capacitor query...
- Thread starter Jovie
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monchito
Boomus Fidelis
norm it looks like the red is for the tweeter i think then there is a gray black line which i believe would be the positive then a white one with the other gray that looks like ground as they look like they are together 
but looking at the thick wires i believe they might be cone tweeters 
but looking at the thick wires i believe they might be cone tweeters 
Its a larger Sanyo C series box.This picture might give you a better idea.This is inside one of the two detachable speakers.I'm not sure if its from the same one I previously photographed though they're probably both the same inside.
I'm not getting any sound out of the tweeters.I've experienced this with another box.Replacing the caps in that one fixed the problem.Other boxes with poor highs have come back to life by replacing the caps also.With this one,its almost as though the bridge between the terminals is broken by a cap so bad its not letting anything through.
Anyway,I'm just trying to find out what type of cap it is,its rating,and where I could get one or a substitute of the same spec.Any ideas?
I'm not getting any sound out of the tweeters.I've experienced this with another box.Replacing the caps in that one fixed the problem.Other boxes with poor highs have come back to life by replacing the caps also.With this one,its almost as though the bridge between the terminals is broken by a cap so bad its not letting anything through.
Anyway,I'm just trying to find out what type of cap it is,its rating,and where I could get one or a substitute of the same spec.Any ideas?
OK. I just wanted to check and see whether that was a high pass capacitor or a low pass inductor. I see now that it's in series with the capacitor so it would seem that it should be a capacitor. Hopefully.
UNFORTUNATELY. 180 on the capacitor works out to 18pf or .018uf which is ridiculously small for a high pass capacitor and the signal passed wouldn't even be in the audio range -- my guess. Unless it's an inductor, in which case, it looks like an 18uH inductor and totally wrong application. Plus if it were an inductor, your tweeter might be blown.
My boombox? I would replace it with a 3.3uf or 4.7uf bipolor capacitor (or use film or polypropylene cap, for better reliability and sound).
UNFORTUNATELY. 180 on the capacitor works out to 18pf or .018uf which is ridiculously small for a high pass capacitor and the signal passed wouldn't even be in the audio range -- my guess. Unless it's an inductor, in which case, it looks like an 18uH inductor and totally wrong application. Plus if it were an inductor, your tweeter might be blown.
My boombox? I would replace it with a 3.3uf or 4.7uf bipolor capacitor (or use film or polypropylene cap, for better reliability and sound).
Thanks Super! Reading what I could on caps,I couldn't make sense of it either.Though I find it hard to believe someone would have made such a mistake,I suppose I'm better off going with what you suggest.This will save myself the additional research.With polypropylene or film types,are they also bipolar?Concerning the difference between 3.3 and 4.7,my experience is that the lower number cap seems to allow more mids to be handled by the tweeters.From my experience this produces a brighter sound which I like.However,the originals might have been closer to 4.7.Do you know typically which number was used in the Sanyos?
Jovie said:
Sanyos? 4.7. Never checked the C series so I'm not sure about them, but the one piecers were mostly 4.7's
Those caps might've been replaced by someone at some time who didn't know what they were doing.
Film or Polypropylene capacitors are found in higher end speakers because they are much more expensive and also larger than similar valued electrolytics. They aren't technically bi-polar. Rather, they are NON-polarized. Expect to pay much more for them if you want to use them. Otherwise, go with some high quality electrolytics and you should be OK. The sound of your typical boombox isn't such high fidelity that you might notice anyhow. The M90 does use film capacitors instead of your garden variety bipolar electrolytics. Also, if you go with film and/or polypropylene, go with the high voltage ones -- they sound better and their rating is actually derated when used in AC applications.
3.3uf will cross-over at a higher frequency than 4.7uf. That means the 3.3 will restrict more of the lower frequencies. I predict that the 4.7 will allow more midrange to reach the tweeter. If your tweeter can handle the mids -- fine. If they can not, then the mids could overwhelm the speaker causing it to affect high range reproduction as well. Could be experimentation time. Try 3.3, 4.7, 10uf. See what sounds best for you.
Use the largest you can. You should at least double the expected voltage at the output. At the very minimum. I have seen boomboxes use 50v capacitors at the speakers. If your boombox consumes 80 watts, it is a fairly heavy hitter. I don't expect the capacitors to blow up but they might last longer. Power consumption is not a reliable indicator of output voltage. Much has to do with efficiency of the amps, effiency of the power supply, input voltage, quiescient / bias current of the devices, whether indicator lamps are lit, the number of features, thus circuits, etc.
When it comes to Film and polypropylene capacitors, I have heard audiophiles wanting to use 100 to 250 volt caps. The reason has to do with the physical size of the cap (higher voltage units are larger) and the resonance of the audio signal as it goes through the cap although I suspect the actual reason is not known. Probably through trial/error was it discovered and the consensus is to use high voltage caps for the crossovers.
You may be overthinking this Jovie. It's a boombox. Toss a couple of 4.7uf or 10uf bipolars in it and if the tweets aren't blown, I think you'll be very happy with the result.
When it comes to Film and polypropylene capacitors, I have heard audiophiles wanting to use 100 to 250 volt caps. The reason has to do with the physical size of the cap (higher voltage units are larger) and the resonance of the audio signal as it goes through the cap although I suspect the actual reason is not known. Probably through trial/error was it discovered and the consensus is to use high voltage caps for the crossovers.
You may be overthinking this Jovie. It's a boombox. Toss a couple of 4.7uf or 10uf bipolars in it and if the tweets aren't blown, I think you'll be very happy with the result.
Superduper-The shop has my Sanyo so I tried replacing the caps in my Prosonic 9962. Stock this box has 10uf 50v.I tried ones of the same value and got identical results.This tells me that the originals are still good.Wanting to experiment I got a pair of 6.8uf 50v caps and soldered them in. The difference is graphic and stunning! Now I love this box as it has gobs of mids/highs. Strangely,the shop also told me to go with a higher value as you did. Whatever the math,I can tell you that lower value caps send more mids to the tweeters. In the case of my 9962,a lot more!
Jovie. The formula for computing the crossover frequency is math so it applies whether it appears to or not. Even though you are experiencing something which may seem to contradict that formula, don't get blinded by that experience and think that there is a flaw there. Numbers never lie. Larger capacitance values will allow lower freqencies (hz) to pass into that circuit. Midrange is a much lower frequency than tweeter range.
Keep in mind that there are many factors involved here. Higher uf ratings always drops the crossover frequency which means that lower frequency (mids) gets transferred to the tweeter. The issue is that you don't have true midrange drivers -- you have tweeters. When the tweeters are asked to handle frequencies outside of the range of their design, it affects their ability to accurately reproduce the sound that it is designed to. Focus the signal to the individual driver and they will perform to their potential.
Also, capacitors aren't all created equal. A perfect capacitor has no resistance. However, capacitors are not perfect and has what is called built in ESR, equivalent series resistance. This could be several ohms. While that may not sound like much, a tweeter that is 4 ohms with another 6 ohms of ESR turns this into what looks like a 10 ohm resistance load to the amp. Low ESR caps are available but are rarer and usually more expensive. Also, caps, especially eletrolytic caps have a wide value tolerance. It could vary as much as 50% or more.
Then there is the speaker drivers impedance, which affects the crossover point. A 6.8 or a 10uf capacitor will affect the crossover point differently in a speaker system depending upon the speaker impedance.
In any case, it is often desirable to experiment with different values and cap type/quality and audition the results.
Keep in mind that there are many factors involved here. Higher uf ratings always drops the crossover frequency which means that lower frequency (mids) gets transferred to the tweeter. The issue is that you don't have true midrange drivers -- you have tweeters. When the tweeters are asked to handle frequencies outside of the range of their design, it affects their ability to accurately reproduce the sound that it is designed to. Focus the signal to the individual driver and they will perform to their potential.
Also, capacitors aren't all created equal. A perfect capacitor has no resistance. However, capacitors are not perfect and has what is called built in ESR, equivalent series resistance. This could be several ohms. While that may not sound like much, a tweeter that is 4 ohms with another 6 ohms of ESR turns this into what looks like a 10 ohm resistance load to the amp. Low ESR caps are available but are rarer and usually more expensive. Also, caps, especially eletrolytic caps have a wide value tolerance. It could vary as much as 50% or more.
Then there is the speaker drivers impedance, which affects the crossover point. A 6.8 or a 10uf capacitor will affect the crossover point differently in a speaker system depending upon the speaker impedance.
In any case, it is often desirable to experiment with different values and cap type/quality and audition the results.
MasterBlaster84
Boomus Fidelis
Come on Norm stop pretending you don't know what your talking about. 
Your becoming the Boomboxery Professor very quickly.
Your becoming the Boomboxery Professor very quickly.
Once you bring out the Gilligan's Island crew, you can no longer pretend to be young, cool, and fashionable. You are a bonifide old dude... 
As for profession -- forget it. I pretend really good.
As for profession -- forget it. I pretend really good.
MasterBlaster84
Boomus Fidelis
Superduper said:Once you bring out the Gilligan's Island crew, you can no longer pretend to be young, cool, and fashionable. You are a bonifide old dude...
I was afraid that might age me, the younger crew here might not even recognize him. 
Well if I don't have more highs,I like what lower value caps effect. I've experienced this on 3 different boxes.They all sound louder for a given volume level.In each case the sound is brighter. I can hear the different instruments better and the sound is more up front (in yo face). My Prosonic 9962 originally had faint wimpy highs with its stock 10s.Yesterday I replaced them with 6.8s and it now belches them out sounding close to the harsh sound of my Techsonic. If you've ever heard a Techsonic,How could I very well imagine THAT?!!!
In fact,the shop guy agrees with you and replaced my Lasonic LPC-990s stock 4.7s with 10s.When I got the box back,it barely sounded like anything was coming out of the tweets. Today,I replaced these with 3.3s and the tweeters are loud and put out significantly more sound. So maybe my world is turned upside down. Superduper,I don't doubt your math.However if all these higher tones I'm hearing defy the math,I'm glad i'm not a mathematician.
If I may suggest and also ask of you,try actually replacing the 4.7s in your Lasonic with 3.3s and tell me just exactly what I'm hearing.
In fact,the shop guy agrees with you and replaced my Lasonic LPC-990s stock 4.7s with 10s.When I got the box back,it barely sounded like anything was coming out of the tweets. Today,I replaced these with 3.3s and the tweeters are loud and put out significantly more sound. So maybe my world is turned upside down. Superduper,I don't doubt your math.However if all these higher tones I'm hearing defy the math,I'm glad i'm not a mathematician.
If I may suggest and also ask of you,try actually replacing the 4.7s in your Lasonic with 3.3s and tell me just exactly what I'm hearing.
MasterBlaster84
Boomus Fidelis
Be careful Jovie, lowering the frequency cutoff point to your tweets will add stress to them and that is especially true if that runs outside of the frequencies the tweeter is designed to cover.
That means it would be easier to blow the tweeters.
That means it would be easier to blow the tweeters.
MasterBlaster84 said:Be careful Jovie, lowering the frequency cutoff point to your tweets will add stress to them and that is especially true if that runs outside of the frequencies the tweeter is designed to cover.
That means it would be easier to blow the tweeters.
Jovie said:
I don't have that Lasonic to try it on, but I can tell you that on the Bombeat 40 that is going back to Ira, the highs were noticeably brighter with 10's rather than 4.7's which I tried first. But he had dual tweets in parallel (one larger than the other) and can handle more mids than single tweet config.
ok so i replace the stock 10uf caps in the 9962 with 6.3ufs.The box now has harsh highs that it didnt have previously. Pain isn't subjective like our perception of sound. The box now just begins to hurt my ears on some sounds (such as "sssss"). We all know this phenomenon and its unmistakable.Distortion like this is caused by drivers handling frequencies they are not able to reproduce well.This would indicate drivers handling more frequencies not less. Can someone find another explanation for the harshness now very present from the box? Something just doesnt seem right here to me. (and yes I know I should put the 10s back into the box)...but I'm not
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