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Why Recap Speakers and When?

This makes me wonder...

Should I have recapped the crossovers in my Advent/1s when I refoamed them? The woofers are date stamped from 1979.
 
Almost There said:
I just picked up a pair of Boston Acoustic A400... can't wait to get them up and running. Woofers are on the bench for a re-foam and while I'm at that, I'm considering a re-cap. Date tag on woofers is "Jan 3 1985". So given that date, do you think a re-cap is in order? :scratch2: I will definitely have a listen after the woofers are done before doing anything drastic, but the opinions and advice from you fine people here at AK is always welcomed. :thmbsp:
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Can't hurt. You _could_ wait 5-6 more years, but prices will be higher then, and you'll miss out on whatever improvement the re-cap WILL give you.
 
YamahaFreak said:
This makes me wonder...

Should I have recapped the crossovers in my Advent/1s when I refoamed them? The woofers are date stamped from 1979.
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My Smaller Advents were date stamped 1973. I re-capped them when I did my W-60E's (about 10 yrs older). The SA's didn't show the big improvement that the W-60's did, but there definitely was an improvement.

I burned them in for 48 hrs at low volume, then gave a critical listening with a few selections that I listened to just before the re-capping. Hopefully, wishful thinking didn't raise it's ugly head, esp. with the SA's. :D

Dayton caps were used in both cases. The AMT-4's await the soldering iron now.
 
dukethejuke said:
Replacing the cap with a non OEM change the intended sound of a speaker? Just wondering.
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It will depend heavily on the current condition of the OEM vintage cap. If it has drifted in uF value and/or ESR, the sound you have become used to will be different with a new, film cap. If it hasn't drifted much, or just a little, you won't hear much difference.
If you looked at my tests in the linked thread, the KLH-5 caps were in sad shape with ESR's well over 1 ohm and beyond. When they are replaced with a film cap with ESR of tenths of an ohm, then the difference is quite noticeable.
Remember though, the OEM cap had some level of ESR. Suppose the original was an NPE with an ESR of 1/4 to 1/3rd ohm which is typical of that type of cap. If you want to duplicate EXACTLY, that level of ESR during a recap, then recap with a new NPE. Then you'll be duplicating the original voicing. Another option is to replace the NPE with a film cap and add a 1/3 to 1/4 ohm resistor in series to in effect, duplicate the NPE ESR.
 
spkrdtr said:
It will depend heavily on the current condition of the OEM vintage cap. If it has drifted in uF value and/or ESR, the sound you have become used to will be different with a new, film cap. If it hasn't drifted much, or just a little, you won't hear much difference.
If you looked at my tests in the linked thread, the KLH-5 caps were in sad shape with ESR's well over 1 ohm and beyond. When they are replaced with a film cap with ESR of tenths of an ohm, then the difference is quite noticeable.
Remember though, the OEM cap had some level of ESR. Suppose the original was an NPE with an ESR of 1/4 to 1/3rd ohm which is typical of that type of cap. If you want to duplicate EXACTLY, that level of ESR during a recap, then recap with a new NPE. Then you'll be duplicating the original voicing. Another option is to replace the NPE with a film cap and add a 1/3 to 1/4 ohm resistor in series to in effect, duplicate the NPE ESR.
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Carl, I just bought a pair of Klipsch Chorus ll"s, I dont know how their supposed to sound, to me they sound good, should I mess with them, I think their early 90"s
 
hugeroost said:
Carl, I just bought a pair of Klipsch Chorus ll"s, I dont know how their supposed to sound, to me they sound good, should I mess with them, I think their early 90"s
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Perhaps if you want to consider boutique caps. Otherwise, the OEM caps most likely haven't drifted yet (assuming there are NPE's in there).
 
Will recapping help with "harsh" vocals?
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The variables are so many that no one can answer you in a helpful manner. My two bits is — if the speakers are older units, get some common non-polars and weld them in. See what happens. If something nice happens, do some research on some more expensive plastic types and see if there is another step up.

Perhaps the harshness is due to your source. If its analogue, something simple like altering cartridge setup may solve it. If you are doing red-book CD — often the D/A converter is not doing you any favours. It could take you minute, months or even years to figure it out. It all depends on what time — and often money — you want to throw at it.
 
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I have recapped several speakers and been pleased with what I perceived as the results. However, I do note that B&W seems to recommend against using films in place of electrolytics here:

We usually find that customers who alter crossover components are not fully satisfied with the results. They find that some aspects are improved, but others made worse. A classic case of this is when a polypropylene or other very low-loss type substitutes an electrolytic capacitor. We all know that polypropylene capacitors can sound inherently better, but the change in internal losses changes the response of the filter, which is designed assuming the losses of the electrolytic component. What usually happens when the low loss component is fitted is that the corners of the roll-off are sharpened, giving a peak in the combined response that can make the sound unpleasant in various ways depending on the crossover frequency. One way of getting round this is to wire a small resistor in series with the capacitor to approximate the original losses. I say approximate because the loss factor is a frequency dependent resistance. The actual value you need depends on the original capacitor loss factor and its capacitance value. The larger the value, the lower the resistance for a given loss factor.

The formula for the equivalent resistance is:
R = d / (2π fC)
where R = resistance in ohms, d = loss factor, f = frequency in Hz and C = capacitance in farads.

Loss factor is usually expressed as a percentage at 1kHz. For a "low-loss" electrolytic such as the values between 1μF and 20μF found in tweeter circuits, d is of the order of 0.025 (loss factor of 2.5%). For values in the hundreds of microfarads it may be of the order of 0.07 or 7%. Typically therefore a good electrolytic capacitor of 5μF would have an equivalent series resistance of 0.8Ω. If the capacitor has a much larger resistor in series with it anyway, it's probably not worth altering.
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I came across those notes when I was considering recapping my B&W 802 Series 80s. My brother owns those now, and they seem a bit "tight" and constrained to me; they won't very play loudly no matter how much power we put into them.

Any thoughts on whether I should use films to recap them? Some of the values are so high that I will probably stick to electrolytics, if and when I do this. I admit that the "loss factor" discussion goes over my head; I think I need to read it a few more times.
 
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Zonker92: Thanks — good post! From what you cite, we can take it that good engineering can trump what may otherwise be meddling. With that being said, and as has been reported so many times on AK, all electrolytic caps lose some of their integrity over time. Changing them out from time to time must be a good thing.

In other places — perhaps in this thread — I have supported and encouraged the changing out of NP electrolytics for plastic caps in speakers — not necessarily the most fashionable "boutique" types. This has been based on very favourable results. In this case I'd go with the manufacturer's message. And, it has me thinking about what I will do when I finally get around to reconstructing an ancient pair of Tannoys.
 
Celt said:
Higher quality caps, non-inductive resistors, robust inductors and better wiring can make a huge difference in performance. QUOTE]

I've asked this question many times but never seem to be able to get an answer from anyone.

What size wire do you use for:
1. tweets
2. mids
3. woofers.

And what manufacture of internal speaker wire do you prefer?

I'm going to be restoring a pair of 1970 speakers next week.

Thanks for your advice! :yes: :music:
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BECtoo said:
Dayton or Solen metalized polypropylene are both good caps with good ESR and test good and well inside their tolerance on capacitance. I haven't tested the Axon caps.

Bypassing the caps in a crossover is a totally meaningless exercise. Just put the value into a capacitive reactance formula and look at the impedance at audio frequencies of the 0.1 uF cap. The 0.1uF cap would have an impedance of 160 ohms at 10 Khz and 80 ohms at 20 Khz. Its effect would in my opinion be inaudible in any crossover circuit.

Bob Crites
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Then why did JBL adopt it a standard practice by the '80s?

I would think Sid would look anywhere he could to save a nickel

Thomas
 
What size wire do you use for:
1. tweets
2. mids
3. woofers.
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What is better wire? Better for what? Inside speakers I would use any gauge that was convenient — but let's not get silly — say 18 to 22. And I'd use it on any driver stuffed into the box. Good — by good I mean reliable copper from a source that can be trusted and is not coated with some other metal. Preferably a Teflon insulator just for the sake of ruling out one miniscule set of worries, but not a big thing there.
And what manufacture of internal speaker wire do you prefer?
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I do not hesitate to go to the local supplier and get two colors of 20 gauge single strand wire and be done with it. In one set of very modified speakers I used the same wire as I used as the main wire to the amp — orange and black, multi-stranded, twisted pair by a well-known maker — and just about the least expensive wire in the audio shop. No, not 'Monster'. I don't believe that boutique wire and special gauges make any difference. And if they did, I for one have other more important things to worry about. If you have any electrolytic caps in your equipment that are more than 7-10 years old and have been subjected to heat, I'd call that a focal point for attention. Internal speaker wire? Not an issue.

That being said, reflowed solder on connections and on the network might make a big difference if the speaker is a veteran or cold joints were performed on assembly
 
HI, elcap capacitor find in many english speaker's, these black with red end 50 v. 6uf , 12uf , 60uf , 100 uf one off each with 5 x Elna 2.2uf 250v and 1x .47uf over 30 years old speaker. I have check the value not ESR in it. Value 6 = 6.40 60= 66uf 100 = 104uf .47 pretty close. 2.2 varie 2.11 - 2.13 - 2.15 - 2.21 -2.24 so I will love to put good quality cap, size do not matter I will probably make external x -over. Claricap esa for 6uf and 12uf - 2.2uf like to go with better ? and .47uf Audyn gold or Mcap supreme-silver in oil 60uf ? 100uf? Like opinion,please ,Yvan.
 
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