Let's measure them with Clio first... I hope to have time in about a week. From my reading of the plane wave tube measurements your drivers may be up to spec... let's measure them.Originally Posted by Zilch
Widget
Let's measure them with Clio first... I hope to have time in about a week. From my reading of the plane wave tube measurements your drivers may be up to spec... let's measure them.
Widget
Fs shifts downward substantially (~150 Hz) when mounted on PT waveguides. See WT2 test data above comparing it with raw driver.
The problem is the PRICE, of course. At $1000 more per each list, they're a bit "dear."
~17 kHz on the 2435H. We'll see what's actually happening on the waveguides when we measure them.
Seems you and me're the only ones what's ever actually HEARD 'em.
Easily done. Maybe Steve will loan us one of his for testing? I'm not ready to start pokin' holes in mine yet.
Next week will be fine. We've got a BUNCH o' stuff to measure here, now.
[I've made a little list....]
(a) Well, a mighty large Thank-You is in order to Giskard for the recent publishing of this 243x compression driver info .
So ; THANK-YOU !!!
(b) And also, thanks to Zilch, who through his continued investments in & his personal studies of ( JBLs' newer "PRO" offerings' ), has had an incalculable effect towards enlightening the rest of us about these SOTA products .
Thanks All Round to both you Guys <> EarlK
Thank Giskard this 243x mystery problem is solved
Our friends at JBL had mercy!
I'm looking forwrd to the Clio results. I'll order my 2431 drivers in June. They are on stock
I, me, the Zilchster, being this day sound of mind and substantive in consciousness, do hereby and herewith certify and attest that biased and bypassed HF crossovers do sound better than merely bypassed ones of identical composition....
Yes! Ja! Si! Da! ....................
That's what I said, but what I say doesn't mean much. I'm glad you and others are trying the technology and posting your results. It's fun.I, me, the Zilchster, being this day sound of mind and substantive in consciousness, do hereby and herewith certify and attest that biased and bypassed HF crossovers do sound better than merely bypassed ones of identical composition....
http://audioheritage.org/vbulletin/showpost.php?p=32732
I, me, the Zilchster, being this day sound of mind and substantive in consciousness, do hereby and herewith certify and attest that biased and bypassed HF crossovers do sound better than merely bypassed ones of identical composition....( Okay, one convert at a time is better than none )
- FWIW;when using my surplus Polystyrene caps , a "DC-biased" Line Level HiPass Filter also sounds noticably more in focus/ "or clearer,sharper" than the non-biased variety .
- I've never tried a "bypassed" LLHPF and have yet to build a LLHPF using the approach of paralleled caps with flipped/mated electrodes ( for some ad hoc signature resonance-cancellation ) .
Biasing the caps in the high pass of the JBL DX-1 was implemented.
After closer examination of the 2435 data I’m quite sure that the PWT 2435H frequency response shown in the AES convention paper “High Frequency components for High Articulated Line Arrays” from Doug Button was a fake. It looks much more like a 2430H
I was always wondering about the limited HF response. Well this is clear now. Interesting that none of the experts realized it.
OK! The REAL 2435 looks soooo good but should be out of budget for most of us.
2431
What makes me worry with the 2431 is the resonance peak at 12,5 kHz. Could this be the reason for the harsh sound? What can we do here? Does resonance compensation in that high frequency ranges make sense? Next prob is the high Fs.
2430
The 2430 looks similar to a 2426 in PWT condition but will bring no real HF improvement. Impedance is also similar to the 2426 too
Not knowing what the conditions were I have no comment.After closer examination of the 2435 data I’m quite sure that the PWT 2435H frequency response shown in the AES convention paper “High Frequency components for High Articulated Line Arrays” from Doug Button was a fake. It looks much more like a 2430H
Do your measurements on the horns you plan to use and make your determinations accordingly.
- As just pointed out, I'd likely be more interested in the 2430 ( in a quasi two-way ) because of its' lower resonance point ( heavier diaphragm ) and design parameters that seem to be closer to those of the 2426.2430
The 2430 looks similar to a 2426 in PWT condition but will bring no real HF improvement. Impedance is also similar to the 2426 too
( I'd accept the ability to better handle midrange frequencies below 1K in trade over having that last octave of über UHF reach. Widgets' going to tell us to use a tweeter past 8.5K, anyhow
- I'd be more interested in the 2431 ( in a quasi three-way with 8s' or 10s' below the horn driver ) because of its' higher resonance point ( lighter diaphragm ) and design parameters that are meant to achieve some form of UHF extension
- I suspect I might find the lightest weighted diaphragm of the 2435 unacceptably "underdamped" for HiFi use. ( That would be an expensive discovery to realize that I want an aquaplassed diaphragm )
- Great to see all this info , BTW .
Note that the 2431 is the same as the 435AL as used in the Consumer 4348.
[QUOTE=Giskard]Not knowing what the conditions were I have no comment./QUOTE]
You are right
And if it was a fake it was a clever one.
2431H "harsh" sound? To the best of my knowledge, only Mr. Widget has said that, and he heard them here in my garage, not mounted in a system, on a SR crossover, hardly "optimum" conditions.
The only other comment I have seen in this forum is that they are "smooth" in comparison to 2426H in a SR system (I forget which one).
For me, after extensive testing and comparisons documented here, I cut them into my L200's, and I can assure you all that was not because I found them "harsh." Neither did I do that impulsively; they sound damn good to me, is what, and I have invited forum members to come here with their "test" CD's and listen.
They now await "fine tuning" of the crossover based upon the forthcoming work of Guido and others. As you see above, I've built biased networks for them as Giskard and Guido suggested as a first refinement, and an improvement in VHF clarity is immediately apparent.
Let's wait for CLIO results on PT waveguides, as Giskard suggests, and proceed from there. I don't think we can conclude anything, good OR bad about them, until more of us have tried them.
Guido: The 13 kHz "resonance" peak is certainly not apparent on the impedance curves I ran this week using WT2 both on the raw driver and with it mounted on PT-F waveguides (above). It's "messy" up there, for sure, but no peak of any magnitude stands out. Perhaps they have refined the design since those early findings three years ago.
Just to confirm, here's a high-resolution sweep I just ran (70 data points) through the area of interest on the same driver on PT-F horn. WT2 does not find any impedance anomalies there:
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