Audible difference in high-end capacitors? - ABX samples

[CtheArgie]

Dammit! All the yuuuuuge amounts of $$$ I could have saved when I built my coffins, er, big speakers. Mundorf. Bloody hell!
Fortunately, there’s ASR now…

 

[pogo]

Which amplifier was used for the tests?
I am thinking of class AB crossover distortion and possible masking effects.

 

[fpitas]

Which amplifier was used for the tests?
I am thinking of class AB crossover distortion and possible masking effects.

Will you use class D for your tests?

 

[Geert]

I am thinking of class AB crossover distortion and possible masking effects.

Which Class AB amp's that you know of have audible crossover distortion?

 

[fpitas]

Which Class AB amp's that you know of have audible crossover distortion?

It's only inaudible because we use crummy capacitors

 

[Geert]

It's only inaudible because we use crummy capacitors

Without golden ears you wouldn't know anyway.

 

[MAB]

Which amplifier was used for the tests?
I am thinking of class AB crossover distortion and possible masking effects.

Maybe you need to start a thread on the 'possible' masking effects of crossover distortion, with your own measurements.

 

[pogo]

Which Class AB amp's that you know of have audible crossover distortion?

Traditional ones: Link

 

[lewdish]

As announced long ago the last part on the subject of audibility of capacitor upgrade in crossovers. The comparison ranges from a very cheap, decades-old film capacitor to an expensive high-end capacitor.

As promised, this time there are short audio samples of each capacitor (in a simple crossover) recorded with a microphone via tweeter (test setup see below).
View attachment 319098
The full mini series:
Capacitor upgrade in crossover - Is it audible?
Capacitor upgrade - part two
Capacitor upgrade - part three
Replace resistor by low-inductance resistor - Is it audible?
Different Binding Posts - is it audible?
Audible difference in high-end capacitors? - ABX samples

Lately there have been YouTube videos and discussions here in the forum for the thousandth time about "capacitor sound" (i.e. the audible difference of film capacitors of the same capacitance in loudspeaker XO, but of different price ranges and manufacturers).

In forums, on websites or in videos you can read or hear something like "Even if the capacitors measure identically, very clear differences can be heard in different price ranges and designs - in short, clearly audible difference, you can't measure".

To end these arguments once and for all (don't worry, I don't believe that myself), here is the ultimate test:
The capacitors are not only measured, but for each capacitor there are also two recorded audio samples, once a few seconds of pink noise and a short sound snippet of the well-known test music track "Fast Car".

Now everyone can easily perform an ABX test (e.g. with foobar) and decide for themselves how much differences are audible**.

1) About the high-end capacitor
The following statements can be found about the high-end capacitor (3.3µF Alumen-Z-Cap from Jantzen) used:


Source: http://www.jantzen-audio.com/alumen-z-cap/


Source: http://www.troelsgravesen.dk/Alumen_Z-Cap.htm


Source: http://www.humblehomemadehifi.com/Cap.html

So, according to these "expert statements" we can assume that the audible differences between the high-end capacitor and the other two capacitors will be dramatically.
Personally, I can hardly stand the tension anymore, how will the measurements and the recordings turn out? Just keep reading...

** The recordings were not made in a studio, so I can not exclude that the recordings are possibly distinguishable by background noise (street noise, children's cough, TV sound,...) or editing - if you notice something like that, please report right here in the thread, so that I can possibly exchange the files.


2) Test setup

The test setup is identical to the previous parts of the mini series (see above). To better protect the tweeter, this time an air coil was used to form a second order electrical high pass together with the capacitor.
View attachment 319101
To measure the next capacitor or to make the next sound recording, only one terminal has to be reconnected to the next capacitor.
This is to prevent the position of the measuring microphone and tweeter from changing in relation to each other.

Measurements itself:
10s of pink noise, 1s pause and then the measurement (for best possible consistency).
The SPL of the measurements were 72dB@1kHz@1m and 90dB@10kHz@1m, more details see the calibrated HD measurement:
View attachment 319141
This SPL should be above the usual listening volume. The tweeters with ring radiator have slightly higher HD2 (but this HD2 will be completely masked) and very low harmonic distortion of higher order. Only the tweeter with ring radiator showed very good consistency, so it was used.



The most important thing, of course, is that the capacitance of the capacitors are almost identical. I have about 30 of the standard 3.3µF film capacitors (about 1$) in stock, so it was possible to find an almost identical capacitance to the 3.3µF high-end Alumen-Z-Cap from Jantzen - about 45$, wasted (?) only for you dear reader.
There were also dozens of very old 1µF film capacitors (about 0.05$ each), of which three pieces together (plus a 0.27µF correction capacitor for 0.5$) make the cheapest and oldest 3.3µF capacitor in the test.

Test cap capacitance
Alumen-Z-Cap (45$): 3.289µF
Standard-Cap (1$): 3.288µF (deviation <0.05% to Alumen-Z-Cap)
Old-Cap (0.15$): 3.292µF (deviation <0.1% to Alumen-Z-Cap)
(measured with TH2821 LCR meter @1kHz)

The differences of the capacitors can be measured without any problems. Here the behavior of the capacitors at 1kHz and 10kHz the order is always
Alumen-Z-Cap, Standard-Cap and Old-Cap @1kHz:
View attachment 319115 View attachment 319116 View attachment 319117
Alumen-Z-Cap, Standard-Cap and Old-Cap @10kHz:
View attachment 319119 View attachment 319120 View attachment 319121
It is easy to see that the resistive part of the capacitors are quiet different and that the difference increases with higher frequencies.

This corresponds to what one would expect from a capacitor, since other unwanted (parasitic) properties exist in addition to capacitance. In the equivalent circuit for a capacitor this looks like this:
View attachment 319185
Source: https://www.elektronik-kompendium.de/sites/bau/0205141.htm

The most important unwanted properties are (the frequency dependent) Equivalent Series Inductivity ESL and Equivalent Series Resistance ESR. However, certain properties often only come into play at very high frequencies in the MHz range or above.

3) Measurement consistency
To get an impression how consistent the frequency response measurements of the tweeter and approximately how large the errors of the measurement are, a capacitor is measured twice with time between the measurements.
The first image shows the FR of the two measurements. The second image shows the FR normalized to one measurement with a very high resolution of only +-0.5dB:
View attachment 319129 View attachment 319130
In the frequency range 1-30kHz, the two measurements differ by a maximum of +-0.04dB. Put simply, this is probably roughly our measurement error.

Below 1000Hz the SPL of the test signals is so low that ambient noise affects the measurement significantly, therefore all measurement results of the tweeter with the different capacitors were limited to 1kHz to low frequencies:
View attachment 319147


4) Tweeter measurements
How do these capacitance and resistive differences affect the frequency response emitted by the tweeter? For this we measure the frequency response of the tweeter with the simple crossover for all three capacitors (see test setup above for details):
View attachment 319126
Those who know the other parts will not be surprised, since the capacitors were selected for the best possible capacitance equality, so you can hardly tell the difference in the FR.

To see differences, we normalize the frequency responses to the FR of the Alumen Z-Cap and look how big the deviations of the other two capacitors are to it (attention the scale is +- 0.5 dB):
View attachment 319131
Only the ancient film capacitor with the largest deviation in capacitance and capacitive impedance shows deviation larger than the measurement error (+-0.04dB).
The deviations of -0.1dB around 10kHz are extremely small and should hardly be audible.

To get a complete picture, let's examine the multi-tone distortion (these include HD and inter-modulation distortion) of the high-end capacitor with the standard capacitor:
View attachment 319138
As expected, the results are nearly identical.

So, the measurements are almost identical, now how drastically will the differences in the recordings be? See next post...

Just curious but do you have measurements for FR from different loudness levels as well 80,95,105db to see if theres any change in compression?

 

[fpitas]

Traditional ones: Link

The AHB2 is a nice amplifier, and in a general sense the feed-forward is a good idea. But we don't know what the Traditional amplifier they used was.

 

[MAB]

Traditional ones: Link

You can hear that?

 

[Doodski]

I've scoped thousands of class A/AB amps and zoomed in for a magnified view and found no visible crossover distortion unless I was changing the bias in a big way and even then I've seen many amps that don't even show crossover distortion when the bias is set very low.

 

[Worth Davis]

Bravo, excellent audio question to test and validate

 

[fpitas]

I've scoped thousands of class A/AB amps and zoomed in for a magnified view and found no visible crossover distortion unless I was changing the bias in a big way and even then I've seen many amps that don't even show crossover distortion when the bias is set very low.

Once Upon a Time they could be pretty bad. That was when I was a kid.

 

[Doodski]

Once Upon a Time they could be pretty bad. That was when I was a kid.

That's what I figured.

 

[beagleman]

+1

And measuring the FR alone is probably not going to show much, if anything. Almost every amp/dac is FR-linear nowadays and they still sound different (sometimes).

For example, the HD measurements above do show a clear difference. Audible or not it's hard to say, but at least it's visible and measurable. Can you also measure distortion @ctrl ?

And maybe some of the caps can add a sort of compression-like effect which is somehow measurable?!

I participated in a blind and sighted amp comparison. Way too many details to go into, but my final outcome, was I felt braindead, forcing myself to be able to tell if there was ANY difference in sound, instead of some huge sound signature change as some guys went in expecting to hear.

In the end, the outcome, including the guys expecting "Big Changes" , was pretty much non conclusive. No one could even tell the amps apart from each other, (For sure), let alone hearing some big huge change.

 

[D!sco]

I've always been for parts that just have accurate ratings and adequate thermal capacity, but the CSS video about making the Typhons included a cap test, which had me curious. They're very no-nonsense, so when the designer of their new flagship wanted hifi nonsense, they decided to use blind testing as their methodology for decision-making. Everyone liked the higher end caps. They still went with their standard Z-caps, but the Duelund caps won every time.

 

[fpitas]

I'm not sure the Typhon is a good example to mention:

CSS Audio's new flagship speaker,the Typhon.

It looks like CSS Audio teamed up with Jay's iyagi from YouTube to create a flagship speaker,although its not a kit it's a fully built speaker. I'm not sure what to make of this one. There's a lot of talk about the sonic differences between caps in his video on it...

www.audiosciencereview.com

 

[fpitas]

Typhon was a loser, anyways

 

[MAB]

I've always been for parts that just have accurate ratings and adequate thermal capacity, but the CSS video about making the Typhons included a cap test, which had me curious. They're very no-nonsense, so when the designer of their new flagship wanted hifi nonsense, they decided to use blind testing as their methodology for decision-making. Everyone liked the higher end caps. They still went with their standard Z-caps, but the Duelund caps won every time.

The only thing curious was the absence of a meaningful test.