Recapping A Classic...The Pros and Cons?

I recapped my IMF TLS-80mk2's with poly's. Although this was an improvement, I needed to add resistors to my mid and high drivers to compensate for the lower ESR compared to electrolytic. Since the loudspeakers are supposed to sound natural I am now struggling to find the right resistor values. Decreasing the highs has brought back the sound prior to recapping. Decreasing the mid with 1 dB has made the sound smoother, but also less prominent with voices. Only a frequency test with microphone would give the right outcomes but I don't have one right now.

If you replace electrolytic capacitors with the same brand and type, assuming they are still available, you avoid this bad kind of resistor juggling. But poly will sound better especially in the highs.

However, whether elcap or poly, it seems everyone here agrees old elcaps should be replaced.
 
pradigmshift said:
I recapped my IMF TLS-80mk2's with poly's. Although this was an improvement, I needed to add resistors to my mid and high drivers to compensate for the lower ESR compared to electrolytic. Since the loudspeakers are supposed to sound natural I am now struggling to find the right resistor values. Decreasing the highs has brought back the sound prior to recapping. Decreasing the mid with 1 dB has made the sound smoother, but also less prominent with voices. Only a frequency test with microphone would give the right outcomes but I don't have one right now.

If you replace electrolytic capacitors with the same brand and type, assuming they are still available, you avoid this bad kind of resistor juggling. But poly will sound better especially in the highs.

However, whether elcap or poly, it seems everyone here agrees old elcaps should be replaced.
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Here's the question; does the speaker now sound as it was designed?

I would guess yes, and what you've become accustomed to is the choked off sound. Adding resistors is functionally the same as restoring the ESR you just removed and which was not part of the crossover design.

I don't think any resistors would be necessary in the crossover as my understanding is that the ESR develops over time and that all caps start out with little or no ESR. Electrolytics and polys can be used interchangeably without any resistor tweaks, at least if you wish the speakers to sound as they were designed to.
 
anthony28 said:
You sure know how to make a new guy to the forums of AK feel good about his Gear..... Truth or not, Thanks
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Myself, I'd love to have those.. something farily rare that you don't often see, and probably pretty nice sounding..

What I was trying to say, and probably not the most graceful, (Which I'm usually not) is that you're not going to hurt the value at all, and sadly we're a strange bunch that at times tend to put too much thought into how much something is really worth staying original, or being upgraded...

Wasn't trying to offend you at all, but rather trying to so make them what you want... There are a lot of bad ass T-Buckets out there that are a lot cooler than if they would have been left as a regular old Model A... Make them what you want that you value the most.
 
Andyman said:
Here's the question; does the speaker now sound as it was designed?

I would guess yes, and what you've become accustomed to is the choked off sound. Adding resistors is functionally the same as restoring the ESR you just removed and which was not part of the crossover design.

I don't think any resistors would be necessary in the crossover as my understanding is that the ESR develops over time and that all caps start out with little or no ESR. Electrolytics and polys can be used interchangeably without any resistor tweaks, at least if you wish the speakers to sound as they were designed to.
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Although the effect may be important, I don't think it is the main issue. The main issue being that elcaps have higher ESR built-in that poly's.

My guess for the typical ESR's would be 0.5 ohms versus 0.05 ohm. The supertweeter route has 4 series caps which were originally elcap (2x) and mylar (2x). Say the mylar is 0.3 ohms (guess) at those frequencies (>13 kHz), that is 1.6 ohms total. Or a difference of 1.4 ohms wrt. poly. I placed a 1.5 ohms resistor in series with the supertweeter and indeed, the supertweeter sounds about right. :yes:

And I left out of consideration poly + resistor compensation still might give a "sharper" sound than a elcap. Somehow the tweeter and mid seem to need more resistance than this calculation will tell.
 
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I was just looking at the schematic for these CS100's they have an impressive crossover. It appears to have a network on its input that equalizes out the resistance of the whole system. I haven't seen that done before. How do these sound as is? Alot of the older speakers have very little in the way of a crossover I'll bet these sound pretty good.
 
I ended up replacing the electrolytic caps, with polypropylene caps, in a pair of Dynaco A-10 speakers.
The finished product, sounds amazingly good!!
Considering the Dynaco A-25, uses a single capacitor as a crossover, the Dynaco A-10 crossovers are FAR more complex!?
To cut costs, I hit Madisound's.....Surplus Capacitor section.
A 10uf, 100v polypropylene capacitor was 60 cents.
I ended up using four of them.....$2.40.
You can't purchase ONE Solen 10uf cap for that price?

Steve
 
MOPAR3 said:
I was just looking at the schematic for these CS100's they have an impressive crossover. It appears to have a network on its input that equalizes out the resistance of the whole system. I haven't seen that done before. How do these sound as is? Alot of the older speakers have very little in the way of a crossover I'll bet these sound pretty good.
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The Sound is just phenomenal! I hear so much in the music that I never heard before....very smooth with brilliant highs, mid-range is like nothing I have ever heard before, very full bodied but not edgy and shrill. The low end is nothing but Superb!! Dark side of the moon - side one intro..Lowest bass I have ever heard from a home speaker with out using a sub.... but yet it's clean tight bass that doesn't boom out of control and blends perfect with the upper freqs. Very nicely made! I love my Infinity ribbons but these horns are just brilliant...and smooth to the ear.

Knowing how they sound now is why this recap idea sounds nice. To think these could sound even better!
I might want someone with an experienced ear and recapping background to check these out first though.


I have tons of other great speakers right now (Polk, Boston, Infinity and such) just collecting dust because of these. Their old but man.......:yes:
 
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They look impressively built to me and by a company that knows what their doing. Would love to have a pair myself. I would recap with the Dayton's if it were me. The 5% Dayton's I purchased all checked in at very close to 1%. Can't beat that. Have fun with those beautiful speakers.
 
I recapped my Nova 8 speaker with the Dayton Metalized Poly caps and the sound is excellent. The original caps in that speaker had leaked. The caps in the other speaker are working OK, but I will be recapping that speaker also later on this summer. Got some other projects to do right now. Parts express had all the values I needed, with the only difference being in the voltage rating. The old were rated for 50 volts, the new for 250 volts. The new were physically larger than the old, but I was able to fit them in OK.
 
Not only did it make my speakers sound better, it was fun to boot! But, someone mentioned the size difference and it is something you may want to pay attention to. I didn't and since all my caps were in a row, it took some doing to get the bigger ones in.

have fun!!
 
DaWoofer said:
They look impressively built to me and by a company that knows what their doing. Would love to have a pair myself. I would recap with the Dayton's if it were me. The 5% Dayton's I purchased all checked in at very close to 1%. Can't beat that. Have fun with those beautiful speakers.
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That's exactly what I was thinking. I had never seen the inside of a pair of those before, and those are some of the most-well-built-looking cabs I've ever seen in a kabuki speaker (THICK). I'd LOVE to have a pair like that. Not sure about the horn though. I'm a dome-tweeter kind of guy. But damn, those look nice. They must weigh a ton.

I have a pair of Wharfedale W60E's (from '73, I think) that I'm really-enjoying at the moment. They have a very-smooth, warm sound that I love. I've thought about a recap, but I'd heard a few stories about people who recapped their speakers and didn't like the sound, and they ended up putting the original caps back in. I don't want that to be the case, but I'm starting to think about doing it after reading the comments here. Mostly, I don't want to lose that smoothness just to get a more-brilliant high-end. The mids are awesome, and I REALLY don't want to mess that up. See? This is the kind of thinking that always stops me from recapping. Plus, I know little about crossovers, and I don't want to screw anything up (but really don't have the money right now to pay a tech to do it). Ah, who knows? I'm so-confused.
 
Gang-Twanger said:
That's exactly what I was thinking. I had never seen the inside of a pair of those before, and those are some of the most-well-built-looking cabs I've ever seen in a kabuki speaker (THICK). I'd LOVE to have a pair like that. Not sure about the horn though. I'm a dome-tweeter kind of guy. But damn, those look nice. They must weigh a ton.

I have a pair of Wharfedale W60E's (from '73, I think) that I'm really-enjoying at the moment. They have a very-smooth, warm sound that I love. I've thought about a recap, but I'd heard a few stories about people who recapped their speakers and didn't like the sound, and they ended up putting the original caps back in. I don't want that to be the case, but I'm starting to think about doing it after reading the comments here. Mostly, I don't want to lose that smoothness just to get a more-brilliant high-end. The mids are awesome, and I REALLY don't want to mess that up. See? This is the kind of thinking that always stops me from recapping. Plus, I know little about crossovers, and I don't want to screw anything up (but really don't have the money right now to pay a tech to do it). Ah, who knows? I'm so-confused.
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Yes they weigh 138.5 Lbs a piece. The cabs are 1 1/2" thick real wood with rosewood veneer. Gold tweed fronts. The boxes (23.62 wide, 37.79 hight, 17.52 inches deep). 15" woofer. Two 6" squawkers and a horn. They made my old HPM-100's look like bookshelf speakers. They sound much, much better too!

Kabuki Speakers?? But those are Audio Blasphemy!!! :no: Here is the link:http://www.urbandictionary.com/define.php?term=Kabuki%20Speaker

Just havin' some fun...:D

yeah, I'm not going to rush into this recap if I do it, as I am still very interested to hear other members comments on this matter.
 
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Here is an updated pic of the CS-100 X-over.

DSCN1367.jpg
 
Anthony if you like the way they sound I'd leave them as is. I have some ads speakers and replaced some caps it threw the balance of the speakers off. The ads used a mix of film and electrolytics so now I will have to retune the crossover with resistors. If these sound better than all your other speakers why mess with a good thing. Do you have a cap tester? Test whats there and see if they meet specs.
 
If you do the mod, post the results. I too did my speakers, Mach One's, and now they sound like new (possibly better?). Look forward to your comments.
 
pradigmshift said:
Although the effect may be important, I don't think it is the main issue. The main issue being that elcaps have higher ESR built-in that poly's.

My guess for the typical ESR's would be 0.5 ohms versus 0.05 ohm. The supertweeter route has 4 series caps which were originally elcap (2x) and mylar (2x). Say the mylar is 0.3 ohms (guess) at those frequencies (>13 kHz), that is 1.6 ohms total. Or a difference of 1.4 ohms wrt. poly. I placed a 1.5 ohms resistor in series with the supertweeter and indeed, the supertweeter sounds about right. :yes:

And I left out of consideration poly + resistor compensation still might give a "sharper" sound than a elcap. Somehow the tweeter and mid seem to need more resistance than this calculation will tell.
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Interesting. If it is true that the electrolytics have a higher ESR than the polys that would mean that most folks out there who replace with polys are actually getting a brighter than designed sound, and should, as you did, install some resistance to tame it down.

Perhaps I should go out and measure some caps for resistance; can this be done with a simple VOM, or is something more sophisticated required???
 
You need to measure the resitance to an ac signal and do a sweep. I was thinking that the woofer tester3 would do. You can get a resitance curve with it.
 
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