I Have AR-5's

[sarals]

8 hours ago, RoyC said:

The Midwest tweeter is very much like the AR-11/10pi/12 tweeter and, like the HiVi tweeter, requires a crossover modification to make it act similarly to the original AR-5/2ax type of tweeter. Since sarals' goal is to keep the 5's as original as possible, the rebuilt tweeters are the best choice. Chris does a very nice job of bringing the old tweeters back to life.

Roy

Roy!  I appreciate the endorsement of Chris1's work.  Thank you!

 

[sarals]

Here is the progress on woofer number two.  I've refoamed three woofers now and have gotten more proficient and a little faster at it!  In the last photo, the dustcap is not glued down, it was placed for a visual.  I decided to use the dustcaps that came with the kit rather than reglue the originals.  They don't look bad, and they will not affect the performance of the driver.

[ra.ra]

1 hour ago, sarals said:

.....the dustcap is not glued down......They don't look bad......

sarals, this is a great thread and your pics and descriptions are most useful. Sorry to hear you've been running into additional challenges which are extending the re-build process, but your step-by-step methodology shows dedication and discipline which should ensure a successful project.

Re: dust cap - - yeah, the new ones don't look bad, but since nothing's glued yet, I'm here to make a pitch to re-use the original flat caps. Just my opinion, but I think it is a distinctive part of the iconic look of the typical AR-5 woofer, similar to the same woofer used in the 2ax and the LST/2. Pic attached shows 2ax alnico woofer with re-used original dust cap and filled fillet foam surround. The choice of cap will not affect performance, but if you're objective is "as original as possible", perhaps this decision deserves some more consideration. 

That said, the earliest AR-5 literature depicted two features that may have never made it into production: one is the side-by-side tweeter and midrange; and the other is the domed dust cap. Subsequent brochures show the more typical features: two small drivers are staggered; and dust cap is flat. 

[RoyC]

"That said, the earliest AR-5 literature depicted two features that may have never made it into production: one is the side-by-side tweeter and midrange; and the other is the domed dust cap."

Actually the AR-5 woofer with the domed dust cap was used in very early AR-5's. I have seen 2 pairs of them over the years. This is most likely the woofer with the slightly different voice coil. Of course, the majority of AR-5 woofers were the same as the "flat dust cap" AR-2ax woofer. It is easy to save the flat dust cap by flapping it back during the re-foam process, and agree with ra.ra regarding saving it whenever possible.

Roy

[ra.ra]

9 minutes ago, RoyC said:

Actually the AR-5 woofer with the domed dust cap was used in very early AR-5's.

Thanks, Roy, I suspected this might be the case but could not be certain. I've never seen the domed cap on the AR-5, but the only reason I thought this might be possible is because of the multiple changes made to this driver (p/n 200004) as evidenced by the notations on the drawing in the library. The graphic depiction shows a domed cap, but under the Revisions list, there are mentions of cap changes, including one that notes a cosmetic cap, perhaps suggesting that at one point this driver had both a flat and a domed cap - - another condition I have never encountered. 

[lARrybody]

.One of my sets of AR5's has the early woofers with the dome dust caps. The other set looks exactly like those that sarals has and have the flat dust caps.  One thing of note is that the early woofer frames have 8 mounting holes and the  later frames have four. This is compared to the early 2ax ceramic magnet foam surround woofers with six mounting holes. The darker painted woofer below was purchased directly from Tom Tyson. 

[bfastr]

I am going to second ra.ra , give the originals a try. if all else fails then you can fall back to the new ones.  

6 hours ago, ra.ra said:

but if you're objective is "as original as possible", perhaps this decision deserves some more consideration. 

 

[sarals]

Gentlemen, this is great - thank you!

I left the flat dust caps on the woofers of my AR-2ax's when I refoamed them.  It certainly was easy to cut a semicircle in the dustcaps and fold them back.  They  flattened back out and reglued with zero issues.  

On the AR-5, yes I do want to keep them as original as possible, but I decided, just to differentiate them a little bit from the AR-2ax woofers, to go ahead and use the domed dustcap Vintage AR provided in the kit.  Let's just call it "artists license"!  Yes, I should be a little chagrined because I stress originality, but I do hope you'll all forgive me this one indiscretion.

@RoyC, I have a question about the spider in these AR-5 woofers.  I've discovered they sit on a masonite ring where they are glued to the basket.  I don't recall such a ring in the AR-2ax woofers I worked on.  (That doesn't mean they weren't there, though.

@ra.ra thank you for the kind words!  

@lARrybody I noticed some resistors across the mid/tweeter terminal on the AR-5's you pictured.  Interesting!

[sarals]

3 minutes ago, bfastr said:

I am going to second ra.ra , give the originals a try. if all else fails then you can fall back to the new ones.  

 

Bob, you're too late!  I already glued on the domed cap. 

 

[lARrybody]

1 hour ago, sarals said:

I noticed some resistors across the mid/tweeter terminal on the AR-5's you pictured.  Interesting

L-pads were used on the midranges, thus 25 ohm resistance were added. Could of been added internally, but works the same. The woofers will look fine with the dome dust caps IMHO.

[RoyC]

5 hours ago, sarals said:

On the AR-5, yes I do want to keep them as original as possible, but I decided, just to differentiate them a little bit from the AR-2ax woofers, to go ahead and use the domed dustcap Vintage AR provided in the kit.  Let's just call it "artists license"!  Yes, I should be a little chagrined because I stress originality, but I do hope you'll all forgive me this one indiscretion.

@RoyC, I have a question about the spider in these AR-5 woofers.  I've discovered they sit on a masonite ring where they are glued to the basket.  I don't recall such a ring in the AR-2ax woofers I worked on.  (That doesn't mean they weren't there, though.

@ra.ra thank you for the kind words!  

@lARrybody I noticed some resistors across the mid/tweeter terminal on the AR-5's you pictured.  Interesting!

Looking good! You're forgiven. :)

It's been awhile, but I don't recall seeing a foam surround 2ax woofer without a mounting ring for the spider.

Roy

 

[bfastr]

Sara,  the new cap looks good,  I probably would have done the same to cover the tracks of the old one anyway. gives it a nice new look

Bob

[sarals]

The AR2ax recone kit I found on eBay arrived yesterday, and wouldn't you know it, the voice coil diameter is smaller than my AR5's 1.5 inch VC.  I considered opening up the spider that came with the kit, but I discovered that won't work because it's a cupped spider, not a flat one like the original.  It wouldn't sit properly on the masonite ring landing.  So, I ordered a spider from Speaker Exchange.

I'm looking at a fairly slow process to restoring these AR5's of mine.  The tweeters are going to be expensive, no matter what route I take, so budgeting will be in order!  They'll be the last thing to be addressed on this adventure.

[fury161]

On 1/10/2019 at 10:43 AM, sarals said:

Here is the progress on woofer number two.  I've refoamed three woofers now and have gotten more proficient and a little faster at it!  In the last photo, the dustcap is not glued down, it was placed for a visual.  I decided to use the dustcaps that came with the kit rather than reglue the originals.  They don't look bad, and they will not affect the performance of the driver

Very nice work! Since I am in the process of rehabing some AR17's, this is particularly relevant to my interests. ? I'll look forward to your future updates. 

[sarals]

11 hours ago, fury161 said:

Very nice work! Since I am in the process of rehabing some AR17's, this is particularly relevant to my interests. ? I'll look forward to your future updates. 

Thank you!

[sarals]

The recone kit from The Speaker Exchange arrived today.  Very nice!  There were two spiders, one cupped, one flat.  Both fit correctly over the voice coil, but neither one was correct in depth to sit on the landing properly and get the VC where it needed to be in the gap.  The cupped spider was the closest to the original, but it still caused the VC and cone to sit slightly proud of the pole piece and basket.

Pondering....

I considered, momentarily, using the entire recone kit - cone, VC and all - and totally revamping the woofer.  However, the cone in the kit is made quite differently than the original.  It seems more rigid, and I would bet it would sound noticeably different from the original.  The parts are beautifully made, and it's a very nice kit.  However....

[frankmarsi]

There's one for sale, I'd ask first, confirm its condition and then jump on it: https://www.ebay.com/itm/ACOUSTIC-RESEARCH-AR-5-WOOFER-ORIGINAL-AR5-LOOK/303039644796?hash=item468e92047c:g:-LYAAOSwSVdb0HIb:rk:2:pf:0   

[sarals]

Thanks for that, Frank!  If I messed mine up, that would make a good fall back.  There is also a pair of woofers on eBay right now, too.

[sarals]

Success!  The spider is installed, and I've attached the new surround, and the dustcap.  I have yet to solder the leads.  I tested my repair, manually (no VC rubbing) and with a signal (it works, no noises!), and I am thrilled!

I had to "shave" the Masonite landing ring slightly to make up for the difference in spider depth from the original.  I used an X-Acto blade, new, and carefully went round and round the landing until I had a uniform cut on it.  I used five minute epoxy to secure the spider to the cone, and once that had set up for a good couple of hours, I applied five minute epoxy to the landing and attached the spider to it.  I used shims to center the VC, and to keep friction on the cone assembly so the spider had good pressure on the landing.  Once all of that had set up, I glued the surround on, starting with the cone, letting it set during the day.  In the evening I glued the surround to the basket, using laundry clothespins to hold the surround in place to the basket.  This morning, I removed the clothespins, tested my work, and then installed the dust-cap.  I've yet to solder the leads to the terminal, that's the last step.

Next I'll recap the crossovers, and then address the tweeters.

[bfastr]

Wow Sara!!  that looks amazing!  I am glad you were able to use the original cone.   that really looks great!

keep the pictures coming!

Bob 

[sarals]

Thank you, Bob!  Will do, definitely!

[fury161]

WOW! Fantastic work, Sara!

[sarals]

6 hours ago, fury161 said:

WOW! Fantastic work, Sara!

Thank you!

 

[Pete B]

Are you able to measure the woofer's free air resonance (Fs)?

I'd be concerned that the new spider is too stiff.

Another good test is to measure the system resonance with the woofers mounting in system.

[sarals]

On 1/28/2019 at 7:57 AM, Pete B said:

Are you able to measure the woofer's free air resonance (Fs)?

I'd be concerned that the new spider is too stiff.

Another good test is to measure the system resonance with the woofers mounting in system.

Hi Pete!  I haven't, but I can give it a try.

Right now, I'm not able to do much of anything.  I had surgery to repair a broken bone in my right foot last Wednesday (Jones Fracture, for those of you familiar).  I'm on crutches, having to keep the foot elevated.  Day to day chores are a challenge.  Working on my speakers is darn near impossible!  I do want to get the tweeters removed and sent to Chris1, I'm hoping to do that (with help) sometime in the next few days.