I thought I'd start a new thread covering my AR94S restoration. I bought these a couple of months ago, and just got into doing some work on them. From what I could tell, they had never been apart before, they still had the original cloth covering on them. I used a strong plastic spreader that I got from an auto body supply store to pop the tops off. Just squeeze it in through the gap, and it should come off easily, the plastic cuts down on any scrapes.
The woofer surrounds were totally rotten, and searching for new ones was difficult. Don't let anyone tell you that the two woofer surrounds are the same, they are not. Look at the pictures of the woofers below. The metal baskets and magnets might be the same, but the cones are not. Here are the measurements I took :
Upper Woofer
outer width of frame 8-1/8"
inner width of frame 7-1/8"
width of surround on frame 7-9/16"
outer roll edge 7"
inner roll edge 5-13/16"
width of cone 5-7/8"
width of surround on cone 5-3/8"
dust cap 2-1/2"
Lower woofer
outer width of frame 8-1/8"
inner width of frame 7-1/8"
width of cone 5-11/16"
dust cap 2-3/4"
The lower woofer has a folded thick paper cone, which appears to have some kind of coating or doping on it, and the original surround is attached to the rear of the cone.
The upper woofer has a formed paper cone, thinner than the lower woofer, with a thinner surround fixed to the front of the cone.
After speaking to several different speaker foam vendors, I finally went with some foams originally meant for JBL woofers, got them from Tom at myaudioaddiction. They had a wider section to attach to the cone, which was important for the lower woofers. Other vendors that sold two identical surrounds for the upper and lower woofers, when they gave me the measurements, I thought there wouldn't be much to attach the surround to the lower woofer cone. As with my other restorations, I chose to remove the dustcaps and shim the voice coils. Since the lower woofer cone didn't sit any further out at rest than the upper one, I chose to mount the surround onto the front of the cone. I still need to get some gaskets, or find a suitable trim ring to cover the edge of the surround and basket.
The tweeters had their dust caps pushed in. After trying duck tape, and a vacuum cleaner, I finally got the dust caps out by gluing a small wooden stick to them with a hot melt glue gun, and pulling the stick (and glue) off once it had set. In the picture, it still looks like they are dented, but the light areas are were a tiny layer of paper got pulled off with the glue. I plan to put some speaker "wet look" paint on them later.
The crossover on these things is weird. They have a capacitor and resistor in parallel, which is then in series with the two woofers. The lower woofer also has an air cored inductor in series with it. The tweeter just has a capacitor in series with it. AR have always gone with the simplistic approach to crossover design, but I wonder about that capacitor/resistor arrangement. I bought some new caps to replace the old ones, nothing fancy, just bipolar electrolytics from Parts Express.
Lee.
The woofer surrounds were totally rotten, and searching for new ones was difficult. Don't let anyone tell you that the two woofer surrounds are the same, they are not. Look at the pictures of the woofers below. The metal baskets and magnets might be the same, but the cones are not. Here are the measurements I took :
Upper Woofer
outer width of frame 8-1/8"
inner width of frame 7-1/8"
width of surround on frame 7-9/16"
outer roll edge 7"
inner roll edge 5-13/16"
width of cone 5-7/8"
width of surround on cone 5-3/8"
dust cap 2-1/2"
Lower woofer
outer width of frame 8-1/8"
inner width of frame 7-1/8"
width of cone 5-11/16"
dust cap 2-3/4"
The lower woofer has a folded thick paper cone, which appears to have some kind of coating or doping on it, and the original surround is attached to the rear of the cone.
The upper woofer has a formed paper cone, thinner than the lower woofer, with a thinner surround fixed to the front of the cone.
After speaking to several different speaker foam vendors, I finally went with some foams originally meant for JBL woofers, got them from Tom at myaudioaddiction. They had a wider section to attach to the cone, which was important for the lower woofers. Other vendors that sold two identical surrounds for the upper and lower woofers, when they gave me the measurements, I thought there wouldn't be much to attach the surround to the lower woofer cone. As with my other restorations, I chose to remove the dustcaps and shim the voice coils. Since the lower woofer cone didn't sit any further out at rest than the upper one, I chose to mount the surround onto the front of the cone. I still need to get some gaskets, or find a suitable trim ring to cover the edge of the surround and basket.
The tweeters had their dust caps pushed in. After trying duck tape, and a vacuum cleaner, I finally got the dust caps out by gluing a small wooden stick to them with a hot melt glue gun, and pulling the stick (and glue) off once it had set. In the picture, it still looks like they are dented, but the light areas are were a tiny layer of paper got pulled off with the glue. I plan to put some speaker "wet look" paint on them later.
The crossover on these things is weird. They have a capacitor and resistor in parallel, which is then in series with the two woofers. The lower woofer also has an air cored inductor in series with it. The tweeter just has a capacitor in series with it. AR have always gone with the simplistic approach to crossover design, but I wonder about that capacitor/resistor arrangement. I bought some new caps to replace the old ones, nothing fancy, just bipolar electrolytics from Parts Express.
Lee.
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Or someone has been in there before....
