Burning in hi-pass capacitors

[chrisn]

Re: Burning in hi-pass capacitors

You know...a very interesting and quantifiable test (might have been done?) would be to wire a typical 6 to 10" woofer into a typical speaker box. Then have a capacitor inside the box wired to an external capacitance logger. Play sweeps, sine waves, white noise etc at different volumes and see if the acoustic compression causes the capacitor value to shift a meaningful amount Could do this with different capacitors of different brand but match values, and same brand of different values. This is doable, with no bias, and can be done with very high accuracy and precision if someone has the right tools. If no one does it in time, I might have to one day when I bring some labview hardware home lol.

I did that and measured no change in cap value. Squeezing the cap also produced no change. I do not remember what brand/value the cap was, only that it was poly.

[Wolf]

Re: Burning in hi-pass capacitors

One very well may, just as one may detect differences in wire types. That's not something that objectivists object to. What we do object to is claims made that differences that may exist cause an improvement in performance only proportional to an increase in price, and for that matter that said differences actually do realize improvement, rather than being just different.

Then why do I prefer PulseX Erse's to Dayton caps? Erse's are less money...
Later,
Wolf

[billfitzmaurice]

Re: Burning in hi-pass capacitors

Then why do I prefer PulseX Erse's to Dayton caps? Erse's are less money...
Later,
Wolf

Because you're sensible? :D

[Wolf]

Re: Burning in hi-pass capacitors

Because you're sensible? :D

No- because the PulseX's sound better than the Daytons. It's not due to price.
Later,
Wolf

[johnnyrichards]

Re: Burning in hi-pass capacitors

I am so glad there are companies like Erse around. Now, if we could just convince PE to carry their capacitors in addition to their coils...

[bkeane1259]

Re: Burning in hi-pass capacitors

I scooped up a multi-meter with LCR measuring and here are the results on the following three pairs of caps:

CLARITY - 8.4
DAYTON - 8.3
SONICAP - 8.2

They match exactly as pairs, but only the Sonicaps measured as rated at 8.2uF. For the purposes of testing for sound quality before and after burn-in, it won't be a problem since they match as pairs.

However, would this difference between brands be a major factor when comparing against each other after burn-in? We're talking about effectively shifting the crossover point by maybe 20-30Hz correct?

[Herman Trivilino]

Re: Burning in hi-pass capacitors

However, would this difference between brands be a major factor when comparing against each other after burn-in? We're talking about effectively shifting the crossover point by maybe 20-30Hz correct?

Remember what got you started on this quest? You heard a huge improvement when you replaced a cap in the xover of a store-bought speaker. By how much did the capacitance change when you did that?

You should be able to measure the capacitance of those caps now with your new meter.

[Pete Schumacher]

Re: Burning in hi-pass capacitors

Remember what got you started on this quest? You heard a huge improvement when you replaced a cap in the xover of a store-bought speaker. By how much did the capacitance change when you did that?

You should be able to measure the capacitance of those caps now with your new meter.

.1uF caps are cheap, pick up a few and put them in parallel with the Sonicap to bring them up to the same value. Then you're SURE it's not the slight change in overall response you'll be hearing.

[bkeane1259]

Re: Burning in hi-pass capacitors

Remember what got you started on this quest? You heard a huge improvement when you replaced a cap in the xover of a store-bought speaker. By how much did the capacitance change when you did that?

You should be able to measure the capacitance of those caps now with your new meter.

8.3uF measured on the Jantzens (they match exactly as a pair) - these replaced OEM NPE's that were 8.0uF bypassed with a 0.22uF mylar. So the capacitance in this case was not a factor in my liking of the Jantzens over the stock hi-pass.:D

[Herman Trivilino]

Re: Burning in hi-pass capacitors

8.3uF measured on the Jantzens (they match exactly as a pair) - these replaced OEM NPE's that were 8.0uF bypassed with a 0.22uF mylar. So the capacitance in this case was not a factor in my liking of the Jantzens over the stock hi-pass.

The STATED value is 8.0 +/- 5%, which means it could be anywhere between 7.6 and 8.4. You need to measure it (if you still have it) with your new meter.

[Herman Trivilino]

Re: Burning in hi-pass capacitors

.1uF caps are cheap, pick up a few and put them in parallel with the Sonicap to bring them up to the same value.

But that cheap bypass cap will ruin the sound!

[Face]

Re: Burning in hi-pass capacitors

But that cheap bypass cap will change the sound!

Fixed.

[bkeane1259]

Re: Burning in hi-pass capacitors

The STATED value is 8.0 +/- 5%, which means it could be anywhere between 7.6 and 8.4. You need to measure it (if you still have it) with your new meter.

Sadly I do not have them - I chucked 'em a few months ago. I did measure the other NPE that is in the XO (in the woofer shunt position) - It's rated 9.1uF and measured 9.7uF. The tweeter NPE cap was the same crappy brand.

Anyway, I'm going to test the new tweeter caps as-is after burn-in. The original purpose of the test was to determine if the caps sounded different AFTER the burn-in process. Since they are all perfectly matched pairs, that test will be fine. I'll cook half and conduct the DBT next weekend.

I've pulled the OEM XO's and rewired the speakers without XO's. The new XO's will be external during tests.

[bkeane1259]

Re: Burning in hi-pass capacitors

But that cheap bypass cap will ruin the sound!

I would have to buy caps from the same manufacturers (Jantzen, Sonicap and Dayton) in order to make identical capacitance across all the hi-pass caps.

Do I really need to do this? I'm certainly NOT going to throw some P.O.S. caps in there just to raise the value of something like a $76/pair Jantzen.

The difference in crossover point is varied only by 10-30Hz anyway correct?

[bkeane1259]

Re: Burning in hi-pass capacitors

New crossover mock-up tested - looks correct - sounds correct.
Gonna secure everything on a board and make the tweeter cap easily swappable via binding terminals for the test.