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A Most Unpopular Subject

cason

cason

AK Subscriber
Subscriber
Hello all,
I have a pair of Bose 901 series V speakers in need of new surrounds. I'm considering undertaking this project. Parts Express has a foam surround kit for $40; Orange County Speaker has a cloth surround kit for $80. Which way should I go? Why? I am a novice at this, so your experience and advice is most welcome.
Thanks,
Bob
 
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cason said:
Hello all,
I have a pair of Bose 901 series V speakers in need of new surrounds. I'm considering undertaking this project. Parts Express has a foam surround kit for $40; Orange County Speaker has a cloth surround kit for $80. Which way should I go? Why? I am a novice at this, so your experience and advice is most welcome.
Thanks,
Bob
Click to expand...

Generally on woofers you want your new surrounds to match as best you can the original surrounds. Otherwise, woofer stiffness and performance will be radically different than the designers intended.

Hope this helps ...

Regards,
Jerry
 
What he said ^

The 901's had either cloth or foam surrounds depending on which series they were. Replace the surrounds with the original material.
 
Replacing woofer surrounds is probably one of the most popular subjects here. Or were you just expecting a lot of Bose-bashing replies?
 
Well it seems to me the deal is the agony of replacing 18 little surrounds.

If you plan on keeping them for more than 20 years, use the cloth, which was original to the first versions.
If you don't plan on keeping them fewer than 20 years, or don't mind refoaming again in 20 years, use the foams, which were what Bose used in that model. I'd go the foam route myself as I doubt you'll have them for a couple more decades...
 
I acquired a cheap pair of 901 Series IV over the summer out of curiousity and am in the process of refoaming them in my spare time. I had similar questions regarding foam vs cloth but decided to go with the foam because that's what the system was designed for. I also think that the new foam materials are far more durable than the OEM stuff. I've got a pair of JBL LE10s I refoamed in the mid 80s that show absolutely no evidence of degradation so I'm not too worried about longevity. BTW, you'll need two of the PE kits as they only do 9 or 10 drivers and a 901 pair has 18 drivers. Can't speak to the Orange County kit.

I've found the refoam process to be tedious and a bit more tricky than typical. I chose not to remove dustcaps so no shims. Unfortunately, the cones are small and the tinsel wilre is stiff enough to seriously mis-align the cone if one isn't careful. Also, the PE foam is not an exact fit to the edge of the cones, at least on my drivers, so further care is required to be sure that both surfaces have adhesive on them and properly contact each other to prevent future buzzes. I also use an oscillator to drive the speaker at low power during the refoam process to verify alignment prior to adhesive cure.

I've finished one system so far and the sonic outcome is unconventional but encouraging. The second should be complete in a couple of weeks so we'll soon see what they can do as a pair.
 
A friend of mine was going to undertake this same project and was told to pull one driver at a time due to the confusion of the # of connections. It seems a reasonable suggestion to me. I too would suggest replacing the surrounds with whatever was original to your drivers and also to make sure you are labeled as to your wiring phase. I usually take a pic of my drivers before I unwire them just to be safe, except on the JBLs who had the sense to polarize the plugging.
 
If they came with foam, then foam is what you need to use. Otherwise, you will be changing the sound, and not necessarily for the better.
 
Thanks guys,
The "unpopular...." was because I know Bose products are not universally loved (tongue firmly in cheek). If I decide to do this project, I'll go with the foam as that's what these have now, and doubt I'll still be listening to them 20 years from now.
Refoaming these seems like a project that may not be worth the effort, as I doubt they'll be an improvement over speakers I'm using now. May just decide to sell them "as is" and let someone with a greater interest/appreciation of these speakers put their effort in them.
Thanks,
Bob
 
I have a set of Series III and a new set of cloth surrounds to go on them - Orange County swore to me that the cloth surrounds match the properties of the old foams. This project is about 5th in line at this point, however.

By the way, I have read that the 901s can be refoamed without taking the drivers out of the enclosure at all. Don't remember where I saw that, but it was on the net somewhere.
 
Go with the foam.

No bashing here, as I happen to really like Bose 901s (if they have the EQ and the pedestal stands)... but I prefer Porsche 901s.

porsche_901_65.jpg
 
A friend of mine refoamed his 901 Series III with cloth surrounds. They originally had foam. He found it made the drivers too "tight", restricted their travel and altered the sound and not for the better. The foams allowed the drivers much more travel. The original 901 series that used a doped cloth roll with lots of travel for the drivers, I am suspect of these new cloth surrounds that are being sold for the 901's....:scratch2:
 
I just did a set of series 4s. piece of cake. I used the parts express kit. They sound like new. You can do them in place with no problem.
 
Celt said:
Before it begins, no bashing will be tolerated. The OP posed a question, please address it if you want to respond.
Click to expand...

this is why I love AK . . . :yes:

everyone is encouraged to play nice and respect each other's opinions & gear :boxing:

thats a whole lotta refoaming to do - aren't there 12 drivers per cabinet ?

I watched birddog refoam a pair of Cerwin Vega woofers, and I learned the last key piece . . . glue either the inside, or outside edge first - don't do 'em at the same time :nono: my 1st large advents I tried doing the whoel surround all at once, and it's not pretty :no:

you could probably get a nice little assembly line going - invite some friends over and it can be a 901 refoam sweatshop :D
 
markus said:
this is why I love AK . . . :yes:

everyone is encouraged to play nice and respect each other's opinions & gear :boxing:

thats a whole lotta refoaming to do - aren't there 12 drivers per cabinet ?

I watched birddog refoam a pair of Cerwin Vega woofers, and I learned the last key piece . . . glue either the inside, or outside edge first - don't do 'em at the same time :nono: my 1st large advents I tried doing the whoel surround all at once, and it's not pretty :no:

you could probably get a nice little assembly line going - invite some friends over and it can be a 901 refoam sweatshop :D
Click to expand...

Its great to play nice, but if you don't like a piece of gear it should be perfectly acceptable to say why. If we all say something is great, and can't express our opinions, people can be misled. I would like to hear peoples true opinions.

If someone does not like something, I want to know why. With a little thought, people could express there opinions, without being confrontational.

I myself enjoy the Bose 901 speaker. I have a series 1 with cloth surrounds. I never had the chance to hear the Series V 901's, but if I owned a pair, and had to refoam it..... Id go with the original foam material.

By the time you need to to refoam them again. Chances are, depending on your age, you will be dead or retired. If your retired, you will be looking for something to do anyways, and will probably enjoy sharing qaulity time with either your Son, or Grandson. I say, go with the foam.


Edit: (Only 9 per cabinet, not 12)
 
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klama2006 said:
Its great to play nice, but if you don't like a piece of gear it should be perfectly acceptable to say why. If we all say something is great, and can't express our opinions, people can be misled. I would like to hear peoples true opinions.

If someone does not like something, I want to know why. With a little thought, people could express there opinions, without being confrontational.
Click to expand...

In this case, the OP was asking for advice on repairing his speakers, not for opinions about them.
 
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