm good if I can get to 600hz and even 700hz to be honest.
I was looking at tad td-4001. Is there a noticeable difference with getting them with original diaphragms vs the radian diaphragms?
I was looking at tad td-4001. Is there a noticeable difference with getting them with original diaphragms vs the radian diaphragms?
I'm using active crossover so will trial and error and do some listening tests. I can also add some eq, phase and time alignment with woofer.
I am considering 18sound XT1464 horn or something like tad TH4001
I am considering 18sound XT1464 horn or something like tad TH4001
Only to show it qualitatively, the ND4015@TH4001 with custom adapter. You may see where it becomes worse towards LF:
Driver response should be the same, but the 4001 has a 49.4mm (~2") exit, the 4003 39mm (~1.5") exit.
2" throat horns generally require more sonic compromises to achieve uniform dispersion above ~10kHz than 1.5" throat horns.
Thanks for this reason I will try and stick to 1.5 or 1.4 throat.
Sorry I'm not versed in these graphs enough to recognise them without a key. Can you help, where do you feel distortion levels are unacceptable?
So I'm thinking
ND1480BE
Purifi ptt10 x 2
XT1464 horn, moving to seos 24 when I move to a dedicated room.
I will crossover at 800hz with the XT1464 then when I move to seos-24 I can drop it to 600hz.
I was a bit worried about beaming with the ptt10 at 1khz crossover but looks like the ND1480BE if fine at 600hz crossover looking at Joseph's review.
Do anyone see a problem crossing over at 600hz? Where I should consider the radian 951be instead?
ND1480BE
Purifi ptt10 x 2
XT1464 horn, moving to seos 24 when I move to a dedicated room.
I will crossover at 800hz with the XT1464 then when I move to seos-24 I can drop it to 600hz.
I was a bit worried about beaming with the ptt10 at 1khz crossover but looks like the ND1480BE if fine at 600hz crossover looking at Joseph's review.
Do anyone see a problem crossing over at 600hz? Where I should consider the radian 951be instead?
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You may recognize the steep increase of distortions below 400Hz? imo the driver should be almost out of the game below this attached to TH4001 so your x-over design should account for this.
Yes thanks. so you are mainly looking at h2? Prior to 400hz it was also rising, at what point exactly is it unacceptable?
Trial and error is rarely conducive to optimal results.
Radian's own 745NEOBePB also features a 3" Be diaphragm.
Yes but what is better and why?
Polymer surround or complete beryllium?
Joseph Crowe review and tested the polymer surround beryllium diaphragm ND1480BE and it seem to perform really well.
From these which use polymer surround diaphragm? Tad, radian 951be, 18sound 4015be?
Polymer surround or complete beryllium?
Joseph Crowe review and tested the polymer surround beryllium diaphragm ND1480BE and it seem to perform really well.
From these which use polymer surround diaphragm? Tad, radian 951be, 18sound 4015be?
Here's what I was able to piece together by reading on the topic.
Radian started as a replacement compression driver diaphragm company. They were successful selling to professionals and eventually developed their own drivers, and started reselling Truextant(tm) Beryllium diaphragms designed by and made by a company called Materion. These Be diaphragms have a polymer suspension and have been produced for more than 20 years. In 2021 Radian and Materion struck some sort of alliance and I suspect that Radian now does some of the manufacturing in house.
Although TAD, Focal and Yamaha also manufacture Beryllium drivers (using a different process), I am not aware of any other 3" sized beryllium diaphragm being made at this time other that the Materion one, which happens to use a polymer suspension.
Yes, 3" is a good size for home use and a crossover frequency in the vicinity of 700 Hz. This pushes HF breakup frequencies above 20kHz while leaving plently of power handling for domestic use. If you want a lower crossover frequency, then 4" diaphragms rule.
I remain a happy user of the Radian 745NEOBe I purchased in 2013. Got a pair of Yamaha JA6681B gathering dust somewhere as well as a pair of TAD TD4002 awaiting testing. Yet I feel no rush to try or change things.
The ND1480Be looks good on paper. This driver was not available when I plunged and purchased the then-new 745NEOBe. My guess is that the ND1480Be uses a Materion diaphragm identical (or closely related) to the Radian's. I expect the ND1480Be to sound good, but have not heard it personally. Both ND1480Be and 745NEOBe exhibit sufficient HF energy to get full range coverage without a tweeter - should you choose to try this.
Either the ND1480Be or 745NEOBe mated to your 1.4" horn of choice would be good choices IMO. Check prices in your area. In my experience, compression drivers benefit from some equalization which is horn-dependent. If you have some measurement equipment and time, then you will have fun and the good folks here will provide plenty of help. I certainly learned a lot from them!
Radian started as a replacement compression driver diaphragm company. They were successful selling to professionals and eventually developed their own drivers, and started reselling Truextant(tm) Beryllium diaphragms designed by and made by a company called Materion. These Be diaphragms have a polymer suspension and have been produced for more than 20 years. In 2021 Radian and Materion struck some sort of alliance and I suspect that Radian now does some of the manufacturing in house.
Although TAD, Focal and Yamaha also manufacture Beryllium drivers (using a different process), I am not aware of any other 3" sized beryllium diaphragm being made at this time other that the Materion one, which happens to use a polymer suspension.
Yes, 3" is a good size for home use and a crossover frequency in the vicinity of 700 Hz. This pushes HF breakup frequencies above 20kHz while leaving plently of power handling for domestic use. If you want a lower crossover frequency, then 4" diaphragms rule.
I remain a happy user of the Radian 745NEOBe I purchased in 2013. Got a pair of Yamaha JA6681B gathering dust somewhere as well as a pair of TAD TD4002 awaiting testing. Yet I feel no rush to try or change things.
The ND1480Be looks good on paper. This driver was not available when I plunged and purchased the then-new 745NEOBe. My guess is that the ND1480Be uses a Materion diaphragm identical (or closely related) to the Radian's. I expect the ND1480Be to sound good, but have not heard it personally. Both ND1480Be and 745NEOBe exhibit sufficient HF energy to get full range coverage without a tweeter - should you choose to try this.
Either the ND1480Be or 745NEOBe mated to your 1.4" horn of choice would be good choices IMO. Check prices in your area. In my experience, compression drivers benefit from some equalization which is horn-dependent. If you have some measurement equipment and time, then you will have fun and the good folks here will provide plenty of help. I certainly learned a lot from them!
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The ND1480BE uses a polymer surround.
The ND3BE uses a beryllium surround.
JBL 2435/435 uses a diaphragm with they're "diamond" patteren, beryllium surround.
All the diaphragms are made of Materion Beryllium foil.
The ND4015be, ND1480be uses a Polymer surround.
All Radian drivers does so.
Radian 1245-8/16 ohm, replacement diaphragms for 9501/951, and JBL 245x, 244x, 375 etc.
Radiad 1225 replacement diaphragm for 1" JBL drivers.
Polymer surrounds on Be diaphragms, originally used in Japan, by Goto. So it's not really a recent thing either.
Go look at post #18.
Where it is clearly described how the half roll surround resonance of the DP-4001 diaphragm (TD-4001/4002), is the reason for the TAD's extended flat top octave.
No they are not, the 4003 uses a different improved 4" diaphragm, a different phase plug and different motor structure using ND magnets. And the response is not the same.
The 4001 and 4002 are using the same diaphragm and phaseplug design.
But the 4002 has a 39mm exit and different throat, with a 2" adapter included unless the 4002z is ordered.
It also has a higher strength ND motor, and if you study the cutout you will see they reduced the size of the VC gap, according to they're own research, from post #16 etc.
Attachments
Thanks. Indeed I had missed the ND3Be and JBLs.
And I am definitely planning to try the TD4002 without it’s stock adapter.
And I am definitely planning to try the TD4002 without it’s stock adapter.
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The TD-4003 spec sheet says "Although the basic design of the phase plug is unchanged, we have made subtle improvements to the shape and material."
From the pictures and information you provided, appears to be more than a subtle change 😉
Both the TD-4001 &4003 spec sheets list the same magnetic flux density of 20,000G, yet the SPL of the TD-4003 is rated 2 dB higher at 112dB.
Have you heard or seen comparisons of the newer 4003 design used on comparable horns to the older TAD designs?
Art