22 responses Add your response
From my reading it is the electrolytic caps which deteriorate with time and change value. If your crossover contains any of those they will be the candidates for replacement.
"Upgrading" any other caps will more likely be a matter of taste. As rcprince suggested, it may not necessarily be better than what the speaker designer chose.
Changing caps to a very different part will be audible, but it will not re create this speaker... It will be more like a difference in character of the speaker.... slightly more or less detail, slightly more rolled off or more extended, etc, but it will not be like changing speakers. This speaker used very good parts overall and it would take a expensive upgrade to make a noticeable difference. For me, not worth them money, For You?
Good Luck either way, Tim
There is a capacitor review on humblehomadehifi.com that you may find interesting. He tested a bunch of them and wrote his impression. I thought about replacing the capacitors in my Infinity Renaissance 90 speakers a few years back but never seemed to have the ambition or time. Evidently Infinity tested each capacitor installed and if it wasn't up to spec they would add, delete or change until it read proper. Two of the same crossovers may have different capacitors in them. I figured there was more of a chance of me messing it up that fixing anything.
Good luck , John
Stolen makes four basic grades of cap, in ascending order: metallized polypropylene (black), tin foil and polypropylene film (white), metallized teflon (blue), and tin foil and teflon film (green). They sound very different.
Metallized poly is the least expensive of the audiophile grades. It sounds relatively smeared. Tin film and foil is a big improvement in clarity, but this may not suit your system as a whole. I find that teflon adds a slight edge, which may make your system unlistenably sharp, or much more life-like, or something in between. As ever, YMMD.
In critical applications I divide the critical value into 3: 1/3 Solen teflon f&f, 2/3 styrene. This gives me a slight edge from the teflon, and a slight rounding from the styrene, for a pleasingly neutral sound. Unfortunately Solen does not sell styrene.
Not only would I do it, I have done it. As you can infer.
To clarify: I have upgraded KEF's, Magnepans and Quad ESL's, not Thiels. But if you like their sound, why not?
When I upgrade to film and foil, I expect increased clarity and decreased harshness. I have found that polypropylene is rounded, polystyrene is very slightly rounded, teflon is slightly edgy. I would never replace old metallized with new metallized. I get good results with MIT Multicap f&f. YMMD
Speaking about Thiel CS7 I have one set since 1997. I changed twice the fragile tweeters in these last long years. Last month again one of my tweeters started to give some "ssshhhhh" on piano and voice recordings. I contacted Thiel Audio for replacing it but they don't have any spare parts because Scan Speak closed production of this driver.
Someone of you can help me in some way to try to recover my old but wonderful sounding CS7s? Thanks!
My point to asking Thiel is to see if you can find either a used or NOS replacement diaphram or driver. If it's a standard SS part then it would looking for it by the standard part number will give you more options to search for, but if it truly was a Thiel-only part then you're going to have to find a used or NOS replacement for the Thiel.
If I remember correctly, this speaker uses mostly the higher voltage Solen Polypropylene caps, The 400 to 630v parts are pretty decent. If someone brought these to me to do, I would first recommend changing the series caps in the upper midrange and next the series cap in the tweeter and lastly the series caps in the lower midrange.... If your replacements are good enough, you'll hear these changes in a positive manor. I'm really not sure that changing anything else will make a marked difference. These crossovers have some fairly extensive compensation circuitry, but I really believe that you'll spend a ton to replace these comp parts with minimal if any improvement. (as long as the compensation parts are polyprop and 250v or higher)
I hope this helps, Tim