Jump to content
The Classic Speaker Pages Discussion Forums
JeffPro

Bungled AR 2ax repair

Recommended Posts

That's fixable, Jeff. Both level controls are still present, as is the #5 inductor. Although for some reason, the person who did the repair cut short one of its leads.

All of the driver leads appear to be intact, although the yellow lead for the tweeter seems to have come free from the new crossover board.

You can easily remove the new crossover board by clipping the woofer (red & blue), midrange (yellow & green) and tweeter (black) wires as close to the crossover board's mounting tabs as you can cut. This will enable you to set the woofer safely aside. It looks as if the two "IN" wires (yellow & yellow/green) can simply be un-clipped from the board. A Philips driver can remove the two screws that hold the board in place, and you can just lift it out - hopefully, the shop did not use any glue.

Save the boards - they have some value on eBay, and you might be able to recoup some of the money that you've spent.

Additional photos would then be useful, but I'm guessing that the AR-2ax experts here can tell you exactly what to do about restoring or replacing the level controls, sorting out the inductor issue, and adding the new capacitors.

On another note, I'm going to suggest that you have a real expert look at your woofers. As has been mentioned, these are very desirable drivers, and certainly worthy of proper repair. All fixed up, this will be a really nice set of speakers.

Share this post


Link to post
Share on other sites

Update:

Roy is advising Jeff on how to glue his woofer back together.

I received a box from Jeff today. Pots are pretty bad and the inductors are slightly mis-matched, plus one inductor has a cut lead. Fortunately I had one in my parts box that's a good match for the one that wasn't cut. Put in an order to Madisound for some Carli caps, L-pads and resistors. Should have them next week and can get started.

-Kent

JP xo1.JPG

Share this post


Link to post
Share on other sites

Just want to state the obvious. Roy and Kent, you guys are great. Those speakers are going to sing like no tomorrow. We are all lucky to have you here. 

Share this post


Link to post
Share on other sites

Well, the crossovers are finished. Just want to test them before sending them back. First photo shows one complete xo. I labeled everything to make it easy to re-install.

Jeff sent all the "guts" he could remove and I just had to share a shot of the kind of work the "speaker specialist" did. Sloppy application of red electrical tape , as on the left in photo 2 hides an incredibly amateurish splice as shown to the right. Hey--I'm just a hobbyist with arthritic fingers, but I did a better job than that "pro" (and I'm humble, too ;) )

-Kent

JP xo 26.JPG

JP xo 28.JPG

Share this post


Link to post
Share on other sites
1 hour ago, JKent said:

Well, the crossovers are finished. Just want to test them before sending them back. First photo shows one complete xo. I labeled everything to make it easy to re-install.

Jeff sent all the "guts" he could remove and I just had to share a shot of the kind of work the "speaker specialist" did. Sloppy application of red electrical tape , as on the left in photo 2 hides an incredibly amateurish splice as shown to the right. Hey--I'm just a hobbyist with arthritic fingers, but I did a better job than that "pro" (and I'm humble, too ;) )

-Kent

 

 

You sure did, Kent. Nice job!

I've provided Jeff with some woofer repair guidance. Since it had already been partially done, he is going to give it a shot himself...so you're doing all the heavy lifting in this adventure. :) Hopefully we will know the outcome in the near future.

Roy

Share this post


Link to post
Share on other sites

Kudos to Kent & Roy for their excellent advice & work on these speakers.

Kent, I really like your "wiring harness" solution - brilliant!

 

Share this post


Link to post
Share on other sites
On 18-2-2017 at 4:03 AM, ar_pro said:

Kudos to Kent & Roy for their excellent advice & work on these speakers.

Kent, I really like your "wiring harness" solution - brilliant!

 

What a great spirit this forum has!

Share this post


Link to post
Share on other sites

I can't agree with Vintage Man more. Kent and Roy set me up big time and I am happy to report the repair is finally completed. Kent had sent me his awesome kits weeks ago, but one thing after another blocked me from getting them hooked up.

If interested, the steps taken:

Glue down the lower edge of the woofer cone with E6000 per Roy - this is strong stuff, good ventilation a must. Before the glue down, inspected the voice coil and it looked alright. My method of making sure it was centered - gently pushing down on the center of the woofer cone to make sure it was not contacting the coil. Crude but I think it worked. The upper lip being glued down and centered helped in some ways, hindered getting the glue to reach to the spots you needed to. I also used popsicle sticks to keep the edge up until I had it all glued, and they also helped to spread the glue to areas I could not initially get to.

Pulled old insulation and weighed it, right around 30 ounces in each speaker. Bought a small roll of the pink stuff, peeled the backing off, and cut it into sections with scissors. Roughly 7" x 12" - 3 up, and five layers deep to match the weight of the old insulation.  The middle section around the wires I broke it up finer to fit in, around and under to take up the air space and hopefully keep anything from vibrating.

The wiring kit Kent provided could not have been easier for somebody like me. Everything was labeled, and with a print out (he provided) of the picture of how it should look installed, it was a breeze. The only hiccup was one of the leads was to short to reach the terminal, but Kent came up with a jumper solution that worked just fine. Wire nuts are my friend. I checked them all at least 3 times to make sure they were tight. Before I sealed them up, I tested each one to make sure I got sound from all three areas.

Once I was set to seal them up, I disconnected to the woofer to make it a little easier to stuff with insulation. When it was full, I laid down a sheet of crinoline (per Roy) fabric to keep the insulation out of the woofer. I snipped a pair of holes to feed the wires through, and tied in the woofers. Last step was rolling out the putty, to make it as air tight as possible around the woofer. Alternated the tightening until it was somewhat firm. Tested the seal by depressing the woofer to watch it rebound slowly.

I did this one by one, leaving one speaker unsealed and not stuffed to hear any difference between the two. To be honest, I was not hearing a big difference at the level I was playing the volume (about 1/4 way). Once both were stuffed and sealed, I tested them slowly upping the volume and did not hear any issues. SUCCESS!

The speakers sound very good to my ears, but I do have questions (below). Using the AR turntable, even some of old LP's my dad got at the same time, it is a great listening/life experience. The other week when my dad was over, I had the turntable hooked up and we used headphones - he had the biggest smile on his face. Can't wait for him to hear the old A2x's again.

Thanks again to this forum, Roy, and especially Kent for helping me out in such a big way. Very grateful and will try to pay it forward if I can.

The new man cave/listening room is starting to shape up nicely. Attached are a few pics, including some shots of my parents apartment showing off his system, the only thing missing is the Fisher amp and tuner (TX100?). Stereo before furniture has been a family trait.

Questions:

Is there such a thing as a break in period with new capacitors and resistors?

Is it common for the tweeter to have the lowest output? The woofer seems strong, and the mid really sounds like it carries the high range. You really have to listen close to hear something coming out of the tweeter. Overall it sounds balanced, just wondered if there is something to this tweeter degradation being talked about on forum.

My last question I will start a new thread on, as it has to do with the current receiver and how that has an effect and what can be done to help.

Cheers!

AR Speakers 002.JPG

AR Speakers 008.JPG

AR Speakers 007.JPG

AR Speakers 010.JPG

Leavitt St 1.jpg

Leavitt St 3 .jpg

Share this post


Link to post
Share on other sites

What a great conclusion for Jeff.  Congrats to JKent and all that helped him.  Absolutely love the old photos Jeff.  That is an example of how people used to get together and communicate before the internet and mobile phones allowed texting!  It is also back when many folks used these bookshelf speakers in bookshelves. (Acoustic suspension design facilitated this.)

 

Jeff the tweeters in these old AR's are not known to produce a lot of output compared to more modern or even newer speakers.  Plus because of their age they just may not be putting out what they once did.  It is the one common concern all of us have about these old AR's and unfortunately there isn't much that can be done.  RoyC may be able to chime in and have some ideas for you and he does do a great job of getting the most out of them.  There is also the option of removing the resistor on the tweeter from the new LPad that some of us do with these and the AR3's. 

Share this post


Link to post
Share on other sites

excellent thread Jeff. anxious to hear further listening impressions of these beauties. as to the tweeter issue from aging that has plagued this community, there is possibly hope. recently an engineer by discipline has developed a rebuild approach for the more common 3/4" tweeter of the slightly later era. in fact I am forwarding a set to him for his magic and will certainly advise the forum of the result. in any case do NOT eliminate the old tweets if you choose to go with a different driver. Someone (like me) would want them!

Geoff

p.s. on the break in question, if there is (which can be a hotly debated topic) it is rapid. the real break in is in your ears and brain.

Share this post


Link to post
Share on other sites
50 minutes ago, DavidDru said:

Jeff the tweeters in these old AR's are not known to produce a lot of output compared to more modern or even newer speakers.  Plus because of their age they just may not be putting out what they once did.  It is the one common concern all of us have about these old AR's and unfortunately there isn't much that can be done.  RoyC may be able to chime in and have some ideas for you and he does do a great job of getting the most out of them.

Second that

51 minutes ago, DavidDru said:

There is also the option of removing the resistor on the tweeter from the new LPad that some of us do with these and the AR3's. 

Jeff's xo only has a resistor on the mid, so unfortunately that won't do it.

28 minutes ago, stupidhead said:

e real break in is in your ears and brain.

Amen!

-Kent

Share this post


Link to post
Share on other sites

I have a pair of HiVi tweeters ready to go into my 3a's but haven't done so yet because there is still output from the original tweeters. I'm torn.

der

Share this post


Link to post
Share on other sites
14 hours ago, JeffPro said:

Overall it sounds balanced, just wondered if there is something to this tweeter degradation being talked about on forum.

another option: Keep an eye out for some MicroStatic supertweeters. They sometimes show up on ebay and if you're lucky they can be had for under $100. Recapping helps those too, unless you get some that originally had film caps.

MicroStatic50020.jpg

Share this post


Link to post
Share on other sites
6 hours ago, DavidDru said:

Jeff the tweeters in these old AR's are not known to produce a lot of output compared to more modern or even newer speakers.  Plus because of their age they just may not be putting out what they once did.  It is the one common concern all of us have about these old AR's and unfortunately there isn't much that can be done.  RoyC may be able to chime in and have some ideas for you

The original orange dome tweeter used in the 2a, early 2ax, and 3 has held up much better than the later, small black dome tweeter of similar construction, so Jeff's tweeters may be OK.

It isn't unusual for people new to AR speakers of this era to comment on the apparent low output of the tweeters. This is partly due to the tweeter's crossover point being very high, giving the impression of "low output". Even replacement tweeters (like the HiVi tweeter), when properly implemented, will seem to have lower output compared to tweeters of later speaker designs. Before performing a tweeter-ectomy, a tweak of the "treble" control is often sufficient to provide adequate tonal balance.

Roy

Share this post


Link to post
Share on other sites

Great thread, great ending, and consistent  with my new experience with this forum where I have received wonderful advice and direct help from Roy and others, in my first AR-2ax restoration.  Expect an update with pics soon (the cabinet refinishing has been a long slog).

I sent one of my tweeters to Chris1this1, who does vintage AR tweeter rebuilds.  The dome was crushed, and I stupidly tore a hole in it trying to pull it out.  Chris's process involves removing the dome, so that means he can reform it, and in my case he deftly patched the hole. But more significantly he rebuilds the voice coil and uses a replacement foam. 

So now the question is, will my other one, which did not have any apparent damage, sound weak compared to the rebuilt one? 

I'll find out as soon as I put them back in. I want to finish the cabs before I put the XO  back in and reconnect the drivers. 

Or is there some way to test the tweeters before reinstalling them?

 

Rob

 

 

Share this post


Link to post
Share on other sites
2 hours ago, Robthomp said:

So now the question is, will my other one, which did not have any apparent damage, sound weak compared to the rebuilt one? 


Rob

The rebuilt tweeter will have more output, Rob. Replacement or repair of these tweeters should be done in pairs for best results.

Roy

Share this post


Link to post
Share on other sites

Can you test a loose 3a tweeter by sending a signal to it with a 6uf capacitor in series with the positive lead? 

Share this post


Link to post
Share on other sites
8 hours ago, RoyC said:

The rebuilt tweeter will have more output, Rob. Replacement or repair of these tweeters should be done in pairs for best results.

Roy

Well,  I tested the tweeters (with my new caps and restored pots).   In retrospect this result could have been easily anticipated. The rebuilt tweeter sounds MUCH louder and clearer. There's no comparison really.  I tested with music (Nora Jones) and then a tone generator.  The non-rebuilt one fared a little better around about 4K and then lagged behind more with higher frequency.  At 10K I couldn't hear it at all.   This test is affected by my poor hearing at higher frequencies, but at 10K I could still hear the rebuilt one clearly.  I think Chris does great work.

tweeter_test.jpg

Share this post


Link to post
Share on other sites
1 hour ago, Robthomp said:

Well,  I tested the tweeters (with my new caps and restored pots).   In retrospect this result could have been easily anticipated. The rebuilt tweeter sounds MUCH louder and clearer. There's no comparison really.  I tested with music (Nora Jones) and then a tone generator.  The non-rebuilt one fared a little better around about 4K and then lagged behind more with higher frequency.  At 10K I couldn't hear it at all.   This test is affected by my poor hearing at higher frequencies, but at 10K I could still hear the rebuilt one clearly.  I think Chris does great work.

tweeter_test.jpg

Just to be clear, I didn't mean to say that the non-rebuilt one did better than the rebuilt one at 4K Hz.  The rebuilt one is significantly louder at all frequencies.  I just meant to say that the discrepancy seemed a little less  at lower frequencies, and then became much more pronounced as the frequency got higher.

Share this post


Link to post
Share on other sites
9 hours ago, Robthomp said:

The rebuilt tweeter sounds MUCH louder and clearer. There's no comparison really.

I think it just goes to show that many (most? all?) of our beloved old tweeters with their "wide dispersion" have declined over the years and have reached the end of their glorious lives. I do not regret having installed Hi-Vi tweets in my 3a's. Hope someone (Roy--you listening?) will come up with suitable replacements for the 3, 2a, 2ax etc. For those willing to spend the money for Chris's repair, fine. But I think we need to look at modern tweeters. OK--let the flaming begin ;)

-Kent

Share this post


Link to post
Share on other sites

no flaming on this post. it speaks loudly to the different approaches that are taken when reworking a set of these classics. I am thrilled that there may be a resource that can bring the old degraded drivers back to life. I live firmly in the oem minded camp, but that does not mean other approaches (non oem) are wrong. I shutter to think of how many old drivers have been tossed with the belief there is no hope though.

it is all about the music and enjoying the fruits of your labors, whatever approach you have chosen.

Share this post


Link to post
Share on other sites
On 3/16/2017 at 9:12 AM, JKent said:

I think it just goes to show that many (most? all?) of our beloved old tweeters with their "wide dispersion" have declined over the years and have reached the end of their glorious lives. I do not regret having installed Hi-Vi tweets in my 3a's. Hope someone (Roy--you listening?) will come up with suitable replacements for the 3, 2a, 2ax etc. For those willing to spend the money for Chris's repair, fine. But I think we need to look at modern tweeters. OK--let the flaming begin ;)

-Kent

Hi Kent,

I guess it depends on your definition of "suitable". The HiVi Q1R is a modern tweeter, as was the AB Tech replacement, and, imo, both have been made (with a crossover mod) to be suitable. Many modern tweeters have been tested and considered, and other than AR-11 onward AR tweeters (which also require a similar crossover modification), there is nothing more "suitable" in the "modern" category. As discussed before, the original AR dome tweeter has very unique construction materials and properties. There will never be a "modern" drop-in equivalent unless some manufacturer decides to specifically develop and manufacture a tweeter with identical mechanical and electrical characteristics...which is extremely unlikely at this point. The rebuilt tweeter Chris is providing, based on the construction materials alone, is likely to be as close as anyone will ever get to providing a modern version of the original tweeter.

When Vintage AR/Larry returns from vacation we will be installing Chris-rebuilds in LST's and 3a's, and will get our first opportunity to hear how they actually integrate with these speakers. On the bench his rebuild shows much greater overall output and somewhat greater extension into the upper midrange frequencies than all the functional original tweeters we had on hand, though not to the same degree as the modern tweeters mentioned above. It will be interesting to hear how it handles the all important overlap with the midrange driver.

Attached are a couple of photos of original tweeters I've rebuilt using a "modern" 3/4 inch dome/voice coil assembly (shown in a couple of AR-5's awaiting cabinet restoration, and later tested in a pair of 3a's.). It actually works quite well, and I would consider it a "suitable" replacement, but it still requires a parallel coil to tame extension into upper midrange frequencies...and like any rebuild, requires an original tweeter carcass.

Roy

 

New Dome Front-wired.JPG

New dome Back-wired.JPG

Share this post


Link to post
Share on other sites

Hi Roy

Maybe I misunderstood. I was under the impression that the Hi-Vi was a good replacement for the 3a tweeter but not 2, 3, 2ax, 5.... Am I mistaken about these? If the Hi-Vi can be used in those, fine.  Your rebuilds look interesting.

-Kent

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×