Hi,
I recently bought a pair of Leak Sandwich speakers - the original 15 Ohm ones - in immaculate condition - as part of my addiction to large teak boxes.
Removing the front grill I found what looks like polyurethane varnish on the woofers (photos attached). Why would someone do this? Damp resonances etc? Was it a common mod in the 1960s and 70s for these drivers?
I suspect its not removable without causing major damage so what's the likely effect of this?
I recently bought a pair of Leak Sandwich speakers - the original 15 Ohm ones - in immaculate condition - as part of my addiction to large teak boxes.
Removing the front grill I found what looks like polyurethane varnish on the woofers (photos attached). Why would someone do this? Damp resonances etc? Was it a common mod in the 1960s and 70s for these drivers?
I suspect its not removable without causing major damage so what's the likely effect of this?
Attachments
To be clear, the varnish is on the voice coil dust cap and not on the aluminium foil of the cone itself.
I suspect this may have been applied at the factory to increase the rigidity of the dust cap.
I suspect this may have been applied at the factory to increase the rigidity of the dust cap.
It has no acoustic effect.
The driver has a 12db filter omitting cone breakup.
I heard the old electrolytic in the box should be replaced for foils or bipolar ones. The Cs inside are polar.
Because one bass was mildly decentered I let change the textile surrounds on both bass drivers for a mellow and damping rubber surround.
Clearly dampens some resonance
The driver has a 12db filter omitting cone breakup.
I heard the old electrolytic in the box should be replaced for foils or bipolar ones. The Cs inside are polar.
Because one bass was mildly decentered I let change the textile surrounds on both bass drivers for a mellow and damping rubber surround.
Clearly dampens some resonance
I presume you have tested the woofers to ensure they are working correctly?
If they are, leave well enough alone. If not report back.
If they are, leave well enough alone. If not report back.
It's on the foil where its dripped down. That's what makes me think its not been applied at the factory and is an owner mod for some unknown reason.
Yes, I saw that.
The essential piece of information required is whether or not the woofers are working correctly.