CMT-340 Surround Foam Rot

[jparr]

Yup, noticed one driver had foam rot, looked at the other side, and sure enough, three of the four drivers have separated the surround from the basket. All on the lower half of the cone. Has anyone else seen this? The speakers aren't particularly old. Purchased 2005 or thereabouts I believe.

[curtis]

first I have heard of this problem. Can you post some pictures? Have you ever used anything to clean them? What kind of climate do you live in?

[jparr]

first I have heard of this problem. Can you post some pictures? Have you ever used anything to clean them? What kind of climate do you live in?
Never cleaned them, other than an occasional (maybe once a year) wipe down with a dry cloth to remove excess dust. Climate is hot and humid, speakers do not get direct sunlight.

[curtis]

Are these SE's or classics? Pictures would be nice.

Now that I think about it....2005 would be classics, and I don't recall what the surrounds look like. The surrounds on my 170SE woofers seem to be rubber. I will have to take a close look at my Parents' classic set.

I am sure Ascend will take care of you.

[davef]

Yup, noticed one driver had foam rot, looked at the other side, and sure enough, three of the four drivers have separated the surround from the basket. All on the lower half of the cone. Has anyone else seen this? The speakers aren't particularly old. Purchased 2005 or thereabouts I believe.

Very sorry to hear this... However, our woofers do not use foam surrounds (classics or SE's) and are not subject to "foam rot". Our surrounds are made from butyl rubber and they will not rot.

We have never received any reports of anything like this and we probably have over 30,000 of these woofers out there. You mention that this problem has occurred on the lower of half of each woofer -- this leads me to believe that there must be some form of environmental factor at work.

Please forward me some pics of your setup so that I can evaluate.

Thanks in advance!

[jparr]

Finally got around to take a few pics of the surround. Three of the four drivers are in identical condition.

http://www.gonzorock.com/gallery/v/Jeremy/Ascend/

[davef]

Finally got around to take a few pics of the surround. Three of the four drivers are in identical condition.

http://www.gonzorock.com/gallery/v/Jeremy/Ascend/

Thanks for posting the pics. After closely looking at the pics, without question, there is definitely some sort of residue on the drivers that has eaten away at the rubber surround and has even started to damage the magnet assembly. If you notice on the pics of each woofer, the tear in the surround is always located where the residue is present. In addition - what really concerns me is picture # P1013732 -- the back of the magnet and label are also showing signs of pitting/rotting. That is not good....

While this would not be considered a warranty issue, we will assist you in replacing the woofers at a fair cost. However, whatever is eating away your speakers might also be eating away at the speaker internals (crossover components etc.). You need to find the culprit what is causing this else this type of damage will simply happen again.

I would recommend sending us the complete speakers for thorough evaluation.

[davef]

Also,

Looking at these again, if you notice there is a lot of residue on the top side of the phase plug and then on the lower half of the woofer cone. This tells me that something is sprinkling downward on to the speakers.

What type of ceiling do you have? Are there air vents above the speakers? Some form of caustic material is sprinkling downward on to your speakers...

[jparr]

Also,

Looking at these again, if you notice there is a lot of residue on the top side of the phase plug and then on the lower half of the woofer cone. This tells me that something is sprinkling downward on to the speakers.

What type of ceiling do you have? Are there air vents above the speakers? Some form of caustic material is sprinkling downward on to your speakers...
The residue is just dust ;-). The speakers are near a window which is open most of the time. Ceilings are painted wood. The three drivers have their surrounds torn on the lower half of the driver, the upper half is intact. Due to shipping expenses (I'm outside the US) I can't ship back the whole cabinets, but could probably send a single driver. The shielding on the back of the driver is definitely corroded, the air is very humid here, and there is ocean within a half mile of my house, so there is also plenty of salt in the air.

[davef]

Salt is highly corrosive and could definitely be the culprit. Since you are not in the US, I would strongly recommend taking the speakers apart and thoroughly cleaning all the components. It will be worthwhile to inspect the crossovers -- salt will also corrode the copper on the PCB and any exposed metal. From there, we can make a thorough assesment as to the best way to proceed.

Honestly, in the environment you have described (open window, very humid and salty air) -- you might be better off with speakers designed for outdoor use. Even with replacement woofers, this same type of damage will most likely occur again (for any indoor style loudspeaker). Speakers designed for marine use would be your best option (sound quality will suffer though :( )

[jparr]

Salt is highly corrosive and could definitely be the culprit. Since you are not in the US, I would strongly recommend taking the speakers apart and thoroughly cleaning all the components. It will be worthwhile to inspect the crossovers -- salt will also corrode the copper on the PCB and any exposed metal. From there, we can make a thorough assesment as to the best way to proceed.

Honestly, in the environment you have described (open window, very humid and salty air) -- you might be better off with speakers designed for outdoor use. Even with replacement woofers, this same type of damage will most likely occur again (for any indoor style loudspeaker). Speakers designed for marine use would be your best option (sound quality will suffer though :( )
On that note, I pulled the crossover and took a look, it seems to be in great shape compared to the woofers.

[jparr]

On that note, I pulled the crossover and took a look, it seems to be in great shape compared to the woofers.

It does beg the question though, whats the switch on the crossover do? ;-)

[get_zwole]

this sucks man sorry to hear. is there anyway you could move them away from the window a bit? Im sure like Dave said its probably the salt. Those speakers def. look bad, ive had mine almost 1.5 years and they still look brand spankin new.

[davef]

I am pleased that the crossover is in good shape!

Send me an email or PM and we can discuss woofer replacement.

Thanks in advance!