SouthernXAudio Posted May 17, 2016 Report Share Posted May 17, 2016 Hi! First time post, having looked thru this forum many times. Ive just landed a pair of AR3a Improved speakers in superb condition. I'm an audio tech mostly working in studio environments, as well as a guitar tech and amp builder. At various times I've stopped to listen only, refreshing my hearing and clearing my thoughts. After one such time of some months listening only to vinyl and not building guitar amps, I came back so refreshed that I came up with a guitar amp idea that was incredibly fresh. I'm at another one f those moments where I know I gotta sit back for a spell and just listen. As has happened one of my clients, a high end hifi distributer here in Melbourne, was clearing some trade in stock that had been stored for some years out the back. I happened along at the right moment to walk into a pair of AR3a Improved in original packaging with receipts, that they traded 10 years ago. My first thought was them foams are gonna need replacing, but upon opening they looked mint. Turned out there was a receipt for refurb in the paperwork. The foams however are a little unresponsive, so they're getting replaced anyway. I had a quick listen there in the large store space and they sounded good enough to take. However set up in my space they were lacking. I decided to recap one last night, as I ever do, one at a time to hear what differences are made. There was some difference for sure but not what I had experienced in the past. There's just no real top end. So had a closer look at the tweeters and I found the problem. One had a broken hair wire, while the other had become unsoldered. I repaired that issue simply enough, then measured the dcr, was under 2 ohms hovering around 1.5. I ran some signal thru them and there was very little making it out. So. I need new tweeters! However I just cant get definitive info on what I need. My tweeters appear to be the #23 model in the repair guide. Kind of. The tabs go thru the back. I'm looking at the HiVi Q1R replacement. And have read the need for a 0.07mH inductor across it. I'm just a little uncertain as to its requirement with the Improved xover that has a 0.1 inductor already. Is the requirement only for the crossover that has no inductor in that place, the pre Improved? Or are we looking to parallel them? The latter doesn't make sense to reduce the inductance for a newer better performing tweeter. I'm so excited to get these running and cant wait, but will have to return to my Advents till parts arrive ;( Ive attached pics of my tweeters hoping to get some direction. My crossover has the .1 over the tweeter plus the single switch. The original sales receipt is dated March 1977 Thanks in advance! Don Link to comment Share on other sites More sharing options...
RoyC Posted May 17, 2016 Report Share Posted May 17, 2016 Welcome to CSP, Don The AR-3a Improved used the back-wired version of the AR-3a tweeter, and was a transitional model to the AR-11. Although the crossover was changed somewhat, the only "improvement" was the elimination of the troublesome rotary level controls ("pots"). On the other hand, the switches that replaced them provide less control. If you were to use the HiVi tweeter you would not use another parallel coil unless you eliminate the one in the crossover. You could use the existing coil, but would have to reduce the tweeter crossover capacitor somewhat (to around 4uf). A better recommendation for this model, however, is to go with used AR-11 or AR-10pi tweeters. It will be more expensive than the HiVi tweeter route, but these tweeters are the same size, are much more reliable than the 3a tweeter, and work very well with this crossover. Imo, it results in an "improved" 3a Improved. If you become interested in this approach I may be able to assist you with finding a pair of these tweeters. Roy Link to comment Share on other sites More sharing options...
SouthernXAudio Posted May 17, 2016 Author Report Share Posted May 17, 2016 Ahh thanks heaps Roy. Will take you up on that! Link to comment Share on other sites More sharing options...
SouthernXAudio Posted May 17, 2016 Author Report Share Posted May 17, 2016 I saw these in looking around and wondered if they might work as advertised, but could find no info on the forum regarding them. I guess that means something http://www.simplyspeakers.com/acoustic-research-replacement-tweeter-12000840.html Link to comment Share on other sites More sharing options...
DavidDru Posted May 18, 2016 Report Share Posted May 18, 2016 Hey roy, what are the wires on those tweeters made of? Link to comment Share on other sites More sharing options...
RoyC Posted May 18, 2016 Report Share Posted May 18, 2016 4 hours ago, SouthernXAudio said: I saw these in looking around and wondered if they might work as advertised, but could find no info on the forum regarding them. I guess that means something http://www.simplyspeakers.com/acoustic-research-replacement-tweeter-12000840.html They fit the hole (after notching for the terminals), but they are on the harsh side of things compared to any original AR tweeter. There is no damping material under the dome...and are overpriced at $80 each. The level control switches are not enough to tame them. Roy Link to comment Share on other sites More sharing options...
RoyC Posted May 18, 2016 Report Share Posted May 18, 2016 1 hour ago, DavidDru said: Hey roy, what are the wires on those tweeters made of? Hi David, If you are referring to the photo of the original AR-3a Improved tweeter shown in the first post, it is copper. Roy Link to comment Share on other sites More sharing options...
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