Sunday, 30 December 2012

IMF TLS80 Transmission-Line Speaker

These are considered one of the best British speakers ever made, "Id go with that"

My first real speakers, I was 18 and handed over £400 for them. What a pair of speakers, nothing but music making machines. I had them setup in a basement once and I can honestly say they were nothing short of amazing. From the deepest bass to the highest crisps, these had it all. Perfect delivery, warm and subtle with all the detail. Sound-stage was huge, with sound wizzing around my head and I mean 360* around!

The real magic to these speakers is the bass. So smooth and deep without ever a booming note. Transmission-Line speakers are the one for me! Tried Cambridge R50 but not enough sub base and the sound was murky as hell. TLS50, I hated everything about them! It has to be the 80s every time. The perfect speaker... Until I found the IMF Studio... more on those later.


Drive Units

Kef B139: 11 3/4" x 8 1/4" flat polystyrene diaphragm

Mid range:

Kef B110: 6" plastic cone containing in separate line


Celestion HF-1300:

Celestion HF2000:


Crossover points: 375 Hz , 3.5 kHz and 15 Khz

Frequency Range
20 Hz to beyond audibility


  1. There have been far superior speakers produced in the last 30 years. Yes these would have been gorgeous when new. Someones ears may have deteriated along with their speakers. So much myth around old speakers. dont be fooled

    1. I don't see any real new technology in speakers for the last 30 years. Normal considering the esoteric Hifi companies size and durability. They have no money for real R&D.
      Someone mind may heve been deteriorated by pure marketing.
      Just compare "myth" old speakers and what you can buy new for the same price and let your ears decide.

    2. couldn't have said it better myself, thanks.

    3. What do you mean by "superior"? Speaker technology has in essence not changed in principle of being a sound radiator. Drive units have been changed in manufacture and so forth. Can you name me a make and model (non Transmission Line design)up to say £20K that has a frequency response of 20Hz to beyond audibility. We would all benefit from your knowledge.Please oblige us.

  2. I still have my TLS80's, had the cross oevers redone and can't find a suitable replacement for under 10K

    1. Nice one! Sadly mine have found a new home but at least I have the memories!

  3. I bought my TLS80's back in 1976 for £320 from Largs in High Holborn. Still have heard nothing better -
    at least for home hi-fi. What did happen recently was that the Celestion 2000's gave up the ghost. Replaced them with Coles 4001 I think they're called. Sounds even better. Don't be tempted to drive them at very very high levels because the super-tweeters will blow. I think that's what happened to the original units. But the other units (bass treble and mid) are all still fine. I'm lucky enough to be able to drive them to high levels - but yes , the super tweeters will blow. Answer - turn the volume down a bit!!!

  4. I used a pair of Rogers Studio Monitors for a long time because I liked them so much. Had good trebble and bass. Then I heard the IMF TLS 50 MkIIs. I bought them for the base performance with pipe organ music. Then stepped up to IMF TLS80 MkII, which I now thoroughly enjow for performance in the upper register as well as the pedal notes of organ music. I can feel the Cathedral/Church in my listening space.
    Probably the moderl TL PMC speakers would improve on these but at a price.

  5. Id like to say a massive thank you to everyone for all the interest and comments on this article. Im glad to see a generally positive response here and hopefully you will enjoy the IMF Studio article coming soon.

  6. So what about the IMF's studios?

  7. Gorgeous speakers in both sound and looks. While they are roundly excellent TLS-80s are not perfect. The Celestion tweeter is a little bit peaky around 3000 hz due to some stored energy. It can give the speaker a bit of an explicit quality in the lower treble which enhances detail in some source material. The midrange has a slight cupped hands quality which is characteristic of certain bextrene drivers. These are minor carpings however and the ear tunes them out quickly as the TLS's 80s virtues grab your attention. One thing to be careful... because they are so big they give some people the impression they are capable of high volume levels. No they are not. The drivers (typical for british speakers in the 70s) are delicate, particularly the tweeters and the power handling and maximum SPL is no better that may British bookshelf speakers that use these tweeters, like Spendor, Rogers and B&W. These are not for metal heads but for most other kinds of music at sane listening levels the IMF TLS-80s will captivate if driven by top notch ancillaries and with attention paid to room acoustics and treatment.

  8. Nice to read some positive comments about a British loudspeaker company that made such an impact on the hi fi scene in the seventies. Having grown up with my TLS50s which I bought for £320,00 in 1975 and enjoyed every minute of them playing every genre of my musical tastes e,g,soft rock,motown,country rock and a smattering of classical. 15 years ago I was offered a pair of 80s for the princely sum of £100.00 needless to say I bit the sellers hand off - had new crossovers made and installed by Wilmslow audio and renewed B139 and B110s - brand new from some guy in Wales --- installed and run in softly for 48 hrs and now sound like they used to.
    With the correct ancillaries and room placement remind me just why I love to listen to music, and have listened to Tannoy DC10s and Linn Isobariks, but always return to my prefered TLS80S for sheer enjoyment.

  9. Just a question from a guy who consider buying a pair of TLS 80 mk2. What is different between TLS 80 and TLS 80 mk2? And witch year did they put the TLS 80 mk2 at the market?
    Do they sound any different kontra the TLS 80?

  10. I've had my TLS-50s since April 1975. I will never part with them. The same with my FONS CQ30 turntable and SME 3009 tonearm. The rest of my system, I have updated, but with the goal of maximizing sound quality from the IMFs.