powerglide Posted February 11 Report Share Posted February 11 Hi been a while since I visited the site. I purchased a pair of AR3a improved today with the intent of restoring them. The boxes seem solid enough but somebody, in all their wisdom, has re-veneered them with a pre glued heat activated product with terrible results. I’ll remove it and see what they were trying to cover. I’ve been told the tweeters are blown but I have not tested anything yet. The tweeters are original and have spades on the back, I have a pair in working condition out of a pair of AR ax2’s which were wired externally. The oval connecting piece is just a blank plate with no terminals. I’m sure I can extend the filaments and run them into the cabinet if the existing ones are blown. Were the ax2’s tweeter the same ohm as the 3a improved? My other problem is there are no phase markings on my old tweeters, how do you determine +/- ? Reading other posts, nobody seems 100% sure on the woofer phasing, I’ll check out my crossovers but still wouldn’t be conclusive and somebody has recapped. thanks PG Quote Link to comment Share on other sites More sharing options...
mike tarelli Posted February 11 Report Share Posted February 11 The tweeters for the 3a improved are the same as the 3a. I would think the ax2 tweeters are quite unsuitable. Best thing to do is have the originals re-built by Roy or Chris from this site. There is a 3a improved schematic in the library. Mike Quote Link to comment Share on other sites More sharing options...
powerglide Posted February 22 Author Report Share Posted February 22 On 2/11/2024 at 9:59 PM, mike tarelli said: Best thing to do is have the originals re-built by Roy or Chris from this site. Bit tough from this side of the planet. @RoyC is this true that the ax2 tweeter is ‘’quite unsuitable’’ for the AR3 improved? They look identical and bolt straight in. I thought the ohms could be the only difference? My ax2’s were also built in Europe, if that helps to identify the tweeter. I just found your post from Tuesday re tweeter polarity, I’ll have a look at mine and see if I can work it out, thanks for that. Quote Link to comment Share on other sites More sharing options...
Aadams Posted February 22 Report Share Posted February 22 The 2 series tweeter is built for an 8ohm system. The 3 series tweeter is built for 4ohm. The 8 ohm tweeter can be rebuilt for 4 ohm application. The 8 ohm cannot be easily adapted to operate correctly in the 4 ohm system. OTOH the 4ohm can be adapted for 8ohm in a pinch. Quote Link to comment Share on other sites More sharing options...
RoyC Posted February 22 Report Share Posted February 22 The higher impedance of the 3/4" dome 2ax tweeter makes it less sensitive than the 3a version. It will also behave differently with the AR-3a crossover. Quote Link to comment Share on other sites More sharing options...
powerglide Posted February 23 Author Report Share Posted February 23 thanks guys, I have some Hi Vi tweeters that I modded for the ax2’s, what would I need to do to them to make them perform in the A3 improved? https://community.classicspeakerpages.net/topic/11274-ar-2-ax/ Quote Link to comment Share on other sites More sharing options...
RoyC Posted February 23 Report Share Posted February 23 Install it as shown in your photo just as you would the 3a. Connect your tweeter's red lead to the crossover's yellow wire, and black to black. Some people have played around with polarity and/or have reduced the 2ax's original 4uf capacitor to 3uf, but don't change anything until you try it as is. Quote Link to comment Share on other sites More sharing options...
powerglide Posted February 23 Author Report Share Posted February 23 Thanks Roy, but I think you misunderstood my question, could I put these tweeters into the AR3a improved as is or would I need to change the modification made for the ax2’s ? I have been running these in my ax2’s for the past couple of years. Quote Link to comment Share on other sites More sharing options...
RoyC Posted February 23 Report Share Posted February 23 8 hours ago, powerglide said: Thanks Roy, but I think you misunderstood my question, could I put these tweeters into the AR3a improved as is or would I need to change the modification made for the ax2’s ? I have been running these in my ax2’s for the past couple of years. Oops, sorry...I had 2ax on the brain. 🙄 There is a .1mh coil for the tweeter in the Improved crossover, so... -You could replace the coil on the back of your HiVi tweeter with a .1mh coil, which would place it in parallel with the existing crossover coil. -or disconnect the internal tweeter coil and leave the one mounted on your tweeter as is. In both cases remove the resistor. The goal is to reduce the parallel coil value for use with the HiVi tweeter. Roy PS Perhaps an easy way to start would be to simply disconnect one of the coil leads (and resistor) from your HiVi tweeters just to see how it sounds with the original .1mh crossover coil. Quote Link to comment Share on other sites More sharing options...
powerglide Posted February 23 Author Report Share Posted February 23 Great stuff Roy. It will be an interesting exercise to reinstate the original tweeters back into the ax2’s as I’ve been listening to the HI-VI’s 8-10 hrs a day in my workshop for the last year and should be able to get a good gauge on the difference (I find it hard to distinguish unless I can A-B test) Probably re mod the HI-VI’s leaving the XO as is for the future, do I need the resistor? It was my understanding they were for the L-pads to function correctly (remember the improved has toggles) If I were able to get the original A3 tweeters to you, what would be the cost of a rebuild? PM me Quote Link to comment Share on other sites More sharing options...
RoyC Posted February 23 Report Share Posted February 23 27 minutes ago, powerglide said: do I need the resistor? It was my understanding they were for the L-pads to function correctly (remember the improved has toggles) Yup...I did mention it above. Remove the resistor regardless of your approach. Quote Link to comment Share on other sites More sharing options...
powerglide Posted February 23 Author Report Share Posted February 23 Whoops, I could go over my notes from last time, but for the coils which would be best an 18 or 21 AWG? Quote Link to comment Share on other sites More sharing options...
RoyC Posted February 23 Report Share Posted February 23 1 hour ago, powerglide said: I could go over my notes from last time, but for the coils which would be best an 18 or 21 AWG? 18ga would be more consistent with the other AR coils, but if the smaller gauge is all you have on hand it won't hurt anything. Quote Link to comment Share on other sites More sharing options...
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