Quote:
Originally Posted by miner
BTW, Bill, what is the safer way to remove the driver? The Sf rep suggested removing the cone and pulling out by basket BUT not knowing for sure if driver was the problem I did not want to do it that way.
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FWIW This is what I did when my Cremona bass driver died.
Not sure the source of this document or I would give due credit.
"Removing Cremona driver
Removing a Sonus driver is a little bit different than with other speakers. When the driver is installed, the leather on the baffle is compressed. Once in place the leather decompresses to fill any open space between the driver frame and the baffle opening. The leather seals the enclosure and firmly holds the driver in place while decoupling it from the baffle. In fact if you overtighten the driver screws you eliminate the decoupling and degrade the sound dramatically.
So how do we remove the driver? I will assume you are alone and have no help. If you have an assistant, you won't need to lay the speaker down but they will need to catch the driver as you remove it.
First you will need 2 2' 2 x4s(or large pieces of packing foam), 3 bath towels, and some microfiber cloths (optional but recommended), a 2' x 1" dowel rod, a rubber mallet(or hammer), a flashlight, a soldering iron with a clean tip and a #2 Phillips screwdriver.
1. Place the 2x4s on the floor spaced so that the speaker's top and bottom would rest on the boards if the speaker was placed face down on them.
2. Next fold 2 of the towels so that at least 4 layers of fabric are over the entire 2x4. Then lay microfiber cloths over the towels.
3. Lay the speaker face down on the covered 2x4s. Roll it onto one side.
4. Fold the remaining towel to create a 1 foot square. Place it on the floor in between the 2x4s so that when you roll the speaker back onto its face, it will be below the driver you are removing.
5. Remove the screws holding the driver in place. Roll the speaker back onto its face. The driver may fall onto the towel at this point but it is not likely.
6. Using the flashlight, look into the port behind the driver you are removing and find the back of the driver magnet.
7. Insert the dowel rod into the port so that it is against the back of the magnet. It is critical that the dowel does not slip off the magnet. Using the mallet, gently tap the other end of the dowel until the driver drops onto the towel below it.
8. Remove the dowel and roll the speaker onto it's side. Note the orientation of the driver before unsoldering it. Unsolder it and solder in the new one making sure you maintain proper polarity. You should be able to do this without adding additional solder.
9. Orient the driver like the old one and reinsert the screws deeply enough to position the driver but not enough to compress the leather. Stand the speaker up vertically. Now screw the screws in to pull the driver tight and compress the leather. Make sure that you evenly tension all screws. Do not overtighten.
The reason that you tighten lightly is that you do not want a solid connection between the basket, screw and baffle. You pull the driver into the baffle tightening th screws. One way to do it is tighten until you feel the screw hard against the baffle and then back out half a turn. Insuring that all the screws are at the same depth is important because the leather will expand to hold the driver. Your method should insure proper alignment to the baffle.
Should you overtighten, there is potential for two problems, one of them catastrophic. The minor problem might be that you strip out the hole. The catastrophic is that you end up with a speaker that sounds like anything but a Sonus faber.
It's much easier with an assistant."
kev