Thanks for the heads up. When you said "surrounds", you mean the spongy membrane on the outer side of the vifa cone?
The circular rubber surround that joins the cone to the basket. It's a critical part of the suspension. Simplistically, the stiffer it is, the higher the driver resonant frequency goes and the less bass you get. Mine got so hard they measured over double the original spec of 60Hz.
You can soften the rubber with pure glycerol. Otherwise if they are used just as midrange, stiff surround is ok.
I wasn't able to make a permanent softening of my Vifa surrounds but didn't try glycerol. Will have to get some. I found a foam surround for a small Boston Acoustics midwoofer that resulted in a fairly close match of the TS parameters after installing on the P13's. A bit of a pain to remove the original surrounds but can be done. A supplier in Netherlands, Audiofriends, also has OEM surrounds available. A bit spendy after shipping to US.
https://www.repairyourspeakers.com/...-surround-sr115-2-kurt-muller/a-2966-10000025Good luck with yours,
John
https://www.repairyourspeakers.com/...-surround-sr115-2-kurt-muller/a-2966-10000025Good luck with yours,
John
OMG! I just checked the surround, and yeah... It stiffens. Thx @nerdorama for the link. Might come handy for sure. Audiofriends has a video showing how to change the surround also. You guys are the best!
OK, I bite the bullet. I ordered the surrounds & some glue from Audiofriends. Shipping & handling are reasonable within Europe and they shipped promptly.
FYI, the surround they are selling is SR115/2.... whilst the original vifa P13WH has SR115/1 (see the photo). But, the specs between SR115/1 & SR115/2 are nearly identical (eg. diameter differs only 0.5-1mm). My next step will be the surround replacement surgery. Btw, I saw your p13wh surround replacement in Audiogon, John. Seems like it's not too difficult. I will post my progress in building this MLTL Ariel.
