Burned crossover Ascent I - Schematics needed

[Markus]

Hi dear fellow Martin Logan owners!

I am new to this forum but has been a happy owner of a pair of Ascent I's since 2006. I drive them with a Krell KRC3/FPB200.

Is it anyone in this forum that have and would like to share the wiring scheme for the crossover filter to Ascent I or know the values of the three air coils, especially the large one in the middle just next to the trafo?
I have a burnt cross over filter and am in great need of the wiring scheme to learn the values of the components so I can replace them. Any tips on potential upgrades I can do while I'm at it are most welcome!

See below for full story:
One week ago I noticed that I lacked bottom in the sound. After closer examination I found out that while the panel was working fine, the bass on one of the speakers were dead.

I dismounted and examined the bass element which looked as good as new and I couldn't detect any loose cables nor any defects.
I contiued with the crossover filter on the back and here it looked really scary.
The plastic body of the large (tall) coil in the middle of the wooden board (backside of the bass cabinette) were melted, heavily deformed (looked like a crooked tower of Piza) and the transparent plastic were burned on the edges. The plastic insulation on the cable from the PCB to the panel had melted away on a small area that must have been in contact with the coil.
The plastic cover on the smaller cap (100V 270uF) were deformed as well, it looked as it had shrunk.

Anyone have any idea what can have caused this, is it simply to loud listening level? My listening room as a fairly large and spacious area so the gain can be pretty high though the sound pressure is comfortable.

Thanks and kind regards,
Markus

P.S. I have pix that I can uppload (once I have figured out how) if that would help the analysis. D.S.

 

[miljac]

Hi Markus,

there you go ....

good luck!

 

[Tosh]

Hej Markus,
It's possible for the coil to spread apart if the plastic spool got hot enough from a lot of power, but to actually lose the solder joint connection seems unlikely. Are there any guilty-looking teenagers around?
One thing that might have triggered the failure is the 270uF cap CX3 shorting (and in effect protecting the woofer), but even so.... I'd like to see pics of the damage before speculating more.

 

[miljac]

Hi Markus,

can you post some photos?

I would agree that some short circuit (the bipolar electrolytic most probably) caused the problem. I can imagine that electrolytic caps would need to be replaced at some point during the speaker's lifetime.

When you're at it -> have a look at Mundorf's web page.