Best Capacitor for Passive Cross over

[randal]

Hi all,

Just wondering, is there any different using expensive capacitor (clarity cap ex) compare with regular capacitor (dayton cap ex)
I am planning to make monitor with best capacitor.

[randal]

Second thought, for this passive cross over, is the resistor quality also matter??

[Face]

What speaker/drivers?

[Thooms]

You're opening a bit of a can of worms here - you'll get both answers :P

For my money, I'd use bipolar electros, certainly for the larger values. They're a lot cheaper and I doubt I'd be able to hear the difference, especially without having anything to compare them to - but if you're using super-duper drivers, there doesn't seem to be much point using the cheapest components you can find.

I don't think resistor quality matters - not in a speaker crossover. Noise is unlikely to be measurable out of the drivers, while it's unlikely you'll be reaching the self resonant frequency. In other applications low noise resistors with high self resonant frequencies might be very important, but this isn't one of them.

Obviously they should be rated for the task, but beyond that I'd say you're fine.

[gadut]

I got the same confussion about this highend components. My DIY Bookshelf with driver Silver Flute W14RC25S-8 & Vifa TC26SF already solen caps,generic resistor&inductor.

If i upgrade into Mcap+Mresist+Goertz inductor, will I get sound improvement ? Based on my calculation, highend crossover components will cost extra 40% of bookshelf price

[JonMarsh]

This is one of those situations where, as I'm sure Face may attest, it all depends...

It depends on the quality and source material of the rest of your system, and what your expectations are.

Think of it this way- any additional component or part in your system can slightly degrade the sonics compared to an ideal of perfection or the ideal piece of straight wire- but depending on your existing source components, amplification, etc., these differences in passive crossover components may make no audible difference or a striking difference, if everything else is really up to snuff.

There are differences between a $200 DAC and a $2,000 DAC- and from my own personal experience, I'd say $2K is about the floor for really decent digital- below that there are many compromises and colorations. So in a system with a good $200 DAC, will midrange quality cap changes (from a Dayton PP cap to a Clarity ESA cap be audible? Maybe not. In the same system with a good $2K DAC, will the difference between a Dayton PP and a Clarity MR cap be audible? And desirable? My experience is yes. Will it be worth the money? That's a very individual question.

Someday soon I'm going to finish my NHT XDS build (NOS cabinets and drivers from the local sale), and as they will probably be mainly used in a system at my girlfriend's with primarily vinyl as a source, with a fairly decent integrated amp (high end Cambridge Audio), I'll use Clarity MR's for the crossover (which is a NatalieP/Modula MT style design).


Just have the cabinets and stands- will have to do my own sub, probably a push-push with 180 degree mounting using Aurasound 10's or 12's.




Fundamentally, it all depends on the complete system context as to whether the value proposition is there or makes sense.

In my own main system, with a Metric Halo LIO-8 driving an 840D power amp directly into either the Modula Xtreme's or Ardents, the value proposition is compelling. (to me...)

[penngray]

There are differences between a $200 DAC and a $2,000 DAC- and from my own personal experience, I'd say $2K is about the floor for really decent digital- below that there are many compromises and colorations.

Interesting POV, are their measurements and controlled tests that show at what point DAC does not have compromises?

[AdelaaR]

Interesting POV, are their measurements and controlled tests that show at what point DAC does not have compromises?

Measurements are invalid as they do not take into account what is being heard by humans but only by electronics.

There have been many controlled tests about sound quality with specific equipment and source material. The general concensus of these double blind tests is that people are shocked to find how little difference there actually is between, for instance, a wellcoded MP3 and the CD from which it was encoded.
Discussing this here may make lots of people angry ... do your own due dilligence and find some double blind listening tests results ... you too will be amazed

[Thooms]

I don't buy the 'measurements are invalid' argument. If you can't measure a difference and there's no difference in a double blind test, there's no difference.

If you can't measure a difference and then you do a sighted test, then it's a waste of time

You may perceive there to be one, but in that case it's entirely psychological.

[JonMarsh]

Well, when equipment can be reliably identified in blind testing, then their is an audible difference. One of the difficulties is correlating what we hear with the types of measurements being done. Signal correlated jitter and non-correlated jitter seems to be good test markers for DAC's as regards imaging and perceptual response. Single tone THD tests, not so much. Kind of like the debates about power amps back in the 70's.

With regards to caps, I'd suggest reading the Clarity white paper on the MR caps- they're the result of a lot of independent third parts tests and evaluations at a large university, including a lot of blind testing.

In general, caps for lower frequency applications are less critical, and something like a Jantzen Cross cap or Dayton PPF seem to work fine. For the midrange and treble, this appears to be the area where capacitor resonances and colorations become an issue. If they're not an issue for you in your system, then don't sweat it. If you've spent time in a studio and you know what live sound is like and what clean mic feeds sound like, and you're not getting their yet at home, then this is one more thing to consider and investigate.

BTW, the issues with passive capacitors are one reason, IMO, why Linkwitz's Orion system sounds rather nice in some detailed ways, because of the lack of passive components in the speaker signal path. To match that quality with a passive crossover is not inexpensive, in my experience.

[Thooms]

It's certainly an interesting discussion. Stray inductance in particular seems like something that could potentially cause problems - it'd be interesting to see some test results of a capacitor where all turns are shorted and one where they aren't.

The mechanical resonance is a bit unclear...I'm not really sure what the vertical axis is telling us?

Still, I enjoyed reading that, thanks for the recommendation.

[maynardg]

I am continuously amused, and more recently irritated, by threads on forums where there are constant demands for DBX testing to demonstrate whether or not differences in caps are audible or not when DBX testing is only relevant to results on average. Rhat is not a particularly relevant question - certainly not interesting as variance in the system is swamped by individual differences. Not to mention such methodologies do nothing to illuminate the real issue - individual preferences and the factors underlying those preferences.

When I say irritated, it is not so much at the participants in such treads, but at the sad state of teaching regarding scientific method, psychological/psychophysical measurement, statistical methods, and philosophy of science.

Science methodology education is dominated by mass teaching of means testings as a route to knowledge - even in University undergrad study. I could care less about whether grey rabbits can outrun white rabbits - on average. The real issue is that the average rabbit is going to get run down by the fox, and only a few of either type will elude capture and consumption by that fox. The interesting part is how the fast ones got away. Now that is useful information - at least to the rabbits.

[impala454]

Try it in one speaker. Sounds better? Ok then buy the parts for the other one. Doesn't sound better? Well then you saved 50% on what you would have spent and now have some spare parts laying around

randal's ear is the most important piece of test equipment here.

[impala454]

Reminds me of the mythbusters show where they tested turning cheap vodka into top shelf via brita filters. Very interesting show.

[impala454]

Here it is btw if anyone is curious (pardon the extremely ironically bad quality sound)

http://www.youtube.com/watch?v=kO077nu2m5E