HF driver diagram failure, defect or too much power

[wg_ski]

The D4400ti appears to be a 2 inch exit driver. I thought the original driver was a 1 inch exit driver using either two or three bolts to mount rather than the usual 18 threads per inch threaded horn.
The D4400ti would take more abuse compared to the original Eminence driver. It would need to fit the horn though.
The original Eminence driver had a two inch voice coil and a 1 inch exit. This means the driver has a 4:1 compression ratio when we think of voice coil and exit area.

My current assumptions about this speaker is it contains two amplifiers in a bi-amp with a DSP filter between the 15 inch woofer and the horn. The horn is molded to fit the cabinet and replacing the horn is not possible. In the past the original driver may have been damaged by excessive power. The second driver was likely damaged by lower frequency signals rather than excessive power. The DSP has some well though out filtering for the drivers that ensures good sound and has a fairly fast rolloff for the HF driver.

You have a few options here
Buy a D280T1 and add some sort of protection filter. You may find there is a fault with the HF amp and may need to abandon the speaker or amps.

Buy the D4400ti and replace the horn if the existing horn is a 1 inch exit. Still add a protection filter in either case.

Compression ratio is way the eff more than that. The aperture size is the sum of the phase plug entry points, which is WAY less than the 1 or 2” diameter “exit”. It doesn’t have to HIT the phase plug to suffer excursion damage. When it hits, well anything will break. But high 8 to 20:1 compression ratios (where compression driver term cones from) can cause the diaphragm to fold just like an Eminence 4015LF being used in a 4:1 CR tapped horn and hit with two kW at 35 Hz. Won’t kill it instantly, but eventually that cone will crumple. Use either driver at higher frequency and nothing bad happens. It still takes excursion (repeatedly) to cause fatigue and failure. The design and construction of that D280 somehow just isn’t up to snuff for that usage.

The 4400Ti is huge. It may never fit the cabinet even if the waveguide can be swapped out. I have cabs with the old Selenium D3300 in them and they are only a little bit smaller. Damn things take up as much space as the woofers. And I cross them at 1200 Hz, because 800 sounds stressful. I’m sure that would shatter the diaphragms eventually. See a pattern here?

You want to bullet proof the cab with something that will fit, try the Eminence 314T. 1.4” exit. Use a 1.4/1 adapter. They are two hundred bucks, but a 1” that could be guaranteed to handle what you are throwing at it will cost as much or more. Put a PSD2002/2013 back in and eventually it will suffer the original thermal failure.

 

[conanski]

Blown drivers in the DSR series were not at all common though.. this is the first one I have ever heard of so it either suffered some abuse to blow the original driver or the amp module has a problem, or maybe the amp module was damaged when the first driver shorted.. a cascsade failure like this isn't unheard of. And because of that any replacement driver is doomed to an early death, as has been mentioned reinventing the wheel should not be necessary here, if the amp module can be tested and repaired the original driver will work just fine.