infinity sm foam deteriation

G series

cerwin vega bass head
whats up everybody, i know that the sm series by infinity are not a very desirable model nor worth very much, but i was wondering if some one can tell me if theres an available recone kit that comes with the foam dustcaps with the infinity logo's on them and the correct surrounds. you see, my father has owned the pair for about 12 years and the foam surrounds are beginning to deteriorate, i know this because when you look at the surround there is a really fine crack in the foam where the surround and the cone meet.the crack goes all the way around the whole sub.now by crack i mean the surround is still in tact and theres no gaps any where but the best way to describe it is kinda how dry rotted tires look how they get those fine cracks in them, sorry bout the long ass post, just trying to describe this really well, and on one speaker theres a missing spot in the surround from my football,ooops, i mean cat, wher it clawed the surround one day when i left the grills off (like to watch them perform) now i know this isnt a really desirable model, but personally, when im relaxing in my living room after a hard days work with a beer and a nice cd, personally i think they thump pretty good, the bass has a nice deepness to it, but i must say if i dont watch myself on the volume nob of my sansui g8000, i'll accidently bottom them out and hear a little pop as a result, and i have looked all over the net and havent found anything, on infinitys site i looked and they had a replacement woofer but they were out of stock,if some one could point me in the right direction that would be awesome, thanks, G
 
oh, iforgot to say they are the sm-155 model in oak with hi and mid l pads with the polycell tweets and beuty rings with the gold rim on them
 
I'm going to speculate that you'll have hard time finding such a kit. It's likely, though, that a generic kit from PE (or whomever) will work fine, but of course, will have plain black dust caps. If you must preserve the original look, you can refoam them without removing the dust caps. There are several methods and everyone seems to have their favorite. As search for "refoaming" in the speakers forum should turn up tons of info. - Mark
 
whats up mark, thank you very very much :D, i think im gonna go with the refoaming process without taking off the dust caps, the only thing im worried about is it not setting right and end up with coil rub, i think it'll be alright though, i've seen some pretty ugly things do to coil rub, i had a sub one time with really bad cone drift from years of abuse/improper care and it blew, when i went to recone it the voice coil had delaminated from the former and looked like a ratsnest of copper wire, i think ill practice on an old speaker of mine just to get a feel for what it will be like, thanks for the reply, G
 
G series said:
...when i went to recone it the voice coil had delaminated from the former and looked like a ratsnest of copper wire...

I recently rebuilt a JBL woofer in the same shape...

Anyway, for shimless refoaming, some guys like the "battery trick", using a test tone, etc., but what I typically do is this: once the basket and cone are cleaned of the old foam/glue, glue the surround to the cone. 4/5 times the surround will sufficiently center up the v/c. Take 4 clothespins, binder clamps, whatever, and secure the surround to the basket at 12, 3, 6 & 9 o'clock - these locations should be marked on the basket (I'm kidding :D ). If the turned up "lip" at the edge of the basket is substantial enough, you may have to add something to the sandwich - I use 1/4" hex nuts - you use whatever. Once the surround is secured to the basket, cycle the cone in and out by hand, feeling/listening for any rubbing/scraping. I like to push off-center a bit - maybe at four places around the dust cap - you are essentially trying to push the cone off center slightly. If you pass this test with no noise, you should be good. If you notice rubbing at one or more locations, re-position the surround and do it again. Once you are satisfied that the v/c is centered, apply glue between the clamps and let cure, then remove the clamps and glue the rest. You pickin' up what I'm puttin' down? - Mark
 
Hey there G series,

I've done 3 pairs of woofers successfully using a shimless method. Just don't want to cut those nice caps off :dunno: (The last ones were the Watkins in my Q2's.....not an insignificant set of speaks to have messed up on :no: )

Anyway, the way I've done it is: , and it's only offered up as another way, another technique...definitely many different techniques out there that work for different folks.

After the foam is set up on the cone, I do the ole push down pull up check on the cone to make sure it's able to be moved without any rubbing. This also allows me to see where the centering of the foam wants to be on the basket...it's not always perfectly symmetrical. Once all looks well, and some key marks and notes are made on the foam position, I lay the glue around the underside of the foam and drop it onto the basket. Again, using the ole push pull technique on the cone to verify the alignment, slowly push the foam down onto basket squeezing out the excess glue. Moving the cone actually puts the foam into position while the glue is still soft, and as long as your aim is true while push/pulling, the foam will find it's spot. I use the previous non-glued position as a reference to see how things are going. As the foam gets closer to laying on the steel frame, it won't move as well as when there is a nice "layer" between the pieces, so the alignment needs to be "on" as time goes by.

I have used the closepins after this, to hold the foam in place while the glue sets, still testing the alignment periodically just in case.

Sounds like you have a good mechanical aptitude, so I think if you can visualize what it is that is to be achieved....VC centered in the gap.....then I think you'll find your own technique as you go along.

Yeah, you may want to practise on a less desireable set if this is your first refoam. :D

Let us know how it goes, it's always nice to have closure to someone elses project.

Good luck :thmbsp:
 
hey whats up, thanks for all the tips :D, and yes, im feelin what your sayin,lol, im pretty sure i can do this, ill let you all know how it goes down in a day or 2, thanks, G

p.s.
no i dont wanna cut them purdy caps off,lol
 
I had a guy here in St. Louis do a pair from some SM120s, but hey, I like the things for rock... I think the Orange County guys could do it too.
 
I have used the foams from MAT Electronics on 2 sets of SM 120's. I can tell you that the trim ring glued to them was the biggest PITA to get off of any refoam job I have done. Broke alot of Exacto knife blades and gave myself a few cuts in the process. Hope yours are not glued on in the same manner.
 
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