canuckaudiog
On a quest for high fidelity
Here is my review of the IMF TLS 80 II.
Before I begin, some information and some pictures.
Inside cut-out
Actual pictures
Technical specifications
Years manufactured: 1977-1981
Original MSRP: 630 british pounds
Drivers: KEF B139, KEF B110A, Celestion HF1300, Celestion HF2000
Recommended Power: 50-100 Watts
Efficiency: Approximately 85dB depending on tilt control
Crossover: 375Hz, 3.5kHz, 13kHz
Vented, Sealed: Transmission Line (info)
Frequency Response: 20hz to beyond audibility
Dimensions (on supplied stands): 41.75" (H) x 18" (W) x 15.75" (D)
Weight: 37kg each, 45kg with stands
Review
First of all let me say that this has been somewhat of a dream speaker for me. My first vintage pair of speakers I have ever owned was a pair of IMF TLS 50 II's that aren't restored. Regardless of their condition I loved the sound that came out of them - lush, inviting, accurate and the bass is incredible. I knew that after hearing such an incredible loudspeaker I had to seek out its bigger brother, the IMF TLS 80.
Now this particular model came in two versions, the earlier version marked as IMF TLS 80 on the badge of the back of the speaker and the later version marked as IMF TLS 80 II. When IMF came out with the second version they borrowed some of the features of their more advanced line of speaker, the RSPM or Reference Series Professional Monitor. They took the foam as well as the stands from this line-up and put it on their TLS 80. Considering how well the RSPM is received (just ask anyone who owns a pair), it made a lot of sense and also brought a lot of value to this line of IMF's. Unfortunately there is not a lot of information on comparisons between the older iteration and the new one, except for a review from the Gramophone who reportedly was able to hear both side by side (source). From the review there seems to be some good improvements made to an already impressively designed speaker. So, these changes are welcome in the second version.
As for the speakers themselves (which are freshly recapped with proper original replacements), the impression they give you is exciting, coherent, accurate and dynamic. Paired with a powerful amplifier, they will fill out their full frequency response down to 20hz and you can feel it. It's quite something else to hear such a large amount of bass coming from just speakers, usually you need to have a subwoofer to perform down to this low of a frequency and have it be felt (as it is, when it gets that low you cannot hear it but only feel it). However in order to properly experience this you must have the speakers distanced properly and also the room plays a large role. Most of the time you will only be able to experience down to perhaps, low as 40hz if you are lucky. Room acoustics are key. But, regardless of that the potential is there and the bass sounds absolutely smooth and effortless. One thing you may question is, will this bass be controlled or overwhelming? In all of my listening tests and experience I have found the bass to be well controlled when paired with a good amplifier. I have had the chance to experience these speakers with several amplifiers, the Sansui G4700, Sansui AU555A, Sony STR-V5 and the current unit they are hooked up to, the Sansui G7700. The Sony was a very heavy sounding unit and made the bass a little uncontrolled. However I was rather surprised at how balanced it sounded regardless, but the Sansui G series amplifiers were much better at controlling it.
Another thing impressive about these speakers is their sheer size. Sitting on their stands they sit at almost 42" tall which is large in the speaker world. Not as large as say, an Infinity QLS-1 (which stands 5' tall!), but still very impressive in that department. With a transmission line, size definitely does matter. Its smaller brother the IMF TLS 50 II, although it is also a nice sized speaker, sounds small in comparison to its bigger brother.
Being a 4-way speaker you may think that the stereo imaging is going to be compromised. I find that after positioning the speakers properly, imaging is very coherent and precise. A 3-way design will have its merits over this design, but the crossover network was designed very carefully by IMF to allow the 4 drivers to complement each other and they most certainly do. An impressive feat is the ability of these speakers to simply disappear and not sound like boxes - just pure music. This is where the transmission line design comes in handy most of all. The bass is not reproduced inside the speaker, but in the room instead so you do not feel as though you are in front of a pair of speakers. You can close your eyes and be transported away to where the music is being recorded, as though the artists are there in front of you.
Another observation I have noted is that these speakers perform well on all types of music. I found from rock, to pop, to disco, to jazz and classical, and to even rap, these speakers performed and executed the recordings with excellent accuracy and great excitement. I thought that like the IMF TLS 50 II's, they would be preferential to types of music, but actually I am finding more and more that these speakers do well with just about any style of music.
Now that is a lot of positive talk for these speakers. Every speaker design has a compromise and the IMF TLS 80 II is not without them. I would say the only compromise of this speaker is the midrange. While very lush and clear, the bass does tend to overpower the midrange a tad bit. Regardless though it's not that it eats it up, it's more that the midrange is a little relaxed.
All in all this speaker was designed with little to no mind of costs. Transmission line speakers are not an easy nor cost-effective model to design and produce, especially considering the fact they are supplied in mirror matched pairs. The drivers used are some of the best drivers to use in a transmission line design as you can tell by other manufacturers who decided to try their hand on t-lines. Ask anyone here who has tried to make a DIY transmission line, it is no easy task. In fact, many say the IMF is what inspired them to try this design (info).
Ratings:
Sonics - 4/5
Design - 4/5
Rarity - 3.5/5
Cosmetics - 4.5/5
An impressive british speaker that is not that well known and most definitely worth a listen if you ever get the chance!
Before I begin, some information and some pictures.
Inside cut-out
Actual pictures
Technical specifications
Years manufactured: 1977-1981
Original MSRP: 630 british pounds
Drivers: KEF B139, KEF B110A, Celestion HF1300, Celestion HF2000
Recommended Power: 50-100 Watts
Efficiency: Approximately 85dB depending on tilt control
Crossover: 375Hz, 3.5kHz, 13kHz
Vented, Sealed: Transmission Line (info)
Frequency Response: 20hz to beyond audibility
Dimensions (on supplied stands): 41.75" (H) x 18" (W) x 15.75" (D)
Weight: 37kg each, 45kg with stands
Review
First of all let me say that this has been somewhat of a dream speaker for me. My first vintage pair of speakers I have ever owned was a pair of IMF TLS 50 II's that aren't restored. Regardless of their condition I loved the sound that came out of them - lush, inviting, accurate and the bass is incredible. I knew that after hearing such an incredible loudspeaker I had to seek out its bigger brother, the IMF TLS 80.
Now this particular model came in two versions, the earlier version marked as IMF TLS 80 on the badge of the back of the speaker and the later version marked as IMF TLS 80 II. When IMF came out with the second version they borrowed some of the features of their more advanced line of speaker, the RSPM or Reference Series Professional Monitor. They took the foam as well as the stands from this line-up and put it on their TLS 80. Considering how well the RSPM is received (just ask anyone who owns a pair), it made a lot of sense and also brought a lot of value to this line of IMF's. Unfortunately there is not a lot of information on comparisons between the older iteration and the new one, except for a review from the Gramophone who reportedly was able to hear both side by side (source). From the review there seems to be some good improvements made to an already impressively designed speaker. So, these changes are welcome in the second version.
As for the speakers themselves (which are freshly recapped with proper original replacements), the impression they give you is exciting, coherent, accurate and dynamic. Paired with a powerful amplifier, they will fill out their full frequency response down to 20hz and you can feel it. It's quite something else to hear such a large amount of bass coming from just speakers, usually you need to have a subwoofer to perform down to this low of a frequency and have it be felt (as it is, when it gets that low you cannot hear it but only feel it). However in order to properly experience this you must have the speakers distanced properly and also the room plays a large role. Most of the time you will only be able to experience down to perhaps, low as 40hz if you are lucky. Room acoustics are key. But, regardless of that the potential is there and the bass sounds absolutely smooth and effortless. One thing you may question is, will this bass be controlled or overwhelming? In all of my listening tests and experience I have found the bass to be well controlled when paired with a good amplifier. I have had the chance to experience these speakers with several amplifiers, the Sansui G4700, Sansui AU555A, Sony STR-V5 and the current unit they are hooked up to, the Sansui G7700. The Sony was a very heavy sounding unit and made the bass a little uncontrolled. However I was rather surprised at how balanced it sounded regardless, but the Sansui G series amplifiers were much better at controlling it.
Another thing impressive about these speakers is their sheer size. Sitting on their stands they sit at almost 42" tall which is large in the speaker world. Not as large as say, an Infinity QLS-1 (which stands 5' tall!), but still very impressive in that department. With a transmission line, size definitely does matter. Its smaller brother the IMF TLS 50 II, although it is also a nice sized speaker, sounds small in comparison to its bigger brother.
Being a 4-way speaker you may think that the stereo imaging is going to be compromised. I find that after positioning the speakers properly, imaging is very coherent and precise. A 3-way design will have its merits over this design, but the crossover network was designed very carefully by IMF to allow the 4 drivers to complement each other and they most certainly do. An impressive feat is the ability of these speakers to simply disappear and not sound like boxes - just pure music. This is where the transmission line design comes in handy most of all. The bass is not reproduced inside the speaker, but in the room instead so you do not feel as though you are in front of a pair of speakers. You can close your eyes and be transported away to where the music is being recorded, as though the artists are there in front of you.
Another observation I have noted is that these speakers perform well on all types of music. I found from rock, to pop, to disco, to jazz and classical, and to even rap, these speakers performed and executed the recordings with excellent accuracy and great excitement. I thought that like the IMF TLS 50 II's, they would be preferential to types of music, but actually I am finding more and more that these speakers do well with just about any style of music.
Now that is a lot of positive talk for these speakers. Every speaker design has a compromise and the IMF TLS 80 II is not without them. I would say the only compromise of this speaker is the midrange. While very lush and clear, the bass does tend to overpower the midrange a tad bit. Regardless though it's not that it eats it up, it's more that the midrange is a little relaxed.
All in all this speaker was designed with little to no mind of costs. Transmission line speakers are not an easy nor cost-effective model to design and produce, especially considering the fact they are supplied in mirror matched pairs. The drivers used are some of the best drivers to use in a transmission line design as you can tell by other manufacturers who decided to try their hand on t-lines. Ask anyone here who has tried to make a DIY transmission line, it is no easy task. In fact, many say the IMF is what inspired them to try this design (info).
Ratings:
Sonics - 4/5
Design - 4/5
Rarity - 3.5/5
Cosmetics - 4.5/5
An impressive british speaker that is not that well known and most definitely worth a listen if you ever get the chance!
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