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It's always good to see the Rectilinear models get some attention here. Shown below are some scraps of info that might be helpful - - it is difficult to get a full rundown on the Rectilinear product line-up, but this might be a start. Not unlike many examples of product nomenclature, I think the Xa represents a later version of the X. I am not entirely sure of this, but I believe there was a change in the driver elements and possibly the corresponding crossover as well. Along with the Mini-III, the X and Xa are the only acoustic suspension (fully sealed cabinets, no port) models in the line-up, and the only ones I am aware of with a 4-ohm nominal impedance rating. I suspect it will be this 4-ohm rating which makes it difficult to find authentic 10" replacement woofers.

Glenn, I am able to view all of the pics in your posts in this thread using both Safari and Chrome web browsers. The only ones that are not showing up for me are from the 12.18.16 post by Klaus where he was quoting you. Man, that Photobucket mess was like a blindside attack - - glad I didn't get caught in the crossfire - - and thanks for reactivating your great pics to these helpful threads. Great job on those AR-12's.

Am curious why you plan to abandon the switch? This is a simple, inexpensive, soft material that I've used with success for the gasket seal between metal basket and cabinet. It would work fine for outer trim rings, too, if desired. First pic shows process of cutting foam sheet, and second pic shows an example of what I often tend to do - - just paint most of the exposed basket metal prior to applying new foam surround. http://www.michaels.com/12x18-foam-sheet-by-creatology/10290391.html#q=foam+sheet&pmpt=qualifying&sz=24&start=12 Re: capacitors, attached are three links for good quality common crossover caps (6.2uF is OK, too). https://www.parts-express.com/dayton-audio-dmpc-62-62uf-250v-polypropylene-capacitor--027-427 https://www.parts-express.com/solen-62uf-400v-polypropylene-capacitor--027-558 https://www.madisoundspeakerstore.com/carli-capacitors/carli-mylar-6-mfd/ That pair looks terrific - - it looks like those cabinets are real wood veneer?

That second pair looks fine, too, and even more fully original than your current pair. Tweeters don't look badly beaten up, and the woofers appear to have a decent re-foam job. Having both pairs, it would be a fun project to mix and match drivers and cabinets to put together a "Better" pair for Living Room and a "Good" pair for bedroom. I think all of the cabinets can be salvaged - - no need to build new ones - - the glue drips can be cleaned up and the cabinet flaking can be reinforced and re-painted. Am not sure what type of parts suppliers you have access to in India, but I'm sure you can locate a reputable source of audio grade components. For the 6uF caps, either a good quality non-polar electrolytic (NPE) or an inexpensive film cap (metalized polyester or polypropylene?) will work just fine. Sometimes the 6uF value is difficult to find, but you can always parallel two caps to create the 6uF value (example: 3uF + 3uF; or 3.3uF + 2.7uF) Maybe you try one type of cap in one pair and a second type of cap for the other pair, and then compare results? Your black caps are probably rated at 50 volts, but most new caps will have higher voltage ratings - - this is normal - - and new caps rated for 100 or 250 volts should present many good options. Generally speaking, as voltage increases, physical dimensions increase as well and so does cost. Translate these estimates as you'd like, but buying replacement 6uF caps here in the U.S., I'd pay no more than $2 or $3 apiece and have a wide selection available. While there is nothing particularly impressive about the original internal wiring (I think it is 18 ga?), it is good quality and there will most likely be no perceptible performance improvement by replacing it with something more exotic.

Hi Sudhir, and welcome to the forum. The speaker model you have is the original AR-18, which later morphed into the AR-18s and then the AR-18b. The "J" that you have noted is part of AR's catalog referencing and requires little attention on your part - - just disregard this designation. It is also interesting to note that the AR-18 used a single serial number (in your case, 062207) for both speakers which were sold as a pair. The AR-18 is a terrific speaker that has developed sort of a cult status in parts of Europe as a near-field professional studio monitor, and your speakers look pretty good. The flaking cabinet can probably be repaired with some liquid epoxy and it is rare to find the original foam grilles in such good condition. I think all of your stuffing is original. While it is always depressing to find these tweeter dust caps dented, this generally has no adverse effect on performance. And it is probably a very good idea to replace that original black/red cap - - I think it is 6uF. The woofer presents a couple of small mysteries, however. The 200001 part number is the correct driver, but that light grey ribbed cone does not look original to me. And, of course, the mirror reflective outer dust cap is not original, but it could have been a simple replacement when the woofers were re-foamed at some point. It is also interesting to note that this woofer originally had two dust caps: inner (flat) and cosmetic outer (domed).

Thanks, Roy, for that fine comparative write-up on the Midwest dome tweeter, and for the excellent pics. Physically, it appears almost identical, and I really like that no delicate tinsel wiring whatsoever is exposed from the front side. My suggestion to anyone using this tweeter would be to not even consider any front-wiring installation, and simply abandon the exposed front terminals and relocate-reconnect the black/yellow crossover wires directly to the rear tweeter terminals. Taking Chris' excellent restorations out of the equation, the viable 'new' tweeter options are the 3/4" Midwest tweeter at $70 (sans cost of added coil) versus the 1-1/8" Hi-Vi tweeter at less than $20 (sans cost of coil). While the new Midwest tweeter is a virtual doppelgänger of the original driver, a $100 cost difference right off the bat for tweeter replacements will become a consideration for many restorers. Nonetheless, it is very good to know that there is another recommended option available. And in that last pic, do those 3's have oak cabinets?

Just wondering what happened to the OP's project in this thread? Again, I hope my comments did not confuse you further. Also just wanted to say that the first pair of AR-6's (....partial, at least ) I ever picked up had already been replaced with a real mish-mash of incorrect and inconsistent drivers - - see first pic attached. Both woofers were the 4x cloth-alnico variety, and the tweeters, while appearing almost identical from the front, were in fact not the same part number and had different sized magnets. They made noise, they played music, sort of - - - but I did not like the way they sounded at all. So I replaced everything with more correct and matching drivers (second pic). I used the 200001-1 woofers which have the smooth cone, flat dustcap, foam surround, and square ferrite magnet. For tweeters, I used slightly newer part number 200038 (dated 1981) which is very similar to original but might have slightly higher power handling ability. Also, I cleaned the pots and replaced the caps, and now I'm very happy with these speakers.

I was reminded of this thread when I began taking a closer look at the AR-38B, and I was surprised to see that this model had not been mentioned anywhere in this discussion. I have no experience with this dual driver component (tweet-mid), and despite my aversion to the styling and cabinet build quality of this series, I have to think this just might be a very good 8" three-way speaker model. The link below includes a schematic circuit diagram as well as the full crossover assembly drawing. This appears to be a complex and sophisticated design. http://www.classicspeakerpages.net/IP.Board/index.php?/topic/6950-ar-38b/

Gabriel, it appears to me like you've currently got a mismatched combination of parts you are trying to assemble, and I hope that my Oct 9 post about various woofers did not add to the confusion. To clarify, that post was trying to state that the ribbedcone/alnico woofer was found in early AR-6's using Crossover A; and the smooth cone/square ferrite magnet woofer was found in later AR-6's which used Crossover B (and C, not shown in this thread). The third woofer shown in that post is the cloth surround alnico woofer found in the AR-4x and 4xa models, which employed crossovers different from all versions of the AR-6. If I am following your current configuration, your cabinets have the two-coil Crossover A as shown in your Oct 5 post; your woofers are alnico-cloth drivers intended for the AR-4x or 4xa; and you have now attached a coil/cap combo to the woofer that was originally used with a ferrite magnet woofer in Crossover B of the AR-6. I guess it's possible that you may have created an excellent hybrid of sorts, but I can't imagine that your assembly as shown is going to perform very well. Added to that, there has not yet been any attention paid to the original tweeter cap (does it still measure close to 10uF?), and the pot control now has a new problem with the wiper spring. Since the AR-6 and AR-4xa models have identical cabinet volumes and you now have drivers that are consistent with the AR-4xa, perhaps your best option is to simplify the crossover to comply with the 4xa model. Attached are pics of 4xa crossover: version with pot; version with switch; and schematic showing switch version.

Those AR-6's look really nice, Larry. I've never seen that grille cloth before but kinda like it - - do you think it might be original? I'm curious about their history - - the paper labels do not show either of the Euro addresses, but the serial number has a two-letter prefix which often shows up on Euro speakers, plus there is that "international guarantee" stamp". Also, you've got those great early-issue woofers with the massive Alnico magnet with the long throw (see below).

Not quite sure how to respond to this question yet. Maybe you can show us a pic of your woofer after it has been cleaned and ready for re-foam, and after you've received your repair kit. YouTube tutorials can be very helpful to give you added confidence, but feel free to ask questions as they arise. The biggest issue that is forever debated with a typical re-foam project was first penned by William Shakespeare: "To shim, or not to shim, that is the question." Pic attached shows an AR-6 woofer with a new foam being loose-fit to the speaker cone after the dust cap has been cut (and removed) and is sitting atop the clear plastic shims that have been installed. When possible, I like to re-use the original dust caps after the shims are removed. "First, foam and cone, and secondly, foam and metallic circle." Yes, this is the correct sequence. ".....the sound design require a tight seal." Yes, this is also correct, and your woofers may require new material to seal them properly, but this is an easy step. "I hope that will balance the tweeter." Airtight assembly is important, but this should not have significant effect on tweeter output. Are you planning to replace the original blue capacitors?

Hello Gabriel. I am still a little confused about exactly what you are trying to do, so here are a few more comments and questions. Actually, there are three versions of AR-6 crossovers, but we do not need to discuss version C which was used in Europe for later models (it had no coil and employed a two-position switch). It is not entirely clear yet how best to advise - - can you post pics of the actual woofers that you are intending to use? Exactly why do you wish to do this?

Are you saying you need some assistance with your first re-foam project? Regarding glue type, I would agree with JKent that a good quality water-based white hobby glue should work best - - - it sets up slowly and gives the installer some necessary time to ensure that parts are properly aligned and bonded. Just one other thought - - I would expect that your woofers have these two rings shown in this first pic. If so, be sure to leave in place the outer "basket ring" when you begin to re-foam the woofers - - you need to glue the new surround to this surface. Also attached are 'before' and 'after' pics of my restored pair which is the same version of AR-6 that you have.

Thanks for those pics - - - the grilles and badges look terrific, and.... WOW... those cabinets have huge potential. I have never seen a veneer like that on AR speakers and it definitely does not resemble the Ponderosa pine found on U.S. "blondies". Thinking about the Euro market, to my eye the grain looks too tight and linear to be birch, but also too light to be teak ..... could it possibly be beech? Very nice speakers you've got there - - after clean-up, they just might look best with an oil finish. Check out the falcon acoustics link - - just trying to save you from unnecessary international shipping charges.

Bonjour and bienvenue, Grish. All of the components in your AR-6's appear totally original, and included here is the schematic of your speaker circuitry. I will suggest that those speakers are fully restorable, but do go slowly with the project and don't try to overwork any step of the process. The tweeter you have provided in the link is not a good idea for this speaker. Although it is a decent tweeter and it has often been used as a replacement in the AR-4x, it will not fit the cabinet holes and prep of your current tweeter. Your tweeters are originals, and if they are both functional, should be re-used in your re-build project. Your comment about them being "shy" is curious, however, because this is normally a tweeter that has a pretty substantial personality, or presence, in my opinion. The other components in the tweeter circuit are also original and normally stable. I cannot read the resistor values, but they appear identical to 3 ohm resistors I've found in a similar AR-6, and the blue can 10uF cap is also very familiar. Typically, these caps are often very stable even 45 years later, but it is possible that this cap value has drifted and might benefit from replacement. The three-position switch is also usually trouble-free, but perhaps some electronic circuit cleaner can be sprayed into the switch from the backside. You should hear some difference in tweeter output between the various switch settings. I am unfamiliar with parts suppliers in Europe, but these might be good places to begin shopping. http://www.falconacoustics.co.uk/alcap-claritycap-solen-audio-capacitors.html http://www.mundorf.com/english 1.1/handelliste/fachhandel/Revendeurs.pdf Regarding the woofers, you will obviously need to locate, order, and install new foam suspension surrounds. The green component attached should be a 10 ohm resistor and should not require replacement. The larger silver can is a 24uF capacitor and probably should be replaced, although this value is often difficult to locate. And the cabinets, which you have mentioned are "blonde". Please provide some pics of these (grilles, too!). If your cabinets are unfinished pine, as I suspect, an oiled finish might not be your best choice, so my advice is to proceed slowly.

Thanks for sending those documents - - - I understand a little better now. And yes, I finally do see the pic of the wood enclosure. That's a rather unique device, and with that unusual 4-wire connecting cable. The Hirsch review was a little difficult to read, but it was interesting that both the review and the product instructions discussed making initial control settings while listening to FM inter-station hiss, and later making subsequent adjustments listening to familiar musical sources.

Interesting thread here, and I may be splitting hairs, but this raises the debatable question of exactly where is this line of demarcation: restoration or mod? ** If you replace original pots with L-pads: restoration or mod? ** If you replace original electrolytic caps with film caps: restoration or mod? ** If you replace original half-round foams with filled fillet replacements: restoration or mod? For the record, I'm good with any and all of these approaches, but each of these decisions may indeed impact future resale value of collectible "vintage" merchandise, and of course, there are performance issues at stake as well. My philosophy is somewhat of a mongrel hybrid, since a modicum of affordable practicality normally needs to factor into the equation. With my own projects, I tend to try my best to understand and respect the original intent of the speaker design; understand any "market value" of my modest collection; and then make restoration or modification decisions based on keeping these speakers alive in sync with the limited realities of my wallet. I find this statement rather perplexing.... 50 years after the fact. In some of my AR speaker 'rescue' projects, I have taken measures to eliminate this particularly vulnerable aspect of the original assembly by making replacements with rear-wired drivers of similar or same characteristics. Please do illuminate: once the wires have been securely located inside the protective and robust cabinets, why would anyone wish to relocate these delicate tinsels outboard again and expose them to unnecessary exposure to damage?

Nice work by JKent, as always. Despite the fact that this multi-level contour crossover concept did not particularly catch fire in the 60's-70's hi-fi era, I find myself somewhat enamored with this squarish floor-standing speaker model and its separate control device. My understanding of the KLH Twelve is that it is a three-way speaker product (including two mids, totaling four drivers), with crossover frequencies at 500Hz and 4000Hz. I am curious about a few things. Regarding the control box casing, is this a thin metal shell that is covered in faux vinyl or is it a thin walnut veneered plywood? And the control dials: do they just rotate about 90 degrees between + and -, with the dot representing a hypothetical "flat" response? And the rear screw terminals: I assume the two-screw terminal is the amplifier connection, but how is the four screw terminal connected to the driver cabinet? The circuitry of this device sort of bewilders me, and my questions are based on the labeled frequencies at each dial on the front panel. With KLH literature stated x-o frequencies at 500 and 4000, is this an accurate understanding of the four dials: left dial controls woofer and very lowest Hz of the mids; second dial controls lower Hz of mid; third dial controls higher Hz of mid and lowest Hz of tweeter; and right dial controls the highest squeaks and brushes of strings and cymbals? Great pics from ReeferDude, too, and welcome aboard to CSP. But....what exactly is a reefer? Is it like a capacitor?...or a resistor?....or an inductor?...or a potentiometer?

Hi Noah, I may be assuming too much here, but after re-reading this thread, it is not entirely apparent to me that you are aware that the cracked and disintegrating foam surrounds on your woofers are fairly easily replaceable, and their deterioration (which is normal) is no reason for discarding the original woofers. Some might challenge the methods used in this video, but at least it will give you a basic understanding of the process of replacing the rotted foams to make your woofers "new" again. Locate yourself a reliable source in the UK for foam replacements, and members here will walk you though the repair process. Once you remove one of the woofers, and before you order any new foam surrounds, post a pic of the crossover and you will get advice about components which may also require attention. Close-up pic of my 10" AR-2ax woofer (same as AR-5 woofer) with new foam is also attached. Looking closely, you can see that I preserved the original flat dust cap after cutting it during the re-foam process.

I suspect this is what you should expect to find - - the pics shown are both AR-6 tweeters. The front-wired tweeter on the left is dated 1971 and appears identical to your original tweeters - - it has the smaller magnet. The rear-wired tweeter on the right is dated 1979 and appears identical to the first link you posted - - this one has the larger magnet.

These comments here are only about the woofers. I want to look closely at some AR-6 speakers I have before commenting further on the tweeter issue, but will try to get back to you soon. Pics shown here are the two versions of woofer I've encountered in AR-6's - - both of these used foam surrounds. The first three-part image shows the Alnico woofer, with large slug magnet, ribbed cone, and flat dust cap. These do not show up very often, and were only used in early manufacturing runs. The second two-part image shows the more common woofer (p/n 200001) with square magnet, smooth cone, and flat dust cap. The woofers you posted in the link (shown here also, third pic) are excellent 8" woofers, and they will "fit" in your cabinets. However that particular woofer (cloth surround, alnico slug magnet, fine mesh dust cap) was developed for and used in the AR-4x and AR-4xa. It was typically used with a #5 coil (1.18 mh) whereas the AR-6 used a #4 coil (0.88 mh) on the woofer, so I would suspect this woofer used as a replacement in an AR-6 would deliver different characteristics.

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Well, it's now clear that you have a Euro model (Holland), but the handwritten serial number offers no further clues as to this speaker's provenance. I am unable to comment at all about the Peerless woofer, and that includes anything about its general quality or its impact on your "muffled highs". Now I understand the problem with your tweeters - - - one of those tiny tinsel wires has become a problem (underneath the grey tape), and your first attempt at a fix was unsuccessful. Your tweeters are fully original, and it might be worth a second try to repair and patch the broken wire before thinking about purchasing new ones, because your primary issue really is finding the correct woofers. Two more thoughts about the tweeters - - - actually, one rant and one caution. My rant (as stated previously in this forum) is that as much as I like the performance of these early 1-1/4" tweeters, I really find these exposed tinsel wires found on several AR drivers to be a serious flaw in the mechanical engineering or industrial design of these drivers - - - it is simply a bad, bad, bad idea to have the wires inside the cabinet, then bring them outboard, and then poke them under the cones while trying to hide behind flimsy electrical tape. My caution is this: the tweeters in the link you provided look excellent - - great condition, correct part number, spot-on DCR readings - - but these appear to have the larger magnet, and you need to first be sure that they will fit in the holes that have been cut in your speaker's baffle board. Particularly if the cabinets and grilles are in good shape, but these speakers are worth restoring, yet it may require some patience and some expense.

I don't know anything about those Peerless woofers, but it's really too bad that the originals are lost and have been replaced. Regarding the blue 10uF Sprague cap, genek is correct that these very well might still be good, but the only way to confirm this is to measure them when out-of-circuit. I have a different version of AR-6 that uses the identical cap, and mine recently measured within spec so I left them alone and the restored speakers are performing extremely well. Your speakers show a few other curiosities, and it would be of interest to see the speaker backside and label - - it is unclear if you have US or European assembled models, and these seem to reveal elements of a hybrid that has perhaps not been identified yet. On the exterior, your speakers exhibit the thin reveal edge that is consistent with the Euro profile. On the inside, the stuffing is yellow fiberglass - - - this was always used in the US, but Euro production typically used a multi-color poly stuffing. If these are in fact Euro models, they are probably relatively early issues, as exemplified by FG stuffing, pot control, and front-wired tweeter - - all more normally associated with US production. But the real unique curiosity is this particular combination of crossover components. The inside of your cabinet clearly shows what we've referred to as Schematic A, which was typically associated with the early Alnico magnet woofer. However, even though the woofers have been replaced with non-AR drivers, that attached cap and resistor shown appears to be consistent with Schematic B, which used the square ceramic magnet woofer. I have never seen these two features together in the same cabinet. I would assume this cap (24uF) and resistor (10 ohm) were removed from the original woofers and simply moved to the Peerless woofers, regardless of performance parameters. Also attached is a pic of this similar assembly from an original AR-6 woofer. I was also unable to find suitable drivers in current ebay UK listings, but be patient (or send a personal message to jurgen 59). Others may know more about this, but I think either woofer should work for your replacements - - - but the added resistor and cap on the woofer should only be used with the square magnet woofer. I will try to post other pics of the Alnico woofer a bit later....

Hi Gabriel - - welcome to the forum - - and congrats on getting your grandpa's speakers. The AR-6 is a terrific bookshelf speaker and I'm sure you will get these performing up to snuff, but they weren't helped by the humid basement conditions, which may have accelerated corrosion of the pots. There were a few variations of AR-6 throughout its production - - different woofers, different crossovers, different tweeters. Since you mention that yours have a potentiometer, I suspect yours are the earliest version, and these most likely have a wax block cap (see pic attached). If so, probably a good idea to replace the 10uF cap, which is not a useless expense if you wish to restore these properly. Also, there is a good chance that the woofers may need new foam surrounds. Please include some pics (cabinets, grilles, drivers and crossover, etc.) and I'm sure you'll receive further explicit assistance on all matters. Two new caps for these could be purchased for between $2 and $15, and a couple new foams should be under $20, too.