Hey guys, I recently moved into a new house and they left behind some Norman Laboratories model 52 speakers they bought in the early 90's. They left them behind because the surround had dry rotted. I almost have a complete system, so I want to repair these. How should I do this?? They have 6.5" woofers that need new surround, and i wanted to know if any had any experience with Norman labs speakers, not many people do.
Norman Labs Surround Repair
- Thread starter bob1033
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terpodion
Active Member
I have no experience with Norman labs but I'll look them up. The trick with any re-foam job is using the right surround. Many foam kits are generic - one size fits all woofers of a given size. You may end up significantly changing the woofers T/S numbers, and not for the better.
terpodion
Active Member
Norman Laboratories is now, unfortunately defunct. Their speakers are desirable however. Your model 52s are of a sealed design. I'm in a similar situation with a pair of AR TSW310s which have rotted surrounds. The surrounds needed to minimize change to this type of woofer's characteristics are the thinner ones used on such woofers - AR, Advent, KLH, etc.
There are several companies that sell surround kits; Speakerworks, Midwest Speaker, My Audio Addiction, etc. But again, the key is getting the right one - not a one size fits all generic.
As far as the actual process of getting the old ones off and putting the new ones on; A lot has been written about it, what solvents to use and not use - acetone, alcohol, brake fluid - and what glues to use, and not use. There are many threads on Ak about replacing foams surrounds.
There are several companies that sell surround kits; Speakerworks, Midwest Speaker, My Audio Addiction, etc. But again, the key is getting the right one - not a one size fits all generic.
As far as the actual process of getting the old ones off and putting the new ones on; A lot has been written about it, what solvents to use and not use - acetone, alcohol, brake fluid - and what glues to use, and not use. There are many threads on Ak about replacing foams surrounds.
terpodion
Active Member
I forgot to mention Simplyspeakers.com. This may be the kit for you as it is for another sealed box design - the Baby Advent. Check everything before ordering - Cone size, type of cone mounting (flat or angled) and outer edge size:
http://www.simplyspeakers.com/advent-speaker-foam-edge-repair-kit-fsk-6.5.html
I'm glad that you brought this subject up. They have surrounds that seem to be the correct ones for my AR TSW310's.
http://www.simplyspeakers.com/advent-speaker-foam-edge-repair-kit-fsk-6.5.html
I'm glad that you brought this subject up. They have surrounds that seem to be the correct ones for my AR TSW310's.
mynameisphun
Active Member
I have a set of 52's as well, and literally the first time I played them (bought a couple years ago) the foams self-destructed. Mine are still in need of foam as well - I bought MAT Electronics surrounds, but haven't fitted them yet.
Yours is the first pair of 52's I've seen besides mine.
Yours is the first pair of 52's I've seen besides mine.
terpodion
Active Member
Yes. There are all kinds of complicated things going on with surrounds. Before I knew much about driver design, I wondered why supposedly competent designers of quality speakers like JBL and AR would use cheapo foam surrounds when they knew that they would in time rot. Well nothing lasts forever - entropy - even rubber surrounds will dry out and fail - it just takes longer. Rubber has different damping qualities, which (among other things) will affect the upper range of the woofer - the midrange. Those designers weren't being cheap. They knew what they were doing.
einstein812
New Member
So happy that these old forum posts are long lasting...I just picked up a pair of Norman Lab Model 52's as well and in need of new surrounds. mynameisphun and bob1033, you both appeared to use different replacement surrounds and I was curious how each worked out. I plan to order replacement surrounds today and your feedback is much appreciated.
