Restoring magnat all ribbon 12

[jerusalem]

I have a speaker that need's a bit restoration, magnat all ribbon 12.Few years ago in a unfortunate party at my home, there where an "accident" and after that it newer played like it should have.Yesterday i opened it up in a whim, and well... see for yourself

This is how it is overall:

Images not available

This is how the crossover should be:

Image not available

This is how it is right now.



Idea is to ask you to give me your tips & recommendations for this project, i have to order parts for crossover , wiring and speaker post.

Crossover parts for 1 speaker, meaning what i could read in there:

10 uf 100 v+- 10% x2
68 uf 63 v+- 10% x1
100 uf 100 v+- bipolar x1
5v 0.47 J x1
5v 2.2 J x1
5v 2.7 J x1
10v 2.2 J x1

What is that gray part upside down, downright in the picture? reads only 5.6 J 100

How can i find out what are those coils? Measure them somehow?


Any suggestions ???

[JonMarsh]

The coils are probably fine. Magnet wire is hard to kill.

The cap is a 5.6 uF 100V. It's probably OK. The blown part is a "non-polar" electrolytic.

The real issue is, what condition are the drivers in? Crossovers are usually MUCH more reliable than drivers, and will take more abuse. That almost looks like an amp went into DC output mode- which will kill drivers pretty thoroughly.

[Kevin P]

JonMarsh beat me to it. The gray part is a foil capacitor, 5.6 uF 100V.

That sucker looks like it had a TON of juice going through it. Or a ton of juice spilled on it.

If the circuit board is ok (it looks pretty toasted though), the electrolytics will likely all have to be replaced. The coils may be ok, but they look like they got hot enough to warp/melt the housings, so they could have shorted out. That 2.2 ohm 10W resistor looks like it got pretty hot too. :#

I'd be surprised if the drivers survived whatever cooked that crossover.

Is it possible to get a replacement crossover from the manufacturer?

5v 0.47 J x1
5v 2.2 J x1
5v 2.7 J x1
10v 2.2 J x1

Those are resistors:

5 Watt 0.47 Ohm x1
5 Watt 2.2 Ohm x1
5 Watt 2.7 Ohm J x1
10 Watt 2.2 Ohm x1

[jerusalem]

I can't tell if the drivers are completely unscathed, but it is miracle that after that accident it could still play almost like normal way.I were the only one who heared something wrong with the speakers compared before accident.
I think drivers should be ok, or at least they look completely unscathed.

I don't think i can order new crossovers from manufacturer, the model is discontinued and these speakers are gray imports from germany.

Original parts in crossover seem to be not so high quality, so i thought if i have to replace old parts anyway, why not uppgrade for better?

Does anyone have experience from capasitors? http://www.humblehomemadehifi.com/Cap.html at least Tony Gee thinks there are differences, while Troels do not think so. Well im going to go cheaply prised capasitors, ASC X386S MKP in oil 600VDC – 10% industrial caps just in case.

I don't know can i use those coils and listen with reassured mind, so if i replase them, air core ones would be right? Btw how can i measure those coils, is it only way to know what they actually are?

[JonMarsh]

I'd suggest a good grade of metalized polyproplene film caps. Here we use Solen, GE, Dayton, and others. Oil caps for speakers, well, never listened to paper and oil dielectric, so I won't say one way or another. Motor start caps for crossovers just doesn't seem the way to go. For higher grade, I use film and foil caps. Expensive, though.

[jerusalem]

This is a translation trought babelfish, original link is http://www.kellerabteil4.at/contenttopic.php?t=19 where they look inside this speaker.Quote under crossover picture:

"Behind the Tieftoener over the connecting terminal at the rear wall the frequency switch sits. The construction unit quality corresponds likewise from the Klipsch, but at least a MKT is used here in the branch of high clay/tone. However, expensive parts are it not - as with nearly all mass-manufactured products with the costs one saves also here. A large luftspule instead of the 4,7 mH ferrite core coil would not have harmed surely however (however more cost)."

It uses ferrite cores!??? I heard that ferrite cores are not a very good solution... But also this translation solves coil problem, the number over coils in crossover means their mh.

So the coils are:

1.25 mh, x1
1.56 mh, x1
4.78 mh, x2

Wich means i can now make new crossover

[jerusalem]

I'm not a very expert when it comes to crossover connections, so verify one problem for me, please.

This is crossover plate seen from under, on the right side there is a section of connections highlighted.As I have understood all the points in one section must be connected to each other in new crossover, right?



So I could use one wire stripped bare (that long black line in middle of numbers), and connect all the parts to it in series 1-8 like in the badly drawn picture?

Or should I buy copper plate and clone the sections like in the original???

[JonMarsh]

You could do it as you describe. Hard wiring may even be lower impedance and sound better than the PCB, depending on the foil weight. PCB foil for crossovers is OK if one uses 3 oz or better foil, but tha'ts rarely the case. Copper plate, OTOH, sounds way over the top.