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Wharfedale W70's sounding very harsh

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pcrosewood

Active Member
Hey All. I recently picked up a pair of W70's. Before choosing to get them, I read the reviews and threads and watched some videos and all pointed toward a very smooth, full, rich speaker that was very tube friendly. Not what I am experiencing at all. I recapped them 2 days ago with Russian paper in oil caps. I have been playing them and waiting for the caps to play in and reduce the harshness but it's not happening. Any one else share this experience with the W70's and does anyone have advice or a fix that may smooth them out. The harshness is in the mid range. The higher the volume, the more harsh they become.
 
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Could be a bad cap, could be a voice coil rubbing in one of the mids. My W70Ds took a long time to break in, I wire them out of phase, stand them face to face and throw a blanket over them. Then play FM at fairly low volume, turn up the volume a bit every day for about a week or so.
 
bigaltx24 said:
Could be a bad cap, could be a voice coil rubbing in one of the mids. My W70Ds took a long time to break in, I wire them out of phase, stand them face to face and throw a blanket over them. Then play FM at fairly low volume, turn up the volume a bit every day for about a week or so.
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I just recapped them with PIO caps from Russia. I tested the caps with two different testers and both testers showed they are good. I actually ordered 6 caps to make sure I got 2 good ones. All 6 tested good. And my W70's have 12uf caps and most I see have 4uf caps. What difference did you notice after a week with the procedure playing FM with a blanket over them?
 
When I got mine they had original caps in them. My first impression with the original caps was that they were very dark, a lot of bass and mids, very little high end. I listened to them for a couple of weeks to let the surrounds loosen up, highs got a little better, but still a kind of dark without much detail. After I recapped with Russian KBGs for the big values and Mudorf EVO Oils for the tweeter. My initial impression after the recap was that they had brightened up quite a bit. After a week under the blanket they had a nice warm balanced sound with great detail and they kept on getting better the more I played them.
 
Hey man,

Not being there and hearing what you're hearing is darned tough to sleuth out what's really going on. We do what we can.

Old, stiff surrounds should break in within a few hours of moderate levels. This is my experience from 4 vintage Wharfedale projects ranging from 1959 to maybe 1962. As much as I dislike vintage PIO caps, it doesn't sound like these are the issue. Especially since it doesn't sound like your midrange has a cap. Both the woofer and midrange are running wide open. You didn't mention which version, or from what year yours are from. But it sounds like you have the earlier version. This is where you have little or no real crossover, maybe just a cap on the tweeter. And gulp, the midrange has no cover over it's behind. What's happening is that the woofer's backwave is messing with the performance of your midrange. It makes it muddy, confused and only gets worse the more power you give them. This could very well be your issue.

Biggles
 
Sounds like your W70's have 2 caps. Mine has just the one 12uf. These sounded harsh with the original caps and continue to do so with the new caps. I'm hoping they mellow some in time. But, I keep thinking maybe there is something not right with them. I know they are all original because I bought them from the son of the original owner who bought them new in the late 60's. They've never been touched according to the son. I'm running them with a Bogen RP-230 tube receiver. I also had them hooked to a very nice working Pioneer SX-737. The speakers are harsh on both receivers. There is no darkness or warmth that you mention.
 
This makes sense to me. Is there a solution? There is a cover over the tweeter but not the midrange. Would a DIY cover help?
 
drbiggles said:
Hey man,

Not being there and hearing what you're hearing is darned tough to sleuth out what's really going on. We do what we can.

Old, stiff surrounds should break in within a few hours of moderate levels. This is my experience from 4 vintage Wharfedale projects ranging from 1959 to maybe 1962. As much as I dislike vintage PIO caps, it doesn't sound like these are the issue. Especially since it doesn't sound like your midrange has a cap. Both the woofer and midrange are running wide open. You didn't mention which version, or from what year yours are from. But it sounds like you have the earlier version. This is where you have little or no real crossover, maybe just a cap on the tweeter. And gulp, the midrange has no cover over it's behind. What's happening is that the woofer's backwave is messing with the performance of your midrange. It makes it muddy, confused and only gets worse the more power you give them. This could very well be your issue.

Biggles
Click to expand...

This makes sense to me. The tweeter has a cover on it. The midrange does not. Sounds like a DIY cover on the midrange may help. I did see where others have done that but I didn't know the reasoning behind it. My w70's are from 1967 and have a single 12uf cap and a single pot on the back near the terminals.
 
pcrosewood said:
This makes sense to me. Is there a solution? There is a cover over the tweeter but not the midrange. Would a DIY cover help?
Click to expand...

Yes, and no. The issue is that the cabinet is already too small for a Wharfedale 12" woofer. If you used a plastic flower pot, lined inside and out with 1" of 100% cotton upholstery batting and installed it, you'd be making the cabinet even smaller. This would probably be about .5 of a cubic foot. AK member DC270 offered to test a set of these Alnico W70 drivers for me on his fancy computer testing rig. He found that the Wharfedale 12" woofer wants a 5 cubic foot box. The W70 is half that, or less. The real solution is to put the drivers into a 5+ cubic foot cabinet, cover the back of the mid and design a proper 3-way crossover.

Biggles
 
pcrosewood said:
This makes sense to me. The tweeter has a cover on it. The midrange does not. Sounds like a DIY cover on the midrange may help. I did see where others have done that but I didn't know the reasoning behind it. My w70's are from 1967 and have a single 12uf cap and a single pot on the back near the terminals.
Click to expand...

The sad thing is that Mr. Briggs knew this, he knew there were issues. This is why the later versions of the W70 actually enclosed the back of the mid, and made proper 3-way crossovers, and made the cabinet a little bigger. Not enough by my opinion. But ever since AR and KLH created stunning bass response in those tiny cabinets, large cabinets were a tougher sell than they used to be.

Biggles
 
So does this mean there is no solution other than a bigger cabinet and a 3 way crossover. Not sure I have the knowledge and skills to go that route.
 
pcrosewood said:
So does this mean there is no solution other than a bigger cabinet and a 3 way crossover. Not sure I have the knowledge and skills to go that route.
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If this is your issue, then no. I know, i know. I went through a lot, and i mean a lot, of time and money to find this out. Spent over 4 hours on the freeway picking up needed parts. Once finished, a/b testing with poly caps vs vintage pio, my only recourse was to sell them.

Biggles
 
W70 Crossovers 001.JPG W70 Crossovers 007.JPG

Here are photos of the inside of my W70. Can anyone identify which model W70 these are. The tag on the back says W70 without any letter following . or can anyone tell me about the drivers?
 
They look similar to mine which were manufactured in 1966. Yours appear to have a more elaborate enclosure for the tweeter, whereas mine in just a plywood box. Also, the port in yours looks to be slightly longer.

w70b.jpg

W70a.jpg

1000286pa.jpg
 
How did you get the front off. I've been taking the back off to access the crossover. And do they sound on the harsh side in the mids? Very nice looking set you there.
 
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Well, here's what I ended doing. I re-soldered all the contact points on the crossovers and on the drivers. The results are surprising. Night and day. All that harshness is gone and very enjoyable speakers. I knew the harshness I was hearing was beyond the normal shortcomings of speakers. Now to play the new caps in. This is a fun hobby and places like this forum and the people on it are great. Still like to know how to get those fronts off.
 
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