Why Replace Speaker Capacitors

[blhagstrom]

One set of old HHScott I found seemed to have lousy bass.
Simple first order cross over, one cap.
Changed it and the speakers worked much better.

A nice set of old University Medallions. Simple bunch of caps crossover, may be just first order also.
Changed them but didn't see a lot of change in the speakers.

Old set of Bose 501(?), refoamed, all drivers worked. played with smaller receivers.
Nothing special.
Hooked up a 50wpc+ new toy.
World of difference, so much better.

I find the biggest change in sound is found by changing the speaker/amp combination.
I suspect that is more the issue you are hearing.

 

[toxcrusadr]

I like this thread.

 

[Collin1141]

I had a B&W where the tweeter began chirping around at 30-40 watts or more load, but sounded ok at low power, issue was the capacitor. even though the old cap measured near to it's original value 4.9uf against 4.7
replacing it fixed the issue.. this is where my higher power higher shift theory comes from.or maybe it was just the tweeter suspension causing chirping due to frequency altered at higher volume .. not about the voltage to the cap. maybe both

How does a cap, good or bad, make a tweeter "chirp"?
Describe what a "chirp" is and sounds like
What model B&Ws? What amp?
Please also tell me what you mean by "at 30-40 watts or more load"
Load what?
Thank you

 

[GlenGC]

How does a cap, good or bad, make a tweeter "chirp"?
Describe what a "chirp" is and sounds like
What model B&Ws? What amp?
Please also tell me what you mean by "at 30-40 watts or more load"
Load what?
Thank you

chirp like overload the suspension.. distort.. say the tweeter cut off frequency originally is 2500hz, but bad cap sends 2200 hz, at low volume it will sound fine,
lets say turning volume up cap shifts to 1900hz or less plus higher wattage puts more resonance to tweeter, and it tries to act like a midrange , cone resonates more than a tweeter is designed for, coil gets out of position due to excursion attempt, hence it generates erratic sounds.. sound breaks like a bug chirping , or sometimes tweeter makes clacking popping sounds..
these were b&w dm 604 s1. amp doesn't matter.. any will respond the same way.. 30-40 watts is an average approximate value based on how much load i put at it. (one third volume for a 100w rated amp, but this would vary greatly from amp to amp and source etc) . such problem might happen at less watts or more watts.. key here is observing changes on the tweeter from low volume to higher volume.. gradually increase the volume and observe ... don't push the speakers too far.. IMO most tweeters sound crap at high watts..

 

[GlenGC]

other thing i can suggest is to use a spectrum analyzer app available for most phones... these aren't usually very accurate but gives some idea of what is the speaker generating..
if bi-wire terminals exist just plug the hi frequency line, if there is a midrange in there you can unplug it.. if no HF LF terminals, then unplug anything but the tweeter,

then play white noise from the resource, observe the frequency graph on phone, watch the changes as you increase the volume.. normally same line should just increase in height with some alteration, if the graph shifts abnormally this could also indicate a cap issue.. as i mentioned there are too many aspects to consider, it's not possible to give one reliable method works for every case really...

 

[eiraved]

I also by-passed them with .01uF film and foils, à la JBL, which I always do

Sounds like if you bypassed the original caps you may have achieved a similar effect of improved performance, especially since the originals measured well within tolerance.

 

[Collin1141]

Sounds like if you bypassed the original caps you may have achieved a similar effect of improved performance, especially since the originals measured well within tolerance.

Possible
You can try that route too, people do it all the time, it certainly won't hurt
The story was intended as an illustrative example
I did what my friend asked for but his were not the only pair of networks I've gone through
Re-capped plenty of JBLs that came from the factory by-passed, results being equally positive to varying degree
Just sharing a story of my own experience not inviting a debate

 

[eiraved]

Just sharing a story of my own experience not inviting a debate

I apologize for the misunderstanding, as a debate was not my intention. The comment was made only to verify my conclusion, as well as satisfying my curiosity and increase my understanding. I've heard of this JBL style bypass before, probably on one of your posts I imagine. Now I shall attempt it one day because of your response. Thank you!

 

[Collin1141]

I apologize for the misunderstanding, as a debate was not my intention. The comment was made only to verify my conclusion, as well as satisfying my curiosity and increase my understanding. I've heard of this JBL style bypass before, probably on one of your posts I imagine. Now I shall attempt it one day because of your response. Thank you!

Sorry if I came across as curt, was not my intention
No need for you to apologize
I've just read so many of the "if it ain't broke" type posts and blogs over the years regarding the to do or not to do re-cap work that it gets me going sometimes
Especially when it comes to wet caps and electronics and it is bad advice, or VERY risky advice at best
I felt like that's where you were headed
My response to you was a reflex of sorts
Please accept my apology
Collin

 

[smoothtune]

I also by-passed them with .01uF film and foils, à la JBL, which I always do

Old thread but would Collin or someone try to explain to me what Collin1141 is doing when he bypasses capacitors, JBL style "?

 

[bluepine27]

I'm having a hard time trying to disseminate a difference in tweeter performance in a pair of KLH 24 (series I) speakers I have. I changed out the caps in both. one of them, the mid and highs sound way better, more detailed and present, forward. And the other speaker the mids and highs sound pulled a bit back, buried, and less detailed.

I also acquired one KLH 24 series II with the pair of series I speakers. The series II had a better cosmetic tweeter and woofer by far and tried putting them in the bad series I speaker and didn't hear any improvement really at all. I also thought recapping the series II would maybe allow it to be close enough to the good series I i have but that also didn't seem to work (i do need to retest this recap since I did put in a polarized cap when advised not to) Series I has a 4uf cap and the Series II ha had a weird combo cap of 8uf and 16uf in the same housing so wasn't feeling confident in the likelihood of these two sounding similar despite same cabinet, stuffing, drivers.

Anybody think I have a bad connection or something else going on in there? I'm under the assumption that the one tweeter is just in better performance than the other tweeter. I'm going to try swapping the tweeters and see if it's the crossover or the tweeter producing the better sound.