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adam2434

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Everything posted by adam2434

  1. Guys, I just refoamed AR18s woofers and removed the dustcaps completely, started with an Exacto knife, and peeled them away from the original adhesive with a tweezers. I did not have to cut them, and was able to reglue them intact. The dustcaps are rubber and did not permanently deform in the removal process. Not sure if the RP woofers would allow this, but just wanted to throw this out there. As an AR refoaming newbie, take this with a grain of salt.
  2. I found the brochure (on this site) for the AR speakers series that included the 18s (the baby of the series). Great read - read it twice on business flights this week! Reading that brochure gave me the impression that AR speaker design was pretty advanced for that time. Looking at all the models in that series, it seems like the paper tweeter models might be the lower tier models in that series vs. the dome tweeter models. Is that correct, and were the dome tweeter models better performers across the series?
  3. Both surrounds are holding fine after several hours of play at fairly loud volume. I do notice that the second woofer completed seems to have a stiffer suspension when I push on the cone. Not sure what’s causing that, but I do not hear a difference in the woofers. Overall, the 18s bass is lighter vs. the NHT SB3 (acoustic suspension bookshelf with 6.5” woofer) that I use in this room (large unfinished portion of basement). I have them on a shelf about head height when standing, with the back of the speakers around 5” from a sheetrock wall that separates the finished and unfinished parts of the basement. I think the bass will improve in a smaller room with the speakers near a wall, possibly with the woofers near the ceiling (I’m thinking mounted in the upper corners of a garage or rec room when my daughter has her own house). The bass they have is tight and detailed though. I think they would mate nicely with a musical, sealed sub to fill in the low end. In general, I am liking the tight bass that the acoustic suspension speakers I own have (18s, NHT SB3, and SB2). My floorstanders in other rooms are ported (Polk LS90 and Klipsch RF-7II), and I am now interested in trying out some acoustic suspension floorstanders, although options are limited vs. ported. Back to the 18s, I am pretty impressed with the way these little, entry-level, unassuming speakers sound. At a glance, they sound better than they should when you compare their dated paper woofer/tweeter and single cap crossover to current models with modern drivers and sophisticated crossovers. The 18s are an eye-opener for me. They make me wonder “how much has speaker design/performance really advanced in the last 35 years?”, given that this inexpensive speaker from 35 years ago sounds so good. I am a bit baffled, but you all are members of a vintage speaker forum, so you must have a reason to like these old speakers. I will keep an eye out for more of the model 18 variants. What are the larger models in this series? Did they make a larger bookshelf and floorstander in this series? OK, sorry, enough rambling...
  4. Mine are not perfectly centered because I looked at the back side after the glue was set-up (a learning moment). I originally thought that using the surround outer edge to frame outer edge would be a good reference for centering, but learned that this does not result in perfect centering. My gut tells me that having the surround off-center a mm or 2 from the cone won't be a problem, as long as there is enough cone to surround bond area everywhere.
  5. The PE instructions did say to apply glue to both surfaces and let the glue cure for 5 minutes before bonding. I followed those instructions, but bonding was still a challenge in some areas on the cone and frame, especially on the second woofer. Hopefully it will hold. I do honestly feel that I put a great deal of time and effort into this, so hopefully the bonds will hold. If they don't, it was still a good learning experience. Any thoughts on the other questions above?
  6. The other 18s refoam and recap is done. Will test tomorrow afternoon after the glue cures around 24 hours. For some reason, the second woofer did not go as smoothly - the foam did not want to adhere to the cone and frame, and took constant work and attention to get it to adhere. Hopefully it holds. I will give them a rigorous test over the next few days. If the foams do not hold, I will probably just part-out the tweeters. My intent is to give these speakers to my daughter to use as garage or rec room speakers when she get a place of her own in a couple years. I showed them to her and she was very appreciative and thought the retro look was cool. Both woofer frames have some rippling (see pic). I have never seen this before. I wonder if this is just an artifact of a crude manufacturing process, or if the ripples are there by design for some reason I don't understand? I also attached a pic of the Dayton cap, which I soldered in place and hit with a got glue gun to secure to the board. Based on the appearance of the woofer and some research on earlier models, seems like these drivers date back to the early 70's, although the speakers were made in 82-83. Is this typical for AR? Here are some learnings and observations from this project, my first refoam: 1) The cone and frame clean-up prep is time-consuming, but straight-forward. 2) I'm glad I decided to shim the voice coil gap. It added a step, but it was no big deal to remove and reattach the dust cap, and it provided some peace of mind. 3) Centering the surround by eye to the frame does not necessarily center the cone on the surround. This was apparent when viewing the back side of the cone. If I decide to refoam again, I will adjust foam placement based on viewing the back side of the cone. Does this sound right? Thanks for all of the input. Adam
  7. First refoamed and recapped speaker works! Bass seems a bit light, which leads to a bit bright overall tonal balance. It sounds very good, but not much bass. However, only one speaker is playing in the large, unfinished portion of our basement. I normally play a pair of NHT SB3 in this area. I'll report back when the other speaker is done. I will also test them in a smaller finished space. Here's a pic of the first speaker. Serviceable repair, although not the prettiest by pro standards I'm sure. A bit of glue seeped beyond the edge of the surround when I applied pressure. Not sure how to avoid this on the next speaker. I was able to reuse the original dust cap after peeling it away from the black adhesive, starting with an Exacto knife and peeling with tweezers.
  8. Nevermind, I soldered one in-place. One speaker done - ready to test! Per reco from RoyC, I used these surrounds and caps: http://www.parts-express.com/parts-express-speaker-surround-re-foam-repair-kit-for-bose-301-jbl-116h--260-914 http://www.parts-express.com/dayton-audio-dmpc-51-51uf-250v-polypropylene-capacitor--027-423
  9. When soldering in a new cap on the 18S, are folks doing this in-place (through the woofer hole) or removing the board that is stapled into the back of the speaker box? I'm used to crossovers mounted on terminal cups that have screws, so the 18S is a bit unfriendly to crossover work.
  10. Thanks for the recos, guys. Seems like there are several recommended surrounds (Rick Cobb, JBL, Boston FF, Audiodogs), and not a unanimous winner. Perhaps some of these are one in the same? I will email Rick Cobb.
  11. Hi, first post here. Picked up a pair of 18s at a thrift store for a few bucks. Heard pretty good things about them. Woofers need to be re-foamed (this will be my first re-foam job). I just tested the speakers and the tweeters work and have no signs of damage. Also, the woofer voice coils do not rub, so I assume they are ok. I’m looking for foam recos that will replicate the stock foam as much as possible. Larrybody's post above mentions Rick Cobb surrounds. Are these the best option? If so, how does one order them? I also found the options below. http://www.simplyspeakers.com/acoustic-research-speaker-foam-edge-repair-kit-fsk-8.html# http://www.parts-express.com/parts-express-speaker-surround-re-foam-repair-kit-for-8-speaker--260-920 I will also replace the tweeter cap, so would appreciate recos for that too. Thanks in advance!
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