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Substitute for Speakerlab S3 Midrange Driver

Thank you, Bratwurst,
I am familiar with the 7's and I heard them fill up a good size function room with sound. I chose the 3 because they were the largest paper driver system they had. That and the fact that I was new to the sport back then and was intimidated by something like the 7.
LOL, no regret.
Yes, improvements can always be made with time.

I'll snap a pic of the crossover but be warned, it's a disaster. Electrons may not care for aesthetics but I believe they would make an exception in this case.
NOTE: You will see a pair of (black) paralleled 2.2uf 100V caps. Those were the best I could come up with on short notice to replace the 4uf 50V cap that my Adcom blew up.
 
There is an auction for a pair that I think are the same as the Speakerlab M608R's but without the coating. The listing doesn't have a Polydax or Audax p/n but they are 8 ohm and look identical to me. I don't think we're supposed to paste auction links but the title is
2 Polydax audax Vintage 5 inch midrange speaker 8ohm driver made France Original
 
I'd stick with originals or it is going to be a crap shoot.

That bike... conventional forks, CV carbs, none radial brakes... Early 90's Yamaha or Kawi?
 
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blipco said:
I saw those but they have a sealed back, unlike what I have.
Click to expand...

If you are referring to the Polydax on the auction, they aren't sealed. Zoom in on one of the pics and you can see the openings on the side. I don't think Polydax made a sealed version.
John
 
kfa888 said:
I'd stick with originals or it is going to be a crap shoot. Way me to it that ones the looks about right.

That bike... conventional forks, CV carbs, none radial brakes... Early 90's Yamaha or Kawi?
Click to expand...

Not bad.
It's a hard bike to figure out looking at parts. I bought it as a winter project.
It's a 2001 Kawi ZR7S.

Those are damper rod forks which I sprung for my weight and used Traxxion Dynamics cartridge emulators (better than the RaceTech emulators by far) and new seals.
I had to totally rebuild those cheesy pin slider brake calipers and master cylinders. New pistons and seals and pads all around.
It has an air/oil cooled 750 engine, the same engine from the 1980 kz750. It's no powerhouse, 65-70 rwhp.
I had to adjust the valves. Interval is 6000 miles yet at 19,000 miles I'm the first one to do it . It needed all of them.

Those carbs are cvk32 Kehein, and they are a mess inside. (The table they are sitting on is one hundred years old).

But all the plastics and inside of the tank is mint, which persuaded me to buy it.
It was well taken care of but never maintained.
The tires were so cracked they wouldn't hold air.
There's more but I forget. It'll run and ride perfectly when I'm done.

I paid $1450 for it and so far an additional $1500 in parts. So when I'm done I'll have $3000 into it (plus a winters worth of labor) for a bike I couldn't sell for two grand. LOL, that's how it goes. So I'm keeping it. (That makes four).
If my nephew likes it I'll most likely give it to him but I haven't told him yet.
 
nerdorama said:
If you are referring to the Polydax on the auction, they aren't sealed. Zoom in on one of the pics and you can see the openings on the side. I don't think Polydax made a sealed version.
John
Click to expand...
Yes, I see that now. They look pretty much like what I have.
So I just ordered them. Thank you John.
One more thing checked off the list. :)
 
Thanks for the crossover photo. :thumbsup:

Concerning the caps, using 2x 2µF caps in parallel instead of 1x 4µF is a good thing, the ESR will be reduced and with the S7 Speakerlab did use 2x yellow 2µF MKT caps. When you get farther along I would replace those elcos with MKP film. If you can't find 2µF just use 1x 1.8µF + 1x 2.2,F. I would also for sure replace the other electrolytics.

Just in case the mids don't work out or you want to try something different, here is some food-for-thought. I replaced the 6.5" mids in my Sevens with Wavecor WF166TU01 mids. They are very sweet sounding mids! For your S3's you might want to look at the WF152BD06, Parts Express has them. Yes, they are fairly expensive. Comparing the specs I think that they would be a pretty good match for the Audax mids but Imho would be a step up in quality. Wavecor seems to be pretty unknown in the US but they make some very nice drivers, I am very very happy with mine.

https://www.parts-express.com/Wavec...er-Glass-Fiber-Cone-Mid-Woofer-8-Ohm-298-1178

Cheers,
James
 

Attachments

Bratwurst, thanks for that information.
Those Wavecors look like a nice driver. Now that my Adcom GFA1 has been replaced by the Parasound A23+, I'm hoping that there will be no more frying of the speakers. Any future repairs that I do will be improvements.

The Parasound has a better protection circuit and it detected the fault in the S3 where the Adcom did not. I'm not even sure the Adcom had such a protection circuit, it does have relays which delay output as the amp powers up.
 
Thanks again to all, it's coming together. But now....

Ok, so I just received my two mids and promptly installed one in the hole. Wow, my right hand speaker really came alive in the mid range compared to the all original left speaker, maybe too much so. (Remember, it was the right hand speaker that I had to repair the crossover). They sound like two different speakers systems.
Next I did was pull the original working mid out of my left enclosure and put the new driver in there.. maybe they are not an exact match to the old drivers. But they are. The left hand speaker is still not as bright as the right hand speaker.

Now when I repaired the crossover, I replaced a 4uf 50v cap with parallel 2.2uf 100v caps giving me 4.4uf instead of the original 4uf.
My question... Could the extra .4uf have made that big of a difference in the crossover frequency to drastically change the way the speaker sounds?

This is what I'm thinking. If so, then what I could do is do the same modification to the other crossover and use the pots on the back of the crossover to tone down the huge increase in midrange. Does that make sense?
 
blipco said:
Thanks again to all, it's coming together. But now....

Ok, so I just received my two mids and promptly installed one in the hole. Wow, my right hand speaker really came alive in the mid range compared to the all original left speaker, maybe too much so. (Remember, it was the right hand speaker that I had to repair the crossover). They sound like two different speakers systems.
Next I did was pull the original working mid out of my left enclosure and put the new driver in there.. maybe they are not an exact match to the old drivers. But they are. The left hand speaker is still not as bright as the right hand speaker.

Now when I repaired the crossover, I replaced a 4uf 50v cap with parallel 2.2uf 100v caps giving me 4.4uf instead of the original 4uf.
My question... Could the extra .4uf have made that big of a difference in the crossover frequency to drastically change the way the speaker sounds?

This is what I'm thinking. If so, then what I could do is do the same modification to the other crossover and use the pots on the back of the crossover to tone down the huge increase in midrange. Does that make sense?
Click to expand...

The 4µF cap would be for the tweeter by my guess. That tweeter will be crossing a little bit lower than the other speaker, but not a major amount and it won't effect the mid. You really need to replace all of the caps (including returning the tweeter cap to 4µF: and re-solder each and every connection to get a return to spec. The quieter side could easily be because of aging caps there and/or aging solder connections. Then re-evaluate.
 
Bratwurst, you are right, the 4uf is for the tweeter. For some reason (most likely from not knowing, LOL) I figured the blown cap and the dead midrange driver were part of the same incident and connected but looking at the crossover it is tied to the tweeter pot.
I'll have to pull the left hand woofer to see what's up in there. Making them perform equally is a must.
 
While you are at it Deoxing and Faderlubing the pots would probably be a good idea also.

Some more guessing:

I'm thinking that there should-be/might-be some more coils and caps that aren't shown in your photo? Under the fiberglass perhaps? One or 2 more coil(s) and another cap(s)?

In any case, for those caps that I can see,

For the tweeter going with 2x 2µF MKP in parallel is what I would do. Gets you exactly 4µF and will sound better than electrolytics or the original MKT caps. Jantzen CrossCap MKP are reasonably priced and I have used them many times with good results.
https://www.partsconnexion.com/product49074.html

A 8µF+16µF=24µF. I'm thinking that those elcos in your photo are the series cap(s) for the mid(s).
8µF and 16µF aren't easy to find, but Jantzen makes a nice un-etched 12µF elco and 2x12µF=24µF.
https://www.partsconnexion.com/product49197.html
I would stay with 2x caps in parallel there because it lowers the ESR and doubles the bandwidth through the caps.
Normally I would expect to also see another parallel cap + series coil for the mid, but Speakerlab did different things with each type of speaker over the years of production. For instance my 3rd generation S7's mids only had a single coil+cap for the bottom end and let the mids roll off naturally on the upper end.

Sometimes Speakerlab only used a series coil on the woofer (6db/octave = shallow slope) and sometimes also a parallel cap (12db/octave = steeper slope).

Cheers,
James
 
James, thank you much. I'm pretty confident that I found all the caps on the crossover. It is a very crude build but that is what they supplied. It evidently did the job though.
I will follow your advice and I'll have to order those parts and rebuild both of those crossovers so that they are the same.
While I can mechanically adept to rebuild those crossovers, my electronic knowledge is nil.

The reason that I bought the 2.2uf caps was because that's all my local electronics place had. My mistake in thinking .4uf wouldn't make a difference. That 10% means a 30% brighter sound. Too bright and it plays louder.

On a side note.. I had forgotten just how good the S3 speakers are having owned them for forty years.
When I was at the stereo store purchasing my power amp, I brought my Adcom GFP1 preamp to test.
I told the salesman what speakers I had, he never heard of them, but I described them so he hooked up JBL L100 speakers. After a couple of hours of listening to cd music I had brought with me I chose the Parasound A23+ power amp.
When I got home and hooked up my stereo, I swear it, the S3 sound better than those $4000 JBL's. Maybe I'm a bit biased but I don't think so. The S3 surely hold their own, at least. They are definitely worth restoring.
Originally I paid $129 for the drivers and crossover/side and built the cabinets to spec with the help of my dad.
Mark.
 
You did not make a huge mistake in buying the 2.2µF caps, especially considering that they were what you could find. The change in crossover point will not be large, it's just pushing the tweeter slope down a bit. But replacing all of the caps will bring you back to what the speakers were like when they were new. Then you can evaluate where you are. I can't stress enough the importance of at least re-touching each and every solder point with a little fresh solder. After 40 years the joints are tired and any one of them can be bad.

When you make your order you might want to add a couple of 0.1µF film caps to the list. Reason being is that if you find the tweeters are too much you can add the 0.1µF caps in parallel to the 24µF mid cap and that will add a bit of sparkle to the mids and add some balance. Conversely, if the mids are overpowering the tweeters you can add the bypass caps there, again, it won't make a large change but can adjust the balance a bit. They are only $1.10 each so it's not a big investment.
https://www.partsconnexion.com/product49053.html

I understand completely your feeling towards the speakers. I've owned my S7's almost as long and they will stay until I go into my own box. Alone the woofers are pretty special. I think that there are very few 12" woofers currently available of the same quality with as low an resonance frequency as Speakerlab made back then. Very cool that you made the cabinets with your father. That alone would make them pretty special and worth restoring. :thumbsup:

I have seen 2 pairs of W1208R that have had split surrounds. If you ever have problems with the surrounds Paul aka The Loudspeaker guy has quality replacements. The pair of W1208R that I had him replace the surrounds on tested at an Fs of 22hz.

Cheers,
James
 
James,
My last test will be to swap the output leads from the power amp just to test that it's not a problem with the amplifying equipment. I'll also give it another good listen. From what I recall, the midrange seemed to take over everything on the right side but I could also hear more detail in the music that I could not hear in the left. (I switched the preamp to mono). The left speaker speared more balanced but with less detailed at the same volume when turning the balance control.

Later today or tomorrow I'll pull the woofer on the left side to see if there's any surprises in there.
I'll take a picture as well.
 
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