teasing...
2435HPL, 2452H, 2450SL (and also 2452SL and 2451H by switching diaphragms)
PT-F95HF, 2332, H9800 clone
measurements will be done with Holm impulse and Arta using a calibrated mic
teasing...
2435HPL, 2452H, 2450SL (and also 2452SL and 2451H by switching diaphragms)
PT-F95HF, 2332, H9800 clone
measurements will be done with Holm impulse and Arta using a calibrated mic
Go Thomas go!
If we knew what the hell we were doing, we wouldn't call it research would we.
What, no Truextents?
Go Thomas;-)
What happened?
Cooky
Well... Given that it was a shootout...Originally Posted by cooky1257
Maybe they all got shot.......
I organized a lot of A/B duels, using digital EQ to get the exact same response (up to the HF at least, UHF being difficult with some of these drivers).
I did most of the listening tests on a PT waveguide with a 1.4khz crossover to a 2020H.
Some measurements can be found here: http://www.audioheritage.org/vbullet...s-measurements
The 2452H got killed first, followed by the 2452SL and the 2450H-1.5 (I swapped diaphragms in one unit of each pair).
The 2450 core is definitely superior to the 2452 one to my hears, less "constrained" (don't know if it is due to the bigger and more dampened backcap or to a better magnet structure, probably the second, as between a TD-4001 and TD-4002...)
The 2450SL was to my hears better than the 2435 (also less constrained), but the 2435 was much more efficient up to 8 or 9khz, and had more "snap".
The 2450H also had a little bit more snap than the 2450SL, but its resonances around 12khz and 17khz became really audible and annoying when doing rapid switches between drivers. I think it is something you can leave with, but ones you have put the finger on it it becomes a real pain (as always in audio, and as Giskard would say, ignorance is bliss
Back to the 2435, it is much more demanding regarding the horn: it does not work well on the 2332 (large dip above 10khz that move in frequency off axis...) and not that much on the PT either (same problem, but less pronounced and a little bit higher in frequency). It does quite well on the H9800, but the directivity collapses rapidly above 8 khz in the horizontal plan (the vertical directivity stays remarkably even, thanks to the diffraction slot).
The 2452 and 2450-1.5 cores seem to have a much better behaved phasing plug, and maintain a surprisingly large and smooth directivity in the UHF on all horns. Of course the SL is the only diaphragm that can take advantage of it.
So the two survivors of this shootout were the 2450SL and as a close second the 2435 when used with a tweeter or on a -preferably vertical- H9800. The 2450SL is less constrained, but the 2435 has more snap.
But then came a new kid in town: the truextent Be diaphragm!
It got rapidly transplanted into the 2450-1.5 core and... damn, it is so much better!!
It got it all: snap, unconstrainedness, efficiency, smoothness, good directivity in the UHF (even if it does not go as high and smooth as the SL, it is good enough), ...
So the winner is definitely the 2450Be
I am still not decided on the horn though: PT or H9800, is will probably depend on the final crossover frequency I settle with.
The short and well behaved PT has its advantages, but the H9800 has a larger directivity (much more than 90° in the midband) that makes it more attractive to the hear (at least when listening in mono, when doing the A/B...) and has a much better (lower in frequency) directivity control in the vertical plan. Using it vertically also has some advantages for the choice of a crossover frequency: the gain in directivity is quite similar to the one of a 12" cone, so you can somewhat choose any crossover frequency between 700 and 1400Hz and get a matched directivity at (and around) the crossover point!
Interesting comparison you've done. Thank you for posting your results.
So what will your system look like. A two way with an 15", passive or active crossover?
B.R,
Jakob
Very nice! Thank you for the details.
Thanks Thomas,
Interesting and very useful observations, I wonder if you'd tried the Truextent in the 2452?
I'll not be changing mine anytime soon-especially on the SAM1-I'm very happy, the Be magic is working well.
Cooky
Thanks guys. I am happy to contribute!
I will use them with a 12" driver (either JBL 2020H or TAD TM1201H, currently leaning to the later) with a digital crossover (Ev DX46, with FIR capabilities).
There is also a pair of 18" (just changed from JBL 2245H to TAD TL1801) for the 30Hz-300Hz range.
No I didn't try this combination (installing and playing with Be diaphragm is frightening, as you know), but given the comparisons I have done I think I have a good idea on how this combination would compare to the others.
Response-wise it would be almost identical to the 2450Be (with maybe 1dB more output in the lower part of its range, as observed with all other diaphragms, probably due to the smaller backcap that "load" the diaphragm more), and also very well behaved off axis. Sound-wise I guess it would be a little bit more constrained than the 2450Be, and probably quite close to the 2435 on the H9800.
The 2450 core sounds more "natural" to my hears than the 2452 (and 2435) one.
For example when listening to a drum roll, what sounds as simple changes in volume with the 2452 really sounds as dynamic variations in the playing with the 2450. Similarly, when listening to a singer with the 2450 it seems you can really estimate the variations of distance of the singer in front of the mic.
Hi Thomas, do I take it then that you are not planning to use the 9800 clones?
If so let me know.....
Those detail(extraordinary resolution-I know;-) observations are very apparent with the 2452/be too-Dusty Springfield, Etta James and Dionne Warwick have this habit.
Could the difference be due to the slight imperfections observed with the clone H9800 throats?-I'm just guessing here.
Shame we cant get hold of the TAD TH-4003 plansTH-4003 - | Pioneer Electronics USA
Frank
Yeah, but reproductions are available.
Widget
Ah, but I'd heard they were eye-wateringly pricey whereas a labour of love could take me till summer to finish and keep me out of the pubYeah, but reproductions are available.
Widget
Frank
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