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dynaco_dan

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  1. Hi Kent; I just ran through the various threads on this topic. I see I was leaning on the KLH fullrange driver, not an Advent, DUH. Looking forward to your driver front photo. I was thinking that it would have an inverted 1/2 roll surround, the same as the KLH 12.5 driver. The Dahlquist DQ-10 speaker is not something I am familiar with at all. Here is a front and rear photo with, I believe, a Philips midrange driver. If so, it will be with it's own plastic casing. I may be wrong here.
  2. >Vern, here is an original Advent driver and a comparison of >the Advent (top) and Philips (bottom). The Advent had a 4-bolt >mounting pattern, the Philips 8. The Philips is mounted on an >aluminum adaptor plate. >btw--what was the "well known speaker that was highly >praised in it's day"? >Kent > Hi Kent; Could you please post a front photo of the original Advent driver. This is the very first time I ever saw one, thank you. Any thought as to where or whom manufactured them for Advent? Cloth surround? Alnico magnet? Certainly not an amatuer adapter plate. Any reviews of the driver that you can reveal? My memory is getting worse, those Philips photos were from a really recent auction, in the past week or so, I believe an Infinity model?, it was stated but I forgot to note it, sorry. This was not the most noteworthy model speaker I was trying to think of. Other than my test bench speakers, I was never a Philips speaker driver fan, cheap and accessable, at that time. I just remember that the driver was not special compared to AR, Advent, etc, but they did show up on occasion, to my surprise. There was at least 3 or 4 models of different brand speakers that used at least one version of that driver, from the front view. Philips dome tweeters were used as well. If I come across other photo examples, I'll post them here. Looking back now I do not know why I didn't use AR or Dynaco drivers? Perhaps because we didn't have the coils, caps, etc, and the sturdy, nicely assembled cabinets for one reason. I built from scratch, plywood cabinets for the Philips drivers I used. There certainly is a lot more to making a sturdy speaker cabinet than it appears from afar.
  3. >Interesting. I see there is a single Advent 400 speaker on >ebay now and it appears to have the same driver. Was that a >standard replacement? The aluminum adaptor plate appears to be >manufactured--not a DIY > >Here's the link to the ebay item >http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...:MEWA:IT&ih=019 > Hi again; This is a set of recent photo's for an auction for the encased Philips driver. This was an option used in cases of mid use, rather than fullrange. They were removed from a well known speaker that was highly praised in it's day. Manufacturers were faced with the optional case or making one themselves, such as was used in the AR-1 or AR-2 dual tweeters. The last 2 photo's are from the auction you make reference to. My best guess is that the Philips driver fit the mounting pattern and was well advertised back then. Unless one has the correct unit, who can tell what sounds best. Unless someone comes forward with a photo of an original Advent driver, I do not know what one looks like. My mind kept thinking about the KLH fullrange driver all along. Kloss's Advent fullrange may have used a Philips driver all along. As always, the dimpled dust domes are optional. LOL
  4. Hi Kent; If you keep your eyes open on ebay, you will see the great number of older speaker systems that used this Philips driver, tweeters and sometimes even their woofers. I built a 3-way Philips speaker system for my test bench back in the 1970's, fused of course. The younger shop techie used an AR 12" woofer to test his amp repairs, it made the amps really work, or not. Because of the supply and demand, I would replace the Philips with an OEM KLH mid/fullrange driver. A proven entity. I only remember that Philips used as a mid, not as a fullrange driver.
  5. Hi Kent; The photos show a Philips mid range driver. It was used in several speaker systems of notariety, as a mid driver. Now when you watch eBay, you will see the various speakers that did use this driver. Often available with and without the sub enclosure shell. In a fullrange enclosure it required it's own sub enclosure, same as AR-1 tweeters. It could be bought with or without it's own plastic moulded sub enclosure. I believe it was available as 4 and 8 ohm.
  6. Hi there; >Great info, Klaus. I believe you are the forum's undisputed >king of AR-6 land! Roy I think that this qualifies for the Guiness Book of World Records. LOL
  7. Hi Craig; The comparison hasn't happened yet. My home was terribly disrupted by a leaking roof and I haven't recovered yet.
  8. dynaco_dan

    Dynaco A-10

    Hi there; The Dynaco A-25 speaker came out sometime in 1969. We have seen the Scan, first issue, and Seas, later issue, speaker drivers. I was just looking at the, Dynaco A-10 April 1972 Stereo Review magazine photo. At this much later date, I see they used a 4 screw, possibly a Scan woofer. The tweeter is the Seas, 8 screw version. Considering that Seas was the primary developer of the Dynaco A-25, I wonder where and how Scan fits into the timetable. The reviewer claimed that the averaged frequency response was, +/-4 db from 50 Hz - 15 Khz, maximum low-frequency output was at 80 Hz and a broad high frequency maximium at 10 Khz. Distortion was @ 1 watt level, was below 5% down to 65 Hz, reaching 10% at 50 Hz. They felt that 50 - 60 Hz was the lower practical limit, not bad for a 6" woofer, in their opinion. There was an extreme loss of highs above 10 Khz. Tone burst response test's were taken at 100 Hz, 1 Khz and 10 Khz, very clean and sharp. Strange that two other magazines found a peak at 9 - 10 Khz and there was no comment about this tweeter having that. Overall the speaker was smooth and the bass, impressive, they gave a B+ in the listening test. The highs output and dispersion were better than average. Pipe organ and bass drum's were not carried off, as in a larger system and the highs were noticeably in less obvious abundance than units using multi-unit dome tweeter arrays.
  9. Hi Carl; >While working on the repair and component upgrading of the >subject crossover, I became curious about exactly how the two >function switchs affect the frequency response. The switch >markings on the back of the speaker are rather vague (i.e. the >2500-7000 switch I call switch "A" has a 'lo, mid >and hi' setting). The greater than 7000 Hz switch I call >switch switch "B" has the same markings. But, what >do they accomplish exactly acoustically? Julian D Hirsch tested the KLH Fives, in Hifi/Stereo Review magazine, (date?). He mentioned that the woofer, he stated 12", not 10", covers from 20 Hz up to 600 Hz. The two mids are then covering from, 600 Hz to 3 KHz, where the single tweeter takes over. He claimed that the two three postion switches adjusted the mids and tweeter about, 2 - 3 db in level, individually. The mids operate from 300 Hz to 3 Khz and are adjusted by the mid switch. By them labeling that switch, 2.5 Khz - 7 Khz, this would be the top end of the mids having some adjustment, just a hair below their cutoff. I will re-read your write-up again, as I see that only the top end, between 2.5 Khz and 3 Khz, should be affected by the mid's adjustment. The 7 Khz switch is obviously only for the tweeter. This will be interesting to see why the crossover and the tweeter are differing, between 3 Khz and 7 Khz. The tweeter is then taking over from 3 Khz, to at least the 14 Khz level that Julian mentioned in his review. He did not clarify, if each increment or total adjustment, was his intention. I will assume, that he meant, each increment. He did comment, that the system went smoothly from 170 Hz - 14 KHz +/- 2.5 db. Woofer distortion was, at 1 watt drive level, loud according to Julian, 5% @ 30Hz, 8% @ 25 Hz, 6% @ 20 Hz and typically less than 1.5% @ 50 Hz and above. > >The model 5 brochure claims "far more precise and >repeatable adjustments than do the simple variable resistors >offered for high-frequency adjustment of most multi-speaker >systems." > >I thought that a bit ambitions; claiming a 3 position switch >could be more precise than a rheostat of the type used in the >early Acoustic Research speakers. You are right, Carl, if they had just said, repeatable settings, then I would have agreed with them. There is much more adjustment with the pots, warts and all, if and when, they are working correctly, but, the switches have a lot going for them, mainly consistancy. If KLH, had used the Dynaco 5 position switch, there would be more selections of repeatable adjustments at least. I do not find any repeatablity with the AR pots, at least not consistantly. After reading his review of the KLH Five, if you covered over the KLH brandname, you could be reading an AR speaker review, they are very similar, which is a compliment. > >Anyway, using a function generator, Tenma digital dB meter, >spare cone midrange and dome tweeter (neither are KLH >products), I generated 108 data points via separate dB >measurements of each driver at 6 different frequencies (2-12 >kHz @ 2kHz intervals) while changing the two switch positions >in 9 different combinations of settings. > >Obviously, because I used NON KLH drivers in the tests, I >can't say with any certainty, what would occur with original >KLH drivers. However, I expect the general up/down trends to >be about the same. > >Here is what I found. (Write me directly at the email address >below and I will send the original M'Soft Excel file >containing the raw data matrix, charts and additional details >of the study). Please ignore the absolute dB readings. Only >the trends are of value in this study. There is no explanation >why the drop in dB level in the midrange at the 4 and 12 kHz >levels. The function generator power setting was set constant >for each driver over the frequences tested but was lowered to >a starting level of 80 dB for the more efficient midrange >driver. > >1)At 2 kHz level there was virtually no change in output of >either driver at the "A" lo switch position. 1-2 >increase in dB level was measured at the mid and hi positions >when switch "A" was moved to the mid and hi >positions. >2)At the 4 kHz level, the tweeter increased about 7 dB going >from lo to hi settings. The midrange stayed about the same or >dropped a few dB at the "A" switch mid and hi >positions. >3)At the 6 kHz level, the tweeter responded about the same >with about a 3 dB increase going from lo to hi. The midrange >driver dropped a bit again as in 2). >4)At the 8 kHz level, about the same results as the 6 kHz >level. >5)At the 10 kHz level, there was about a 2 dB increase for the >tweeter going from lo to hi. The mid dropped again. >6)At the 12 kHz level, the tweeter increased 3-5 dB while the >midrange behaved the same as in 2)-5). > >carlspeak@aol.com > >It's all about the music > >Carl >Carl's Custom Loudspeakers Thank you, Carl, for all of your work in doing this study.
  10. Hi Bob; I just read your write-up of your KLH Five's in the KLH library. Nicely done write-up. Now maybe we can do a schematic for the KLH Twelve speaker system. It will be interesting to see the differences between the Fives and the Twelves crossover, if there are any, if someone here can do it.
  11. Hi Pete; Thank you very much for posting this very interesting piece of Advent history.
  12. >I did some more research before I applied the tacky glue and >found out in some threads here that Armorall (2 coats in 24 >hours) was one way to treat the surrounds. My surrounds aren't >leaking just needed to have something applied that will keep >them from drying out. This is what I did on my AR3's and 4X's. >I think I read the tacky glue fix at AK...Glad I came over >here and did some more research... Hi again; What pray tell is AK, please? You had me squirming when you mentioned, "tack glue", to be honest with you. Pardon my ignorance of the product and the results. I've been running off at the mouth, as much as possible with using the Armorall 2 coats over a two day period technique. Ditto with fusing and larger cables. I am certain that the originator of using Armorall was Tom Tyson, but I cannot say 100% for sure. He may have been told or read it somewhere. I stand corrected, if I am wrong on that point. At least Armorall is the same all over North America and does not need thinning or any additives to apply. In theory we should all have the same outcome with it. We need something to sometimes coat the cloth surrounds with if needed, by that I mean if never done before or a set was just bought and needed it, not on a regular basis. It should be not harmful to the surrounds, not negatively affecting the sound, to a noticeable degree at least, readily available, at least at a reasonable price and quantity, consistant results and without a lot of skill required to apply. With a few other treatments, waterdowned or thinned, unless we all know the exact amount, a few may go too far in an application and YOWZER, a ruined surround. I have yet to read that Armorall is not one of the correct solution's or has done any harm, as in degrade the sound or deteriorate a single surround. I can only comment on original AR and KLH cloth surrounds, this may apply to other cloth surrounds as well. Another option would be that someone starts making cloth surrounds. I don't see any present manufacturer running out and killing their foam surround repeat sales every 5 - 10 - 15 years. It would need to be a rebel or an upstart company. About 10 or so years ago I bought something from, I believe California. I talked to the man's wife and she said that he was trying to make older style rubberized cloth surrounds, copy's of the originals. I lost that information long ago. I did buy, from ebay, a few rubber surrounds several years ago, probably among my very first purchases. They were 10 and 12 inchers. These are new, as in not used, rubber (neoprene) surrounds, probably overstock from a manufacturer, perhaps in Britain or Europe. I emailed the seller numerous times requesting what other sizes were available, never ever received a reply and never saw them for sale again. When I worked here at the local Dynaco warantee depot, I used to save the rubber surrounds from the Dynaco A-25's that were destroyed. I had several hundred rubber surrounds at home, why I don't know. We had several cartons of Dynaco A-25 aluminum woofer baskets. They all were dumpstered many years ago, sadly.
  13. > >Those are the woofers I am going to install. I did take some >tacky glue and dilute it with water and applied a good coat >around the surrounds. Hope that was OK. Where did you get the advice to use, diluted with water tacky glue, on the cloth surrounds?
  14. Hi there; There is a pair of AR-4's with, "hot cross bun" woofers, with full fiberglass covered tweeters on ebay as I write. The green one is probably for St Patricks Day.
  15. >>Hi there; >> >>I have AR-4X's, not AR-4's, with both foam and cloth >>surrounds. >> >>The link to ebay shows the, hot cross bun woofer cones, >but >>the tweeters are not AR-4X's. >> >>These are the AR CTS tweeters less the fiberglass full >front >>muffler. >> >>Unless my glasses need cleaning again. >> >>I just now went up to see John's jpg of the AR-4 and >AR-4X >>speakers. >> >>I have not ever seen an introductory photo of the AR-4 >speaker >>before, if that is an intro photo. >> >>I have only ever seen the CTS 3 1/2" cone completely >>covered w/fiberglass and with the screen cover. >> >>This is also the AR-2AX mid driver and AR-2X tweeter as >well. >> >>Perhaps the AR-4 with the partial tweeter fiberglass >surround >>was an earlier prototype. >> >>Nice to see heavy speaker cables for the AR-3A's. > >Thanks Vern...they are AR3's. Speaker wire was a tight fit on >the binding posts...LOL....Anybody know where I can find some >of the number "3"'s? >I saw a set of them go for $66 on eprey. Oh well...... > Hi Rick; I just came back again and another link, in Korean? It wasn't there when I posted? I now have seen at least 6 different woofers used by the AR-4 series of speakers. Makes ones shake their head when buying as to which ones you'll get and will they be matched. Perhaps you have a Radio Shack near you. Buy loop, hook or u style solder connectors. Just wrapping a loop at the wires end and soldering together will give you a strong loop which which fit the threaded screw. Loose bare stranded wires can un-twist and touch each other and cause a short as well as slip from under the fingernut/washer. Today, most amplifiers can probably rely on self protection, othewise the amp may self destruct, if shorted, if not fused. Do you have speaker fuses installed? If not, goto, "OTHER" forum, goto "fast blow fuses", for a reading and reference session.
  16. Hi there; I have AR-4X's, not AR-4's, with both foam and cloth surrounds. The link to ebay shows the, hot cross bun woofer cones, but the tweeters are not AR-4X's. These are the AR CTS tweeters less the fiberglass full front muffler. Unless my glasses need cleaning again. I just now went up to see John's jpg of the AR-4 and AR-4X speakers. I have not ever seen an introductory photo of the AR-4 speaker before, if that is an intro photo. I have only ever seen the CTS 3 1/2" cone completely covered w/fiberglass and with the screen cover. This is also the AR-2AX mid driver and AR-2X tweeter as well. Perhaps the AR-4 with the partial tweeter fiberglass surround was an earlier prototype. Nice to see heavy speaker cables for the AR-3A's.
  17. Hi Jim; Welcome aboard. This site is fabulous. Someone asks a question and years later the answer comes forth. Thank you for coming forward with your information, Jim.
  18. >>Hi Matt; >> >>There is no housing with these two. >> >>They are wired in parallel, they must be 16 ohms each. > >Hi Vern - I thought the dual drivers were wired in series. Are >you refering to the dual mid drivers used in the 2a? > >Matt Hi again Matt; Yes, these are the dual mid/tweeters of the AR-2 and mids only of the AR-2A of which, both speaker systems are 8 ohm rated. The leads from each are soldered together in parallel just behind the plastic/aluminum enclosure.
  19. Hi Matt; There is no housing with these two. They are wired in parallel, they must be 16 ohms each.
  20. Hi again; Well I think I've done all I can to lessen the exporting to Asia of dual AR drivers. There doesn't seem to be anyone else in North America buying them for restoration purposes anymore. I just won 2 and there was no other bidders from North America. Am I the antique here?
  21. Hi Carl; You're going to laugh at this. I've rambled here for almost 3 years and never saw that AR-1 photo before. I was hoping that TomT would come forward on this topic with a photo of several different versions of AR-1X's. I hope, I hope, I hope. Or at least with his wisdom, which he always displays. At least another member with an AR introduction of the AR-1X and AR-2X series speaker would be really great, I am assuming they were publicly announced the same as other models. AR was very generous, upon request, they would mail you oodles of their product literature. I've tried finding older photo's and literature about AR, most difficult now considering that it is now 35+ years later, but I continue to look anyways.
  22. > >>Yes, the AR-2AX has the flat front wire meshed cone >driver >>with fiberglass as it's midrange driver. This third party >>driver was also used as the earlier AR-4, AR-1X, AR-2X >>mid/tweeter driver. > > >Vern, > >Hate to be a nit-picker, but in the interest of historical >accuracy, the tweeter in the 1x was the 2 1/2" tweeter >(similar to the 4x), not the 3 1/2" unit from the 4, old >2x and 2ax. > >Steve F. Hi Steve; No problem with wanting historical accuracy, Steve, I may be wrong. I believe the earliest AR-1X was the older aluminum frame alnico magnet woofer and 3 1/2" tweeter. I do not have any data as to when the woofer was phased over to the ceramic woofer and when to the 2 1/2" tweeter. I am positive I've seen photos of a AR-1X with the older woofer and older 3 1/2" tweeter on ebay. This is the same with the AR-2X but there is also the transitional 10" to 11" adapter used for a period as well, which I own, which has the 2 1/2" tweeter. Also the aluminum frame 10" with 3 1/3" tweeter, which I own as well. Or even if the woofers and tweeters were changed over at the same time. I could be mistaken, Steve, I have been compiling a lot of differences, some small, between several model speakers including AR-LST model variations. Unless a speaker was announced new from scratch, such as the AR-5, we then knew those drivers and when they were introduced. The AR-3A used the older woofer at it's introduction, but AR continued to publish their literature for several years with the earliest photos, with the alnico magnet woofer, long after the switch to the ceramic magnet and foam surrounds. This was not to deceive buyers, but to allow warehouses and dealers to clear out the older stock. I do not believe there was any special notations on shipping cartons as to the changover. My own AR-3A cartons have no notations and they were made just around the conversion time period and have the ceramic woofers with foam surrounds, darn. The dealers must have had more than a few disgruntled customers. A. Who would want an older model AR-3A if a newer and improved version was out. B. Mixing older with newer speakers may have cost them a few headaches, if not, at least lot's of letter writing and perhaps money exchanging speakers or drivers. TomT may have documented driver conversion dates or serial numbers for these models, either the AR-1X or AR-2X's. I have been wrong before, that is why I carry a pencil with an eraser, for the occasional mistake that I do make. While this topic is of speakers 40+ years old, there is still a great interest in the facts and these speakers. Speaks well of the loyalty of it's owners. YEH!
  23. >Vern. Are you sure those are tweeters and not the mids? >I've worked on some 2a's and can confirm what you are showing >are the midranges which measure about 5 inches. They were the >predecessor to the flat and dome mids to follow in later >versions. I've got a pair of salvaged flat dome mids from a >pair of 2a's. > >The AR history table in the library does not show a pair of >tweeters for the 2 or 2a. It does list a pair of 5 inch mids >for the 2a. > > >It's all about the music > >Carl >Carl's Custom Loudspeakers Hi Carl; These are the AR-2 dual mid/tweeters for lack of a better definition, they span from 1khz and up. They were also used as AR-2A mid drivers only, as that speaker has also the 1 3/8" tweeter, sometimes referred to as a super tweeter. Yes, the AR-2AX has the flat front wire meshed cone driver with fiberglass as it's midrange driver. This third party driver was also used as the earlier AR-4, AR-1X, AR-2X mid/tweeter driver.
  24. Hi again; Here is a few more dual tweeter photos. Photo 1 shows the four screws holding each driver into the plastic housing. Photo 2 is the rear view of the housing, it is sealed from the enclosure so that there is no woofer back pressure to damage the open backed tweeters. The leads are spliced in parallel and the holes where they come out of the housing are sealed with a rubber type glue. Photo 3 and 4 is 2 set's of drivers I received destroyed by the seller, when he inserted bubblewrap between the cones and then fastened them face to face. The bubblewrap split open each of the cones. In this case the seller did his very best to protect them, rather than the haphaszard way I usually see. Some slight rippling can be seen on the cone material which appears to be quite common.
  25. Hi again; I have downloaded the Crown EQ-2 Equalizer owners manual. On page 3-13 there is a write-up which, in part; Generally the experts will agree that the best response for a room is flat from 20hz - 8khz and then rolling off at 6 - 8 dB per octave downward. Among other good reading there is a musical instrument chart as to what frequencies the various instruments operate in. This may be decades old information but it should still be valid today. Perhaps this is why a speakers highend could slope downward and still be quite acceptable to most listeners. If speakers were flat from 20hz - 20khz would we find them coloured, too bright or just more transparent?
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