ADS B7 Crossover Help

[pjrey]

Hi all,

I’m struggling with how to read a couple components on this crossover. The 4 ohm & 3.4 ohm resistors are clear. As is the 18uf electrolytic cap. But the B32524 film cap and the round yellow thing that reads XD-090 708B I’m not sure about. Thoughts?

 

[StimpyWan]

B32524 is in reference to the physical size and shape of the capacitor. It doesn't signify a value. The 8u2k100 number is the value. It might mean 8uF or 8.2uF, at 100V. I'm not 100% sure of the K meaning, but I think it refers to the tolerance of the cap? It's a Metallized Polyester Film cap, so you should be good as is.

The XD-090 708B part is a polyswitch. It is a protective circuit breaker for the tweeter. It kicks in if the tweeters are over driven? If your tweeters sound fine at normal levels, you should be good there too. Though, if needed, Parts Express sells new polyswitches.

 

[pjrey]

B32524 is in reference to the physical size and shape of the capacitor. It doesn't signify a value. The 8u2k100 number is the value. It might mean 8uF or 8.2uF, at 100V. I'm not 100% sure of the K meaning, but I think it refers to the tolerance of the cap? It's a Metallized Polyester Film cap, so you should be good as is.

The XD-090 708B part is a polyswitch. It is a protective circuit breaker for the tweeter. It kicks in if the tweeters are over driven? If your tweeters sound fine at normal levels, you should be good there too. Though, if needed, Parts Express sells new polyswitches.

Thanks so much! That's super helpful. The poly switch looked vaguely like a ceramic capacitor but that didn't seem to make sense.

Tweeter are sounding great so I guess I'll just test that resistors are on spec and only replace the electrolytic if those are good.

Thanks again.

 

[ra.ra]

....and only replace the electrolytic if those are good.

ADS crossovers are extremely well-engineered and constructed. Why are you thinking of replacing the caps if they are "good"? What do you expect to accomplish with this change?

 

[toxcrusadr]

Electrolytics do have a shorter life than films, but I have no idea how old these speakers are, so ra.ra has a point. If less than 20 yrs I probably wouldn't replace anything unless it actually read out of spec, or sounded bad. With caps you have to measure not only capacitance but ESR to really know, and not many people have an ESR meter anyway.

OTOH a good 18 uf electrolytic isn't that expensive at all.

 

[LemonproX]

View attachment 1543684 View attachment 1543685 View attachment 1543686 Hi all,

I’m struggling with how to read a couple components on this crossover. The 4 ohm & 3.4 ohm resistors are clear. As is the 18uf electrolytic cap. But the B32524 film cap and the round yellow thing that reads XD-090 708B I’m not sure about. Thoughts?

Any chance you ended up working on this? I’m considering replacing the cap but I’m having trouble accessing the back of the circuit board since that panel is attached

 

[pjrey]

Any chance you ended up working on this? I’m considering replacing the cap but I’m having trouble accessing the back of the circuit board since that panel is attached

Yes, I did. IIRC, you have to unsolder the main leads from the speaker binding posts so that you can lift the circuit board from the plastic panel. It’s also held on by some screws.

 

[LemonproX]

Yes, I did. IIRC, you have to unsolder the main leads from the speaker binding posts so that you can lift the circuit board from the plastic panel. It’s also held on by some screws.

How satisfied with the results were you?

I am on the fence about recapping since my B7's sound good if they are properly equalized, but I would prefer not to rely on EQ at some point. I'm not sure how these are "supposed" to sound, but after running some tests I can see that the midrange is too high and the highs really fall off. I was wondering if recapping would help get a smoother response.

Do you happen to remember where you purchased replacement caps / what the specs were? I've been having difficulty finding a match

Thanks