Any Infinity experts here?

Discussion in 'Infinity Loudspeakers' started by tom1356, Feb 11, 2006.

  1. tom1356

    tom1356 Super Member

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    New Hampshire
    Would anyone know anything about the Infinity Monitor 1A Loudspeakers. Circa 1974. A three way floor stander with what may be an inverted walsh tweeter??
    Thanks
    Tom
     
  2. Charivari

    Charivari Fighting Naïve Realism

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    Infinity experts? Well, I like to don the Infinity cap every once in a while and make play at being knowledgeable on the subject. So, I'll give helping you a shot.

    For your model, you can find some information and the brochure at this Infinity Classics page.

    IIrc, the Monitor series were reasonably well-regarded speakers thanks in large part to the Walsh tweeter. However, the cost of licensing the technology proved to be prohibitive, so Arnie Nudell et al decided to invent a better driver -- the EMIT that came out with the next series, the Quantum Line Source.

    - JP
     
  3. tom1356

    tom1356 Super Member

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    1,497
    Location:
    New Hampshire
    Wow that was quick! :) That is exactly what I was looking for. Thanks! I wonder why Google didn't turn that up. Just FYI the original owner said he paid $900 for them.
    Thanks again
    tom
     
  4. cableguy

    cableguy In Twang We Trust

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    :ntwrthy:
     
  5. macaltec

    macaltec Metal Master Subscriber

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    Show off :yes: . Who's next, anyone? I'd be curious to here them with a spec of 22Hz's for the low range :scratch2: . I'm no expert but I know what sounds good.

    mac
     
  6. russkish

    russkish Active Member

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    368
    I remember this speaker well. I am not sure it sold for as much as 900 at the time, but it was probably pretty close to that. I heard this speaker on several occasions when it was a popular model in the Infinity line, and it was a wonderful speaker. The Walsh tweeter really gave this speaker some tremendous imaging capabilities, and the midrange and large woofer were not bad either. This was a sweet sounding floorstander.
     
  7. Nakdoc

    Nakdoc nakamichi spoken here

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    2,953
    Location:
    Nashville, TN
    Take care of the walsh tweeters. They are no longer available. The cabinet is ported. Infinity would put heavy goop on the woofer to move the low frequency resonance down, but I'm sure the 22Hz is a lie. These speakers do image well, and are rock and roll in balance.
     
  8. Charivari

    Charivari Fighting Naïve Realism

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    4,185
    Location:
    Ellensburg, WA
    The specs don't include the +/- dB data. So, they could very well reach 22 Hz, though they could very well be 12 dB down by that point. This is all too common with speakers as a means for the manufacturer to advertise a more impressive freq response than could ever be reached in the typical +/-3dB measure. However, Infinity tended to be much more honest with their better offerings than many of their contemporaries. So, though they're likely down further than 3 dB at 22 Hz, in room the response may actually be not that much more down.

    Now, if that bass driver was a Watkins driver, I'd scoff at the 22 Hz measure and consider it much too conservative. I've measured mine doing incredible things.

    - JP
     
  9. Nakdoc

    Nakdoc nakamichi spoken here

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    Have you ever heard the DSOTM heartbeat through Infinitesimals? These had 4" watkins woofers and wouldn't double until you got moderately loud.
     
  10. Charivari

    Charivari Fighting Naïve Realism

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    Location:
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    'Fraid not, but I'd love to get my hands on a pair someday. I hear they're supposed to have incredible sound for such little speakers, which size-to-performance were only surpassed by Infinity's later Modulus system (that I'd really love to have). When I mentioned the Watkins woofers, I wasn't talking about the 5" in the Infinitesimal, but the 12" that was the standard in the higher end models through several series back in the late '70s through the early '80s.

    [​IMG]

    - JP
     
  11. taineasy

    taineasy New Member

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    44
    Original specs on the monitor 1A are as follows:
    26 Hz to 32 Khz +/- 4 db
    33 Hz to 21 Khz +/- 2 db
    Max Power: 200 watts per channel
    Min Power: 35 watts per channel
    Crossover: 500 Hz, 5000 Hz
    Dimensions: 38" H, 14" W, 13" Deep
    Bass is transmission line loaded/vented
    I purchased these new after trading in my dad's 2000A's and still use them. Much preferred these to the 2000's .
    Bass plays with authority and detail down to 24/25 Hz ( more detailed and a much more natural timber than the poly-cones likw the watkins). One of the most natural sounding speakers I have ever heard. HF response is pretty much to "infinity" as the mass per unit is lighter than air to beyond 30 Khz. Unfortunately infinity had no choice but to add a low tweeter to the model 2a as most 1A owners were blowing the Walsh's with low powered amp turned up to high. Warranty repairs were getting out of hand so they added the peerless but in my opinion hurt the overall sound
     
  12. tubed

    tubed Lunatic Member

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    Early Monitor owners may have damaged their Walsh tweeters but not because of low powered amps but probably because the Walsh was being overdriven for what it was capable, imo.

    I'm curious as to the crossover points of the original monitor, de Classic site only has 1200Hz listed.
    Does this model even employ a crossover for the Walsh at full signal???

    I'd definitely like to find out how low a frquency the Walsh can play successfully:idea:
     
  13. tubed

    tubed Lunatic Member

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    12,582
    Location:
    Aztlan
    I'm not sure which model you are referring to, any pics?
     
  14. taineasy

    taineasy New Member

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    44
    These are specs for the original Infinity Monitor 1a. I have the speakers and the original spec brochure. The 1a is a mid 1970's three-way tower with 12" Infinity designed woofer and dome mid with the Walsh tweeter/super tweeter. The subsequent Monitor 11 looked similar but had a dome low tweeter added with a new crossover and some cabinet changes.
     
  15. Coastsider

    Coastsider Curmudgeon

    In those early Infinity models most of the drivers were sourced from other manufacturers. The 12" woofers in the mid-70's Monitor series as well as the 2000II's, 2000AXT's, and several other smaller models like the 1001A were actually manufactured by CTS and modified by Infinity with the doping that is present to one degree or another on the cones. CTS made guitar speakers and amps.
     
  16. taineasy

    taineasy New Member

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    Arnie did invent a replacement tweeter (EMIT) but IMO not a better tweeter.
     
  17. taineasy

    taineasy New Member

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    44
    You are correct that the tweeters were being over driven and were failing even though they are fused. I dropped my fuse down by 1/2 amp. There were only a handful of amps available that could drive these correctly and safely back in the early/mid 70's. Have compared the tweeters to Heil, Emit and they are superior. They are similar to the B & W diamonds in range and tone quality. Speakers are not very efficient and require amps of 100++ steady continuous watts with good headroom. Most were attempting to run these with entry level 50-70 watts continuous power integrated receiver amps such as a Marantz 2265 and in order to get desired volume were driving them to the limit. I have never had an issue with the walsh's in the 40 years I have owned them. The cabinet is transmission line loaded (the vent is at the top rear of cabinet) and will play clean with detail into the 24-27 hz range. The woofer is alnico and heavily doped ( to reduce transients) especially near the voice coil to improve linear piston action. No rubbing or distortion at any listenable volume.
     
  18. taineasy

    taineasy New Member

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    44
    One of the nice things about the Monitor 11 was that Infinity moved the domes mid out flush to the baffle board which improved mid SPL and reduced diffraction. Not sure what Arnie Nudell was thinking by countersinking the mid "dome" on the early 1a's as it caused a lot of diffraction, reduced off-axis spl and generally left the mid range a tad dull sounding. If you have the skills I recommend owners do this to their 1a's using a wood plug to raise the mid. It is very much worth the effort as it does improve the speaker considerably.
     
  19. Rex81

    Rex81 AK Subscriber Subscriber

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    Location:
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    It took me a second to comprehend which speaker you were talking about. You don't mean "Monitor 11", but rather "Monitor II". Pronounced "Monitor 2", but written with Roman numerals, two upper case i's. I don't mean to be a stickler, but these designations are important, especially with Infinity's history of wacky naming conventions.

    It seems there are far more Monitor II out there than your model, the Monitor 1a. In fact, you're the first person I've heard mention the original monitors. Can you post a picture?

    I'm interested in these models, because I own and am quite happy with their cousins, the WTLC (Wave Transmission Line Column) and their successor, the Column II. Both are fantastic speakers, the WTLC sharing the Walsh tweeter with the Monitor series, and then Infinity giving up the Walsh for an excellent pair of Motorola piezos in the Column II. I consider the WTLC to be the speaker capable of greater finesse, with the Walsh tweeter doing lovely things for the very highest end of the specturm, while the Column II is a bigger, tougher, fuller sounding speaker, while at the same time able to produce fine details from the forward and rear facing piezos. I think I prefer the Column II to the WTLC, but I'm glad I own both.

    I'd love to compare either of these to the Monitor 1 or II. I've heard from people who own both the Monitor II and Column II. Some say they prefer the Column, others say they prefer the Monitor. Interesting.
     

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