Hi needing suggestions for a capacitor replacement in my crossover. The cap pictured was what was originally in my speakers (Mission 734). I replaced this electrolytic cap with a polypropylene cap and found the sound improved in terms of clarity but became harsh/brash. The replacement cap was a custom designed one that id like to replace with a good brand. Can anyone recommend a cap that will sound softer like the original cap but still offer the improvements in other areas. Please name the brand and cap value that i could use as i dont understand the writing on the cap pictured. Thanks
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5.6uF
Any voltage above the 50v written on your cap will be fine.
I'm a fan of Jantzen caps. On a budget try their cross cap.
Brand loyalty and subjective sound is massive can of worms that is more than massive.
I believe in 'break in', so maybe give it a few weeks to see how it sounds then.
Any voltage above the 50v written on your cap will be fine.
I'm a fan of Jantzen caps. On a budget try their cross cap.
Brand loyalty and subjective sound is massive can of worms that is more than massive.
I believe in 'break in', so maybe give it a few weeks to see how it sounds then.
'Clarity' and 'harshness' suggest the tweeter is playing louder than before.
The original cap is an electrolytic capacitor. They have significant losses and their capacitance drifts over time (> 10 years). The capacitance can go either way, an increase of a factor of two is possible, but a decrease down to zero is possible as well if the electrolyte dries out. I would suggest to measure the capacitance and ESR of the original capacitor, so you know what has changed by replacing it.
Polypropylene caps have negligible losses. You can emulate the losses of the original capacitor by wiring a one ohm resistor in series with the replacement capacitor. The losses will slightly attenuate the tweeter. Experiment with the resistor value.
The original cap is an electrolytic capacitor. They have significant losses and their capacitance drifts over time (> 10 years). The capacitance can go either way, an increase of a factor of two is possible, but a decrease down to zero is possible as well if the electrolyte dries out. I would suggest to measure the capacitance and ESR of the original capacitor, so you know what has changed by replacing it.
Polypropylene caps have negligible losses. You can emulate the losses of the original capacitor by wiring a one ohm resistor in series with the replacement capacitor. The losses will slightly attenuate the tweeter. Experiment with the resistor value.
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My usual suggestion in this case is to replace an electrolytic cap with another electrolytic cap. The reason is that electrolytic caps have much higher ESR than film caps and a sensible manufacturer should have taken the ESR into account in the crossover. As TBTL said, to emulate the original crossover with a film cap you need to wire in series a resistor equivalent to the ESR of the original cap. Unfortunately to measure ESR you need special measurement devices, so most people can't properly measure the ESR. So I suggest a replacement with an electrolytic cap just to be sure.
With a new speaker, with electrolytic caps working at nominal value, you can easily replace them with film caps + appropriate resistor provided you can measure the FR curve before and after so to carefully choose the right resistor that match the ESR. However if the original cap has changed its value this method don't work as you don't have anymore a reference FR.
Again I agree with TBTL that clarity in this case is probably only the effect of a louder tweeter. The problem in maintaining the film cap without an ESR correction is that you get accustomed to this bad response.
Ralf
With a new speaker, with electrolytic caps working at nominal value, you can easily replace them with film caps + appropriate resistor provided you can measure the FR curve before and after so to carefully choose the right resistor that match the ESR. However if the original cap has changed its value this method don't work as you don't have anymore a reference FR.
Again I agree with TBTL that clarity in this case is probably only the effect of a louder tweeter. The problem in maintaining the film cap without an ESR correction is that you get accustomed to this bad response.
Ralf
100$ for a 5.6 uF cap? Costing more than the full speaker? And still with an ESR that doesn’t match the original one.
Ralf
Ralf
I don't get what's all the fuss with esr of the caps. There is ARTA limp and REW, and a whole lot more systems capable of measuring impedance of whatever you like, caps including and by knowing phase angle and magnitude, the real part of the complex number is esr. Its value varies with frequency so one has to make some decisions.
edit: when you exchange one old npe cap for another new polypropylene one, measure both esr and uF value to not lose out of sight what is really happening.
edit: when you exchange one old npe cap for another new polypropylene one, measure both esr and uF value to not lose out of sight what is really happening.
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Or you could discover the truth about capacitors.
Capacitor upgrade in crossover - Is it audible? | Audio Science Review (ASR) Forum
Dont miss parts 2 and 3.
Thanks everyone for your input.
So u are saying i need an extra resistor if the ESR of the replacement polypropylene cap is different to the electrolytic one???? I dont have instruments to measure ESR can u suggest a resistor value???
To be honest I didnt notice any extra volume from the tweeter - the sound improved tho - greater instrumental separation and definition but it was definitely harder on the ears even from the woofers!! I replaced the original TESLA electrolytic capacitor with a custom built polypropylene one that cost 50AUD but that was many years ago and im wanting to revert to the softer sound of the original TESLA cap which was claimed to be "LOW LOSS" variety. Does the low loss mean low ESR???
I have actually now purchased a Janzten polypropylene cap and im waiting for its arrival. Do i need to observe polarity when i insert it, I have attached an image of the original crossover with tesla cap - please ignore the hand written markings its just an image i sourced from a google search
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polarity with film caps is not important as they are non-polar.
And for the resistor, if you can't measure the ESR you will have to guess and try. Start with 1R and see if it's good, if the tweeter is too low, add a lower value, if it's to high, add a higher value. As long as we don't know the ESR of that cap we can't tell what it should be.
And for the resistor, if you can't measure the ESR you will have to guess and try. Start with 1R and see if it's good, if the tweeter is too low, add a lower value, if it's to high, add a higher value. As long as we don't know the ESR of that cap we can't tell what it should be.
What you describe is how one notices "extra volume from the tweeter" or a different crossover point caused by a different capacitance.
As woofer and tweeter reproduce different parts of the spectrum and as they are physically so close to each other a perception as "the speaker on the left wall is suddenly much loader than the speaker on the right wall" will not occur.