Are these speakers worth refoaming? I picked them up on Freecycle and they are in good shape.

I'd say yes.

People love the EMIT tweeters more, but the Polycell, if not their best, is still good. In my opinion.

Some say great performance, some say maybe a tad muddy in the bass, but for free, and $20 in foam, and a few hours, they'll shame most anything for 10 times as much that you'd buy new nowadays.

I've got a pair I'm going to refoam myself too.

G'day from fellow Infinity fan in Australia

I have owned a pair of "reference studio monitors" (12" bass, mid, emit tweeter and attentuation panel on angled stands) and a pair of sm120's (the less said about these the better) since new. I think it was 1984 or maybe 1985 I bought the rsm's and 1989 the sm120s. I bought the rsms here in aust but bought the sm120s at the clarke airbase px in the phillipines. Anyway, all have suffered from the dreaded foam rot, here I was thinking it was only a problem in australia, but it seems it happens elsewhere. Infinity has never responded to any of me emails asking what can be done about it, not even offering to sell me replacement drivers, so I assume they dont care about past customers and I thought all was lost until I discovered this site :) Where do you people get replacement roll surrounds for 12" woofers? Do they come as a kit and are they foam or rubber? Do the suppliers sell online and ship os?

Any advice appreciated.

JAS

Welcome to AK and the Infinity forum Jason!

Site sponsor Parts Express sells a nice kit that should work fine, look at the bottom of the page here for the link.

Jason,

Welcome to the forum. Now, not to chase you away, but if you search this and the Speaker forum you should find many threads and posts on refoaming, re-edging, surrounds etc. The more you read you will catch on to the buzz words and be able to do more searching.

Here is a link to a post in a sticky here on the Infinity forum with a few good links to refoaming (especially the movie, it's good, it's visual:thmbsp: ): http://audiokarma.org/forums/showpost.php?p=686218&postcount=11


Depending on the speaker, getting the right foam surrounds can be tricky. A few basics are in order.

(1) The foams are mounted either on the outside of the cone or the inside of the cone. The foam sizing is a little more critical for the inside mount, because the diameter to the inside of the roll has to just clear the outside diameter of the cone. Mounting to the inside is a little bit more tricky to do as well, but not insurmountable :D There is debate here about keeping an original inside mount intact vs just doing the refoam on the outside. I'm a purist, and like to keep mine original, also the Voice Coil position could be changed IMO.

(2) There is an angle mount style, and a flat mount style. The 12" Watkins woofer is a flat mount. The outside periphery of the cone has a flange that is parallel to the speaker baffle plate. The inside and outside flanges of the surround are both co-planar. Most cones just end at the cones natural angle, therefore the inner flange of the foam surround is angled wrt to the outer flange. Again, I like to keep the replacements the same as original so as to not affect the voice coil position.

(3) Refoam techniques. This is worth researching. There are a few different methods of ensuring that the voice coil is properly centered after the new foam is glued in place.
(a) Shimming the voice coil. Requires cutting off the dust cap and putting another on. If you get into the details, there are different types of dustcap materials and shapes. In some driver designs, the dustcap is an integral part of the system.
(b) Not shimming, leaving the dust cap on, and using tactile senses to feel that there is no voice coil rubbing going on during the curing of the glue to the basket frame. (my method :yes: )
(c) Not shimming, leaving the dust cap on, and using applied voltage signals to the voice coil to naturally center it in the magnetic field.
(d) Others I'm sure :D


Another interesting thread in light of the above:
http://audiokarma.org/forums/showthread.php?t=99675&highlight=speaker+refoaming

Well, this is a start. Like I said, there is a wealth of info on the AK site. Yours to find and learn, and develop your own unique refoam techniques .

Also, I'm sure there are suppliers in Australia that sell foam surrounds and/or kits. Although if you can find an store online that sells your model specifically in a kit, then you know you are getting a proven system.

Good luck. Keep us posted on your progress and results. Always fun to share.

For Jason (If he ever comes back); Foam Surround online store in Australia:

http://stores.ebay.ca/QUEENSLAND-SPEAKER-REPAIRS

Thanks for the link :) I'll be back often :) On another note, I also found another local supplier of surrounds but they are rubber, does anyone have any opinions/preferences on rubber versus foam?

Jason,
A belated welcome to the forum. It is additionally nice to have someone far away as a member here. The folks here are nice and knowledgable. Stick around and share the campfire.
Vito

Thanks for the link :) I'll be back often :) On another note, I also found another local supplier of surrounds but they are rubber, does anyone have any opinions/preferences on rubber versus foam?

Well, I always keep them stock, even if I do not know what the difference will be if any.

Vito

I agree with Vito. Keeping the surround the same as the original type, ensures the driver characteristics stay the same, hence the voicing or sound of the speaker will be the same, plus avoid any damage due to possible overexcursions etc of the cone/voicecoil.

Now, I haven't come across any discussions on the topic of replacing foam surrounds with rubber, but that indeed could be very interesting :scratch2:

It would take some experimenting on expendable drivers with measuring equipment to compare before and after driver parameters,