I need correct 8" foam surround

[Giorgio AR]

Even if the topic on the 8" foam is already covered, I have to ask for advice on finding a surround foam that is more in line with the original measurements.
The problem in this case is double: the 200001-1 woofer with a cone with an external measurement of 150 mm.
the woofer 538 (specific AR7) has an external cone size of 155 mm.
The original internal connection of the foam measures 142 and 145 mm respectively.
The foam I bought from Vintage AR (now more than a year ago and never used) has a 134 mm inner edge. therefore lower than the original diameter of the 200001-1 woofer (the other foam measurements: fine cone, metal frame attachment are OK, probably apart from the aesthetics that visually decreases the paper cone, this foam has a good overall replacement ), and much smaller than the diameter of the AR7 woofer (here also the beginning of the roll falls into the cone which has a larger diameter).
I have 4 x 200001-1 woofers from refoaming and other 4 x AR7 woofers to replace the foam and I would not buy incorrect products (unfortunately buying from Italy there is a great cost of shipping and higher taxes and customs!).
Furthermore, among the 8" woofers, the AR7 is different in design from all the others, if I'm not mistaken even spiders and coils should have unique characteristics, as well as the original foam had specific roll.
I ask for competent help to find 2 + 2 pairs of foam that are closer and conform to the originals, mainly I think the biggest problem is the AR7 woofer replacement.
Below are the photos of the two types of woofers, the measures (not perfect for optical deformation), but we catch the differences and finally the foam, placed eccentric but with the left edge where there was the original attachment to show how much foam interior is smaller.

I thank all those who can help me in advance, especially in my search for the best replacement for the AR7 woofer.

Giorgio

[Giorgio AR]

Anything? No more suitable foam advice or experiences to report?
I hope to find a valid help and if possible measurements of the internal attachment of the foam on the cone, measured and different from the values I detected with the 8" foam of v. AR,.

Giorgio

[Phoenix]

Giorgio,

I understand your wariness in using generic 8-inch replacement.
I did, and I do, regularly re-foaming; 8-inchers the most frequent of them all.
Having explored the replacement surrounds market for a while I got use to some flexibility.
The inner circumference of the surround has become the least of my worries.
As far as it sits well inside the rim of the cone, it's all good.
Far more important is to get the proper width of the bump.
Commercial spares are usually too narrow in order to service well AR and Bose that used wider "hinges".
The times that i decided to be fastidious I had to resort to the US market (I'm located in Australia).
According to memory, I couldn't find the correct size at Vintage AR, I had to go through a search on eBay and, eventually, I found a trader with the correct foams.
They didn't come cheap.
Ebayers, usually, list their surrounds with the four diameter lenghts necessary to identify the ones you need.
Good luck with your quest

Alberto (alberto_baldin@hotmail.com)

 

[Giorgio AR]

On 5/9/2020 at 4:33 AM, Phoenix said:

Giorgio,

I understand your wariness in using generic 8-inch replacement.
Thank you

In the end I bought the foam surrounds in Italy, choosing the most correct ones also for the roll size. A pair of foam is purchased from Vintage AR.
I am attaching a photo with 10 speakers after refoaming: 3 pairs of 12" and two of 10", with the correct foams and with a perfect aesthetic and functional effect. It is more complicated to work on 8" woofers which in a pair have the specific paper cone and foam (AR6 and AR7), the other types of woofers should have the same foam.