The fog is lifting...;-) Thanks much for your great explanations! I am wondering about the 'shimming' procedure that you mentioned in Pepps' thread. Is the gap marked with the arrow where you shim with the plastic strips? (Pepps: I hope you do not mind that I borrowed your pic - thanks for posting it! - I like to look at things before whipping out the carpet knife...;-).

HarryPierce wrote:

Is the gap marked with the arrow where you shim with the plastic strips?

Exactly right, be very careful with the shimming part, its important to get the same amount of strips at all 3 points, and all strips all the way to the bottum of the gap, therefore I allway cut the strips to the same length, and check that the cone moves in and out a little harder than free.

The check with a 0.1 Mm strip, where the cone moves hard with the 0.1 inserted at one point, and nearly freely when not there, is the best way to check it, take your time shimming.

Got it. With regard to glue, is the sticky glue you mentioned "Aleene's Original Tacky Glue"? Seems there are a variety of Aleene's out there.

On a different note, can you recommend a good source for the capacitors in the crossovers?

Thanks!

HarryPierce wrote:

Got it. With regard to glue, is the sticky glue you mentioned "Aleene's Original Tacky Glue"? Seems there are a variety of Aleene's out there.

On a different note, can you recommend a good source for the capacitors in the crossovers?

Thanks!

Glue yes, I have been surfing the US and it gets expensive, or they screw you on shipping, at least down to Mexico.

The best one in the US I think is

I ordered everything...I will report back about my experiences with this project. I hope you will get your parts soon!

Rudy

HarryPierce wrote:

I ordered everything...I will report back about my experiences with this project. I hope you will get your parts soon!

Rudy

Done for the day ?, come to Evans Party Here

Yes that is another 'party' for me, too...recapping the humming 3000-2...🙂

HarryPierce wrote:

Yes that is another 'party' for me, too...recapping the humming 3000-2...🙂

The easy way, is to get a cap and lamp kit from Martin, before that open the unit and check the trimmer and order these too.

The problem with the 3/4000 is the front, its a PIB to get off and on.

I thought I would post an update about my 3702 project: I basically followed Soren's advice. First I removed the old foams as good as I could and cut off the dust caps:

The next step was to glue on the new foams (I used the ebay store Soren recommended - very fast and nice quality). Here it was important to not put too much glue on the foam. One wants to avoid that a significant amount of glue gets squeezed out from inbetween foam and cone since this can get messy. I had to remove the foam the first time and take 50% of the glue off, then put it back on:

Attached to cone. I simply pressed the foam on the cone going around the cone again and again and pressing them together. After ~5 min the foam remained stuck down (less glue works better...)

The next step was shimming. It turned out that laser printer transparencies are perfect. These woofers took two strips (~0.13mm thickness) in three locations. After putting them in the speaker cone was almost immobilized, but would still move if pushed.

Next step: Glueing the foam to the cage. Here I used a perfectly matching dinner plate to hold it down during drying:

One day later, I glued the dustcaps back on. A thin layer of glue does it (glue is still white in the pic):

On to the cross overs (again followed Soren's advice, and bought from Parts Express; a nice experience):

Here the old crossover:

And here after cap exchange:

I tried to match the original capacitances as good as possible, i.e. I used some combinations in parallel, since the original values were not available.

Strange thing: The original caps seemed to have been mostly ordinary polar electrolyte caps. I guess one can make an argument that that may work since the signal is mostly true AC without DC component, i.e. the electrochemical dissolution of the electrodes under reverse bias should reverse itself during the next halfwave at opposite polarity...I measured the ESR and capacitance of the old caps. Most seem to have survived well...all except the 12uF ones were at spec.

The next step was cleaning off the doghair from the sticky midrange speaker (quite a mess!!). Ethanol finally did it, but most of the sticky laquer came off in the process:

I am wondering if I should leave it like this, or paint them again with some glossy black??

I still did not put the woofers back in. I am discussing right now the philosophical question whether to insert cable terminals into the back panel of the speakers or leave everything original with the cables directly soldered on to the crossover...Right now I am leaning towards the terminals and using nice modern cables.

HarryPierce wrote:

I still did not put the woofers back in. I am discussing right now the philosophical question whether to insert cable terminals into the back panel of the speakers or leave everything original with the cables directly soldered on to the crossover...Right now I am leaning towards the terminals and using nice modern cables.

I would go for the terminals, all other speakers I have repaired has terminals, and its a lot easier to get the drivers out with terminals.

I didn't get my caps from Martin yet, so I could not preceed, Parts Express wants me to buy for at least USD 50.00 and then they charge me more or less the same for shipping to Mexico, so I will just have to wait until I get up there, or try again with Martin.

Now please get on with it, I'm real curius abaut the result.🤒

About the old caps, they are bipolar, but just marked with plus and minus, because in some positions they use the shield as ground connection.

About the lacquer on the mid range, there are some special brands out there, but I dont know anything about it, so maybe another member could give some advice about it.

Very good job and lovely pics. Congrats