IMF speakers, anybody?

Discussion in 'Monitoring' started by sign, Feb 15, 2004.

  1. sign

    sign Guest

    Hi all

    I was working with a well known Dutch pianist and he has a pair of IMF speakers in his rehearsal studio. The type is ALS40, these speakers sound very good, well balanced and a very accurate mid plus really nice low end.

    Anybody who's familiar with them speakers?

    Peace, Han
  2. Mike Kruger who posts on here has a pair. I'm sure he will give you the down low. I will send him this way!!!
  3. mkruger

    mkruger Guest

    IMF stands for "Irving M. Fried", after the guy who designed and the speakers. His nickname was “Bud”. IMF Electronics went out of business in the late 80's. TDL was the successor company of IMF and run by most of the same people. TDL also eventually went under. There is a new company called "IMF Audio" that bought the name, but the speakers are nothing of the sort. Bud Fried was one of the greatest speaker designers who ever lived; he died a few years ago.

    The speakers you saw were manufactured between 1977 and 1983. All of IMF designs were based on the "transmission line" theory. Very different from bass reflex or any other designs you might see today. The basic principal is to use smaller drivers for accuracy and space with engineered cabinets to gain frequency response with higher levels. Many of the designs also incorporate phase shifting switches on the crossovers. The transmission line theory has never been fully developed because it’s so complex. IMF and TDL probably had the best designs.

    IMF’s are hard to find vintage speakers. Do you know if you saw the "ALS40" or "ALS40II Studio"? They look the same but are radically different. ALS40’s are a compact smaller breed of IMF's, but great for near field monitoring. The ALS40’s are more abundant on the used market then some other better models. They used an 8" bextrene bass unit, 8" bextrene sub-bass unit, 4" rolled surround impregnated cone mid-range with domed tweeter. The dome tweeter was probably made by Coles. Cabinets were generally very high quality. I think part of the reason they went out of business is because the speakers where made without cost in mind.

    I use a pair of IMF “Studio Monitors”, they are one of a kind. If anyone is still using them today, like me, I would venture a guess that they have had new crossovers custom made. The originals were good at the time but new ones can make those speakers sound unbelievably good. A funny thing is that Bud didn’t think the quality of wiring was an important factor in acoustics, he actually said that. Bottom line is that their great.

    Anyway, I could write a huge book about this so I’ll just stop here. If you want to know more visit this link or just ask, I’ll be happy to talk more! And thanks for the great post! I don't run into many people who have ever even herd of IMF, let alone actually using them in a studio. There are a couple of factual errors I noticed on this site but you’ll find a lot of useful info including dates and timelines, frequency charts, parts that were used, crossovers, history, interviews... If this stuff interests you click on links at the bottom, they will guide you to other great websites of transmission line interest.

    There is also a discussion group on yahoo called “imf-electronics”
    audiokid likes this.
  4. mkruger

    mkruger Guest

    One thing I forgot to mention is that IMF is a European company. You won't really find them in the United States unless some old rich lady moved to the US from England and had a yard sale or leaves them to you in her will when she died.
  5. mkruger

    mkruger Guest

    In my case it was the old lady having a yard sale, $200, great condition, can't beat that! and no one had to die.
  6. sign

    sign Guest

    Mike, thanks for your great and very detailed post.
    It were the ALS40II I've listened to and they sound wonderful.

    I have traced a pair of ALS40's in Amsterdam, don't know whether it's ALS40 or 40II and the guy says they are painted black.

    I want them for mastering, I can't imagine these speakers are so rare, because IMHO there are very little speakers that sound so balanced as the IMF.

    Actually there's a pair of TLS50's or TLS80's on Ebay right now.

    Peace, Han
  7. mkruger

    mkruger Guest

    Yeah I see a few TLS50's and 80's on ebay from time to time. They seem to be most common. When I mentioned the speakers are rare, I was just referring to other models that were designed specifically for studio or reference use and are still in decent shape.

    Notice that the TLS 50's that are on eBay are not the "TLS 50II Studio" that has major differences. Not all IMF's should be used to reference on just because they sound good, some of his designs were ment to be colored. Even IMF's in poor shape fetch good money on the used market.

    Anyway you seem interested so do all the research and keep your eyes peeled for some. Look for TDL too. Europe probebly has more floating around.
  8. sign

    sign Guest

    Mike, I have an appointment coming saturday to see a pair of ALS40II's.

    I'm exited about it! I'll keep you informed.

    Peace, Han
  9. sign

    sign Guest

    Mike, I've got them, a pair of ALS40II's in mint condition. Testing tomorrow!
  10. mkruger

    mkruger Guest

    SWEET!! Let me know how they sound. My IMF drivers are off having the voice-coils replaced. If you need work done I know a good guy.
  11. sign

    sign Guest

    Like you said, they're one of a kind.
    I've listened to all kinds of music and these speakers seem very neutral sounding to me.

    A very nice low end, the mids are not spectacular, but very neutral and the high and is quite nice and silky. The stereo image is wonderful.

    If you compare the sound to the NS10 for example, you can hear the NS10's +7db peak at 1.5 khz very clearly.

    I think these are the most neutral sounding speakers I've heard so far, they sound far from 'hyped', but far from 'dull' as well.

    The guy I've bought them from, has sold them because his wife found them to big. Oh, I love women! :D

    Peace, Han
  12. mkruger

    mkruger Guest

    I'm glad your happy with your purchase. I felt like the mids where very flat on mine. I also thought the highs sounded like tin. I tweaked the xovers and that fixed it. I might suggest you want to think about replacing your capacitors.

    Do you know anything about PMC Monitors? I'm checking them out and was wondering of you ever listened to them, there a European company. Anyway, enjoy your speaks and take it easy Han.
  13. sign

    sign Guest

    Mike, I have listened to PMC monitors at AES a while ago. This were small monitors and it sounded quite impressive there.

    Later I was in a studio that has PMC's, NS10's and Auratones and it was almost shocking how different the PMC's sounded from the NS10's and the good old Auratones.

    The best sounding monitors at AES IMHO were the Earthworks'.

    But, the discussion about studio monitors on the many forums is a never ending story. I have had so many monitors in my studio (my gearpimp comes every now and then with a number of them) and 'THE' monitor doesn't exist.

    I can make good mixes on the horrible sounding NS10's because I've got to know them. I think once you know your monitors, you can mix on them.

    I will get to know the IMF's the coming weeks and I will make some mixes and listen to them on many stereo's, hi fi speakers. I'm really curious how they translate, they sure sound very nice, but so very different from many other monitors as well.

    Take care! :p:
  14. mkruger

    mkruger Guest

    The reason I asked about the PMC's was because they are designed on the same theory as the IMF's, which is transmission line. I'm going to try and pick up a pair of small PMC's for near-fields.

    My goal is to have a couple sets of really nice speakers and use them exclusivly for many years so I can get used to them and not worry about buying new monitors and getting to know them all over again. I don't really care much about the latest and greatest or brand names, but i still take it all into consideration.
  15. sign

    sign Guest

    Mike, I believe I've heard the AML 1 and this small monitor sounds very 'big' for such a small one, but also very different from Genelecs etc.

    And they're quite expensive as far as I know.

    Have you had the opportunity to hear the ADAM monitors? Made in Germany and very popular among the (American)musicplayer forumites, but nobody is talking about them in the Netherlands, very odd.
    They're very nice sounding monitors although the highs are spectacular IMO.

    Peace, Han
  16. mkruger

    mkruger Guest

    I'm looking at a pair of TB1's. A few steps down from the AML1's. The AML's probebly sound better but I'm more of a fan of passive speakers. I just don't like the idea of amps built into the speakers, for too many reasons to list here. So I could never bring myself to buy powered monitors, but that day may come.

    A nice thing about a correctly designed transmission line speaker like the PMC's, IMF's, and TDL's is that the frequency response doesn't have the inherant dips and spikes as conventional design does. Even at low listening levels you don't have to boost low-end and tweak the eq like you normally would. The frequecny response and volume hold together nicely. Good for mixing at moderate levels to avoid ear fatigue...
    Do you know what i mean? If not you'll soon find out after listening to your TLS50's for a while.

    Iv'e only heard one other person mention ADAM monitors, he said they were awsome, but I forgot about them and never had the chance to check them out. Now that you've reminded me I think i'll try and find some to listen to.
    I used Genelec's for about a year and did not like the smaller reference type of nearfiels they manufacture, but I do like the studio monitors they make for impressing clients and that sort of stuff.

    [ March 03, 2004, 01:39 PM: Message edited by: Mike Kruger ]
  17. sign

    sign Guest

    Mike, check the ADAM S3A monitors.

    I have been working most of the day in the studio and used the IMF's as my monitors.
    It's incredible, not a trace of fatique. I switched every now and then to NS10's and I can't believe I've spent so many hours of listening to these little bastards.

    To anybody who uses NS10's, tweak them as soon as possible, get rid of that +7db at 1.5 khz.

    The ALS40II's are the best purchase in a long time and only 150 euro :D

    Cheers, Han
  18. sign

    sign Guest

    Hey Mike, I've just collected my third pair of IMF speakers.

    I have the ALS40II, the Compact II and the Compact monitor 2's now.

    Next week I going to get the Super Compact's, so I will have four pair of IMF speakers.

    They all sound great, it's my intention to buy all IMF's in the Netherlands. :D
  19. mkruger

    mkruger Guest

    Han, you are the man! I'm so jeleous of you. I wish I had the resources to gather up all the IMF's I could. We will definatly have to stay in touch...

    I'll be sending you a private message. The RO posts are moving to a new server so let me know if you dont get it.
  20. sign

    sign Guest

    Mike, the odd thing is that I'd never heard of IMF before I was at that pianist's studio.

    Now I have three pair of them and I can say that the Compact Monitor 2 is by far the best sounding small monitor I've heard in a very long time.

    You can put them aganst the Earthworks and ADAM monitors, but the funniest part is that I only payed 80 euros for them, which is as much as $103.20

    I hear details in mixes and well known CD's that I'd never heard before. And that incredible stereo image!

    And when I switch to the NS10's.....sigh.

    It seems to me that IMF monitors are extremely unknown among engineers, nobody else is reacting so far, same thing on other forums. When you realize they were there 25 years ago that's very odd.

    Cheers, Han
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