Jas77 Posted January 16, 2022 Report Share Posted January 16, 2022 Hi all I have just acquired a pair of Acoustic Research AR18s speakers which sound a bit flat so opened them up to find the positive and negative wired incorrectly inside the speaker. With hope that this would change the lower end sound but unfortunately although better it wasn’t as good as expected! I am now wondering if the mid/bass speaker has been replaced with an inferior speaker although all the serial numbers look like they match original parts listing but I was led to believe that most of not all the speakers had the square magnet design whereas the ones installed in the speakers I have are round? If anyone could confirm this that would be great as if the case is that the speakers are incorrect then I will try to source the originals and replace them and give the speakers another go. Quote Link to comment Share on other sites More sharing options...
Giorgio AR Posted January 16, 2022 Report Share Posted January 16, 2022 I can confirm that the woofers are not original (the label on the magnet though yes), even if these are probably Tonegen, however they are not the correct substitutes (if replacement Tonegen they would sound almost indistinguishable from the woofers built in USA and original for AR18S. If you do not find the correspondents, the most valid and easy to find replacement is always the "universal woofer", as defined by Acoustic Research 200001-1 Giorgio. Quote Link to comment Share on other sites More sharing options...
Jas77 Posted January 16, 2022 Author Report Share Posted January 16, 2022 Thanks for the reply, so I’m taking it that these are inferior and are not the correct replacements and if I manage to find the correct replacement then they would sound a lot better?? Thanks Quote Link to comment Share on other sites More sharing options...
genek Posted January 16, 2022 Report Share Posted January 16, 2022 These are the woofers AR listed as replacements for the 18 series in 1986. The label says they're US made, so they're not Tonegen. Is there a gasket under the woofer? If not, you don't have a seal. Even if there is a gasket, it may be too compressed to seal well. Try some new foam tape or sealing putty and see what that does. Quote Link to comment Share on other sites More sharing options...
Jas77 Posted January 16, 2022 Author Report Share Posted January 16, 2022 4 minutes ago, genek said: These are the woofers AR listed as replacements for the 18 series in 1986. The label says they're US made, so they're not Tonegen. Is there a gasket under the woofer? If not, you don't have a seal. Even if there is a gasket, it may be too compressed to seal well. Try some new foam tape or sealing putty and see what that does. Thanks for the reply. There is no gasket under woofer so will give that a go but would I be better off getting the original woofers for them as no one I have asked seems to know much about the ones a I currently have?? Quote Link to comment Share on other sites More sharing options...
genek Posted January 16, 2022 Report Share Posted January 16, 2022 Try the seal first and see how you like the sound. You already have the woofers AR would have provided as replacements back in the 1980s. Quote Link to comment Share on other sites More sharing options...
Jas77 Posted January 16, 2022 Author Report Share Posted January 16, 2022 11 minutes ago, genek said: Try the seal first and see how you like the sound. You already have the woofers AR would have provided as replacements back in the 1980s. Thanks and will give this a go and see if there is a difference. Quote Link to comment Share on other sites More sharing options...
AR55 Posted January 16, 2022 Report Share Posted January 16, 2022 The 200037 woofer is the woofer that was provided in AR-18s. It is almost a direct copy of the original 200001 woofer. Your pictures of the 2 woofers show that the original foam gasket is still on the inside flange, but it probably no longer provides a good seal. I agree with genek, a new seal could make all the difference. I use a gasketing tape sold by Parts Express - https://www.parts-express.com/Speaker-Gasketing-Tape-1-8-x-1-2-x-50-ft.-Roll-260-542. Remove the old gasket first before you install the new one. Quote Link to comment Share on other sites More sharing options...
Aadams Posted January 17, 2022 Report Share Posted January 17, 2022 I agree with Giorgio. There is something odd about these woofers. I have examined the front baffle photo on three different monitors and it looks to me like the voice coil covers are concave, the surrounds are attached on the back side of the cone and are shiny like butyl rather than dull like foam. Tell me I am wrong please. Quote Link to comment Share on other sites More sharing options...
lARrybody Posted January 17, 2022 Report Share Posted January 17, 2022 I am also perplexed by these woofers. They remind me of Tonegen 1210037-2A woofers but that label dose not belong and the terminal plate is different along with the dust cap. I am a big fan of the AR18S and own half a dozen examples. Here is a 200037 woofer and a Tonegen 1210037. To me they sound identical. Quote Link to comment Share on other sites More sharing options...
AR55 Posted January 17, 2022 Report Share Posted January 17, 2022 You guys are right. The woofers don't look like the 200037. It looks like someone took a Sharpe and marked out the actual label and stuck on the 200037 labels. Jas77, if you have a multimeter, check the DC resistance of the woofers. If they don't measure somewhere between 4.4 ohms & 4.8 ohms, it is very unlikely that they are either the 200037's or 1210037's. Quote Link to comment Share on other sites More sharing options...
genek Posted January 17, 2022 Report Share Posted January 17, 2022 I'd put some cleaner to the black smudge and try to see what's under it. Quote Link to comment Share on other sites More sharing options...
Jas77 Posted January 17, 2022 Author Report Share Posted January 17, 2022 16 hours ago, Aadams said: I agree with Giorgio. There is something odd about these woofers. I have examined the front baffle photo on three different monitors and it looks to me like the voice coil covers are concave, the surrounds are attached on the back side of the cone and are shiny like butyl rather than dull like foam. Tell me I am wrong please. Hi the voice coil cover is indeed concave and as you say the surrounds are attached to the back of the cone but they are foam. Quote Link to comment Share on other sites More sharing options...
Jas77 Posted January 17, 2022 Author Report Share Posted January 17, 2022 13 hours ago, AR55 said: You guys are right. The woofers don't look like the 200037. It looks like someone took a Sharpe and marked out the actual label and stuck on the 200037 labels. Jas77, if you have a multimeter, check the DC resistance of the woofers. If they don't measure somewhere between 4.4 ohms & 4.8 ohms, it is very unlikely that they are either the 200037's or 1210037's. The resistance across the coil is about 3.2ohms Quote Link to comment Share on other sites More sharing options...
Jas77 Posted January 17, 2022 Author Report Share Posted January 17, 2022 Some more photos. The speaker cabinets seem to be made out of a chipboard type of material? Quote Link to comment Share on other sites More sharing options...
lARrybody Posted January 17, 2022 Report Share Posted January 17, 2022 You do have the correct 200038-0 tweeters. One of the best sounding cone tweeters I have come across. If you are looking for replacement woofers they were used in some other models. The AR28S and the AR18B I believe. If you can find a pair of Rock Partners they will have the Tonegen 1210037 woofers which will work just fine. The Rock Partners will also have the 1210038 Tonegen tweeters which can be back up replacements. Here they are the on the left and the AR USA made ones on the right. It looks like you 5uf cap has been replaced because all of mine came with a Unicon electrolyte. I used a Dayton 5.1 and binding post from Parts Express to replace those spring clips. Quote Link to comment Share on other sites More sharing options...
cd0nc Posted January 19, 2022 Report Share Posted January 19, 2022 The light blue Interlec caps are probably original. I have seen them on a number of later speakers in the same range as the AR8 - AR9 range here in the UK. Quote Link to comment Share on other sites More sharing options...
Jas77 Posted January 19, 2022 Author Report Share Posted January 19, 2022 58 minutes ago, cd0nc said: The light blue Interlec caps are probably original. I have seen them on a number of later speakers in the same range as the AR8 - AR9 range here in the UK. Thanks for the info, do you think the speaker cabinets look correct? Quote Link to comment Share on other sites More sharing options...
Jas77 Posted January 19, 2022 Author Report Share Posted January 19, 2022 On 1/17/2022 at 11:21 PM, lARrybody said: You do have the correct 200038-0 tweeters. One of the best sounding cone tweeters I have come across. If you are looking for replacement woofers they were used in some other models. The AR28S and the AR18B I believe. If you can find a pair of Rock Partners they will have the Tonegen 1210037 woofers which will work just fine. The Rock Partners will also have the 1210038 Tonegen tweeters which can be back up replacements. Here they are the on the left and the AR USA made ones on the right. It looks like you 5uf cap has been replaced because all of mine came with a Unicon electrolyte. I used a Dayton 5.1 and binding post from Parts Express to replace those spring clips. Ideal thanks for the info👍🏻 will probably look at changing the spring clips like you have if I can find some replacement woofers. Quote Link to comment Share on other sites More sharing options...
Giorgio AR Posted January 20, 2022 Report Share Posted January 20, 2022 On 1/18/2022 at 12:21 AM, lARrybody said: It looks like you 5uf cap has been replaced because all of mine came with a Unicon electrolyte I confirm the use of Interlec capacitors in this period, they are also present in my AR48B crossovers, tested unlike the Elcap / Callins, the nominal values differ from the original specifications by about 20%, much less than the infamous black / red Callins ! Quote Link to comment Share on other sites More sharing options...
genek Posted January 20, 2022 Report Share Posted January 20, 2022 Did you find out what's under the black smudge on the woofers? Quote Link to comment Share on other sites More sharing options...
Jas77 Posted January 20, 2022 Author Report Share Posted January 20, 2022 5 minutes ago, genek said: Did you find out what's under the black smudge on the woofers? Yes managed to get the black stuff off but unfortunately nothing written under it? Quote Link to comment Share on other sites More sharing options...
genek Posted January 20, 2022 Report Share Posted January 20, 2022 I wonder if they might have been reconed. Hard to imagine someone going to the effort to take the P/N on a woofer that's going to be out of sight when the speakers are closed up. Quote Link to comment Share on other sites More sharing options...
dna Posted February 15, 2022 Report Share Posted February 15, 2022 My 200001-1. Note the square magnet. In my first set of AR 17 the magnets were square too. Quote Link to comment Share on other sites More sharing options...
dna Posted February 28, 2022 Report Share Posted February 28, 2022 On 1/17/2022 at 9:03 AM, Jas77 said: Some more photos. The speaker cabinets seem to be made out of a chipboard type of material? Fiber board, there is LDF Low Density Fiberboard, Medium (MDF), and High or HDF. I think AR and other high end companies used HDF. Quote Link to comment Share on other sites More sharing options...
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