The JBL 476be diaphrams have a diamond pattern surround,,,The BrushWelman be phrams have a mylar type surround.
The JBL 476be diaphrams have a diamond pattern surround,,,The BrushWelman be phrams have a mylar type surround.
Hi Scott, for me, the improvement was across the board. Not so much in tonality, detail, or extention, but in clairty without harshness. With the TADs if we cranked it up, I could hear a harshness that was not there with the TrueX. The one thing I really like with both the TADs and the 2445-Be was they sounded SOOO much better than my 2441s with Radian Diaphragms. With those I MUST run a tweeter. Not so with either the TAD or 2445-Be.
I hope that is the case Widget. I have a pair of re-maged 2441s with Radian diaphragms and as soon as I can I will get the TrueX. Nothing wrong with the Radian....in it's place. I think with a Digital amp they would sound better but they are just too smooth for tube amps.
First of all, let me state that I will make a few comments about TADs, not so much as to defend them but to explain them and to share my experience.
When you compared the TAD TD-4001s to the 2445Bes were you using factory fresh TADs? Because TAD drivers and the replacement diaphragms are so expensive most people have only heard used TADs. I have measured (and listened to) a number of new and used TADs over the years, and just like our beloved JBLs, many of the used drivers are tired and no longer sound like a new driver. You can remedy this by buying a pair of new TAD 4001 diaphragms, but they cost $3K a pair!!!
Another point. The TAD driver is essentially a copy of the JBL 375/2440/2441 with a slightly larger alnico magnet. The Be diaphragm though is not the same as the Brush Wellman material. As has been mentioned before, it is made by a vapor deposition process which makes a more rigid diaphragm than the stamped foil that Brush Wellman uses. The two negatives that I can think of for using the TAD diaphragms are that when they do fail, they do so rather violently and the dust is toxic, and they tend to have a rather pronounced UHF break up mode. That said, I imagine the more rigid TAD diaphragm may offer a slightly more detailed sound.
All that aside, I have done most of my listening to TAD's TD-4003. It uses a unique 4" diaphragm that has a Be half roll suspension much like the old 2440 diaphragm and it operates through a more modern phase plug and 1.5" exit. The JBL 476Be uses somewhat similar geometry and a JBL spec Brush Wellman diaphragm. Both of these are a significant step up from the TAD TD-4001 or 2445Be. The JBL 476Be is really unavailable and the TAD TD-4003 is remarkably expensive. If I were considering a new DIY project, I'd seriously consider a pro JBL 4" diaphragm 1.5" exit driver with one of these Be diaphragms installed.
Widget
Would think the 2446+ phase plug might be of some benefit in the 2" exit format
if considering going two-way... or the newer OA 1.5" exit, but then the horn
is another variable for comparison purposes.
People who have hurt their ears with Ti diaphragms clammer for smooth... with Be, you get smooth, but what I find more compelling is the electrostat like details that you get while still maintaining the dynamics of horns.
Another thought about preferring the 2445Be over the TD-4001... perhaps the electronics weren't the greatest and hearing more detail was not desirable? I am speculating here since I have not heard the TrueXtent diaphragms, and I could except that an individual might like the 2445Be more than the TD-4001, but I doubt it is superior.
Widget
Good point, Widget. They were used drivers, but they were only used in home HiFi, probably not to the use levels seen in PA/SR. Were they 100%.. I dunno..
I can point blank tell you that the 2445Be was close to the level of the 4001s that we heard. I readily accept that one person may hear differently or choose one over another. In my mind, that's a given.
Here's an offer for you, if you have some big JBL bodies, I'll send you my pair of TrueXtent diaphragms for you to listen to... It will have to be before or after AKFest though (May 1-2) as they will be in my listening room at the fest.. Hell, I'd be tempted to fly out there with them in hand..
In any case, they sound good. Really good. Are JBLs with the TrueXtents the equal of TAD TD-4003, JBL 2452H-SL, 476Be, etc etc.. I don't have a clue. I have never heard the aforementioned. Two of the three are so pricey that few people have them or just plain unavailable. But I can say that the 2445Be sound as good as or better than any driver I have heard.
Perhaps, one of these days I will be lucky enough to own or hear something better.. I would wholeheartedly welcome the opportunity to hear something better. Then I'd know where to go next. Until that day, the 2445 with Truextent diaphragms are the best driver I believe I have heard..
In any case, compared to other options and their performance, for the cost they are great!
I am just wondering if in each case the horns were either electronically or passively equalised for a flat response (on axis)?
Most of these horns are not constant directivity and depending on the driver/horn combination you may have a flat/ non flat on axis or off axis response. That can add up to audible differences that make sound quality comparisons difficult to quantify.
They do look very nice.My favorite combo was Rick's Yuichi horns with Dan's JBL 2445 drivers
Yes, I hear you on this.
And for me, the fact that I DO use tweeters, when I used the TAD drivers, it was too much VHF output, even with rolling the driver off, actively.
I also found the drivers work better on some horns than others. This has been said in this thread too.
In my application, and as I stated I have tweeters, the JBL has better lower end sound to me, the TAD and Be phragm more in the upper ranges.
scottyj
OK, so, then it should be no problem for or with JBL!
After all, everything is based upon capitalism. Some want them so someone will sell them.
And, this is just another example of how we will get on, even if it is without stateside JBL.
So what I extrapolate is that IF I cannot replace what I use with JBL parts, I could give Truextent a try, and come out with stellar results, too.
Whether or not they are exactly to JBL spec as IF they were making and marketing them, they are getting really good review here.
Either way, we go on.
scottyj
Very generous. A few years ago I'd be sending you a PM, but I am not really doing the DIY bit these days. I won't say that I can't see myself ever doing it again, but at present I am more than happy with what I have and don't have time to explore every avenue just for the sake of exploration.
I am sure you are right though. I am sure they do sound very, very good.
Widget
Maybe as JBL USA corporate implodes...market savy, high quality cottage industry here in the US will have better opportunities because of the vaccuum....
I wonder how soon Brush Wellman will have 1" diaphragms available... I thought I heard or read it was coming.
I have always loved JBL vintage stuff. If this is a way to go on and actually improve, with technology, on the original, I am good with it. I love the sound I am getting now. It may not be the best available, but it's pretty freakin' good. The combo of the 2445Be and E145-8 is pretty sweet, in my mind.
Long live JBL.
I agree, I found things throughout the years that either defy conventional wisdom, or were NOT of the original manufacturer. And for whatever reason, worked to my satisfaction, or exceeded my expectations.
If you never experiment, you will never know. Also, just so you know, I am in no way trying to be confrontational, or saying the Truextents do not perform as your ears tell you they do. I am just asking questions, as I, too, am interested in these. I have six TAD 4002 drivers, and on my 2395 horns, in a 3 way full range configuration, don't care for them. Conversely, put them on a different horn, possibly the TAD AFAST horn, but NLA today, in a 2 way configuration, I thought they were great. But, a very different sound, to my ears, than the JBL family of compression drivers.
Years ago, Meyer Sound was having JBL make 2441,s for them, even after JBL stopped making them, and Meyer had their drivers with a Be diaphragm FROM JBL. So, the use of Truextent 'Be' diaphragms has my interest.
Thanks for sharing, keep it coming, YES this is how we KEEP ON!
scottyj
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