Diaphragm

[ChitoBG]

What are the indications that diaphragms for compression drivers need to be changed. Specifically for 2440 and 2405. Kindly note that I'm only using an 8Watt 300B amp to drive my speakers.Thanks in Advance.

[script56]

The driver doesn't produce sound. That's when it needs replacing.

[mech986]

Either it sounds distorted at anything over low to moderate volume, HF extension is gone, or much reduced output.

[ChitoBG]

Thanks for the inputs. Relative to this, what are the advantages of beryllium diaphragm considering its cost.

TIA!

[teddyboy]

I asked myself the same. How do I spot a bad 2440 or 2441 diaphragm? I know they are getting bad over time and this is a slow process.
I have a self made JBL Paragon with 2 2440 drivers. One has a 2441 diaphragm while the other has the 2440. You never know what abuse they have been trough when you purchase them used on Ebay.
Right now my 2440 sounds much better than the 2441. I'm not yet shure if I should buy a new genuine 2440 diaphragm to replace the 2441, or buy 2 new Radian diaphragms.
It's not an easy and it's a costly decision. I have the feeling, the stereo-image on the Paragon can only be good, when the drivers are of exactly the same quality. I have to think it over for a couple of weeks;
maybe someone has similar experience?

[frank23]

As the 2440 and 2441 diaphragm are both constructed with the dome and the suspension from the same aluminium, the suspension part will eventually harden over time. Titanium does not suffer from this. I am not sure how to hear if the suspension of an aluminium dome has hardened but it would seem the resonance frequency would creep up and large excursions and high frequencies would suffer.

A year ago I replaced by 2420 diaphragms with Radians, and as they use mylar suspension, they do not age or harden. The sound became more open and less stressfull. I would suggest buying a pair of radian diaphragms and try them out. 2445 titanium does not seem to be a better solution as the titanium has less self dampening and sounds harsher than aluminium.

[NickH]

I saw cracks on the inside of my 2440 phrams. Other then that I had no warning besides my eyes. The cracks look like scratches on the inside of the diaphragms. But if you look at them under magnification you can tell a scratch from a crack.

Nick