Refurbish Apogee Duetta Signature

[WongKN]

At the moment, I have decided to do some simple refurbishing of my Duetta Signature on my own while slowly accumulating the funds for the ribbon replacement. Currently both MRT and bass ribbons plays fine though there is slight buzz on the bass ribbons. I have already discussed with Graz with regards to the logistics and cost of doing the ribbon replacement and general reconditioning of the speakers and due to a very unfavourable exchange rate between the USD and RM (my local currency), I am planning for this only in the near term future, perhaps as far away as a couple of years time. In the meantime, I have been studying the condition of my DS and have found several areas where I can do some repair and refurbishing of my own, and which if I exercise care, that should not affect the efficiency of my future ribbon replacement.

I have already started two previous threads on this effort but as I foresee I will be asking lots of other questions on other areas of the speakers, I decided to just start another new thread and focus everything on this thread only from now on. Unfortunately I am a bit late to this 'game' and most people who are doing what I am doing have already done so, so there will probably be little interest in my effort. Still I hope that I will get guidance and advice from this forum instead.

At the moment, thanks to feedback and advice from the forum, I have determined that the shop assistant whom 'refurbished' my speakers prior to selling them to me did a very poor job. My immediate focus is to correct the errors that he made, one is that he covered the front of the MRT with the socks. This I have now done quite successfully.

My next focus is on the strips of foam which are placed on the -face-, the front of the speakers. There are six such strips.

1. Two strips of foam runs along both sides of the MRT assembly and sits on top of the ribbon strip attached to the side of the assembly. The photo below shows them. As expected, due to age, the form has disintegrated into powder.


2. One strip of foam on the surface of each of the clamp/blocks that holds the bass ribbon, totally four strips of foam as there are four such clamp/blocks, two horizontal top and bottom and two vertical on either side of the bass ribbon 'window'. The photo below shows two of them. Like the foam above, they have also disintegrated.


I have used foam strips before, supposedly weatherproof ones designed for use on exteriors and supposedly long lasting. All of them disintegrates like this and generally leaves a mess. However as Apogee has used them at these areas, so I believe they must be put there for a reason. So my questions:

1. What are the function of these foam strips ? My gut feel is that they are used to 'seal' the bass and MRT ribbon 'windows' against the back of the cover so isolating them and enhancing their working efficiency. If so, I am getting degraded sound as the originals are rotted bad.

2. Instead of using foam strips, I am thinking of using vinyl rubber strips instead. These performs the same function as foam strips for sealing of window and door frames but is made of rubber. I am currently using them on my door and window frames instead of foam and they have lasted a lot longer and actually seals better than foam. However, they are also a bit less soft than foam. But, as the original foam strips are simply pressing against the back of the cover, the softness/toughness should not matter that much I think. One type of vinyl rubber strip I am referring to is below. Any thoughts or comments or feedbacks on this ?
http://www.raven.com.au/domino/raven/RPCEN.nsf/$defaultview/4882AC561F008837E9256B6E00085B1D

I thank everyone who have taken the trouble and interest to read this far and for any comment and advice that will be given.

Best Regards,
WongKN