I have spent several hours over the past two days searching for size/shape compatible surrounds. The most likely candidate so far are surrounds from Simply Speakers.
The surrounds attach to the underside of the SBX500 woofer discs which is a shiny metal surface - presumably aluminum.
Two years ago I attempted surround replacement to the undrside of 5" woofers with a poly cone and those surrounds coincidently came from Simply Speakers. That attempt was not successful due to the awkwardess of accessing the underside of the cone and the clear, fast setting adhesive provided by Simply Speakers. I think that clear glue was rubber based. There was not enough time for me to position the surround on the cone before the glue got too stickey to work with. They then sent me some conventional slower setting white glue.
I expect that gluing a surround to the underside of these Technics SBX500 woofer discs will be fiddly and somewhat time consuming. My question is will the conventional white' slower setting glue bond properly with the metal surface of the disc's inderside?
The attached photos are as they are now. The residual old surround material on the disc's underside is still in place. I am debating on attempted removal by blade & scraping or trying some type of solvent.
The surrounds attach to the underside of the SBX500 woofer discs which is a shiny metal surface - presumably aluminum.
Two years ago I attempted surround replacement to the undrside of 5" woofers with a poly cone and those surrounds coincidently came from Simply Speakers. That attempt was not successful due to the awkwardess of accessing the underside of the cone and the clear, fast setting adhesive provided by Simply Speakers. I think that clear glue was rubber based. There was not enough time for me to position the surround on the cone before the glue got too stickey to work with. They then sent me some conventional slower setting white glue.
I expect that gluing a surround to the underside of these Technics SBX500 woofer discs will be fiddly and somewhat time consuming. My question is will the conventional white' slower setting glue bond properly with the metal surface of the disc's inderside?
The attached photos are as they are now. The residual old surround material on the disc's underside is still in place. I am debating on attempted removal by blade & scraping or trying some type of solvent.
What a coincidence! I've had a smaller variant of this model sitting around waiting for a while. I used a water based adhesive on the first unit and it worked well. I have however checked with T7000/B7000 and it doesn't seem to affect the foam, nor the honeycomb face but not that it should.
What I did do however, was to make some jigs and plastic parts to stabilise the cone so it would stay centered. I basically kept it in a chokehold between the spokes of the basket. That helped tremendously in reducing the amount of fiddling I needed to do.
What I did do however, was to make some jigs and plastic parts to stabilise the cone so it would stay centered. I basically kept it in a chokehold between the spokes of the basket. That helped tremendously in reducing the amount of fiddling I needed to do.
Due to a prior negative experience with Simply Speakers I decided not to patronize them again. I found what I think is an extremely close candidate at Midwest Speaker Repair so placed my order there.
But I have a concern about the included glue.
They said that after 1 to 2 minutes it becomes too tacky to make adjustments. I guess I will learn by doing whether or not I can lay a bead of glue, spread it out and position the surrounds that quickly before the glue sets.
@HumbleDeer - What method did you use to remove the old foam residue from the underside of your woofer discs?
But I have a concern about the included glue.
They said that after 1 to 2 minutes it becomes too tacky to make adjustments. I guess I will learn by doing whether or not I can lay a bead of glue, spread it out and position the surrounds that quickly before the glue sets.
@HumbleDeer - What method did you use to remove the old foam residue from the underside of your woofer discs?
This is not an endorsement but have you thought about silicone sealants? Lexel is very sticky, cures much slower than normal adhesives, and stays somewhat flexible. I use it as a waterproofing sealant and if I’m not careful, it’ll glue things together that I don’t want. Because it’s so thick and sticky, it can be a pain to work with (stringy) and cleanup is not easy. It could, however, negatively react with a surround depending upon the material.
I actually have some Lexal. It was used to attach drivers onto baffles of some other speakers when fasteners were not an option. Good point on potentially reacting with surround foam. I had not considered using it thusfar but that thought may have crossed my mind later.
When the refoam kits arrive I intend to experiment beforehand on how fast the provided adhesive sets up. I also intend to devise a way, if possible, to position the surround and maintain it's position, keeping it place, while I apply the adhesive as fast as possible.
I ordered two kits in case the first attempt does not go well.
When the refoam kits arrive I intend to experiment beforehand on how fast the provided adhesive sets up. I also intend to devise a way, if possible, to position the surround and maintain it's position, keeping it place, while I apply the adhesive as fast as possible.
I ordered two kits in case the first attempt does not go well.
I’ve found white (PVA) glue to bond well enough if some of the original glue remains, ie if you scrape off most of the old so the surface is reasonably flat, but not right back to smooth metal.
Even this type of glue may cause some warping of the surround, requiring something to hold it down until it cures. Made harder by having an inverted surround in this case, which won’t be self-centering.
Contact adhesive is another option and may also warp the surround slightly, but you don’t have to stick the whole perimeter all at once, you can just apply it to a length of one surface and work your way around gradually, adjusting the position as you go and as the glue sets.
Even this type of glue may cause some warping of the surround, requiring something to hold it down until it cures. Made harder by having an inverted surround in this case, which won’t be self-centering.
Contact adhesive is another option and may also warp the surround slightly, but you don’t have to stick the whole perimeter all at once, you can just apply it to a length of one surface and work your way around gradually, adjusting the position as you go and as the glue sets.
That method is one I've considered using with the supplied "poly" glue contained in the kit I've ordered. I need to do a "dry try" first which means waiting til the kit arrives. Which will be, I expect, in 2 to 3 weeks. Destination: Canada.
I've refoamed some other larger drivers and found that applying just small sections of glue around the surround is useful because it reduces the time between application and sticking it on. That allows me to reposition, while the glue being in patches around the cone/surround means the glue does still hold it in position enough for me to come back after a few hours and glue down the rest of the rims.