Evol2121 Posted February 23, 2021 Report Share Posted February 23, 2021 Hello all! I had originally gotten help here when doing a partial restore of a pair of AR-2ax >> I've got an issue with one of the speakers that popped up after wires got crossed. They came loose from the screw terminals in the back and touched each other. I don't think I had it cranked up and honestly don't remember the tweeter or mid going out immediately. Now that speaker definitely doesn't have sound coming out of the tweeter or midrange. At first I thought it was just the mid. I did the toilet paper roll test and swear I could hear stuff coming through the tweeter. So I bought an original midrange of Ebay for cheap and put it in - but not dice. I was hoping to get guidance on how to trouble shoot this. I'm thinking my first step will be sure to check the pots. They were pretty corroded the first time I got in the cabs and I cleaned them up. I think I'd like to replace them altogether. I honestly kept both mid and tweeter all the way up anyways. Question 1: If the pots have continuity what is the next step you would take. I do have a voltmeter. While I was in there the rock wool was just crumbling and kicking up big clouds of dust. I had a mask on and all that but I'd rather put something else back in.Question 2: I know there seems to be consensus that the rock wool is the only stuff that has the correct density/strand size (I think) to replicate original sound. Any second bests? I actually have a fair amount of cotton/sheep's wool I could use if applicable. Question 3 (last one!): The highs on these were subdued prior to the tweeter going out. Is there value in trying to source some original tweeters? The ones in them now have a sort of brown/red domed center. Thank you all in advance for your knowledge, time and advice! Quote Link to comment Share on other sites More sharing options...
Aadams Posted February 23, 2021 Report Share Posted February 23, 2021 Is the jumper wire connected between the T and 2 terminals? Quote Link to comment Share on other sites More sharing options...
Evol2121 Posted February 24, 2021 Author Report Share Posted February 24, 2021 @Aadams You know I feel silly. It looked like it was at a glance but that is obviously something I need to verify. I did remove it awhile back and put it back on. Maybe something got screwy with that connection. I will check on this! Quote Link to comment Share on other sites More sharing options...
Evol2121 Posted February 26, 2021 Author Report Share Posted February 26, 2021 @AadamsWell color me embarrassed. I unhooked that little wire and put it back, tightening everything down really good. Seems to have solved the issue! One thing I noticed when I replaced the midrange was that it had two rectangular blocks that the wires passed through that the midrange I took out did not have. The picture below is the midrange I removed. The one I put in had these two rectangles on the back of the magnet that the wires went through. Anyone know what those were? Also - I did throw away all the crumbling rock wool. I've got some actual wool and cotton blend shown in the pictures below. Think this will work to replace it? Quote Link to comment Share on other sites More sharing options...
Aadams Posted February 26, 2021 Report Share Posted February 26, 2021 2 minutes ago, Evol2121 said: Think this will work to replace it? Anything will work if you know the correct quantity because all stuffings damp differently. The only proven filling is the original quantity of factory rock wool or its replacement, about 18oz of fiberglass chunks Corning or Johns Manville works. Color doesn't matter. Every other filling is a local experiment. Which tweeter do you have? Provide a photo. Quote Link to comment Share on other sites More sharing options...
Evol2121 Posted February 26, 2021 Author Report Share Posted February 26, 2021 @Aadams I found an exact picture of the midrange I installed vs the midrange I took out in another thread. I think I'll put the original back in just so both speakers are the same. I'll have to tinker around with the stuffing. I definitely get that it'll be trial and error. Regarding dialing in the stuffing if you were in my shoes would you go completely off your own ears or would you try to use some measuring device - even if just an app on a phone for example? Thank you for your help and advice so far! Thread on the difference in midrange drivers below: Quote Link to comment Share on other sites More sharing options...
Aadams Posted February 26, 2021 Report Share Posted February 26, 2021 I think your midrange difference was accounted for in another recent thread. The unit with the resistors is a later engineering change related to a change of woofers. If the resistor mid works use it and keep the other as a backup expecting to add resistors if you use it in these 2axs. The stuffing I would install 18-20 oz of fiberglass torn into large chunks, as did AR, and cover the woofer hole with thin batting, fiber screen fabric or low count linen and be done with it. That wool and especially the cotton will hold moisture. Quote Link to comment Share on other sites More sharing options...
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