SM255 Woofers

gotitforfree

Active Member
I picked up a second pair of SM255's the other day, got them for cheap since they needed foam. In removing the old foam I found that both woofer voice coils are separated from the spider and cone completely and the coils, (visible through the frame), are burnt.
The mids, tweeters, and crossovers all look fine?
The only thing I can figure is that they drove the woofers to death after the foam rotted away and cooked the voice coils?

These woofers are aluminum framed, and appear different than those used on the SM155 model.

I'd like to find another pair of woofers for these as the cabinets are minty perfect. Not so much as a scratch on them.
The woofer p/n is 333513-001, its a 15" woofer.
I thought about just replacing the voice coils since everything is basically unglued already, but the voice coils are super long, they're not that large in diameter, but over 4" long from the cone to the bottom. There's a long distance between where the woofer stops and the windings begin, about 2 inches and the coil former is perforated with large holes I suppose for venting?

Did they use these woofers in any other model?
Any idea where to get replacement parts to fix these?
The woofer is listed as being 3.6 ohms DC resistance on the spec sheet.
 
Ebay.
You might want to set an alert.
Or just check often.

I'm going out on a limb here...I think the 2XX series was better regarded than the 1XX series.
For some reason I'm thinking the 2XX series was more common outside the USA, like overseas.
If true then you may need to expand your search area.
I do not know if other models used the same woofers.

Some one smarter than me will hopefully add to this.
 
I bet Millersound can fix them.

If I could find the voice coils, I could fix them, but the VCs are oddball looking compared to most speakers I've seen.
The magnet is set back on a bracket off the frame of the speaker, therefore the voice coil is longer. There are four or five
open holes in the frame below the spider where I can see the tube of the VC, its at least three fingers long. If I lift the cone, I can see
burnt coils. The cone is some sort of fiber with a shiny poly coating. The dust cap is almost 4" but the voice coil is smaller.
I didn't want to cut the speaker apart in case I do end up sending it out. I didn't figure they'd want to deal with a box of speaker parts sent in for repair.
Both woofer cones are separated from the voice coil tubes, but only one is burnt. The burnt voice coil also came unglued from the spider and was hanging out of the
magnet and spider when I found it. The voice coil former had slid up forward against the inside of the dust cap.
Funny thing is both ohm out perfect.

I figured it may be cheaper to just by a used pair of woofers to refoam vs. getting these overhauled. I'd be concerned that they would end up replacing the cones and all and I'd end up with something that didn't sound much like what they did when new.

Both pair of these I have here were bought in Germany by a buddy who was stationed there in the 90's.
I basically got these for refoaming the mids and woofers in his SM155's, which were also bought over there. The SM155's he's got look similar to what we see here but they had all European made drivers and a very similar woofer to the SM255 but with a smaller magnet and less depth to the cone. His SM155's had better fit and finish and the cabinets were heavier than the cheap looking boxes they have here.

These SM255's have a cabinet made from 1" particle board with a quality wood grain vinyl finish. The inside of the cabinet is broken up into four sections, with each mid having its own chamber and the tweeter being blocked off from behind as well. The cabinet is fiberglass lined about two inches thick, there are several side panel braces and stiffener panels added. These things are heavy, just under 100 lbs each.
One thing that I didn't like is that each driver is glued into the cabinet with butyl rubber, like the stuff they use to glue in car windshields. After removing the hex head screws, it takes a lot of patience to free up the speaker without doing any damage. On mine, I removed the butyl rubber sealer and made up foam gaskets for each driver.
 
Finding one of those woofers may take a while, I've got a pair and need one mid range and have been searching for over a year now. I've only seen one other pair of those other than mine.
The pair I've got was brought here from overseas by the former owner.
The woofer from the 100 series won't work, as far as I know, the SM255 used a woofer all its own. I've not see it used in any other model
 
That's just about what they wanted for them new! Without all the dings and scratches.
I remember back then when I was 'upgrading' my system, I was looking for a new pair of main speakers and an amp.
My choices got narrowed down to the Infinity SM255's, the JBL 250ti Jubilee and the JBL XPL200A. I was running a pair of vintage Hafler amps at the time and one had blown smoke taking out a speaker.
I opted for two Adcom GFA5802 amps, and a pair of 250ti speakers, but later went back and also bought the XPL200A's as well. A few years later, I ended up buying two SM255's that buddy had bought around that time, he was getting married and needed cash. The SM255's are good speakers but they are not on the same level as the JBL's.
Over the years I've owned dozens of speakers, my favorites have been the Polk SDA's, and even the Monitor 12's I had for a while. The SM255's were a good compromise speakers, they were pretty good overall with some hard hitting bass if I put enough power to them. To me they were sort of a refined Cerwin Vega or sorts. The SM255's didn't have the strong hitting bass that the CV's had, maybe not even as much as the Polks but they had their purpose. After having them all these years, I can say I wouldn't spend $2500 on a pair, new or otherwise. They fall into that 'also ran' category so to speak.
 
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