Okay,
Yes it looks cool.
See if you can get the 2426 Ti diaphragm dusted?
(I am investigating an alternative to acquaplas for future projects.)
The dusted 2426 in the 4344mk11 (diy) is a lot better than it has any right to be.
It's smoother and allows the 2405 to deliver crystal clear highs.
Assuming you want to try say your 4003 for grins what l would do is make an adaptor that pops on the existing flange that opens up to 1.5 inches rather than chopping the 2346 (thus making the throat length shorter)
Going the other way you will likely loose high frequency diffraction
I love your input Ian, and all others in fact. Thanks once again. I am unfamiliar with dusting-but will check it out. I am sure there must be alternatives to Aquaplas
The 2346 horns I expect to be getting will have a 2" throat, so that of course allows adaption to smaller throat cd's, notwithstanding seabackmans comments on adaptors and horn character changes
I could easily use 4003's or S2's (or RCA 9584) and might do so for a period of time, but I want to keep the 4003 for another horn based project. The 4003 has a "very nice" sound but being fluid, dynamic and highly tranparent, but is somewhat different to the big, bold, live JBL sound which I wish to retain in a JBL DD55000 clone/tribute/copy
The stock 2346 mates directly to the stock 1 inch 2426 driver.
"Dusted" is simply a light coating on the diaphragm of a water based damping compound.
If it can be arranged l think it's a good option.
The systems in the mid 90s offered this if you look through the JBL Library.
You have to understand that if JBL thought a large format compression driver was the way to go on the 1st statement system for a very long time they would have used one.
Looking at the large mouth area of this horn the loading on the driver would be sufficient @850 Hz as to not impede performance as is often the case with small format horns. Given this horn was used commercially before the Everest l doubt the use of the 2425/6 was a performance limitation.
Another point to be a peace with is that it a unlikely that a home diy effort is ever going to surpass the engineering prowess of JBL so just clone it .
Yes, I realise thisThe stock 2346 mates directly to the stock 1 inch 2426 driver.
So is there a DIY version of a simple water based dampimg compund?? There must be?"Dusted" is simply a light coating on the diaphragm of a water based damping compound.
This did occur to me too, although there is a school of thought Down Under that suspects JBL engineers went to the parts bin first finding drivers and horn that had been used before. Crossover components too are not special. The intense design certainly went into enginnering the bits to work exceptionally well as a whole. Clones made down here are somewhat varied in their designs and components, but sound better than the original. I guy owns an original and built a better sounding clone-in his words. The effort went into (predictably) the cabinets and passive crossovers. The horn is obviously quite specialYou have to understand that if JBL thought a large format compression driver was the way to go on the 1st statement system for a very long time they would have used one.
I tend to agree that the 2425/6 is not a problem, its just what could sound better??Looking at the large mouth area of this horn the loading on the driver would be sufficient @850 Hz as to not impede performance as is often the case with small format horns. Given this horn was used commercially before the Everest l doubt the use of the 2425/6 was a performance limitation.The 2425/6 are quite readily available and relatively cheaper than "newer" larger format alternatives...and their fancy diaphrams!
Alan
There is a 3M aerosol product that might work.
In the mid 80's those drivers were soa.
Pm to discuss further
For more on the M2 by some of the people who designed it, check out the Home Theater Geeks podcast, episode 216. https://twit.tv/shows/home-theater-geeks/episodes/216Originally Posted by aertex
They had quite a bit to say about the horn. The drivers are pretty innovative as well.
I control the treble.
I control the bass.
Thanks HTwillie
Would like to keep this thread going, what would be the real world results of running a 2" driver on a 1" horn such as the 2346?
The JBL page for the various throat adapters states the 1" to 2" adapter can be used backwards to go from 2" driver to 1" horn
with "some response loss above 8K"
The Australian folks have been doing some neat development work on dd55000 clones using a 2" driver on the 1" entry 2346 horn with results that are stated
to be excellent.
I am interested in this as a possible upgrade for my DD55000.
I would at least use a 1.5" throatless driver like the 2450SL or a 2451SL and lathe an adapter from 1.5" to 1". Going from the 1.5" phase plug in a slow transition to 2" then back to 1" has to be much worse.
Thinking about it a bit, (have to get a driver out to look) I wonder if you could just mate a 1.5" large format throatless driver to an adapter that just terminates the outer ring of the phase plug with a one inch bore at the driver?
At home listening level the increase in compression ratio shouldn't be mechanically destructive.
Barry.
If we knew what the hell we were doing, we wouldn't call it research would we.
the drivers used have adaptors to match the 2" throat of the clone horn and non 2425 drivers
Hi,
I'd love to see some pics of this mysterious 2346 clone horn ( I'm mostly interested in seeing the 2" entry area / & how that was executed ).
I don't doubt that a larger diaphragmed driver could be a nice upgrade on that large a horn ( especially since the 2405 is still there to cover off the UHF duties ).
There are currently 1 users browsing this thread. (0 members and 1 guests)
Posting Permissions
Reply With Quote