RoyC Posted February 9 Report Share Posted February 9 11 minutes ago, Andre_Db66 said: So what would be the height to position the cone? Is there way of determining what the correct height is? There is no measurement. Just line it up with the edge of the basket. Look at a woofer with an intact surround and you will see where it should be. Quote Link to comment Share on other sites More sharing options...
Andre_Db66 Posted February 9 Author Report Share Posted February 9 I have created the .16 coils. There is something unclear to me. In the improved schematic i see a series coil of 0.16mH value and parallel 0.1 coil. The first seems to be the one i have to add but its position is the same as in the ar3a schematic. The parallel seems the additional coil. I have not measured the original coils so forgive me if i seem stubborn but shouldnt i be adding .1 coil parallel? Obviously i cannot find an unlimited schematic anywhere... hence my confusion. What should be the value and postion of my additional coil? I have created the 2.6mH coil but in the improved scheme i see it working together with #4 which means there is only addition of mid freq by the woofer but no subtraction on the mid side. You mentioned this coil should preferably be reduced in value. Can i not compare these schematics to each other? Does anyone have the unlimited schematic so i can compare it to what i am building? Quote Link to comment Share on other sites More sharing options...
Andre_Db66 Posted February 11 Author Report Share Posted February 11 Q about the coils used... I am completely new to the tools and values here. What resistance should a 1.6mH coil have? Is it the wire thickness that dictates the outcome? I have 2 very different coils and both 1.6mH value both in size and resistance value, obviously gauge also. I measure 0.18R and 0.54R Any suggestions? Quote Link to comment Share on other sites More sharing options...
RoyC Posted February 12 Report Share Posted February 12 15 hours ago, Andre_Db66 said: Q about the coils used... I am completely new to the tools and values here. What resistance should a 1.6mH coil have? Is it the wire thickness that dictates the outcome? I have 2 very different coils and both 1.6mH value both in size and resistance value, obviously gauge also. I measure 0.18R and 0.54R Any suggestions? First of all, the coil on the back of the tweeter should be .16mh not 1.6mh. Don't worry about its resistance...which is dependent on the gauge of coil wire. The 2.6mh woofer coil of the Limited simply replaces the 2.85mh coil of the original 3a. As I mentioned above, just deal with the tweeters and the woofer caps and you will be all set. Roy Quote Link to comment Share on other sites More sharing options...
Andre_Db66 Posted February 12 Author Report Share Posted February 12 My bad... they are actually 160uH, so yes .16mF. Get confused always with the pico nano micro mili etc The gauge was actually my concern. The little coil adjacent is equally .16mH, could that also be used instead? I read about the gauge being responsible for characteristic AR sound... does it count for all drivers? I used 1.15mm now, closest i could find. I have refoamed the woofers. Today i make the final touch and will be stacking 2 pairs ar3a with only difference between them being the tweeters and rubber vs foam surround. Have tested individually and sound is great. Regarding the tweeters old style with 3 points of glue. I came across a youtube how to instruction film. That bloke removed the resonance damping and glued all around the gap. Would that be the way to go in order to revitalize dried out glue tweeters? I have 5 working tweeters in this state... Cheers Quote Link to comment Share on other sites More sharing options...
Giorgio AR Posted February 12 Report Share Posted February 12 On 2/5/2024 at 8:48 PM, Andre_Db66 said: Woofer swap with rubber surround Tonegem and made the tweeter black again. The appearance of your AR3a is perfect and the photo shows two possibilities: the first if the domes were made of paper (as in the '90 Tonegen tws produced for the re-issue) it looks like a splendid and rare pair of "Reissue" AR3a, like second you have a splendid pair of AR3a updated with original, compatible and authorized components... the sound will be unique, with AR characteristics. Regarding the 12" Tonegen woofers, it would be important to use Polyfill as in the AR10MKII, with less weight than the AR material used previously (for this purpose, there is advice from the good Luigi Fedele on the use of sound-absorbing material with the Tonegen woofers. Your AR3a and owned sisters are beautiful! Quote Link to comment Share on other sites More sharing options...
Andre_Db66 Posted February 12 Author Report Share Posted February 12 The newest tweeters are made of fabric textile and the Frankenstein are the earlier paper cone tweeters with inside connectors. They are all finished as of this morning and stacked upon original stands. I am about to pick up a set of alnico ar6(i hope) and my focus shall shift to the LST2. I have all the parts needed now. This afternoon i will hook up the ar3a to 2 yamahas, pc2602 and m2 to have the closest sound signature from the amps, driven by a philios preamp. I have heard the ar3a and LST togerher and that was amazing. However, the designated amp here for the LST is the 845 push pull mono blocs. I shall have a look around as far as the polyfill is concerned. Cheers Quote Link to comment Share on other sites More sharing options...
RoyC Posted February 12 Report Share Posted February 12 12 hours ago, Andre_Db66 said: Regarding the tweeters old style with 3 points of glue. I came across a youtube how to instruction film. That bloke removed the resonance damping and glued all around the gap. Would that be the way to go in order to revitalize dried out glue tweeters? Hmmm...post a link. I would be interested to see what this person is doing with the tweeters. " I used 1.15mm now, closest i could find." For what? Obviously that value won't work for anything. I assume you meant you removed some wire from it to make the proper value? Later AR-11 and 10pi cabinets used 11 ounces of dense audio grade polyester. The earliest AR-11 used 20 ounces of fiberglass stuffing. The Tonegen woofer had a slightly stiffer suspension, resulting in a somewhat higher Fs/Fc. With the guidance of Ken Kantor, we conducted many measurements of various amounts of both types of damping material when we put together the Library's 3a restoration guide. As long as you are in the general vicinity of the above amounts you will be ok, as small variations did not make a significant difference in performance. Also, bear in mind that a refurbished woofer will not measure the same as it did when it was new. Roy Quote Link to comment Share on other sites More sharing options...
Andre_Db66 Posted February 12 Author Report Share Posted February 12 I measured the wire used in AR coils and it is 1.25mm thick. I have 1.15mm insulated wire from which i manufactured the coils for the late 3a tweeters @ .16mH using a Peaktech LCR tool. It shows it is around .18R. The small coil with much thinner wire and slightly smaller air core is a coil i unwound until .16mH measuring .5R. This is how i came to my Q about how much the wire gauge is specifically dictating the typical AR sound, or whether it doesnt matter in this case? The first coil with 1.15mm has been applied and thestacked set sound beyond belief. I have/had quite some different speakers but this is amazing! Dre Quote Link to comment Share on other sites More sharing options...
Aadams Posted February 12 Report Share Posted February 12 Re the Tweeter video. Eventually................ he turns it into a different tweeter that is not the same mechanically as what he started with. When he demonstrates it working at the end there is too much piano playing through the tweeter. The highest fundamental note on a piano barely reaches the low range of the orange dot tweeter. Quote Link to comment Share on other sites More sharing options...
RoyC Posted February 12 Report Share Posted February 12 10 minutes ago, Aadams said: Re the Tweeter video. Eventually................ he turns it into a different tweeter that is not the same mechanically as what he started with. Agreed. I have experimented with that dome assembly in the past. At the very least, the crossover would have to change for it to work properly. Additionally, setting the dome without shims is risky, and he did not provide a resistance (dcr) reading. Andre...In your previous post I didn't notice you were referring to wire thickness (mm) and not value (mh). Wire thickness is usually expressed in "gauge". For example, the original AR coils were 17ga, and by the time of the Limited it was 18ga. It's good to hear everything went well. Roy Quote Link to comment Share on other sites More sharing options...
Andre_Db66 Posted February 12 Author Report Share Posted February 12 What i know from experience with rcf and jbl is you at least use a tone generator to verify the position of the coil. Shims i have no experience with and would not know the approach. Leaving out the resonance dampening obviously changes the charachteristics. Is a touch up with regard to dried out glue and resonance cushion even possible or best to to leave it as if it aint broke dont fix it philosophy? Perhaps gently remove the 3 points one by one, whilst adding a ring of new glue, leaving the dampening intact, also the postion of the coil and dome... Quote Link to comment Share on other sites More sharing options...
newandold Posted February 19 Report Share Posted February 19 On 1/31/2024 at 4:20 PM, Gaston said: Woofers are original, they need to be refoamed. Tweeters are probably from next gen AR-11/10π. Mids looks like Tonegen replacement drivers. AFAIK everything is ok-ish with drivers unless you want an all original pair. The unknown lies inside, since there are no pots, there is a big concern that the crossover has been modified. I give kudos to anyone who modifies the acoustic research loudspeaker to get a nice listenable midpoint on those pots and just leave it there and do away with them all together. The AR pots are what ultimately drove me away from those loudspeakers not worth it for me for all the fussing. I see a lot of guys going through to try to make them work. Not an effort at all that’s worth it to me. Quote Link to comment Share on other sites More sharing options...
Andre_Db66 Posted February 19 Author Report Share Posted February 19 1 hour ago, newandold said: I give kudos to anyone who modifies the acoustic research loudspeaker to get a nice listenable midpoint on those pots and just leave it there and do away with them all together. The AR pots are what ultimately drove me away from those loudspeakers not worth it for me for all the fussing. I see a lot of guys going through to try to make them work. Not an effort at all that’s worth it to me. Well there is a subjective setting pleasant to the ears. After finding this setting one could always opt to measure the impedance and replace it with the correct resistors. To buy them with the resistors to someone elses taste is not how i want to start out with these speakers for myself. As Roy mentioned, it was an equivalent of them being almost open fully clockwise and that is certainly not to my taste. Each his own... Quote Link to comment Share on other sites More sharing options...
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