uarnutz Posted January 2, 2023 Report Share Posted January 2, 2023 New here and looking for some basic help on my newly acquired AR 90 pair. Some background, I picked these up locally since I had heard good things about them and they were reasonably priced. I have rebuilt Ar 2ax and 4xa speakers in the past so, I thought this would make a good winter project. They are probably more speaker than the boss will allow but, who knows? They are in place for now. All the woofer surrounds were totally disintegrated so, I am preparing to redo the 8 inch and 10 inch surrounds with the Vintage AR kit. All these tested to spec for resistance. One of the UMR speakers (1.5 inch) has a collapsed dome. Is this easily remedied? If so, what's the technique? Thanks for any advice. I am excited to get better acquainted with these fine speakers. Quote Link to comment Share on other sites More sharing options...
Aadams Posted January 2, 2023 Report Share Posted January 2, 2023 I used duct tape applied to the dented area and gently tugged it out. You may still see evidence of a dent. Others have had success with a vacuum cleaner nozzle I was not willing to try that method on the first attempt. Quote Link to comment Share on other sites More sharing options...
ar_pro Posted January 2, 2023 Report Share Posted January 2, 2023 26 minutes ago, Aadams said: I used duct tape applied to the dented area and gently tugged it out. You may still see evidence of a dent. Others have had success with a vacuum cleaner nozzle I was not willing to try that method on the first attempt. Seconded. Duct tape works really well, but try to use a top-grade tape like 3M, and proceed with care. Sometimes, a hair dryer on low heat setting will help remove or reduce creases after you've pulled the dome back into position. Quote Link to comment Share on other sites More sharing options...
Stimpy Posted January 3, 2023 Report Share Posted January 3, 2023 That's not too bad. That dent should pull out fairly cleanly. Also, from experience, if your 90s have any black/red Callins capacitors in your crossover, please replace those at least. Those Callins caps do not age well. Good luck! Quote Link to comment Share on other sites More sharing options...
uarnutz Posted January 3, 2023 Author Report Share Posted January 3, 2023 Thanks everyone. I could not get it to work using the dampening and suction (by mouth, using a cardboard tube.) I can see the crease pulled out but, it immediately collapses back. It seems to have some sort of memory. How wet does it need to be? I actually let a wet piece of paper towel rest on it for a minute or two. Quote Link to comment Share on other sites More sharing options...
AR surround Posted January 3, 2023 Report Share Posted January 3, 2023 This fellow uses a piece of packing tape: https://www.youtube.com/watch?v=K-tN7zg4Skw I also saw a video where the fellow used a glue stick, but it was on a woofer dust cap. I don't think that using a glue stick on a dome driver would be a good idea because the residue left on the dome might actually make things worse. Quote Link to comment Share on other sites More sharing options...
JKent Posted January 3, 2023 Report Share Posted January 3, 2023 Welcome uarnutz I like that packing tape video though I doubt it’s that simple. I’ve had success with wetting and vacuum but only on paper dust caps. I don’t think water will soften your mid’s dome. I’d give the tape a try. Kent Quote Link to comment Share on other sites More sharing options...
lance G Posted January 3, 2023 Report Share Posted January 3, 2023 12 hours ago, uarnutz said: Thanks everyone. I could not get it to work using the dampening and suction (by mouth, using a cardboard tube.) I can see the crease pulled out but, it immediately collapses back. It seems to have some sort of memory. How wet does it need to be? I actually let a wet piece of paper towel rest on it for a minute or two. I have had the same issue with a used (identical) driver imported from the USA into the UK for my AR9's. I think the pressurisation/temperature change during the flight likely caused what amounted to the total collapse/inversion of the cone. I don't personally think that wetting will make much difference, the cones seem to be coated (sealed?) with a type of tacky/sticky resin (therefore airtight?) I do wonder if the units are sealed ? or at least pretty much airtight, it appears that there is a battle against an internal vacuum when in my efforts to pull the cone out, as you also seem to have experienced, just saw the cone being apparently sucked back in. I ultimately had some reasonable/moderate sucess by gently heating, the use of tape and the gentle, dexterous use of a vacuum cleaner. In the end not a perfect result visually, but at least it resulted in an apparently serviceable driver. I suspect very gentle efforts, trying to allow some time for air to gently "flow" back inside the driver is the way to go, "little and often" or "softly, softly catchee Monkey" would seem to be the order of the day ! I believe the driver is a 200028-0? Used only in the AR9 and AR90 models. Getting hard to find good working replacements now, so do take your time and exercise caution. I had AR90's in the past and loved them, I eventually got my bucket list AR9's here in the UK. IMHO any careful effort you put into your speakers will likely be richly rewarded, they are cracking speakers, easier to live with than the AR9 (physically), and right up there sound wise. Good Luck ! And do please update us on your efforts. Quote Link to comment Share on other sites More sharing options...
uarnutz Posted January 3, 2023 Author Report Share Posted January 3, 2023 Thanks. Yes, it definitely looks as if it is actually being sucked in under vacuum. I suppose that means the seals are good anyway. Are these drivers the ones that are mounted in a tube? Maybe I should loosen the mounting screws and then apply suction. Quote Link to comment Share on other sites More sharing options...
lance G Posted January 3, 2023 Report Share Posted January 3, 2023 3 minutes ago, uarnutz said: Thanks. Yes, it definitely looks as if it is actually being sucked in under vacuum. I suppose that means the seals are good anyway. Are these drivers the ones that are mounted in a tube? Maybe I should loosen the mounting screws and then apply suction. This will not make any difference. You could remove the driver altogether and it wouldn't help, other than you will likely be able to confirm that it's a (to my mind, in my experience an apparently?) sealed unit. From what I can see in your picture I would personally try using the tape method for starters, but you will need a tape that is strong enough to stay adhered while you gently start pulling, but of course can then be readily removed when you have hopefully succeeded. Perhaps first gently heat the cone with a hair dryer (?) and keep a gentle sustained pull on the tape to allow time for any air to (hopefully via somewhere!) find its way back into the space behind the cone, thereby re-balancing the internal with the external air pressure. Not something I would ultimately be keen to try, but perhaps a worst case MIGHT be to gently insert a small needle tip just through the centre of the indentation to both allow some air into the driver and to tease out the dent. A tiny drop of clear sealer of some type could be used to seal the hole. Again I would try this on a previously warmed cone. DISCLAIMER ! All the previous is based on my own experience and opinions. Please don't blame me if when (perhaps foolishly😀) following my suggestions you bugger it up ! Perhaps wait a little longer for other members, who very likely know far more than I, further input while you crack on and replace the perished woofer and lower midrange foams ?👍 And as the sage Stimpy very wisely suggested change the (if relevant) Callins capacitors. Quote Link to comment Share on other sites More sharing options...
DavidR Posted January 3, 2023 Report Share Posted January 3, 2023 I've done what Aadams suggested and with great success. Quote Link to comment Share on other sites More sharing options...
Aadams Posted January 3, 2023 Report Share Posted January 3, 2023 19 hours ago, ar_pro said: Duct tape works really well, but try to use a top-grade tape like 3M, and proceed with care. Sometimes, a hair dryer on low heat setting will help remove or reduce creases after you've pulled the dome back into position. Premium duct tape is much stickier than the less expensive per/length rolls and is your best and safest method. And it works. Quote Link to comment Share on other sites More sharing options...
uarnutz Posted January 3, 2023 Author Report Share Posted January 3, 2023 Eureka. It worked! Here's rev 1 using a professional riggers tape. You know, the kind that sound and lighting engineers use for laying their cables. That was after trying generic duct tape and packaging tape. It's not 100% but, I may still try to find an even stickier tape. What do you think? Thanks for the tip. Quote Link to comment Share on other sites More sharing options...
Aadams Posted January 3, 2023 Report Share Posted January 3, 2023 18 minutes ago, uarnutz said: What do you think? I think you need to stop. Quote Link to comment Share on other sites More sharing options...
Stimpy Posted January 3, 2023 Report Share Posted January 3, 2023 Well done...! Quote Link to comment Share on other sites More sharing options...
lance G Posted January 3, 2023 Report Share Posted January 3, 2023 34 minutes ago, uarnutz said: Eureka. It worked! Here's rev 1 using a professional riggers tape. You know, the kind that sound and lighting engineers use for laying their cables. That was after trying generic duct tape and packaging tape. It's not 100% but, I may still try to find an even stickier tape. What do you think? Thanks for the tip. Well done ! That should be enough, quit while you're ahead. My driver was far, far worse that yours. I think mine was likely subjected to freezing temperatures and pressurisation in the aeroplane cargo hold which totally reversed/collapsed the complete dome. Report back when the rest of the work is done with an update, and enjoy ! Quote Link to comment Share on other sites More sharing options...
DavidR Posted January 3, 2023 Report Share Posted January 3, 2023 That's it and is all that is needed. Good work. Quote Link to comment Share on other sites More sharing options...
johnfalc Posted January 3, 2023 Report Share Posted January 3, 2023 Looking good ... at this point I'd stop and get to listening. Quote Link to comment Share on other sites More sharing options...
uarnutz Posted January 4, 2023 Author Report Share Posted January 4, 2023 Thanks everyone. If only it were all that easy... Quote Link to comment Share on other sites More sharing options...
lance G Posted January 4, 2023 Report Share Posted January 4, 2023 You were relatively lucky. This was mine ! Quote Link to comment Share on other sites More sharing options...
Willy Posted January 8, 2023 Report Share Posted January 8, 2023 Hi all, i still have NOS from this Midrange 200028 for the AR9 and AR 90 in my collection. with best regards Stephan I make a Photo from a used and from a new one, i have more Quote Link to comment Share on other sites More sharing options...
uarnutz Posted January 10, 2023 Author Report Share Posted January 10, 2023 On 1/8/2023 at 7:43 AM, Willy said: Hi all, i still have NOS from this Midrange 200028 for the AR9 and AR 90 in my collection. with best regards Stephan I make a Photo from a used and from a new one, i have more Are you selling? If so, pls PM me. Quote Link to comment Share on other sites More sharing options...
Willy Posted January 11, 2023 Report Share Posted January 11, 2023 Hi yes i selling most of my spareparts which i don't need. Stephan One new one i have now sold Quote Link to comment Share on other sites More sharing options...
Willy Posted January 12, 2023 Report Share Posted January 12, 2023 Now i have one 200028 of my collection sold. But i still have more new and used. Also i have new 200044 Midrange and 200032 used in my collection. with best regards Stephan Quote Link to comment Share on other sites More sharing options...
Willy Posted January 12, 2023 Report Share Posted January 12, 2023 Quote Link to comment Share on other sites More sharing options...
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