Please give more information about the fabric surround.
Is it a replacement surround or one on an old speaker?
Is it a replacement surround or one on an old speaker?
I now see you have added a second image in post #1 that clearly shows the fabric surrounds.
They will probably soften with use as the speaker cone vibrates.
If you wish to make them airtight there are PVA sealants to treat and seal accordion cloth & fabric surrounds, such as this:
https://www.simplyspeakers.com/speaker-repair-adhesive-mi-1291.html
They will probably soften with use as the speaker cone vibrates.
If you wish to make them airtight there are PVA sealants to treat and seal accordion cloth & fabric surrounds, such as this:
https://www.simplyspeakers.com/speaker-repair-adhesive-mi-1291.html
A solution to this issue would be nice. Stiff Surround Syndrome has been seemn by many looking at old drivers. In particular i have seen more than a few Coral made drivers that would get a new life if this issue could be sorted.
dave
dave
So, the resonant frequency of the cone has risen after fitting the replacement surround.
Was 48 Hz the resonant frequency when the speaker was new or as measured with the perished surround?
Perhaps you need to loosen the surround by running the speaker for some time with a 50 Hz tone of reasonably high amplitude.
The PVA adhesive/sealant I mentioned earlier is unlikely to improve the elasticity of the surround, only seal it and make it airtight.
