Radfordman
Super Member
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IMF owners thread!
- Thread starter canuckaudiog
- Start date
canuckaudiog
On a quest for high fidelity
So it is the EMI driver! Well you learn something new everyday. Thanks for that information.
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jimmymcfarre
New Member
SimplySound said:
Thanks very much!
One pic shows the ALS-40s & Mk3 monitors set up together. The Mk3s are now gone, the ALS-40s are with me at my girlfriends & in daily use. Watching this years Glastonbury festival from the comfort of her non-muddy flat, in the dry & with the audio playing through the ALS-40s was possibly a preferable choice to actually being there! ALS-40 sized speakers are about the largest speakers I can get away with in this flat.
The RSPM4s are still at my parents house. The pic of them also shows the Mk3s pushed into the corner of the room awaiting collection by their new owner - who paid but failed to arrive - i kept them for him for 3 years before selling them again; half wish I hadn't as I'd quite like a cheap pair like that to "do up" but atleast someone else is getting use out of them now.
Next place we move into together must have room for full size TL monitors so i can rescue the RSPM4s from my rents'....
I also own a couple pairs of ARC (Audio Reproduction Company) speakers - made in Manchester in 80s, no x-overs, used with active Nytech / A&R Cambridge amps & recently being remanufactured by Nero Audio in Germany; but that's another story....
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jimmymcfarre
New Member
Just paid a visit to my parents & spent a very happy hour listening to my RSPM4s, I'd almost forgotten how good they sound & how much I miss them. Definitely need to move somewhere more suited to housing them so i can reclaim them from the rents' asap!
canuckaudiog
On a quest for high fidelity
How do the PM3s compare to the Mk IVs? I've heard PM1s myself, but I do believe the PM3 is a step up in performance.
jimmymcfarre
New Member
The most obvious difference I've found is that the RSPM4s inspire more confidence in their ability not to shake themselves to bits. This is a slight over exaggeration admittedly but I was always worried about killing the mk3s which rarely happens with the RSPM4s. It was very easy to get the old style B139 flapping about all over the place, walking heavily across the wooden floor was dangerous with the turntable selected on my amp; tapping my hifi stand was similarly problematic. I can't remember what used to cause this but something i occasionally accidentally used to do would start the b139 w obbling increasingly more violently and if it hadn't've been stopped it looked like it would've kept going until it shook itself apart. There was also times when the arm of my record player would slide across the disk to the run-out groove; can't remember if this happened while the bass cone was flapping uncontrollably or if it was caused by heavy footsteps or what, but whatever the cause it was a bit scary. I haven't had any of these problems with the RSPM4s, whether the issues listed above were CAUSED by the mk3s or due to them somehow interacting badly with the rest of my kit. I don't use the filters on the RSPM4s so it can't be down to the lack of a sub-sonic filter on the mk3s.
As for how they sound, the RSPM4s produce bass that's a bit tighter and more controlled, although given the "flappyness" I've reported about the 6171 B-139 that's hardly surprising. The RSPM4s are generally more enjoyable, they play louder, they're possibly a bit crisper sounding and they look nicer!
canuckaudiog
On a quest for high fidelity
Right on, thanks for sharing!
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Sent from my iPhone using Tapatalk
oiio
New Member
It all started with a gift ..
A pair of early ALS40 cabinets with damaged crossovers, but the sub drivers were intact. It took me a few years, but I found a pair of SC2s on ebay, planning to simply swap over the drivers. But the foam on the mids was rotting .. Another pair of ALS40s came along, also with damaged crossovers and Audax bass drivers which didn't actually fit well enough to make a seal.
So I botched together a 'working' pair of ALS40s, but they sounded different to each other. After a few months my amplifier started to misbehave and I discovered that re-capping was the answer.
However .. ebay intervened yet again with a pair of early TLS50s in the depths of darkest Wales.Negelected and abused. The bass drivers had been 're-foamed' with packing-grade polystyrene and the 2 knobs on the back did nothing. Straight away I recapped them with the set just ordered from Falcon Acoustics for the ALS40s.
Golly but these sound promising!
And then there was a totally gorgeous pair of ALS50mk2s on ebay (collection only) and I never dreamed such a low bid would succeed. Shame about the scraping bass and perished mids.
So now I have 5 pairs of IMF speakers. Capacitors from Falcon ready to solder. A collection of Kef B200s from ebay.
BUT there are burnt-out RESISTORS on the crossovers. So badly burnt as to be unidentifiable. Can anybody help with circuit schematics for these models?
Should I upgrade the power handling for new components? Is there abetter way to mount the crossover boards to reduce the risk of combustion? (there is charring in places on the foam).
I'll try to assemble some pictures.
A pair of early ALS40 cabinets with damaged crossovers, but the sub drivers were intact. It took me a few years, but I found a pair of SC2s on ebay, planning to simply swap over the drivers. But the foam on the mids was rotting .. Another pair of ALS40s came along, also with damaged crossovers and Audax bass drivers which didn't actually fit well enough to make a seal.
So I botched together a 'working' pair of ALS40s, but they sounded different to each other. After a few months my amplifier started to misbehave and I discovered that re-capping was the answer.
However .. ebay intervened yet again with a pair of early TLS50s in the depths of darkest Wales.Negelected and abused. The bass drivers had been 're-foamed' with packing-grade polystyrene and the 2 knobs on the back did nothing. Straight away I recapped them with the set just ordered from Falcon Acoustics for the ALS40s.
Golly but these sound promising!
And then there was a totally gorgeous pair of ALS50mk2s on ebay (collection only) and I never dreamed such a low bid would succeed. Shame about the scraping bass and perished mids.
So now I have 5 pairs of IMF speakers. Capacitors from Falcon ready to solder. A collection of Kef B200s from ebay.
BUT there are burnt-out RESISTORS on the crossovers. So badly burnt as to be unidentifiable. Can anybody help with circuit schematics for these models?
Should I upgrade the power handling for new components? Is there abetter way to mount the crossover boards to reduce the risk of combustion? (there is charring in places on the foam).
I'll try to assemble some pictures.
canuckaudiog
On a quest for high fidelity
Hey there, I have the schematic with parts for the TLS50 and ALS40. PM me your email and I'll send it over.
radine
Active Member
IMF TLS50 update
Well, I had the TLS50s recapped and have to admit, it was very worthwhile. Thanks for the encouragement canuckaudiog! Prior to the recap, I felt the speakers had a slightly recessed midrange which made then sound a little bright or forward. The recap has resulted in a fuller midrange and overall they now sound more balanced.
With regard to the Proac Response 2S, it is a simply outstanding standmount and if I had the money I would have kept both the Proacs and IMFs. That said, I have no regrets about letting the Proacs go and feel the IMFs have better synergy with my vintage system. I agree with you SimplySound: the fact that the IMFs have replaced the Proacs says a lot about the quality of the TLS50s. An under rated vintage speaker imo that can still be picked up for reasonable money.
Edit - By the way, can someone tell me what are the drive units in the mk1 TLS50?
Well, I had the TLS50s recapped and have to admit, it was very worthwhile. Thanks for the encouragement canuckaudiog! Prior to the recap, I felt the speakers had a slightly recessed midrange which made then sound a little bright or forward. The recap has resulted in a fuller midrange and overall they now sound more balanced.
With regard to the Proac Response 2S, it is a simply outstanding standmount and if I had the money I would have kept both the Proacs and IMFs. That said, I have no regrets about letting the Proacs go and feel the IMFs have better synergy with my vintage system. I agree with you SimplySound: the fact that the IMFs have replaced the Proacs says a lot about the quality of the TLS50s. An under rated vintage speaker imo that can still be picked up for reasonable money.
Edit - By the way, can someone tell me what are the drive units in the mk1 TLS50?
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c-atle-79bay
Super Member
Hi all, i just picked up a set of linn SARA isobariks, nice enough speaker but I now have 4 kef b200 1014 (if the sources ive read are correct) would these be acceptable replacements in The STUDIO? Or perhaps, super compacts?
Also reason I mentioned Super Compacts is I'm visiting a pair tomorrow at some time. Nice looking with the EMI mid drivers so no foam (thanks prior posts). They look pretty good shape and the price is pretty good, don't need um, but I want um. Anything to watch out for?
Nevermind, found canuckdogs earlier posts about the supers. Can't wait.
Thanks
Also reason I mentioned Super Compacts is I'm visiting a pair tomorrow at some time. Nice looking with the EMI mid drivers so no foam (thanks prior posts). They look pretty good shape and the price is pretty good, don't need um, but I want um. Anything to watch out for?
Nevermind, found canuckdogs earlier posts about the supers. Can't wait.
Thanks
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c-atle-79bay
Super Member
Here are my NTM super compacts, in fantastic condition, purchased from the original owner who picked them up, after a small discussion, with his wife in about 74. Owner was familier with speaker technology, and the other IMF I own, The Studio. Is friend was an audio producer/engineer that would modify speakers by building in own air cooled inductors, beyond me really.
Sound really nice too.
Sound really nice too.
Attachments
canuckaudiog
On a quest for high fidelity
Those look great! Great pick-up and congrats. The early models are rather nice because all you have to do is replace the caps and they're ready to go. At least, I haven't ready anywhere the peerless tweeters use a coating over the dome so they should be fine.
@radine
Check out the SC's in the above post from c-atle-79bay, those are the ones. a Kef B200 SP1014, peerless tweeter and an EMI midrange. I don't have specific model numbers for the peerless or EMI - I do have a marking that is on the magnet of the EMI mid and the peerless tweeter model is stored somewhere.
@radine
Check out the SC's in the above post from c-atle-79bay, those are the ones. a Kef B200 SP1014, peerless tweeter and an EMI midrange. I don't have specific model numbers for the peerless or EMI - I do have a marking that is on the magnet of the EMI mid and the peerless tweeter model is stored somewhere.
c-atle-79bay
Super Member
These are a great "little" speaker, but wow they sound BIG. Just something about that rich midrange that I love in a speaker.
So on the efficiency of them, am I reading it correctly when they say, "Efficiency Measured via Pink Noise at 1 metre on axis for 40 watts 100dB" that these are 100db efficient? If so opens up lots of amps. Thinking TPA or Bottlehead.
So on the efficiency of them, am I reading it correctly when they say, "Efficiency Measured via Pink Noise at 1 metre on axis for 40 watts 100dB" that these are 100db efficient? If so opens up lots of amps. Thinking TPA or Bottlehead.
canuckaudiog
On a quest for high fidelity
That's at 40 watts - more realistically they're around the 86dB mark at 1 watt, which is the measurement we're used to seeing.
Yep, that is what I find about the SC as well - big sound out of a small package, and astonishingly similar to the big models. That is one thing I liked about IMFs philosophy is you didn't lose out much on the sound quality or the character of the sound even in the smaller models.
mccarty350
Super Member
Guys, with the help of Mech986 it sounds like I'm finally going to get my IMF's. He's turned me onto a pair that I will be purchasing on a family vacation in October so it might be a little bit before I have them but I'm eager to get with the restoration, etc.
Mech986 is speculating that the model that I'm getting is:
http://www.imf-electronics.com/Home/imf/speaker-range/reference-speakers/professional-monitor
Does anyone have any knowledge or opinions on how this compares to the RSPM and TLS-80's? Apparently this version of the Professional Monitor is heavily based on the RSPM VII but looks like it has a slightly smaller cabinet.
Any input will be appreciated.
Unfortunately this model utilized the foam grills that are no longer present and the stand will not be included so I will have to figure out a way to fabricate the grills.
Mech986 is speculating that the model that I'm getting is:
http://www.imf-electronics.com/Home/imf/speaker-range/reference-speakers/professional-monitor
Does anyone have any knowledge or opinions on how this compares to the RSPM and TLS-80's? Apparently this version of the Professional Monitor is heavily based on the RSPM VII but looks like it has a slightly smaller cabinet.
Any input will be appreciated.
Unfortunately this model utilized the foam grills that are no longer present and the stand will not be included so I will have to figure out a way to fabricate the grills.
canuckaudiog
On a quest for high fidelity
Based on your description it sounds like you are talking about this model (ignore the caption, these are not RSPM MK VIIs):
This is the 1980s replacement to the TLS 80 II. Not to be confused with the early Professional Monitor Mk I, II and III.
How does it compare? That's hard to say. I haven't laid ear on the last generation of IMFs, so I can't tell you from personal experience. The major difference here is that they changed the isolation inside the enclosure for the midrange driver - you'll notice it's now sitting on top of the tweeters instead of beneath, and the change here was that they built an internal cabinet inside that uses the upper portion of the cabinet for the midrange, instead of using a tube inside to isolate the midrange. To me this is a smart move as it will be better isolated.
You'll also notice the tweeters and mid are lined up in a line instead of being offset. This, as far as I know, was not a change that John Wright himself initiated. He left IMF Electronics to pursue Ambisonics around 1980 and as I recall these models came out afterwards. Is it a smart move? Probably.. it brings the tweeter down to more of an ear level and isolates the mid better.
The other major change of course is that the drivers are all Elac produced, instead of the traditional Kef/Celestion drivers you see. A good friend of mine very familiar with IMF speakers has said that upon his own inspection of the Elac drivers, he found them to be inferior to the Kef drivers, but again this is his perception. By all means the design of the drivers should be superior to their counterparts they replaced - the bass driver was designed to have superior power handling which was a downfall of the Kef driver.
But how does it sound in comparison? Tricky to say, as I mentioned. But, I can tell you that they are excellent speakers, and there is no reason to turn them down. Anything with the IMF name on them is generally guaranteed to be excellent. They will at least give you a solid taste of the brand's sound until you can find one of the reference models.
In short, I would pick them up. They will be great. Of course, they'll be due for a recap, but I think you know that already. Keep us posted!
This is the 1980s replacement to the TLS 80 II. Not to be confused with the early Professional Monitor Mk I, II and III.
How does it compare? That's hard to say. I haven't laid ear on the last generation of IMFs, so I can't tell you from personal experience. The major difference here is that they changed the isolation inside the enclosure for the midrange driver - you'll notice it's now sitting on top of the tweeters instead of beneath, and the change here was that they built an internal cabinet inside that uses the upper portion of the cabinet for the midrange, instead of using a tube inside to isolate the midrange. To me this is a smart move as it will be better isolated.
You'll also notice the tweeters and mid are lined up in a line instead of being offset. This, as far as I know, was not a change that John Wright himself initiated. He left IMF Electronics to pursue Ambisonics around 1980 and as I recall these models came out afterwards. Is it a smart move? Probably.. it brings the tweeter down to more of an ear level and isolates the mid better.
The other major change of course is that the drivers are all Elac produced, instead of the traditional Kef/Celestion drivers you see. A good friend of mine very familiar with IMF speakers has said that upon his own inspection of the Elac drivers, he found them to be inferior to the Kef drivers, but again this is his perception. By all means the design of the drivers should be superior to their counterparts they replaced - the bass driver was designed to have superior power handling which was a downfall of the Kef driver.
But how does it sound in comparison? Tricky to say, as I mentioned. But, I can tell you that they are excellent speakers, and there is no reason to turn them down. Anything with the IMF name on them is generally guaranteed to be excellent. They will at least give you a solid taste of the brand's sound until you can find one of the reference models.
In short, I would pick them up. They will be great. Of course, they'll be due for a recap, but I think you know that already. Keep us posted!
mccarty350
Super Member
Canuck, Mech and I both just discussed this earlier today and came to the same conclusion that this model falls into place as a modernized TLS 80 variant i.e. the home version.
Great explanation regarding the isolation of the mid. I personally agree that the way that the drivers are organized on the baffle on this version should be slightly better but who knows.
The elac nature of the drivers is what I am the most concerned with. My primary question was "Since this is one of the last models produced by IMF does that mean that it has the ultimate evolution of their drivers as far as optimizations or does it go into a period in the 80's where they were more concerned with cost cutting than with improvement." So are the drivers produced by Elac basically the same drivers from a design perspective that were manufactured by KEF/Celestion just actually built by a different company (Elac) or are they entirely different/new drivers? Hopefully that question makes sense.
Agreed, I am not turning them down I am very excited. I'm just doing my research up front because it's all interesting to me.
I won't have them in my hands until October but I'm very excited and indeed, I will be recapping them right out the gate as I usually do with my purchases. I will definitely photograph/document my progress and provide it to the general community.
I also see that you sold your 107's and got KEF LS50's. I'm quit curious. Have you found a sub to supplement the low end on the LS50's that integrates well to give you the full sound or are you currently still operating on the LS50's? I'd LOVE to audition the pair because of the hype. The fact that you love your pair is a huge endorsement.
Great explanation regarding the isolation of the mid. I personally agree that the way that the drivers are organized on the baffle on this version should be slightly better but who knows.
The elac nature of the drivers is what I am the most concerned with. My primary question was "Since this is one of the last models produced by IMF does that mean that it has the ultimate evolution of their drivers as far as optimizations or does it go into a period in the 80's where they were more concerned with cost cutting than with improvement." So are the drivers produced by Elac basically the same drivers from a design perspective that were manufactured by KEF/Celestion just actually built by a different company (Elac) or are they entirely different/new drivers? Hopefully that question makes sense.
Agreed, I am not turning them down I am very excited. I'm just doing my research up front because it's all interesting to me.
I won't have them in my hands until October but I'm very excited and indeed, I will be recapping them right out the gate as I usually do with my purchases. I will definitely photograph/document my progress and provide it to the general community.
I also see that you sold your 107's and got KEF LS50's. I'm quit curious. Have you found a sub to supplement the low end on the LS50's that integrates well to give you the full sound or are you currently still operating on the LS50's? I'd LOVE to audition the pair because of the hype. The fact that you love your pair is a huge endorsement.
canuckaudiog
On a quest for high fidelity
Hey there, sorry about my late reply.
To your first question, of course only the gentleman behind the design could answer that but from my speculation, as far as I can tell it was a way to save the company money but still produce a high quality product. The Elac drivers were indeed designed to mimic and in fact surpass their counterparts. Like I mentioned above someone very familiar with IMF speakers stated that he found the Elac drivers to be inferior - but, that is only what he has said and is strictly speaking from a design point of view. He did find the Kef/Celestion drivers to sound more pleasing, but again this could be his preference and pure subjectivity. He did mention though that regardless of if they are Elac or Kef/Celestion, they are much better than most other speakers out there and the fact they have Elac or Kef/Celestion shouldn't be a deterrent. That was my take. But to answer your question, I don't think it was an evolution, it was more of a cost cutting measure in my eyes.
As for the Kefs, this is a bit off topic but that's okay
Yes, I did sell my 107s in favor the Kef LS50s. I actually didn't really do a side by side comparison, either, it was more I listened to one.. then when it left I listened to the other. I can definitely say I enjoyed the LS50s more than the 107s, and that is purely because of my listening preference. The LS50s fit my tastes more than the 107s did. This speaks volumes about their sonic capabilities, considering the 107 was a flagship speaker with an MSRP of $5000. They are both engineer's loudspeakers and it shows. As for the low end, nope, I never did get a subwoofer. The bass out of the LS50s stock was more than enough for me. There were some tracks that I could tell the difference with, but overall the LS50s filled out the bass in just about all of the music I listen to so I never felt the need. Really, the 107s only added one more octave to the balance, and I would say 95% of music doesn't utilize that first octave. Of course, if you are a pipe organ listener or love electronic music, than you may want a subwoofer. But even then, the LS50s are likely just fine on their own as I found.In follow-up to that, I've actually sold off the LS50s now in favor of headphones, but that was due to the room acoustics more than the speakers themselves. If I am in the market for a pair of small speakers again, I will definitely be buying another pair of LS50s. I just couldn't get the little room I had them in to sound good.. being in a mobile home has its challenges unfortunately.
