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Acoustic Research AR-5 restore questions. Speaker padding/crossovers

jellyfish182

New Member
Hello all! I got a sweet score on a pair of AR-5's and already go new grills (there were holes), have original badges, refoaming woofers as we speak, serial numbers within 8 and both speakers have both papers stapled to the back-all complete. I plan on going all out on these so price isn't that big of deal. I'm fine spending around $400 for everything.

Cabinets:
If I wanted to replace/upgrade the insulation that was in there already, what kind do I buy, and any particular way I put it in there? I went to Menards today and there were A LOT of different ratings on insulation that I thought I'd seek some advice. Is the higher the rating=better quality and should be used, or are certain kinds to be avoided? (fiberglass vs denim etc)

The sealant puddy for the woofers, should I add it to the tweet and mids too, or since they aren't bumping out of the box-not to worry about it?

Crossovers:
Since the values of the capacitors are uncommon now 4uf, 24uf and 72uf, should I get the next closest rating or combine to create exact values? For learning purposes, what would happen if I changed the values slightly up or down?


My goal is to make them sound and look their best while maintaining authenticity of appearance and sound, unless they sound better-I won't mind! Is it sacrilege to want to add some nice single banana plugs to replace those screw termals on the back? Kicking the idea around. I also plan to replace the pots to something a little more reliable too. The ones in there now are shot. Thank you so much, hope my questions can help others as well!
 
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Unbacked fiberglass, approximately the same weight as the original, will work fine. Why would you
replace what's in there? It should be reusable.

Won't hurt to seal all the drivers.

Caps within 10% of the originals will work fine.
 
Thanks. I wasn't sure if the modern fiberglass would be better or change the sound any. There is a lot more in there than I thought there was! I'll probably reuse it like you suggest. I have a friend helping me do the job and he is worried about the small wires from the mids and tweets when resealing the drivers. Are those pretty fragile? Looks like they used little foam gaskets for sealing, but was going to get the woofer sealer from vintage AR because they have the pots too.
 
Early AR's had insulation that folks do replace but the later stuff is typically fine.
Yes, those wires are very fragile and I would just leave them alone unless you have to remove them for some reason. Roy C serviced the mids on my AR3's (one ended up being replaced) and he provided new leads in that case.
foam gaskets? Sealer? Post a few photos.
The Pots are often the weak point so those need to be cleaned up. Plenty of posts on here and ClassicSpeakerPages on that.

Check out this thread about them. Pan down to the info that Tom tyson posted with brochure pages and his insider knowledge.
http://www.classicspeakerpages.net/IP.Board/index.php?/topic/8825-dating-ar-5s-by-serial-number/
 
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Pic 1: Here is a photo of the woofer with the sealer/putty I found online. I guess it is essentially "plug duct seal compound" at home depot and $3 for a pound. Or enough to do a single woofer for $5 on ebay. Glad I kept researching!

Pic 2: This is what was in mine. Its pretty flattened out now.

That was some interesting info on my speakers. Thanks for the link. Were they designed to lay horizontal? That's how a lot of brochures show them. P1020470.jpg foam.jpg
 

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They were classified as bookshelf speakers so yes, you could lay them horizontal. The badges would just be rotated. most dont do that now though of course.
You can use the stuff from home depot if you want otherwise Parts Express sells a roll of foam driver sealer stuff that most of us use so you open them back up again easier.
Many tricks of the AR trade can be found in the AR3a restoration guide you can download over at Classic Speaker Pages. It is for the AR3a and 3 but many aspects apply to the 5 and other AR speakers in terms of process and tips.
 
Nice project........... and it looks to me like your pots have possibly already been replaced with L-pads - - - which would be fine - - - but what makes you think that yours are "shot"? On the woofer, it appears you have added new dust caps, and did you install the inner foam edge under the cone? Can we see the backside of a woofer?

And yes, be very careful with those tiny exposed wires for mid and tweeter.

Re: caps, this is just one set of suggestions to get you thinking about it. 3.9uF is far more common that 4.0uF and close enough; and 70uF or 73 uF (33+40) is close enough to 72uF for the woofer circuit.
http://www.erseaudio.com/Products/PulseX250v/MPX25-03-3-90
http://www.erseaudio.com/Products/PEx250v/3-9uF-250-volt-Metallized-Polyester-Mylar-Film-Capacitor
http://www.erseaudio.com/Products/PulseX250v/MPX25-03-24-00
http://www.erseaudio.com/Products/PEx250v/24uF-250-volt-Metallized-Polyester-Mylar-Film-Capacitor
http://www.erseaudio.com/Products/NonPolarElectrolyticAll/ANP10-05-70-0-PB
http://www.erseaudio.com/Products/NonPolarElectrolyticAll/ANP10C-05-33-0-PB
http://www.erseaudio.com/Products/NonPolarElectrolyticAll/ANP10C-05-40-0-PB
 
I still haven't taken out the fiberglass yet-thinking of ordering new pots but trying to decide which ones and where to get them. When I was testing them, I had a hard time even getting sound out of the tweets and they grind something awful when I turn them. woofers.jpg woofer2.jpg The picture posted of the woofer was not mine, but one I found online showing the putty. Mine look like this:
 
OK, then never mind my previous comments about woofers and pots in relation to the pic that is not yours. These woofers look much better - - 1972 date stamp, flat dust cap, alnico magnet. Nice job cleaning up those woofers, and yes, you might need new pots (or L-pads) if yours are too crunchy and beyond repair.
 
Thanks :) I just put the foams on last night. (my friend did the glueing and centering. I just do the prepping because I didn't want to mess them up). I'll practice sometime on speakers I'm not in love with. Any suggestions on the pots vs L-pads? Which is better/which ones to get/where to get them? That will be my next purchase. I've never repaired pots beyond spraying with deoxit, but I have no problem just buying new and having piece of mind that they won't go bad anytime soon.
 
+1 what ra.ra. says above. You will be ordering caps from one of those 2 so include the lpads, resistors and the driver sealing gasket tape. The lpads are less than $5 each.
 
image.jpg
Nice project........... and it looks to me like your pots have possibly already been replaced with L-pads - - - which would be fine - - - but what makes you think that yours are "shot"? On the woofer, it appears you have added new dust caps, and did you install the inner foam edge under the cone? Can we see the backside of a woofer?

And yes, be very careful with those tiny exposed wires for mid and tweeter.

Re: caps, this is just one set of suggestions to get you thinking about it. 3.9uF is far more common that 4.0uF and close enough; and 70uF or 73 uF (33+40) is close enough to 72uF for the woofer circuit.
http://www.erseaudio.com/Products/PulseX250v/MPX25-03-3-90
http://www.erseaudio.com/Products/PEx250v/3-9uF-250-volt-Metallized-Polyester-Mylar-Film-Capacitor
http://www.erseaudio.com/Products/PulseX250v/MPX25-03-24-00
http://www.erseaudio.com/Products/PEx250v/24uF-250-volt-Metallized-Polyester-Mylar-Film-Capacitor
http://www.erseaudio.com/Products/NonPolarElectrolyticAll/ANP10-05-70-0-PB
http://www.erseaudio.com/Products/NonPolarElectrolyticAll/ANP10C-05-33-0-PB
http://www.erseaudio.com/Products/NonPolarElectrolyticAll/ANP10C-05-40-0-PB
Can you tell me correct resistance or ohms reading on a good woofer, mainly this one? I checked with multimeter but not sure if done correctly. I used this setting and got a reading of 7.0IMG_5211.JPGIMG_5210.JPG
 
My pair of nominal 8-ohm AR-2ax uses essentially the identical woofer, and my notes from several years ago show readings of 6.1 and 6.6 ohms DCR - - both woofers are performing fine. In order to get a proper reading, you first need to disconnect the woofer from the rest of the speaker circuitry.
 
If I remember right it should be around 8 ohm. If you are getting between 6.5-9 ohm I think it's be just fine. If you getting something crazy like 22 or 140 ohm or something, I'd be concerned. I've seen a car audio sub test close to 150! It was toast ;)
 
I forgot to update the thread. This is how everything turned out. Did the L-pads, cardas copper/gold banana jacks and some nice Russian film caps. Sounds amazing! Finished the cabinets up and replaced the grills. _storage_emulated_0_Vault_Downloads_IMG_5046.JPG_storage_emulated_0_DCIM_Camera_20160920_215848.jpgIMG_1503.JPGIMG_1470.JPG
 
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