Tweeter trouble on AR 2x.

[Guest mrsimontibbs]

Hello. I just finished working on my thrift store 2x speakers that I posted about last year. Thanks to users Jkent, onplane and chartliner for their replies. I installed new L-pads, refoamed the woofers and sealed with new putty. I'm having two problems:

1) The tweeters seem weak, even with the L-pads rotated up all the way. Compared to a set of KLH's I have with upgraded tweeters, the 2x lack presence and seem flat. The woofers are nice and beefy though and overall the 2x's sound lively.

2) One of the tweeters has gone out twice. I resoldered the wiring and that fixed it, but then it quit again. Between powering on the stereo, (not during playback), it just stopped. No noise or fizzle or anything.

I can't afford new tweeters at the moment and kind of like having all the original parts, but do you have any suggestions? If I did buy new tweeters, what are some good options?

Thanks for your time,

TED

[Guest audiocarp]

I would like to know how the heck you get an AR-2a cabinet open? I too have the dead tweeter issue...

[Guest mrsimontibbs]

I used a putty knife to gently pry up the edges. If you're careful, the grills will remain intact. There are dots of glue in the corners and sides which you can aim for.

[soundminded]

I had to open a pair of AR2as last summer and I can tell you it was one sweet....never mind. Anyway, here's the problem I had. AR used the world's best putty. Even after more than forty years it had not cured, it was soft, it was thick, it was like glue. Contrast that to Bose 901s whose putty had hardened to cement which didn't stick to anything. Anyway, I fashioned a tool with a short projection at a right angle at the end which allowed me to slowly scrape bit by bit, small amounts of putty from under the outer edge of the woofer by working it between the routed recess and the metal frame. Finally after what seemed like hours, I got enough of it off so that what remained was not so strong I couldn't pry the rest of the woofer out with a screwdriver and another tool I used as a fulcrum. It took a long time and a lot of patience I admit. The trick is to do it without damaging the cone...or injuring your fingers. Once I got it out, I scraped more of it off so it would never stick again. Unless the problem is the tweeter itself, the rest of the circuit can be accessed through the woofer opening. BTW, save the fiberglass stuffing, try not to crumple or tear it too much, and don't get too much of it on your skin. You might want to take it out using a pair of rubber gloves and put it in a plastic bag for reinstallation later. Hope this helps.

[dynaco_dan]

Hi there;

If you should need replacement tweeters either the, CTS 3 1/2" or AR 2 1/2", ebay usually has some on the auction block.

The 3 1/2" usually go for around $10.00 each and the 2 1/2" usually go for $15.00 each.

I picked up a few 3 1/2" at $9.99 for two.

One time I bought 5 from Dale in Reno for $.99.

They go up and down with the demand at the time.

A caution on the smaller tweeters.

The surround glue/adhesive can still be sticky after all these years.

If the seller will place a nut between the frames when they are fastened, face to face.

I have had tweeters tear apart when the surrounds touched and stayed together.

I believe it is TomT that uses a paint can opener to pry the drivers out of their recess.

A metal paint scraper will pass between the frame and the cabinet.

There is various levels of scraper, wide, narrow and in between.

I use a 1 1/2" wide heavy guage blade and I place a sheet metal angle piece on the cabinet edges so as not to damage the veneer.

Patience and gentlness is required, there is possibly a dozen or so staples as well, at least mine had some, as well as the glue.

I also use typical high rubber type dishwashing gloves for the fiberglass.

If you already have surgical gloves, either latex or vinyl, they will do as well.

I see that the topic is AR-2X but one writer mentioned AR-2/AR-2A.

These will have different tweeters and capacitors.

With the really old ugly grille cloths they seemed to use a black glue.

[Guest matty g]

Hi -

I find it helps to unscrew the badge and partially drive in a drywall screw. This will give you a handle with wich you can carefully lift the edge. Once you have the edge lifted, you can usually take a paint can opener or a butter knife bent at an angle and pop the glue points out. Keep a thick piece of cardboard between the cabinet and whatever tool you use to prevent marring the cabinet.

The badge can be replaced in the hole if you fill the enlarged hole with putty or the end of a matchstick or some such. Hope this helps.

Matt

[onplane]

Ted,

Many of us have experienced similar results with the original AR tweeters. There are a few who believe the tweeters simply no longer put out the SPL that they once did.

Many of us believe that the tweeters just never were as good as today's tweeters.

Now, there are two things you can try that won't cost much:

1. remove the 25 ohm resistor that's across the l-pad (if you used Roy's solution) - then set the l-pad to max this will gain you approx. 1 db in the tweeter

2. bi-amp (aka Jerry-rig) - here you use a separate smaller amp (25 to 40 wpc) to drive just the mids/tweeters. Then you set the tweeter l-pad to max and slowly keep decreasing the mid l-pad until you reach the desired balance between the mid and tweeter. Balance between the woofer and mid will be controlled by the volume control on the amp driving the mid/tweeter.

Hope this helps ...

Regards,

Jerry

[charger3834]

I think Jerry may have missed that Ted has AR-2x's not AR-2ax's. Therefore there is no 3/4" tweeter in the system. This two way design uses either a 2.5" or 3.5" cone mid/tweeter depending on the era as Vern pointed out. It would be pretty hard to argue that those units have low output, Albeit they may not the frequency response of other systems. Also keep in mind that AR's goal was not to make the speaker "brighter" than real live music.

IMO Ted has one of four possible issues; control pot in need of rebuilding, blown tweeter, cold solder joint, or bad capacitor (not likely, as the old blocks tend to drift in value not totally fail.

Most likely the control pot has to much corrosion or one tweeter is damaged.

I would like to know what version AR-2x Ted has ? The old 2x has a cloth surround woofer with a 3.5" tweeter covered by fiberglass and steel mesh. The new, post 1970 AR-2x has the foam surround woofer and the 2.5" tweeter.

[onplane]

>I think Jerry may have missed that Ted has AR-2x's not

>AR-2ax's. Therefore there is no 3/4" tweeter in the

>system. This two way design uses either a 2.5" or

>3.5" cone mid/tweeter depending on the era as Vern

>pointed out. It would be pretty hard to argue that those units

>have low output, Albeit they may not the frequency response of

>other systems. Also keep in mind that AR's goal was not to

>make the speaker "brighter" than real live music.

>

Brad, you are 100% correct! I read that as the AR-2ax.

I actually own a Jensen made clone of the 2x. 10" acoustic suspension woofer with a 2" cone tweeter. It's actually a decent sounding speaker providing you don't wander too far off axis. (My sister gave it to me 10 years ago.)

Do the 2x's have the famous AR arrangement of three terminals?

Regards,

Jerry

[soundminded]

Blasphemy! Heresy! How dare I say what I am about to say about such a venerated speaker, it was after all made by AR. Well here it is folks, last summer as some you you may remember I received among my treasure trove (someone elses esrtwhile trash for the curb) a pair of AR2as. And frankly, upon listening to them they were a real disappointment. No high end, midrange all out of proportion, they were not particularly accurate to my ears. Examining them carefully, I concluded that they worked fine, nothing broken, all I had done was disassemble and clean the pots and replaced the capacitors. But never being one to write anything off, I decided to give them some help. One thing I noticed pretty quickly was how deep and distortion free the bass was. I'll bet the AR 10" woofer in an AR 2 series speaker system will give the $1800 Von Schweikert 10" AS woofer a run for its money. I decided what was needed was much more high end. And this is what I settled on. I used 3 3/8" mylar tweeters per channel. I made a small h shaped baffle out of masonite and aimed one tweeter face forward, the other two mounted horizontally face up aimed at the ceiling hidden behind the front facing baffle so they are indirect firing. The up firing tweeters are each in series with a 2.7 mfd npc and the forward firing one is in series with a 2.2 mfd npc and a 12 ohm 10 watt resistor. All are in phase and parallel with each other and in phase with and parallel to the main speaker. I also put a 10 mfd npc across the woofer voice coil to cut its high end. If you try this, I recommend using 8 ohm 20 or 30 watt mylar tweeters about 90 or 91 db sensitivity similar to Audax AW010E1

http://www.partsexpress.com/pe/showdetl.cf...tnumber=276-020

If you try it, please let me know what you think.

[charger3834]

>

>Do the 2x's have the famous AR arrangement of three

>terminals?

Yes they do :-)

[Guest mrsimontibbs]

These are the later model with foam woofer surround and smaller tweeter. I probably do have a bad solder joint, which I'll try to re-do this weekend. As for the tweeter weakness, I could try bi-amping them as someone suggested but I'll probably replace the tweeters at some point. Thanks. I'll keep you posted.

[dynaco_dan]

Hi there;

I came across a service problem with a single AR-4X when I worked at the local AR warantee depot.

This was the second time back for a bad tweeter.

The tweeter had just been previously replaced under warantee.

When a typical item was serviced, a small sticker with invoice number and initials was stuck to the inside of the enclosures.

The same repeat fault was, no tweeter.

I cannot remember the exact details but I ended up looking at the solder connections on the crossover.

There was a single tinned bare wire that was used as a jumper, which connection I do not remember.

The connection on one end was soldered from the factory, not quite to my liking though.

I resoldered and used rosin core solder but the solder joint would not give the correct appearance, it didn't matter how much solder that I used.

I decided to remove this short jumper and found out it was tempered steel, which will not normally solder at all.

I used a short piece of copper wire and everything was aok.

I didn't get paid for my troubleshooting but I did learn something new and can pass this information on.

There probably is not too many troubleshooters that can claim to have come across such a small but important error.

There is a better chance of winning a lottery, than ever seeing and diagnosing this problem.

AR used, for a period of time, resista wire for the resistors in certain crossovers rather than wire-wound resistors.

It would be easy for a piece to fall into a batch of short tinned jumpers, they look almost exactly the same.

Had each end of the wire been turned under pressure and soldered then it may have never been a problem.

Your problem is very likely not the above mentioned but if you are looking around inside do not overlook this possiblity.

As far a replacement tweeters go, I've already mentioned ebay for used ones, $10.00 each +/-.

There is not very many old or new tweeters that can be substituted, with any success and satisfaction, because of the efficiency and low crossover point.

I own several versions of the AR-2X's and am looking forward to comparing them.

When I first owned AR-4X's, I was contemplating buying a single AR-1X for the center channel bass, it never happended.