Jump to content

iso

Members
  • Posts

    299
  • Joined

  • Last visited

About iso

  • Birthday 06/12/1958

Profile Information

  • Gender
    Male
  • Location
    Tampere, Finland
  • Interests
    Classic Hifi, old cars, vintage wrist watches, collecting and drinking good wines, music

Recent Profile Visitors

3,301 profile views

iso's Achievements

Newbie

Newbie (1/14)

0

Reputation

  1. Hello Kent, Robert, David and other memebers too... I haven´t been around here for some time, but I found recently nice looking pair of Mordaunt Short MS-400 (sold as the original series 1 model). I have not received yet this nice looking original condition pair from early 70´s. I do not have any idea what they are, as information about these is scarce as hens teeth. However, construction seems to be good as even back sides are veneered. According to spec sheet this floor standing model does use 13x8" EMI woofer with laminated cone. MS-400 is not true 3-way design, as woofer is crossed to Kef T15 tweeter at highish 2 kHz and Kef unit is crossed at 12 kHz to Coles supertweeter. EMI woofer design was aged in early 70´s and Kef T15 was early 60´s design. Coles 4001 is still in production, but I do not know when it was introduced. I let you know if there is something worth posting when I receive these speakers. They may be considered obsolete or "odd ball", but at least they are not standard run of the mill product. Maybe we'll start an EMI following here as Kent suggested. Kimmo
  2. 3M 8984 adhesive cleaner is quite easy to use and effective solution for removing contact cement, silicone, wax etc... http://3mcollision.com/3m-general-purpose-adhesive-cleaner-08984.html Kimmo
  3. Roy´s articles about room acoustics in 1980´s are very informative and sound minded. RIP Roy...
  4. Horizontal passive is definetelly way to go if you are runnig close to power capabilities of amplifiers. When amplifiers are overdriven, this happens most likely to amps driving woofers and other amp driving mid to hf can still perform well. However if amps are true dual mono designs there should not be difference if amplifiers are truly similar. Kimmo
  5. Geoff From pics it seems that crossover inductors are placed quite closely to mounting plate made most likely from aluminium. Whe I redid Kef Cantatas with similar construction few years ago, considerable improvement in sound quality materialized when aluminium mounting plate was replaced with one made from masonite. I suppose aluminium mounting plate introduced some kind of crostalk between cored inductrors. Kimmo
  6. Even your thanks have been adressed to other persons... welcome to this friendly forum. Best Regards Kimmo
  7. There is no bracing in AR5 cabinet. But anyway, production cost of AR Igored should not bee too much different to AR5, which was not big success on AR scale. So... only valid reason for choosing AR Igored would be smaller size. AR2ax with 8" woofer may have been better product... but 2ax in original form was very good product. Best Regards Kimmo ..
  8. Classic British BBC oriented 12" x 12 " x 24" 3-way format has lot to offer, if high volume is not needed. However this was actually two way design with super tweeter, as 8" woofer (bexetrene or polyprop cone) was crossed at about 3 kHz. Rogers made many different versions of this one. Spendor saga is still going on and there were others too. I suppose that lack of good mid ranges capable to lower crossover frequency was reason for using Celestion tweeter that was capable only for 3000 Hz crossover. Super tweeters were used from other marques as well. When ATC introduced SM 150-75 3" soft dome in 1976. This made it possible to make ATC SL50 true 3-way high power monitor in 1980´s with dimensions only slightly more than those classic dimensions. However ATC did not have any 8" woofer in production, so they used their 9" woofer instead. Ruggedness of ATC design is substantial as it can deliver continuous 112dB SPL@1m. It has proved worthy design, as they are in production still after 30 years of continuous production. http://www.atcloudspeakers.co.uk/hi-fi/loudspeakers/classic-series/scm50/ There are other 3-way designs that would fit format ar_pro mentioned, but I think that above mentioned two look best to me. Igorizing 3-way AR with 8" is good idea... and I think also that AR might have lost some sales. But how much is only guess. After all AR5 did not sell too well and it was not too far from AR Igored. What is interesting in this idea is that there were not too many choices for good mid range unit in 70´s. AR mid had been in production for a while, even one used for 9-series was new design. ATC SM 150-75 arrived in 1976 and I suppose that it was quite expensive even in these days, as new ones sell today for 372,00 GBP ea. ITT produced good 50 mm soft dome mid range also 70´s, but I do not know when it was introduced. All the best to AR Igored... Best Regards Kimmo.
  9. I have not seen recently similar cone material that was used for original AR foam surround woofers... it feels like mixture of asphalt or bitumen and pulp? Is it possible to increase weight of replacement cone with weight around VC opening or doping back side of cone with PVA and something with a bit more weight. This may work with AR3a and AR9 if additional weight does not decrease efficiency too much. As HF response would be wild quess, this may not be OK with AR3 . Refoaming good original woofer would be best option anyway... but every day less original ones do exist. Debating differences in such things as capacitors, level controls, and amps is nuisance compared to performance of old drive units, like Roy says. Drive units in vintage gear are old and most likely do not meet original specs too often. I was a bit irritated when I received second set of AR2ax mids in last December. Even the resonance problem of first pair was cured... this pair was not perfect either. But... using some other drive unit feels like cheating. Best Regards Kimmo
  10. Simply Speakers seems to have recone kit available for 12" AR woofer. http://www.simplyspeakers.com/acoustic-research-speaker-recone-kit-ar3-ar9-ar11-rk-ar11.html Any thoughts... Best Regards Kimmo
  11. AR3 drive units are well documented in 3a rebuild section. As our experts do have considerable know how and inventory of drive unit anyway, does anybody have time to make similar survey about other drive units used in early AR speakers? Best Regards Kimmo
×
×
  • Create New...