DavidR Posted February 2, 2018 Author Report Share Posted February 2, 2018 Thanks alkermes. I need to AB the AR91 vs 10pi. I have a feeling the bass of the 10pi will easily surpass the 91's. It maybe a while before I get to the 9's. At least I don't have to refoam any drivers. Quote Link to comment Share on other sites More sharing options...
DavidR Posted February 2, 2018 Author Report Share Posted February 2, 2018 My AR10pi speakers are the MkII version. They have polyfiber and not fiberglass stuffing. Could this be original? I still need to peek at the crossovers and see what's in there for caps. Hoping for Sprauges but I've seen pics with Callins caps in some. Quote Link to comment Share on other sites More sharing options...
Stimpy Posted February 2, 2018 Report Share Posted February 2, 2018 The stock Unicon brand of capacitors, in my 58S's, still seem to sound fine. So, if your 10pi speakers have those, you'd probably be good for a while. If Callins, I'd upgrade (replace). Quote Link to comment Share on other sites More sharing options...
fedeleluigi Posted February 2, 2018 Report Share Posted February 2, 2018 On 2/2/2018 at 4:40 AM, DavidR said: My AR10pi speakers are the MkII version. They have polyfiber and not fiberglass stuffing. Could this be original? Could you better describe the stuffing ( better if you would post some pictures of it) and  exactly weigh it? Both these factors are very important for woofer damping. Luigi Quote Link to comment Share on other sites More sharing options...
RoyC Posted February 2, 2018 Report Share Posted February 2, 2018 12 hours ago, DavidR said: My AR10pi speakers are the MkII version. They have polyfiber and not fiberglass stuffing. Could this be original? I still need to peek at the crossovers and see what's in there for caps. Hoping for Sprauges but I've seen pics with Callins caps in some. David, Polyfiber was used as the cabinet damping material in later AR-11's and 10pi's. I believe it was 11 or 12 ounces. Roy Quote Link to comment Share on other sites More sharing options...
DavidR Posted February 2, 2018 Author Report Share Posted February 2, 2018 Thanks Roy. You are a plethora of information and your knowledge is greatly appreciated. Quote Link to comment Share on other sites More sharing options...
DavidR Posted February 5, 2018 Author Report Share Posted February 5, 2018 Does anyone have the spec for the black paint used in the 9 series speakers? Mostly used on the backs of the speakers. Quote Link to comment Share on other sites More sharing options...
Stimpy Posted February 6, 2018 Report Share Posted February 6, 2018 55 minutes ago, DavidR said: Does anyone have the spec for the black paint used in the 9 series speakers? Mostly used on the backs of the speakers. Eastern Chem-Lac 37038 Lusterless Black H-8241. It's in the AR-9 Cabinet Plans that Ken uploaded. Cabinet Drawing 1 references Drawing 6, which lists the paint, in Note 6.  Quote Link to comment Share on other sites More sharing options...
DavidR Posted February 6, 2018 Author Report Share Posted February 6, 2018 Could you give me a little more info? LOL Thanks Stewart Quote Link to comment Share on other sites More sharing options...
lARrybody Posted February 6, 2018 Report Share Posted February 6, 2018 26 minutes ago, Stimpy said: Eastern Chem-Lac 37038 Lusterless Black H-8241 Here is what a google search turned out. http://www.randolphproducts.com/products/industrial-coatings/#ecl It is definitely not a flat black. Not really a black black. It does have a slight luster. I recently used some chalkboard black on some AR 6 baffles. Now that is a black black. If the paint doesn't match perfectly it would not be too hard to do the entire back and base. I was just going to use a sharpie on the little rub on one of my backs.  Quote Link to comment Share on other sites More sharing options...
Stimpy Posted February 6, 2018 Report Share Posted February 6, 2018 I think I'll just stick with Rust-Oleum satin black. That makes my brain hurt less...! Quote Link to comment Share on other sites More sharing options...
Stimpy Posted February 6, 2018 Report Share Posted February 6, 2018 18 minutes ago, DavidR said: Could you give me a little more info? LOL Thanks Stewart Just trying to be thorough.  Quote Link to comment Share on other sites More sharing options...
ar_pro Posted February 6, 2018 Report Share Posted February 6, 2018 As larrybody has mentioned, the finish has a certain amount of luster - it's definitely not a flat black - and it should pass a fingernail scratch test. Rust-Oleum satin black gives a nice result for the rear of the cabinet, as well as the painted front edges. Quote Link to comment Share on other sites More sharing options...
DavidR Posted February 6, 2018 Author Report Share Posted February 6, 2018 I was thinking it was more of a satin. I knew it wasn't a flat black. Quote Link to comment Share on other sites More sharing options...
DavidR Posted February 6, 2018 Author Report Share Posted February 6, 2018 I did some exploring. No work done to the crossovers and it looks like their age has caught up with them. I'm glad I only hooked these up to an inexpensive amp. Does anyone know what the DCR of the woofers should read? Quote Link to comment Share on other sites More sharing options...
RoyC Posted February 6, 2018 Report Share Posted February 6, 2018 10 minutes ago, DavidR said: I did some exploring. No work done to the crossovers and it looks like their age has caught up with them. I'm glad I only hooked these up to a inexpensive amp. Does anyone know what the DCR of the woofers should read? David, The caps are not Sprague, but I have never known them to damage an amp. The DCR of the AR 12 inch woofer is 2.6 ohms. Roy Quote Link to comment Share on other sites More sharing options...
DavidR Posted February 6, 2018 Author Report Share Posted February 6, 2018 They are/were leaking and have a light brown crusty gunk on the ends. Feared a short. That's exactly what my woofers read. I felt that was a bit low. Thanks again Roy Quote Link to comment Share on other sites More sharing options...
DavidR Posted February 6, 2018 Author Report Share Posted February 6, 2018 Adding a few more pics... Quote Link to comment Share on other sites More sharing options...
GD70 Posted February 7, 2018 Report Share Posted February 7, 2018 On 1/31/2018 at 1:57 PM, alkermes said: First of all, congratulations DavidR, I am envious! Good luck with your restoration, I'm sure they will be marvellous. Glenn's tip just caught my eye, I had never thought of a cast-off cabinet as a source for veneer. Someone was showing me a pair of derelict Optimus speakers which have a beautiful veneer. Maybe there is a way to repurpose them, they are large speakers, lots of nice veneer (looked like walnut). That's where I've harvested all my old veneer. Old trashed or re-veneered speaker projects are perfect because it ha aged and will blend in well with the surrounding veneer. I've put out requests as well for veneer from people I know are doing a re-veneer, send the old stuff to me! Glenn Quote Link to comment Share on other sites More sharing options...
GD70 Posted February 7, 2018 Report Share Posted February 7, 2018 6 hours ago, DavidR said: Adding a few more pics... A thing of beauty! Quote Link to comment Share on other sites More sharing options...
fedeleluigi Posted February 11, 2018 Report Share Posted February 11, 2018 On 2/6/2018 at 8:34 PM, DavidR said:  On 2/2/2018 at 4:40 AM, DavidR said: My AR10pi speakers are the MkII version. They have polyfiber and not fiberglass stuffing. Could this be original? I still need to peek at the crossovers and see what's in there for caps. Hoping for Sprauges but I've seen pics with Callins caps in some.  David, In a previous post of mine I asked you to describe the type and weigh of polyester present in your 10 Pis. That was because in the two European AR factories were used different types of polyester wadding during AR 10 Pi and AR 11 MKII lifespan. If I have time to disassemble some AR 10 Pi to show it I'll take some pictures and post them. The weigh of the poliester wadding changes according to the type of polyester used. By the photo you posted I can recognize the type of poliester wadding used in your AR 10 Pi. The AR engineering file states that were used 10 oz of that type of polyester. Anyway, I've found in AR 10 Pi and 11 MKII an average of about 250g (8.82 oz, that is -12% compared to 10 oz) ) with this type of white polyester . As I'm interested in knowing the polyester weigh of the AR 10 Pi and 11 MKII manufactured in the US, could you please weigh it in both speakers? Thank you PS I post the engineering file (sheet 2) of the AR 10 MKII. It dates 18 Apr 1977, and the revision of cabinet wadding dates 9 Nov 1977. The AR 11 MKII engineering file show the same dates of revisions to new design (18 Apr 1977) and change of wadding ( item 11, 9 Nov 1977) and the signatures of the same engineer (probably Tim Holl). Thank you        This is an European AR-10 Pi MKII showing a soft multi-coloured polyester stuffing but other type of stuffing were used as well. The white polyester was only used at the end of production. Obviously, the stuffing weight changed depending on the different materials. Quote Link to comment Share on other sites More sharing options...
DavidR Posted February 12, 2018 Author Report Share Posted February 12, 2018 Luigi, thanks for the drawings. Unfortunately I have no means of weighing the polyfiber. I have a bathroom scale - not sensitive enough and a jewelers scale 0 to 100 grams and its small. Quote Link to comment Share on other sites More sharing options...
fedeleluigi Posted February 12, 2018 Report Share Posted February 12, 2018 Thanks David, I do hope some member of this forum  that has an AR 10 Pi MKII or 11 MKII manufactured in the USA can share that information (type of polyester and weigh measured with a good scale). Thank you  Quote Link to comment Share on other sites More sharing options...
JKent Posted February 12, 2018 Report Share Posted February 12, 2018 11 hours ago, DavidR said: I have no means of weighing the polyfiber. https://www.amazon.com/Electronic-Digital-WELIKERA-Hanging-Luggage/dp/B0788JWC59/ref=sr_1_2?ie=UTF8&qid=1518442870&sr=8-2&keywords=fish+scale Quote Link to comment Share on other sites More sharing options...
DavidR Posted February 27, 2018 Author Report Share Posted February 27, 2018 I finally recovered from the flu and took some time to pull all the drivers from the 9's and record the part numbers and voice coil DCR (below). (FYI: I always label/choose a left and right speaker when restoring). All the drivers except one tweeter had replacement stickers on the magnet (WTF?). Since three of the woofers are late production models will I loose bass? Or can I expect them to perform as if all drivers were the originals? Quote Link to comment Share on other sites More sharing options...
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