That's OK Zilch. Your secret is safe with me.
Widget
That's OK Zilch. Your secret is safe with me.
Widget
JBL did some earlier work attempting to resolve the aesthetics issue. In Asia, they were considered downright offensive, apparently.Originally Posted by Mr. Widget
http://audioheritage.org/vbulletin/s...light=4425+MK2
There are other flat-front Biradial horns, of course, but none with the wide 100° x 100° pattern of the 2344(A) used in 4430. I tried 2370A first in this project, and have used it successfully before in others, but its limited (40°) vertical dispersion is just too much of a compromise for this one.
That's (in part) why the new PT horns are of particular interest here. While the square one (12" x 12") won't fit into L200 any better than 2344(A) (it gets pushed right up under the top overhang, and cannot maintain the 4430's center to center spacing), the rectangular one looks like it would fit nicely while retaining the 4430's 100° x 100° distribution. The aesthetics are not an issue, really. Even the 2344A will fit behind the L200's grille, though probably not with 4430's additional 1" time-alignment compensation.
According to the technical note, the rectangular PT horn has lower distortion, but not quite as good pattern control. I don't think we care about the patten so much, as long as it approaches 4430 performance. It'd be a major plus if it could be successfully mated with L200 and L200B's 16-Ohm LE85, which we have already determined is a worthy contender in this upgrade.
The problem, of course, is the crossover. L200's LX16 seems a total loss, but, as we have shown, there may yet be hope for modified N200B. Whether the new horns will play down to 800 Hz is also a major issue. We may end up reworking N3134 for 16-Ohms as an option. It's largely contingent on how the PT "waveguides" measure out.
http://www.jblpro.com/ae/pdf/PT_WaveGuide.pdf
Note: The P-Audio horn isn't entirely out of the running. It sounds mighty nice with 2431H running it. Also, Mr. Widget hasn't yet had opportunity to do critical listening to the OASR horns. Me neither....
They store those horns in a safe with electronic time lock and every morning only the ones needed for AE production are given out
I couldn't understand this behavior when I tried to get them and I do not understand it now.
I really hope they will become available.
"Even the 2344A will fit behind the L200's grille, though probably not with 4430's additional 1" time-alignment compensation."
Look at your sloped L200 baffle. I think you will need substantially greater than 1" to get them back into alignment.
How about I build you a nice set of 4430 boxes in exchange for those L200 cabinets?
Widget
And what would YOU put in these exceptional, rare, and uniquely well-preserved L200 cabs, Mr. Widget?
[Heh, heh....]
I would put a 2235 in the big hole, fabricate a reversible mount to put an 077 or 076 in the small hole and put one of these on top of the cabinet.
Widget
[Wonders if 2427H with stock 2" throat adapter from TimG will play on them black TAD horns Mr. Widget's been wantin' to dispose of over there....]
IMO, I agree with Widget, L200īs are "vintage", my brother and I have 4 really mint, not eBay mint, and I added 4 external tweeters, 4 S120PII subs, and it really rocks on the boardroom at his office, otherwise known as the drunkodrome, We even have a big pottery piggy bank for contributions toward a big screen, We already have a medium duty icemaker; The point is, pls leave the oldies alone.
I can see what Zilch is about but I tend to agree with Alex.
Perhaps all this great R & D could be used for a nice current day JBL of your own design.
Ian
There's no denying we're learnin' stuff here, and havin' plenty good fun too!
I'm thinkin' something scaled down a bit, with LE14H-1 as the LF driver. Put some of them LE14A's out there (and in here, as well) back into service, maybe.
[Wonders how high LE14H-3 will play?]
That's another thread, tho, once we get there....
I've seriously considered pairing the LE14H-1's with my 4430 top ends but the efficiency hit pains me.
It looks really nice though... I might have to give it a go anyway...
You sound like some folks at JBL.
Yeah, I'll refrain from raining on the parade.
Amps'r cheap.
'Course there's ALWAYS the possibliity of doublin' up for quasi-4435.
Heh. We've got some surprises yet comin', I betcha....
2431H phase plug structure is different, no? Hard to photograph through the screen, there appears to be a 3/8" bore down the center. Illuminated with a flashlight, I THINK I can see straight through to the diaphragm. Nope, I'm NOT gonna disassemble for a more definitive look.
After a day's breakin, I found them playing even brighter than initially, and had to back down the HF boost about 4 dB on N3134. Further investigation with RTA revealed a symmetrical 6 dB peak at 8 kHz, shown below (crossover levels set at 0 db). With proper EQ, 2431H could potentially sweeten 4430 by pushing response to 20 kHz or beyond, so long as distortion doesn't take over. Rightmost column is 20 kHz, next is 16 kHz.
[Note: 2431H is a 1.5" driver and does not fit directly on 1" 2344A horn.]
2431H seemingly does not collapse at HF like the other drivers we've tried here, at least not at quite so low a frequency. More details after better and more comprehensive testing. Independent confirmation always appreciated (I've been fooled before).
Guido: If you don't have 2431H's yet, get them and mount on your P-Audio horns. Your rep may have been correct in suggesting that N3134/5 does not have the optimum EQ, but I think you'll be pleased in any case. (Don't forget to turn the horns 90°, tho....
This project's most pleasant surprise thus far, I didn't believe OASR horns would deserve a separate system designation until I gave them a good listen with EQ. At a paltry $76 a pair, these are credible performers.
At standard biamped 4430 crossover EQ, they run head to head with 2344A on 2427H drivers. They're more up front (less transparent) than the biradials, and lack their wide field constant directivity (see earlier tests by Mr. Widget here), but they sound mightily good. They remind me of Meyer Sound horns, actually.
Mount directly to threaded snoot of 2426 or 2427, or use throat adapter on three-bolt 1" drivers such as 2425 and LE85. I used P-Audio PC-35 ($10) for testing on LE85, available here:
http://www.loudspeakersplus.com/html...oadapters.html
Note: $49.99 (9-Volt battery NOT included) Radio Shack dB meter (C scale) says I'm running 80 dB typical SPL in listening tests here. That's pretty safe, allegedly, but it's certainly worth knowing. Zilchster recommended hearing preservation equipment; includes instructions for plotting and adjusting system frequency response the hard way using test tone disc (by others)....
I met someone up in the Sierra's who used a Behringer UltraCurve to create the desired EQ for a Tad 2001 on the 2344 I sold him.
He then tweaked the stock JBL 3134 values until the passive EQ matched the Ultra Curve EQ'd reponse.
That was the smartest bit of crossover design I saw in my travels across the USA. The guy was Kent English c /- Passlabs.
I may even buy an UltraCurve myself , they quite reasonably priced.
Ian
Ps I recall him saying the Tad need less upper lift
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