Re Post: Inherited AR-4x speakers. How much do I rebuild?

[JKent]

The old capacitor wires do nothing, so clip them short. On mine I left them long and hot-glued them to the board but that's not really the way to do it. Just clip them and forget them.

No need to replace all the wires. Best wire is 18 ga marine grade or "tinned" stranded wire.

The cap does need to be held down. You can use silicone glue, construction adhesive, Goop, a cable tie on a mounting block. Some use hot melt glue but CSP member John O'Hanlon warns the extreme heat could damage film caps. Not everyone agrees but John is a professor of electrical engineering, so he knows what he's talking about. The pink things on larrybody's cap are ny-ties like this https://www.amazon.com/Pack-Clear-Nylon-Cable-Ties/dp/B002PNW5XU mounted on these https://www.amazon.com/Startech-HC102-Adhesive-Cable-Mounts/dp/B00008VFBE/ref=sr_1_1?ie=UTF8&qid=1473992467&sr=8-1&keywords=cable+tie+block

Zen and some other "high end" caps have insulated leads. Not necessary--just make sure the bare wires are not touching any other metal. You "could" get a piece of 1/16" heat shrink tubing to slip over the leads. Nice but not necessary.

btw, you bought flux and flux brushes. Not needed. 

You can google "how to solder electronics" and click on "Videos" on top of the page to find several helpful YouTube vids.

-Kent

[Roland]

I finally finished the rewiring of my AR-4x speakers! The sound is excellent. I was a happy guy when, after all the work was done, they worked. 

I got stuck on the soldering. Going no where with my attempts I shelved the project until last month when I collared my handy brother-in-law to teach me how to solder. The lessons were "hands on" on the very speakers and both were done in one night, abet long night, long with a few beers. The speakers sounded fantastic at 2 in the morning which is when we finally finished. I used my ipad, google play with the audio jack input going into a JVC receiver which the speakers where hooked up to. 

I reused the same stuffing,  used marine wire, as was suggested in this thread, when I used new wire. The wiring to the speakers I left alone. I did use new cord caulking to seal the woofers, I never took out the tweeters.  I used a screw mounted mount which accepted a strap to mount the capacitor which at my brother in laws suggestion has some foam for cushioning. See attached photo.

I got most of my kit from skycraft surplus in Orlando which just seem to be a "makers" heaven. 

I did screw up the threads of two of the woofer screw mounts when I used the wrong screws. Ace hardware did not have a replacement, which if I every find I will mount with epoxy. Ace suggested contacting a furniture maker. Any suggestions are welcome.

Going forward I was thinking of cleaning up the speaker linen with Oxyclean and possibly refinishing the veneer, though not high on the priority list.

Thank you very much for all the input. The color photos supplied by JKent helped me the most with the wiring, me being a neophyte. The speakers sound great and they are an important heirloom of my father who passed a couple of years ago.

 

 

[Roland]

Hello

I may have done something stupid. I connected some external tweeters, to the speaker connections in back, and now the speaker sound is muffled. How can I trouble shoot I may have broke something?  

Any feedback is much appreciated.

[JKent]

Yeah--Skycraft is pretty cool. A few years ago I got some of those hard-to-get Ohmite pots from them for about $7 each. And they had the white twisted pair wire I needed for KLH Model Eight speakers. Last year we were driving home from Orlando and stopped at a Tiffany museum in Winter Park. When we left we were about to pull onto the interstate when I spotted Skycraft! Had to go in and browse.

But as for your question

1 hour ago, Roland said:

I connected some external tweeters, to the speaker connections in back, and now the speaker sound is muffled.

That should not have caused a problem. I have external tweeters connected to my AR speakers. In fact, MicroStatic made a tweeter array specifically for AR and KLH.

I'm thinking a connection in the tweeter circuit came loose. Is it both speakers?

[Roland]

Yes. If it were only one speaker that had the issue. Both do.

I checked and tried all manner of combinations for the speaker  wire +/- connections to the speaker and receiver.

If it is the "tweeter circuit" I would open the speaker and check my tweeter connection and any "joins" in the wiring?

What kind of trouble shooting can I do?

Thanks so much for your reply.

Roland

[JKent]

I can't see the wiring clearly in your photo. When you installed the L-pads did you follow the L-pad wiring diagram that came with them? If so, that may be the problem. Here's a photo provided by Roy. 

Tab 1 on the L-pad corresponds to tab 2 on the pot

Tab 2 on the L-pad corresponds to tab B on the pot

Tab 3 on the L-pad corresponds to tab 1 on the pot

So I "think" you have the green and yellow wires reversed on yours. edit: No. Yours are correct.

[Roland]

Hi JKent

I may be repeating your observation: My yellow (middle) goes to the tweeter and my far right green goes to the capacitor. It sounds like they should be reversed. If you have the time would you look at my supplied neophyte diagram and photo for confirmation?

Thank you very much for your attention.

[JKent]

4 hours ago, Roland said:

It sounds like they should be reversed.

yup

edit: nope

[ra.ra]

Hi Roland,

The wire colors and the tab numbering can be confusing, but before you modify any internal wiring, I'd suggest that you first disconnect the "external tweeters" that you have mentioned, and then make a better determination about the performance of your 4x re-hab project.

From what I can tell, the image attached below looks like a correctly wired AR-4x with new cap (black) and L-pad (but no added resistor - - by owner choice, I presume). The blue cap is the original that has been abandoned. This pic was posted by member Tim D from this thread (which confirms the confusion, re: tab numbers):

http://www.classicspeakerpages.net/IP.Board/index.php?/topic/9871-another-acoustic-research-ar-4x-refurb/

In my own 4x restorations (using re-furbished original pots), the yellow tweeter wire connects with the pot's "B" tab, consistent with this schematic produced by John O. As JKent has noted, "B" on the pot corresponds to "2" on the L-pad, which is the center terminal.

Ditch those external tweeters and let us know how things sound.

[RoyC]

1 hour ago, JKent said:

yup

I don't think so, Kent. The crossover appears to be correctly wired to me.

Roland, I agree with ra.ra regarding ditching the external tweeters if you haven't already done so.

The external tweeters would not have "broken" anything in the crossover. If it is not a simple speaker connection issue, it could be an amp issue. Are you sure you didn't short your speaker leads when connecting the external tweeters? Do you have another amp to test the speakers with?

Roy

 

[JKent]

Roland, et. al.

I'm sorry. I looked at a picture of my own 4x xo and the schematic. Clearly the yellow wire goes to the center tab, just as you have it. I think I got thrown off by the photo of the unidentified pot and L-pad. Glad Roy jumped in. Hope he caught my mistake before you tore into your speakers again.

As ra.ra wisely noted;

Quote

The wire colors and the tab numbering can be confusing

I was confused.

Kent

 

[Roland]

The external tweeters were used only once months back and returned to their owner.  I will leave the wiring as I have it and test in the coming days on a new amp. 

Regarding "but no added resistor - - by owner choice, I presume". "by owner ignorance" might be more correct. I am a complete neophyte and have no idea. If my speakers turn out to be fine I would be interested in adding a resistor if it would help. Any extra info would greatly be appreciated.

Thanks to all for the feedback.

Roland

 

[RoyC]

15 minutes ago, Roland said:

If my speakers turn out to be fine I would be interested in adding a resistor if it would help.

 

Roland

If it would "help" what? What was the reason for using the external tweeters in the first place? Adding the resistor will decrease tweeter output.

Roy

[Roland]

Help the speaker sound better.

The external tweeters were on a whim. I friend had a pair...I plugged them in to see how they sounded. 

Roland

 

 

[JKent]

42 minutes ago, RoyC said:

If it would "help" what? What was the reason for using the external tweeters in the first place? Adding the resistor will decrease tweeter output.

Roy

I think Roland was responding to ra.ra's "no added resistor" comment which in turn was a reference to your recommendation to put a 25 Ohm resistor between the L-pad tabs 1 & 2 for midrange circuits.

External tweeters may be nice with some AR speakers. Back in the day MicroStatic sold supertweeters specifically designed to add some "sparkle" or "air" to the "laid-back" sounding AR and KLH speakers. Those MS supertweeters had built-in crossovers, switchable between 3.5kHz and 7kHz. I'm guessing the external tweeters Roland borrowed were something similar.

Kent

[ra.ra]

3 hours ago, Roland said:

Regarding "but no added resistor - - by owner choice, I presume"

Roland, my only reason for including that statement is that - - if you read fully thru that thread that I linked - - you'll see that member lARrybody did include the resistor with his AR-4x w/L-pad set-up; but member Tim D opted to not include the resistor. You'll also find RoyC's comments on when to include the added resistor and what it's purpose is intended to accomplish. I have no personal case study to share or hands-on experience with this (L-pad+R) solution, but I would guess that either approach is valid - - this decision mostly depends on your subjective evaluation of the aged tweeter output relative to the woofer.

3 hours ago, Roland said:

I would be interested in adding a resistor if it would help....

You described your speakers as sounding "muffled". My off-the-cuff guess is that either your aged tweeters are only capable of producing a minimal level of output ; or perhaps your L-pads were not adjusted properly.  The reason for adding the resistor when using a new L-pad is to more accurately re-create the effect of the original potentiometer, but unless your tweeters are sounding a bit too strong or dominant, the resistor is probably not going to provide added benefit. 

[RoyC]

8 hours ago, JKent said:

I think Roland was responding to ra.ra's "no added resistor" comment which in turn was a reference to your recommendation to put a 25 Ohm resistor between the L-pad tabs 1 & 2 for midrange circuits.

Kent

I know...the 25 ohm resistor will only reduce the tweeters' output to a greater degree. He needs to forget all about the resistor, and figure out why his speakers are sounding "muffled". :)

Roy

[Roland]

My ARs do not have the "muffled" sound  nor any kind of distortion after testing (me being a neophyte) with a new amp/receiver (yamaha R-N602 for wifi connectivity). Good for me since I thought I had blown the speakers I rebuilt. Not possible without the support/advice from this list BTW. Bad for wasting  any ones time. Apologies.

Thinking my speakers were shot I got a pair of Klipsch Reference Premiere RP-160M. I have been using an Echo/Spotify as my music source for way to long! I may return  the Klipschs if I am happy enough with the ARs. Though at first listening they have more power and range than my ARs. I do not know if comparing the two would be fair. 

Once again thanks to everyone on this thread for helping me rebuild my late fathers speakers which were a fixture in our home as I was growing up.