10" second "dust cap"?

[Rlowe]

Should I install a second paper "dust" cap in the 10" speaker under the hemispherical dust cap?

I recently decided to refoam a 10" speaker with a square magnet. When I removed the fabric dust cap I found another smaller paper cap closer to the apex of the cone very close to the start of the voice coil. It was flat a circular (approx 1 1/4" diameter), made from speaker cone material.

I replaced this cap in the reconstruction with a pizza box material after I had sealed the smooth side with a smearing of glue and scraped off excess paper to approximate the original cap weight.

I then decided to refoam a modern AR speaker replacecment which has a circular magnet. This time when I removed the top dust cap there was no secondary cap.

Should I install a secondary paper cap like the originl square magnet speaker?

Would the secondary cap would have some impact on the sound as it appears to form a partially sealed air compartment at the top of the the coil when it moves quickly on sudden excursions, could it limit the movement of the cone in both a forward and backward direction due to the compression or suction created by the secondary cap?

Would this secondary cap alter the response of the 10" speaker over its frequency range?

[Guest dogmeninreno]

Hello, A lot of the 10" woofers had flat dust caps. I am familar with the AR5 and LST2 which used the square magnet type with flat dust caps. Later production units as I recall had the circular magnet but I think they used flat dust covers also. Are you sure someone didn't add a second cap to the woofers? Sound wise, I doubt that any audible difference would be heard. Tom probably can fill in the gaps here? Dale

[ninohernes]

The original woofer in the AR-2 has a flat, very rigid, cardboard dustcap.

[Rlowe]

Thanks dale. I'm sure it was the original as the "black glue" for the inner dust cap is the same as that used for the coil wires on the cone.

I'll try and add a picture this time. Previous attempts have not worked.

Richard