2461 Replaced diaphragm with DR82425

Hello All - First post...:)

Years ago, I purchased 2 - 2461 CDs for a project. I was essentially building an SR4725 clone which consists of 2226H bass driver, 2426H CD and 2307A Horn (plus x-over). As you may know, these are PA units, but I figured I could also use them for the odd casual listening sessions with the guys at the cottage as well. (We've been JBL fans for 40 years...) Long story short, I had the bass driver and horn, but couldn't come up with the 2426s (or 2425s) at the time and eventually found the 2461s. They were "J" models (16 ohms), but someone told me all I had to do was change the diaphragm to the 2425H phragm (DR82425) and they would become 8 ohm drivers - OK.

At the time though, I didn't realize that the 2461 was actually an upper mid CD, with response limited to around 12K. And to be honest, we never heard any lack of top end out of these monitors and we've been using them for years. I've heard anecdotally, that changing the diaphragm in a CD like the 2461 to a 2425 diaphragm, the CD will produce the same frequency response as a 2425. ie. up to around 20K.

Can someone confirm or deny this for me? I currently want to use the 2461s in another project and am curious to know what freq response they actually have using the 2425 phragms. (Sorry about the long post, but wanted to explain the whole story...)

Thanks guys,

further extension, beyond 15KHz would likely require a different "motor" for the diaphragm ... ala 2420 with it's silver "impedance controlling ring"

2410/LE-175 level of performance might be possible (if phase plug is the same).

http://www.audioheritage.org/vbullet...ge-of-a-LE-175

The alnico le175/2410/2461 body ( magnetic structure ) loaded with a D8R2425 diaphragm in it, sounds good ( musical & nicely controlled ) .

It's a nice combo and certainly worthy of being included in any DIY project.

As Grumpy mentioned, response starts to roll off after about 13-14K ( but can be EQed flat out to @ 16K > using a simple 4430-inspired, LCR resonance circuit ).

Perhaps worth mentioning, JBL themselves re-visited this smaller driver combo themselves ( re-appearing in the form of the 175nd-x which uses a neodymium magnet instead of the older alnico ).

It sure seems to me to be a direct development of their older 175/2410.

JBL has seen fit to include it a few of their smaller HT offerings.

http://www.studio-22.com/jbl/images/...omponentes.jpg

https://thumbs.worthpoint.com/zoom/i...595c8a43c0.jpg

:)

Thanks for your help, guys. Seems you've answered my query. Looks like using the DR82425 can improve the response a little, but not up to 2425/2426 levels. As it turns out, since I first posted the question, a pair of 2624's have surfaced, so I guess I'll put the 2461's on the block as I'll have no use for them.

Thanks again!http://www.audioheritage.org/vbullet...cons/icon7.png