Ferguson Posted March 23, 2019 Report Share Posted March 23, 2019 I was very happy to see a pair of AR-7's for £20 today and snapped them up. I always keep an eye on gumtree and ebay so I was very happy to see some in a local secondhand shop. In my excitement I didn't even take a proper look at the speakers themselves before buying. The second I got home I saw they weren't in as good condition as I'd hoped. From the outside they aren't too bad. There is some staining on one of the grills and light scratching in the wood, no big chips. Behind the grills though is another matter. It looks like someone has had a go at re foaming/repairing the woofers and made a very messy job of it. I gave the speakers a test and it seems the tweeter on one of them isn't making any sound at all. I don't mind tidying their looks from the outside but I'm nervous to start poking around at the woofers to try to get that glue off. Is there any advice as to where to start with these and the tweeter? Any poke in the right direction would be greatly appreciated! Thank you all! Link to comment Share on other sites More sharing options...
Giorgio AR Posted March 23, 2019 Report Share Posted March 23, 2019 Hi, the tweeter problem can be an interruption due to oxidation of the thin cable that runs on the surface of the cone, it carefully observes the two wires (+ and -), perhaps with the help of a good magnifying glass. Although not very easy, the wire can be restored by welding and adding an appropriate new piece. It also happened on my tweeter of an AR6, now fully functional, I am attaching 3 photos of the tweeter repaired by me, if you look carefully at the photos, you will see that the other wire shows an oxidation green color, so sooner or later this will also stop and then be repaired. Apart from the white glue that you see in the first photo (drying the glue becomes transparent), the repair is practically invisible in the following photos! Second problem, the two woofers: if the transparent material put in abundance on the 2 cones is silicone, I think the removal is impossible (probably you can reposition only the new surround foam where now there is the old degraded material that should be removed without many difficulties). If it is not silicone, in my opinion you should try it by heating the cone with a hair dryer, the softening glue can be removed without removing the upper pulp of the cone (removing it a little at a time with the help of a suitable not sharp spatula ). Do not continue with the work if the pulp is too loose in addition to small traces of paper fiber! Last tip: in Italy, there are currently two original AR7 woofers for sale, but offered at a high price. of these two cones one is Ok, with new foam, the other unfortunately has the suspension not in foam, but in rubber (to replace for a correct operation) try to look for them with the help of HiFi Shark. I hope I've been helpful Giorgio Link to comment Share on other sites More sharing options...
ra.ra Posted March 24, 2019 Report Share Posted March 24, 2019 Hi Ferguson, and welcome to the CSP forum. I love the little AR-7 speaker model, and I believe your wood veneer cabinets and fabric grilles can be refreshed to very satisfactory levels. Not sure why one tweeter has gone silent, but Giorgio's advice about the tiny wires could be the problem. Also, with rear-wired tweeters, these use the push-on (non-soldered) type of wire connection, and it is possible that one wire has come loose. The tweeters can be tested by carefully (very low volume) applying amplified speaker wire directly to the tweeter terminals to confirm output....or none. Those woofers are a far different challenge altogether, and I've never seen such a frightful mess. Even though the warden has already sentenced these prisoners to death, it is very possible that they might be rescued for life with miraculous acts of mercy. Again, Giorgio's observations are prudent, but it's really hard to tell if this situation can be salvaged. If those were my speakers, I would remove and disconnect the woofers, and then begin a very slow and deliberate effort to gently clean them up with heat, solvents, and very specific physical removal of detritus. Link to comment Share on other sites More sharing options...
djcheung Posted March 25, 2019 Report Share Posted March 25, 2019 Hi Ferguson, I was working on one similar molested woofer sometime ago and it took me over 5 days picking on the silicon bit by bit. Just take your time and you will get there eventually. Link to comment Share on other sites More sharing options...
DavidDru Posted March 25, 2019 Report Share Posted March 25, 2019 Yikes, those woofers. Not sure they can be salvaged. Just gotta hope the glue isn't as strong is it is ugly. I would start by separating the surrounds at the edge of the cone and removing all of that through the frame first to make it at least seem manageable. May want to make sure you have operation tweeters first though, and if you don't, I'd be calling it a day with those and maybe the remaining tweeter and badges being of help to someone else. I've got an AR7 woofer sitting here doing nothing but taking up shelf space that I could send you, but shipping would just make that prohibitive. Link to comment Share on other sites More sharing options...
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