How to Refoam the Woofer of an Infinity SM152 Speaker and clean the potentiometer
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- Опубліковано 2 лип 2024
- By checking out online this video • Speaker Repair Infinit... I was able to refoam the woofer of an Infinity SM152 speaker. I made a video form this job since it might be nice to show you that it really is quite easy, not only for the professional. This video can apply to any other woofer refoam job (for tweeters you might want to have some professional centering equipment).
During the drying of the glue I was also able to fix the potentiometer that is in the filter. This is also explained somewhere on youtube but that is usually done with air and is quite likely to fail again soon. - Навчання та стиль
One last thing- when I refoam these SM woofers, I've never glued the trim rings onto the new foam surrounds. The tension of the ring alone is fine, and the surround being glued to the basket is more than sufficient. There's no need to glue the trim ring AT ALL. All that will do is expose the surround to additional unnecessary glue marks and blemishes. For the surround, we want to use as little glue as possible for the whole process to keep the cone as light as possible. For the trim ring, it already has the tension of 8 screws which hold the plastic against foam just fine.
Just revisiting this to give some advice after I've reconed quite a few of the SM woofers. It is extremely important to test fit the trim ring around the surround BEFORE you glue the outer edge of the surround to the basket!!! Two of the largest distributors of "Infinity refoam kits" are shipping surrounds which have a relaxed width that is wider than stock. As I found out the hard way, simply gluing the surround to the basket where the edge naturally lies is a bad idea. When it dries and you go to install it into the cabinet with the trim ring, you'll find that in many cases, the trim ring cannot fit around the surround! OR.. it might clear it but make contact with it, resulting in buzzing noises as the surround squeaks against the inner surface area of the trim ring. What you have to do to avoid this is be mindful of where you should set the surround when gluing it to the basket. Index marks can be difficult to see here if your glue covers them up. You may have to act quick and push the outer diameter edge of the surround inward as it sets, all while quickly test fitting with the trim ring for a visual alignment. Also, this may or may not coincide with your potential VC shimming (or alignment because you might not be shimming). And this means maybe you need to start the setting early so you have time to move the huge 14-15" surround before the glue cures! This also means that the glue is going to be more wet, and most contact adhesives will react with the foam. This also depends on what kind of foam. The larger American distributors actually are using a very porus, textured lighter grey surround which reacts more with contact cement (lime Devcon Home) than the better quality ones I find on AliExpress. It sounds backwards, but I've been getting much better quality foam from China than what large USA companies are offering. Not sure why. Anyway, the Infinity SM series are the toughest testers of patience I've dealt with.
I just checked two original sets of SM152 I have here near my bench, and I took both trim rings off to inspect the underside. They came off so easily without any effort. Neither of these were glued to the surrounds from the Infinity factory. The black plastic surface is mint condition and has no sign of adhesive. I'm not sure where the idea of gluing these trim rings came from. I did have a pair of SM82 which I restored, and on those the trim rings had some glue under them, very small amount, but it was there... so maybe only the smaller woofers were done that way.
Dit was echt een nuttige video!! Ik heb dezelfde speakers en bij mij kraken de potmeters heel erg. Contactspray werkte maar kort, na een tijdje kraakten ze weer. Ik ga het binnenkort met alcohol proberen!
Christiaan Staps goed om te horen! Contactspray zorgt voor een geleidend laagje maar oxideerde zelf ook weer heel snel waardoor ie het probleem tijdelijk oplost maar eigenlijk alleen maar verergerd. Met alcohol maak je het daadwerkelijk schoon. Succes!
I didn't hear mention about foam surrounds being melted or deformed from the use of contact cement.
How'd yo7 get the speaker outta the cabinet
SE SACAN POR DELANTE. LO HICE UNA VEZ CUANDO LOS COMPRÉ PORQUE EL TÉCNICO TENÍA QUE COLOCAR LANA DE VIDRIO A LA CAJA PORQUE NO TRAÍA. SM112 SON LOS MÍOS. CREO QUE LOS BORNES SON A PRESIÓN POR ESO FUE FÁCIL HACERLO. CUANDO SACÁS EL ARO DE PLÁSTICO (SÓLO ATORNILLADO PORQUE AQUÍ LO PEGAN?); EL PARLANTE SE MUESTRA CON EL BORDE MUY REDUCIDO, ES DECIR QUE EL ARO DE PLÁSTICO ES MÁS ANCHO. PERO BUENO, ES ALGO QUE NO SE VE DE TODOS MODOS UNA VEZ COLOCADO
Hello, can I name the adhesive and is there any of it in the Xpress?
No sorry, it came with the speaker rings. I know that the best glue is a waterbased white one, I actually think that white wood glue which you thin out a bit with water could do the job fine but you'll have to google (or just try...) that.
I cant really cleanup the rest of the foam off back of the speaker cone argh
I could say "alcohol is the solution to everything" but that's not really true. It is however what I used to clean the back and worked quite well.
@@creativewithtech3239 I'll give it another shot, maybe I wasn't patient enough. Thanks for the video