Mach3 Posted June 9, 2012 Report Share Posted June 9, 2012 So recently was able to secure a very nice set of AR-2ax off the 'bay. Local guy and he delivered to my door in their original boxes. The grills had never been removed. Very nice cabinets with hardly a flaw. These were made in June, '73.Of course the woofer foam surrounds were gone with the wind - replaced them easy enough and while in there I decided to "rebuild" the crossover which consisted of only two capacitors (4 uF and a 6 uF). Used Solen precision caps (+/- 1% tolerance) as I believe that a capacitor with a tighter specified tolerance is in fact a "better" capacitor - such means that the production processes being employed are "in control" and hence the product is more regular. I don't listen to various capacitors - but I do believe that AR speakers in general respond with considerable sonic improvement when the old electrolytics are replaced with modern film types (polystyrene, polypropylene, metallized films et cetera).While doing this work I began to contemplate how this crossover worked - and in fact it is surprisingly crude (or sophisticated depending on your perspective). Both the mid and the tweeter are simply hi-passed - which means they receive ALL frequencies above their crossover point (1400 Hz for the mid and 5k Hz for the tweeter). The woofer is low-passed with a coil. Simplicity - not even a first order crossover - just two high-passes and a low pass in parallel.This means the designer was relying on the natural electrical and mechanical roll-off of the mid range unit to cut off its response above 5 kHz. - I also suspect that this is the reason the mid-range on the AR-2ax has a thick section of felt on top of it (or is it fiberglass padding?). This tends to suppress break up sounds when the mid is being sent frequencies that are beyond its ability to play.How does it sound? Exactly as I remember it - good clarity, detailed, very rich sounding, with a warm presence and with excellent bass per the AR 10" woofer. I am playing it with a Marantz 2252 receiver - and the combination makes one wonder if we in fact have made ANY progress in regards stereo gear in the intervening 39 years. I have heard many $50k to $100k systems - and while they are possessed of supernatural clarity - almost create an x-ray image of the music - they are far less enjoyable than this $700 rig.What gives with this?BTW: Many of the "uber" speakers out there right now - the ones with the incredible price tags - employ a similar crossover/driver technique - such a minimalist approach to crossover design is considered very "moderne". Of course AR was doing this in what? 66? or so? Link to comment Share on other sites More sharing options...
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