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Any experience of IMF loudspeakers? I got a pair today!

Discussion in 'classic' started by beammeup, Apr 30, 2019.

  1. Arkless Electronics

    Arkless Electronics Trade: Amp design and repairs.

    The weak point is the original tweeters. A later version called the 3090 had "Isodynamic" tweeters, a form of ribbon tweeter similar to the Infinity "Emit" units. It should be fairly easy to replace them with better modern tweeters depending of course on if originality is a thing for you!
  2. beammeup

    beammeup pfm Member

    The image above which I assume refers to the first generation Super Compacts you were describing in your post, shows that - if you look at the woofer, the rebate is larger than the face-plate of the driver!

    Take a look at my woofer in my pictures - the rebate is again larger than the face-plate of the driver - this made me suspicious that the woofers had been replaced - but that may not be the case.

    Should I unscrew all the drivers (including the tweeter) and check the manufacturer of each? It would be good to know if I have all the original drivers in my IMF speakers at least so that they will perform as designed!

    I have been running them now for a few days continuously at low volume - it will be time to turn the wick up soon.
  3. ToTo Man

    ToTo Man the band not the dog

    I'm 99% confident all the drivers in your Super Compacts are original, but if you want to check, the bass units should be KEF B200. I agree the oversized rebate is odd, as is the overlap with the mid driver, but I've seen many early IMFs that look this way so I assume cosmetic streamlining wasn't among IMF's top priorities in their early years!

    To clarify, the first image in post #16 is a TLS 50 mk1, the second is a TLS 50 mk2, and the third is a TLS 80 mk2. A word of warning regarding the TLS 50's, the supertweeter in early models was actually a microphone capsule that was stuck into the baffle with mastic and reportedly very difficult to remove without damaging it, so unless faulty I would leave it alone. The Coles 4001 was the nearest to a drop-in replacement for it IIRC.

    Post #10 shows my pair of Super Compacts which I believe were made just before the changeover to mk2 because although the rear labels don't say 'mk2' they have the mk2 tweeters and more WAF veneered baffles with streamlined driver rebates.
  4. snowman_al

    snowman_al pfm Member

    Your Super Compacts are original. They are identical to the ones I had. The bass cut out was like that on contemporary IMF speakers so correct.
    The Bass is a KEF B200. The Mid is an ELAC unit that IMF added a 'finish' to and has the original concave rubber surround, I doubt if there is a makers name on them. The Tweeters are Peerless but I cannot remember which. I think they had a white mastic seal - but it could be memory tricks...
    The ones ToTo Man has are different in the Mid (a convex foam surround) and the Tweeter units, so there was some development during the first Super Compact 'phase' obviously.
    The Compact II was a 2 way speaker and probably better for that.
  5. beammeup

    beammeup pfm Member

    There's an incredible amount of knowledge on this forum! I never heard of IMF yet some on this forum can give a detailed experienced account of them!

    Later on can I start giving my SC's some welly without risking damage to the cones due to their age do you think? I won't go mad obviously.
  6. Martyn Miles

    Martyn Miles pfm Member

    I inherited a pair of little IMFs which I assumed were Compacts, but earlier models.
    They didn’t have Kef B200s, but a paper-coned bass drivers. They had paper coned mid. drivers with roll surrounds that had deteriorated.
    The tweeters were also paper coned. They looked like the ones Keesonic used in their Kub speakers.
    I never did get them repaired, but sold them on.
  7. retrospective

    retrospective pfm Member

    I like them a lot there's a fulness to their sound,i don't feel like anything's missing tonally or dynamically.
    I've had a few hours tonight with Dire Straits,Tracy Chapman,The Carpenters and Abba ..and the wife's not complained once (her playlist and 2 bottles of wine though)
    Yes my speaker list is extensive! I could happily live with these.
  8. beammeup

    beammeup pfm Member

    Heck - up to this point in time I've not taken these (somewhat ugly) speakers seriously - they are now in the main right hooked up to my Croft pre/power and boy do they sing!!

    The sound is so incredibly modern with great control and fantastic highs for such old speakers like this (in fact you wouldn't know they were old)! Really I don't know what to say except I am really gobsmacked.

    I guess I now worry about how long a pair of speakers like this will last without something popping or giving up!
  9. david ellwood

    david ellwood Kirabosi Kognoscente

    You have to be careful or they have a tendency to self destruct within five seconds.
    ToTo Man likes this.
  10. beammeup

    beammeup pfm Member

    You’re jesting of course ...

    They held out to bit of Croft bashing tonight at quite some sturdy volume levels.
  11. david ellwood

    david ellwood Kirabosi Kognoscente

    I’m sorry I thought my joke too obvious to require an explanation.
  12. beammeup

    beammeup pfm Member

    Are my IMF Super Compacts transmission lines of sort?
  13. sp25

    sp25 pfm Member

    No, aperiodics IIRC
  14. retrospective

    retrospective pfm Member

    Blowing speakers up is a blessing in you an excuse to hunt down some new ones.

    Enjoy them until that day comes
  15. beammeup

    beammeup pfm Member

    I am continually surprised how good these speakers sound! This spurred me onto doing further research on the net to see if anyone else had the same findings. I found a chap in Italy called Motxam who has an admiration for Grundig components - in addition he has a list of recommended components ( where in fact by grading of his 'star' award system the IMF Super Compact First Series is right there high up on this list.

    On his list the first series have a higher score than the IMF second series - and the IMF SC first series sits above the Klipsch Heresy, Snell Type A and Quad ESL 63.

    All subjective I know but, interesting nevertheless. They certainly can't be bad speakers sitting in amongst that lot! And in my personal experience they are indeed very good speakers.
  16. I found TLS50 and I was so impressed, I have TLS80 MK2 at the moment. Like the BASS on organ music.
    a.palfreyman likes this.
  17. beammeup

    beammeup pfm Member

    I still have mine in the main lounge they are that impressive (I had to cure a slight buzz from the cabinets but they are perfect now). I have them side by side with my Role Audio Enterprise's.
  18. Tom Hardwick

    Tom Hardwick New Member

    IMF TLS80 2As here. Had them since 1983, just LOVE the way the bass oozes out of them, rolls across the carpet and beats me in the chest.
    They're part of my surround sound system and sit alongside the 65'' LG OLED. WOW.
    A couple of friends have asked me where I've hidden the sub the room. Squuze me?
  19. Craig B

    Craig B Re:trophile

    I wonder if "5/36" was a Dalesford OEM reference...i.e. 5" cone, .36 total Q. Dalesford did a number of KEF-alikes.
  20. andrew tooley

    andrew tooley pfm Member

    I would love a pair of leak 2075,s or 3090,s!

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