My first re-foam project, the PSB 40R

Over the last year I've managed to accumulate a few sets of used speakers, and soon some of them can be called "vintage" . I picked up a set of "near perfect" cosmetically 40Rs. The original owner had never taken the grills off, so everything was original, and surprisingly looked in good shape, no cracks on the foams, grills are near perfect with only a couple small threads sticking out, all drivers worked and the vinyl veneer was immaculate. This is what one of them looked like a I got it home:


So over the course of a weekend with me wanting to hear them, I managed to bust both foams with one session of the Crystal Method at a pretty tame volume. Yikes!


While researching re-foaming these, I realized there is basically not a lot of information available online about the R series from PSB. There are very few pictures (couple on e-*ay), literally no literature or reviews. The literature I'd like as a collector and information nerd, otherwise it's not important to me. Here's a showing of some specs.


So reading a few dozen threads here at AK led to me GordonW of AudioAtlanta(AK sponsor) for the supply of proper surrounds. A couple weeks later they arrived. Apparently there are several types of woofers in 40Rs, as was mentioned by Gordon. Mine happened to be of the EPI variety.


I followed instructions from the internet, which I think they are basically the same everywhere, just with different glues. Here's some pics of the woofer numbers I snagged.



And here is my stripped woofer, ready for the new foam.


I found the second woofer easier to do. I'd not put enough glue on the first one to allow me to shift it easily. Second time around I used a bit more glue and managed to do a better job IMO.

I didn't shim but used the 30 hz test tone method, and as far as I can tell it worked well. I'm a bit concerned about whether or not the job is done well, or if it would be considered a hack job :nono:. How noticeable is a botched refoam job to spot or hear? I know my job wasn't perfect, but I want to make sure I won't damage the woofers.

At any rate, I've been listening to them all weekend and they sound great. Furthermore, they passed the Crystal Method - High Roller (note, speaker busting track not quite mentioned earlier) test with flying colors. Here is a pic of the first 40R I refoamed.


I just wanted to thank all of you who before me learned how to do this, and have shared your experiences and knowledge which allowed me to do this project. And a big thanks to GordonW/AudioAtlanta for providing me with an easy ordering experience, good help and some good products.

I've got loads more pictures, but you've all seen lots of those threads, so I just wanted to add some PSB 40R information to the site, and the WWW and to say thanks to you guys. :yes: :tresbon:

Cheers,

THC

Did you glue the new surround to the top of the cone or underneath it?

HomeBody said:

Did you glue the new surround to the top of the cone or underneath it?

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I glued it to the top of the cone just as the original (see the first and last pics for before & after). I also have a pair of 70Rs that need to be refoamed soon as well, and they will be much harder (I'd expect as much anyway) as they are glued to the back of the cone and I haven't yet found a foam replacement for them.

I gotta say, these things sound great!! I is very 'appy (Bromwell High reference )

Cheers,

THC

I've paid attention to several cone suspensions and have noticed that oem surrounds are, indeed, affixed to the underside of the cone's lip. Facing a refoam project myself, and surfing the 'net hi and lo...it is apparent that all 'How To' instructions point to the path of placing the foam atop the cone. This raised alot of curiosity as I'm wondering if the speaker's compliance is altered.
I understand that the spider must be true and level. This makes sense.
So, I wondered if people that are refoaming are considering this aspect (spider relationship)

Perhaps all the instructional video's you've seen are for woofers that are supposed to have the surrounds attached to to the tops of the cones? I imagine the speaker compliance would most definitely be changed if you altered the surround in any way (stiffness, thickness, size, material, top/bottom attachment, etc). I expect that most people put their replacement surrounds in the same place the originals were though I suspect not nearly all of them are replaced with proper or identical to original units.

I can tell you that I didn't consider the "spider relationship" directly. I suppose you could say that I did, considering I found an as identical to the original foam surround that I think could be found and read instructions and such...?

Nice job!

FWIW, when I can't get ahold of a proper surround (i.e. something like the specific surround for this pair) I sometimes glue to the opposite side of the original surround if it's really a stretch. Most of the time you don't have to do that, and its foolish to do so if you have a properly fitting surround.

TwoHardCore said:

I glued it to the top of the cone just as the original (see the first and last pics for before & after). I also have a pair of 70Rs that need to be refoamed soon as well, and they will be much harder (I'd expect as much anyway) as they are glued to the back of the cone and I haven't yet found a foam replacement for them.

I gotta say, these things sound great!! I is very 'appy (Bromwell High reference )

Cheers,

THC

Click to expand...

Having had experience with both types, I feel that the surrounds that go under the lip of the cone are easier to put on, so I wouldn't feel intimidated if I were you. I had a pair of those PSB's. The tweeter is excellent.

Sir.Byrd said:

Nice job!

FWIW, when I can't get ahold of a proper surround (i.e. something like the specific surround for this pair) I sometimes glue to the opposite side of the original surround if it's really a stretch. Most of the time you don't have to do that, and its foolish to do so if you have a properly fitting surround.

Click to expand...

Thanks Sir.Byrd for the information and encouragement!

sealy said:

Having had experience with both types, I feel that the surrounds that go under the lip of the cone are easier to put on, so I wouldn't feel intimidated if I were you. I had a pair of those PSB's. The tweeter is excellent.

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Thanks for this info sealy! It seems strange to me that it would be easier to do these ones, but I'll take your word for it :yes:. Most of the PSB's I have also have this same tweeter; all 5 speakers in my home theatre plus the 40R & 70Rs. I think PSB has used this tweeter (or a 3/4" version of it) in a lot of their boxes (earlier ones w/out ferrofluid) over the years!

Cheers,

THC