You may have observed that the 2.5 mH inductors in the W3 are wound with thick aluminium wire.
I presume Wharfedale would have been focused on keeping costs down.
It would be advisable to avoid disturbing the attachment points at each end of the coil because I assume they will have been specially terminated.
Any comments on the use of aluminium wound inductors AllenB? Copper replacements would be quite costly.
Nothing specific.
Looking at the circuit I'd presume the mid and treble would be quiet if the inductor shorted. If this were the case, the amplifier could be under stress at higher frequencies.
Looking at the circuit I'd presume the mid and treble would be quiet if the inductor shorted. If this were the case, the amplifier could be under stress at higher frequencies.
Thanks AllenB. The chances that the inductor has been overloaded are small since the speaker hails from the era of low power valve amplification.
The W3's maximum input was stated as 15 watts. We haven't seen a proper picture of them yet, so here's one:
It is more likely that one or more of the individual drivers has failed. I do hope Craig has tested each of them individually.
The W3's maximum input was stated as 15 watts. We haven't seen a proper picture of them yet, so here's one:
It is more likely that one or more of the individual drivers has failed. I do hope Craig has tested each of them individually.
Here are a couple of pictures of the crossover in the W3's I have. As Galu commented the coils are aluminium. I'm about to refelt the tweeter and mid driver and would welcome any advice on how best to do this. I've never stripped a driver down and I'm anxious about making errors that might cause damage. Any advice about the sequence I need to follow would be very very welcome.
I'd caution against replacing the felt surrounds unless absolutely necessary.
Some local patching up of holes may suffice. The last thing you want to do is risk damaging the paper cones.
I believe the felt surround doesn't contribute much in the way of support for the cone - most of that is provided by the rear suspension.
The way the 5" and 3" drivers fire into free air, as shown in the image below, reinforces my opinion that the felt surrounds need not be perfect.
You certainly wouldn't strip the driver down in the sense of taking it to bits.
You may require the help of a rounded No.10 scalpel blade (pictured below) to separate the felt from the rear circumference of the paper cone, being extremely careful not to damage the cone in the process. Separating the felt from the speaker basket would be less problematical.
Some local patching up of holes may suffice. The last thing you want to do is risk damaging the paper cones.
I believe the felt surround doesn't contribute much in the way of support for the cone - most of that is provided by the rear suspension.
The way the 5" and 3" drivers fire into free air, as shown in the image below, reinforces my opinion that the felt surrounds need not be perfect.
You certainly wouldn't strip the driver down in the sense of taking it to bits.
You may require the help of a rounded No.10 scalpel blade (pictured below) to separate the felt from the rear circumference of the paper cone, being extremely careful not to damage the cone in the process. Separating the felt from the speaker basket would be less problematical.
Here's more information from the Yorkshire Triangle! 😎
First offered in spring 1959 at a cost of £40, the W3 had a bass resonance of 30 Hz (undistorted at 4 watts output) and a cabinet volume of 2.7 cu ft .
The WLS/12 woofer and special 5" treble unit were specifically designed for the W3 (as well as its W2 and W4 companions). These drivers were not sold separately, although the Super 5 was reintroduced into Wharfedale's range at that time.
First offered in spring 1959 at a cost of £40, the W3 had a bass resonance of 30 Hz (undistorted at 4 watts output) and a cabinet volume of 2.7 cu ft .
The WLS/12 woofer and special 5" treble unit were specifically designed for the W3 (as well as its W2 and W4 companions). These drivers were not sold separately, although the Super 5 was reintroduced into Wharfedale's range at that time.
Thanks Galu, as you can hopefully see from the picture the felt is shot on the 5"'s. If I understand you correctly you are advocating cutting away the old felt with a scaple andglueing new felt in it's place. Do you suggest I do this with the cone in place? I think I can comfortably trim the old felt off, howver getting it off the paper cone may prove difficult. I might just trim the felt around the cone and then glue the new felt onto the remaining old felt which is attached to the cone. What do you think? Ideally, I'd like to clamp the new felt while the glue sets and aim to fashion some a jig out of 6mm ply.
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Thanks for posting the information. So I'm puzzled as to whether the W3's should be used "on their side' as shown in the picture you posted or upright as should in the original brochure I have?
Absolutely!
On no account try to remove the cone!!
I was suggesting using the scalpel to separate the felt from the cone, but you could just trim the felt off round the edge of the cone as you suggest.
If you use the tacky PVA glue I recommended it will grip the felt and paper cone fairly quickly and you may require nothing more sophisticated than maintaining light pressure around the circumference for a while with your fingers.
A jig may prove handy for the felt to speaker basket interface. I just use modelling clamps.
The speakers could be orientated horizontally or vertically.
Notice that the Wharfedale badge was placed in the corner of the baffle at an angle so as to accommodate either orientation.
Another thought!
At present, the felt is stuck to the rear of the cone's circumference.
You could equally stick it to the front of the cone giving you a fresh felt/paper interface and allowing you to apply light pressure while the glue sets.
At present, the felt is stuck to the rear of the cone's circumference.
You could equally stick it to the front of the cone giving you a fresh felt/paper interface and allowing you to apply light pressure while the glue sets.
Notice that the W3 blurb above says that the speaker is as "equally versatile" as the rectangular W2 model.
Here's the description from the W2 blurb that will make the versatility clear:
"It is equally suitable as a floor standing model and for shelf or table mounting. The cabinet is fully finished on all four sides, and can therefore be used either horizontally or vertically."
Just a quick thought, is there any advantage to removing the old felt support? Would simply gluing the new felt over the old felt work?
Maybe, it's hard to say whether it's worth worrying about. The differences might include the effect on natural cone flexure changing breakup, as well as whether it imbalances each side. Then the concern of asymmetrical cone balance leading to rocking modes. You also have the simple mass differences which would alter the main resonance.
I'd like to reiterate that it would be wise to test the drivers to see if they are working before going to all the trouble of 'refelting'.
Ageing can be unkind to these drivers in more ways than simply causing their felt surrounds to perish.
A quick test I use to check if a driver is producing sound is to connect it to the headphone socket of a monophonic portable radio.
I have a 3.5 mm mono jack plug to alligator clips cable especially for the purpose.
At the very least, measure the DC resistance of the voice coils, to check they are not open circuit.
Ageing can be unkind to these drivers in more ways than simply causing their felt surrounds to perish.
A quick test I use to check if a driver is producing sound is to connect it to the headphone socket of a monophonic portable radio.
I have a 3.5 mm mono jack plug to alligator clips cable especially for the purpose.
At the very least, measure the DC resistance of the voice coils, to check they are not open circuit.