Juan9568 Posted June 26, 2017 Author Report Share Posted June 26, 2017 Hi Guys, thanks for all of your suggestions. I will definitely paint them black, but that will be the very last part of the restoration. About the Ar3-a crossover I've seen the schematics and is very different from the improved version....also the inductors are different, so I would need to build that one from scratch right?? What are the cutoff frequencies for the Ar3-a and the improved?? I could use the woofer inductors of the improved version as is and rebuild the ones for the mids and highs...? like an hybrid between the improved and the ar3-a... I know this is a matter of matching the drivers frequency response with the proper crossover Link to comment Share on other sites More sharing options...
Glitch Posted June 30, 2017 Report Share Posted June 30, 2017 Juan, For a resto-mod, I would try to selectively restore the crossover as an original AR3a improved. Based on the schematic in JKent’s post, L1, R1, & C1 make the low pass filter for the woofer. Using the stock values would be a safe start. This will give you the crossover frequency that the AR engineers felt was acceptable for the woofer. The rest of the circuit gets more complicated. I would leave the switch out of the circuit and hard wire the circuit equivalent to the switch position shown. C2+C3 & L3 set the high pass frequency for the midrange. The stock values for these will give you a reasonable match to the woofer low pass circuit. L2 and C4 set the low pass for the midrange. These may be OK for whatever midrange you end up using or might not work at all. You will need to check the driver spec sheet to know for sure. C5 & L4 set the high pass for the tweeter. As with the midrange, these values may or may not work with whatever tweeter you pick. I believe that this is what Roy has been trying to warn you about. The other resistors in the circuit may not be needed. What is more likely is different resistor values would be required to level match the various drivers. If you pick the right set of midrange and tweeters, the crossover design could be fairly straightforward. This is why I was suggesting that you use an existing DIY design as a start. These designs typically use very forgiving drivers that work with simple crossovers. You may not get the results of a more expensive setup, but it should be very listenable. The hard part (maybe very hard) is finding a design with drivers that fit the existing holes. Have you decided which direction that you want to take the project (i.e. restoration, resto-mod, or something in between)? Glitch Link to comment Share on other sites More sharing options...
Juan9568 Posted July 1, 2017 Author Report Share Posted July 1, 2017 On 6/29/2017 at 9:08 PM, Glitch said: Juan, For a resto-mod, I would try to selectively restore the crossover as an original AR3a improved. Based on the schematic in JKent’s post, L1, R1, & C1 make the low pass filter for the woofer. Using the stock values would be a safe start. This will give you the crossover frequency that the AR engineers felt was acceptable for the woofer. The rest of the circuit gets more complicated. I would leave the switch out of the circuit and hard wire the circuit equivalent to the switch position shown. C2+C3 & L3 set the high pass frequency for the midrange. The stock values for these will give you a reasonable match to the woofer low pass circuit. L2 and C4 set the low pass for the midrange. These may be OK for whatever midrange you end up using or might not work at all. You will need to check the driver spec sheet to know for sure. C5 & L4 set the high pass for the tweeter. As with the midrange, these values may or may not work with whatever tweeter you pick. I believe that this is what Roy has been trying to warn you about. The other resistors in the circuit may not be needed. What is more likely is different resistor values would be required to level match the various drivers. If you pick the right set of midrange and tweeters, the crossover design could be fairly straightforward. This is why I was suggesting that you use an existing DIY design as a start. These designs typically use very forgiving drivers that work with simple crossovers. You may not get the results of a more expensive setup, but it should be very listenable. The hard part (maybe very hard) is finding a design with drivers that fit the existing holes. Have you decided which direction that you want to take the project (i.e. restoration, resto-mod, or something in between)? Glitch Yes, that's what I was thinking. I'll go for a resto-mod or something in between. Thinking of using the crossover as is for the woofer and hi-vi tweeters and then figure out what to do with the mids. Can you tell if this info is correct? Woofer: Lo-Pass at 525Hz Mid: Lo-Pass at 5000Hz and Hi-Pass at 525Hz Tweeter: Hi-Pass at 5000Hz Link to comment Share on other sites More sharing options...
bassment142 Posted July 3, 2017 Report Share Posted July 3, 2017 Holy cow, is this the worst pair anyone has found so far? I'd part out the woofers and throw the rest in a dumpster. Link to comment Share on other sites More sharing options...
michiganpat Posted July 6, 2017 Report Share Posted July 6, 2017 my resto-mod suggestion would be if you want to spend some large amounts of cash, to track down the mids and tweets carl used in his 3a "super mod" and build those up to spend lesser amounts of cash, probably seal up the mid and tweet holes, and use a simple first or 2nd order low pass filter and turn them into passive subs. then set some AR 18's on top to handle the midbass through treble regions... Link to comment Share on other sites More sharing options...
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