Why so much hype over caps?

[Heavy-D]

Let's start from the beginning. I noticed the highs from my speakers were not as crisp as they used to be, so I started asking questions and found out electrolytic caps were used and can degrade over time. It was suggested they be replaced with polypropylene caps. Started looking for replacement caps and have been blown away by all of the hype on caps. Crazy price ranges and reviews on caps? Years ago I don't remember it being this bad now that I've picked up the hobby again it takes more effort to avoid all of the BS that's out there.
What's your take on this?

[warnerwh]

My take is the same as yours. There are better quality caps out there but paying for the exotic caps is more than likely a waste of money. You'll find that even wire is commonly said to have these great attributes and how it can make such a large difference in the sound quality of your system. Again, either make your own like me or buy some inexpensive ones from some place like Parts Express.

So yes there's a ton of B.S. out there and it's about enough to make me vomit. I'm very glad I've found how DIY is far more interesting and so far I haven't seen any insane claims for speaker wire that costs 10,000 dollars or interconnects that cost 15,000 a pair.

Parts Express sells alot of caps too. It very well could be it would be a good idea to replace your caps. If you go to Parts Express who have excellent prices be sure to use the link at the top of the page to get there and make your purchase.

Good thing you came here on some forums your post may have started a war of large proportions. I've seen numerous arguements started with an innocent question like yours.

As soon as someone can identify a wire or cap in a double blind test consistently I'll listen. If you can't tell which is which when you don't know which one is in there does it matter? I would use a quality capacitor, just none of the high dollar ones.

My opinion is that if there is a difference it's so small it's not worth worrying about. You're far better off spending your money on a digital equalizer and room treatments and bass traps. You will hear a significant improvement with these.

[Heavy-D]

I plan on buying from parts express through this site which is why I posted here. Will do a simple rebuild replacing caps and resistors. If this works fine, if not will look at the tweeter diaphram. I have Klipsch KSF speakers which are 7 to 10 years old btw.

[Amphiprion]

The problem with caps is that there are HUGE differences between different types of caps (electrolytic, ceramic, polypropylene, etc) and relatively minor to negligible differences within a type of capacitor.

Audiophools, however, do not let that stop them from 'hearing' differences between one capacitor and another, when both are of the same type (such as polypropylene) and have good characteristics.

When you get into electronics design, you learn very quickly what matters about capacitors, the reasons the different types exist, and when and where to use them.

If the reason an expensive high-end capacitor is better isn't in a datasheet that comes with it, the likelihood of total bullshit is very high.

For you, you should replace the electrolytic with some sort of metallized film. Polypropylene is an excellent choise, but polyester/mylar would be OK too if you want to cheap out. And you should replace the electrolytic with a film type not just because of age, but because they are the much more appropriate type for the application. Madisound has some cheap caps (both polypro and mylar) and shipping is usually cheaper than PE, so if you are only ordering caps I would go with Madisound.

[Bri]

So I'm in the process of sourcing all my parts for the Modula MTM crossovers, and I can save about $60 per unit if I use cheaper caps in the highpass section. The original BOM suggests $30 PPT Theta AudioCap film and foil capacitors, #027-730, but these Solen metallized polypropylene are only $5-6: #027-576, #027-580. The more expensive part has worse tolerance (10% vs 5%). I've heard that film&foil have lower ESR and better current capacity, just wondering if I would be able to hear the difference?

[Heavy-D]

And you should replace the electrolytic with a film type not just because of age, but because they are the much more appropriate type for the application.

Learn something new everyday. Could you tell me why poly caps are more appropriate would really like to know.

[Amphiprion]

When you apply voltage to an electrolytic, current flows through the cap. Inside you have a metal conductor, and an electrolytic solution. As the current passes from one to the other, an oxide layer builds up on the metal conductor. This forms the capacitor dielectric, making the metal conductor one 'plate' of the capacitor and the electrolytic solution the other. Building up this oxide layer takes some voltage, and represents a nonlinearity. Also, it's better to only run the current in one direction through the cap (is why electrolytics are polar) because it don't work to well in reverse. You can get away with pure AC but you really should have a good DC bias on an electrolytic whenever you use one (non-polar types excepted, they are built differently - two anodes I think instead of one). Electro's are great wherever you have a DC bias on them, or in pure DC applications (power supply caps) because you get HUGE values for a given size. For example, I put a 470uF electrolytic on a board I assembled the other day that was smaller than a 1uF Solen polypropylene that I have in my xo parts box.

Anyway, metallized film caps don't have this problem. Very linear, nice capacitors with good frequency characteristics. Just large and expensive for a given value.

Anyone with more knowledge on the subject feel free to add or correct me on anything. I was a comp eng / dsp type but landed a great job as an embedded systems designer/prototyper and am learning a lot about this stuff recently.

[Rudy Jakubin]

When someone says they like a certain brand of cap they may have stumbled onto a matched pair. As an experiment I replaced my matched pair of Solen's with Electrolytic's and tightened up the tolerance with .01uF Film & Foil to get a value of 10.06. I couldn't hear a difference. Get a good meter and match them caps. I found that this 'does' make a difference.

[Amphiprion]

True that, tolerances can make anywhere from negligible to huge differences; in a Zobel 5 or 10% might not be a big deal. But for something like notching out a metal cone breakup, 5 to 10% can ruin a speaker. I'm more skeptical about inter-speaker matching of components (like a cap in one speaker is +2% over and its analogue in the other is -3%) but it certainly is possible for it to be audible, I just don't think it's importance is as high as one would assume.

Which brings up another thing - some types of caps will generally have better tolerances than others. Polypropylene you can get 1%, polyester isn't near as good (5-10% from most places). But given one of each that just happen to have the same value, performance should be very similar.

[cotdt]

actually, different caps do seem to sound different, but i'm not in a position to argue if someone else says that all caps sound the same.

[ThomasW]

The original BOM suggests $30 PPT Theta AudioCap film and foil capacitors, #027-730, but these Solen metallized polypropylene are only $5-6: #027-576, #027-580.

He's referring to one only cap in the tweeter circuit.

The more expensive part has worse tolerance (10% vs 5%). I've heard that film&foil have lower ESR and better current capacity, just wondering if I would be able to hear the difference?

If you have high-end playback equipment you'll hear a difference.

[Heavy-D]

The more expensive part has worse tolerance (10% vs 5%). I've heard that film&foil have lower ESR and better current capacity, just wondering if I would be able to hear the difference?

If you have high-end playback equipment you'll hear a difference.

I've read this many times could someone be specific as to what is "high-end playback equipment"? I know my Onkyo doesn't qualify but it's much better than the JVC it replaced. Someday I'll get that Sansui AU-717 or AU-919.

[cotdt]

I've read this many times could someone be specific as to what is "high-end playback equipment"? I know my Onkyo doesn't qualify but it's much better than the JVC it replaced. Someday I'll get that Sansui AU-717 or AU-919.

I think he means a decent source and amp. IMHO these are the Benchmark DAC1, Lavry, Apogee, Aqvox DACs and there are a number of decent amps like Tripath, UcD, SET amps, and discrete Class A amps.

[JonMarsh]

All kinds of stuff can fall into that "high end playback equipment category".

Some other recommendations/examples:

Ayre Acoustics (non loop feedback solid state preamps, power amps, disk players, phono preamps, power conditioners)

Theta Digitral

Balanced Audio Technology

Pass Audio

Conrad Johnson

Audio Research

Music Fidelity

Arcam

Many others... some since departed, like Sonic Frontiers.

[TacoD]

I even heard those Duelund copper foil caps, and yes they sound different, not necessarily beter than other fine caps (Mundorf supreme series).

On stuff mentioned by Jon the difference are more obvious, because these pieces of equipment already have more resolution. If you are working with mainstream equipment you can better put the money in other parts of you system.

Everybody has to decide for themselves, even if there is no measurable difference, maybe it's the idea of using these caps that will bring better sound (psychogical effects). Other things you can try to improve the sound are alcohol/ food/ setting/ inviting friends/ type of music.

[Heavy-D]

Part of DIY is learning what works and what doesn't work for the individual. I'm going to replace the tweeter caps and resistors to see what happens. If it works fine, if not at least I tried. This article has helped me alot. Our HT room does need some treatments and if this still doesn't work I either need to build or buy speakers to get what I'm looking for.

I want to thank everyone for your responses it's helped me learn that not everyone buys into the hype.

[Bri]

Thanks for the response Thomas. I'm interpreting it as basically saying that the difference might be small compared the errors introduced by lower quality electronics, and it would take a very clean signal to expose the capacitor difference. And since the electronics errors are probably pretty low compared to speaker error, room issues, and my lack of a refined ear for sound quality (hopefully changing for the better once I start to build more!), it's probably not something I'll care about right now.

Since I only have an Onkyo receiver at the moment, I'll stick with a metalized cap and then try a double blind ABX test on a film/foil later on. Maybe after upgrading the electronics.

Why was I reading the AVS Forum for so long? This is the place to be for speaker folks!