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IMF Professional Monitor IV

Hi IMF knowledgeables, I have a pair of large problem that I'd like to know more about. They're supposedly IMF Professional Monitors, but having spent several hours on Google trying to find references without luck have booked in here to try another thread. The speakers are 42" H x 24" W x 17" D. panel layout is as Prof.Mon. terminals and two switches occupy upper corner rear in a recess. Drivers are KEF bass and mid. HELP!
These are redundant due to space, but I ran them on a new NAD C355 (Wot a Nerd!) with good results. The sound stage and bite were the best I'd heard from them, with other semi-cond. amps comparatively lousy.
 
Set the mid control at rear to + and the tweeter to - (you may have rapidly "clean" the switch contacts by flicking back and forth). This gives the flattest response from mid bass upwards. Everything below 90Hz or so will be well up in level so.

A good used amp buy for them would be the UK Audiolab 8000S integrated and especially the non cap-coupled 8000PX power amp.
 
I have a pair of RSPM Mk:IV speakers still in working order and in near perfect physical condition (apart from a slight scuff to the woodwork on the side of one) They need an overhaul to get the best out of them again but they are truly an amazing piece of equipment. Unfortunately due to the fact i am currently living in a one bedroom flat i just don't have the room for them and they are currently up for sale.
 
Fraser said:
I have a pair of RSPM Mk:IV speakers still in working order and in near perfect physical condition (apart from a slight scuff to the woodwork on the side of one) They need an overhaul to get the best out of them again but they are truly an amazing piece of equipment. Unfortunately due to the fact i am currently living in a one bedroom flat i just don't have the room for them and they are currently up for sale.
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I've got to ask how much in the hope that some kind soul will give them a loving home and restore them to as new or better condition...
 
Well i've listed them (along with some classic technics seperates) in the classified ads section of the forum, to be honest i'm open to offers as i want them to have a good home rather than just sell them for all i can get. I adore these speakers and with more cash and space would be having them overhauled myself. So if anyone wants to make me an offer i'm open to suggestions.
 
Fraser said:
Well i've listed them (along with some classic technics seperates) in the classified ads section of the forum, to be honest i'm open to offers as i want them to have a good home rather than just sell them for all i can get. I adore these speakers and with more cash and space would be having them overhauled myself. So if anyone wants to make me an offer i'm open to suggestions.
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Fraser, hi, I've pm'd you on the RSPM 1V's. Jerry
 
Paul, hi, wonder if you can help. I have a pair of the earlier IMF SACM's with the 3-switch x-over, 81-82dB efficency. Need a bit of driving. Would you happen to remember if the later and much simpler SACM 2-switch x-over without all the capacitors was any more amplifier friendly?

Jerry
 
Holy mother of god! (Sastusbulbasa's post) Which model is this one with 2xB139s per side=4xB139s total !!!!??? I have never seen this model before anywhere (and its not on the IMF site either). I would certainly love to hear those! I home-built and still use very large transmission line speakers with KEF B139, B110 and T27 drivers and still have not heard better bass from any modern speaker. I altered the origonal crossovers to the upgrade specs from the IMF group on yahoogroups (a great source of info) and replaced the tweeter caps with polyester and it sounds even better. I drive them with a "lowly" Pioneer A400 with 70 wpc and the bass is still very good and tight but I want to get a beafier amp soon, perhaps bi-amping with the A400 on mids/highs as it is such a good amp. Playing the William Orbit produced Caroline Lavelle CD "Spirit" with its seismic bass is absolute heaven.
 
The A400 was a great power amp with a volume control on the front.........

Regarding the switches on the pre mk4 models. The flattest bass/mid response was with the mid control turned UP the the + position (only a db or two but it helped) and, if there was a tweeter one, I turned it to -, as sometimes they could sssssting a bit if you weren't careful.

Regarding amps for them, I wonder how well the later Audiolab 8000PX/MX amps would do (and the Tag derivatives)? These were direct coupled, avoiding the output caps as I remember and should have a tighter cleaner bass with old IMF's...
 
I still have here a nice pair of IMF Super Compact's...MK1 I believe. However at some point in the past the mids have been replaced with some crummy generic ones and they do not sound their best. I am still on the look out for some original mids, or maybe some capable equivalents. Details of the Super Compact can be found below.


http://imf-electronics.com/SuperCompact/index.html
 
Best amps for driving tls80,s. I currently use Electron Kinetics Eagle 400 mono blocks massive damping factor >800 drive down to less than 2ohms. Also electron kinetics eagle 2 renowned for exceptional bass power and control. 400,s 350rms eagle 2 110rms. These amps are classics from the 80,s and are fairly cheap now. Blow Krells away IMHO.
Speed in the bass is not an issue with these amps in control.

New here have always loved the sound of the IMF,s have never found a speaker that sounds as complete through the whole range from bass to top end.
 
DSJR said:
Regarding amps for them, I wonder how well the later Audiolab 8000PX/MX amps would do (and the Tag derivatives)? These were direct coupled, avoiding the output caps as I remember and should have a tighter cleaner bass with old IMF's...
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Hi everybody, I've just joined this forum after reading this thread (I only visited by chance becuase google turned it up).
As a proud owner of a pair or IMF MK3 monitors and RSPM IVs I felt obliged to add my opinion. The RSPMs are driven by a TAG (F3 series) 60i (audiolab 8000a?) from a Rega P3 and (free) Sony SACD player. The sound is better than anything I've heard for sensible money, and the setup has cost less than a grand all in. IThe amp does sound dull though, a Pioneer A400 was a much more lively listen despite being ultimatly less detailed.
The MK3s are used with my PC in a room measuring 13' x 6' with an A&R A60 and sound HUGE, makes Media Player a great experience. I'm only using them as I cant sell them and as Ive got them I might as well use them.
The A&R A60 sound be used with its matching SA60 power amp which is fitted with the X-over board for the ARC's 050s Ive also got.
On this active vintage theme Ive also got a pair of ARC 101s with Nytech amplification currently not in use. Anyone remember ARC and Nytech?
Its all a bit of a bodge together at the moment, but the active systems will soon have permenant homes in my house (just got the A&R T60 tuner, so that lot can act as a radio somewhere) and I can use the Nytech setup on the PC once I shift the MK3s. That leaves me looking for ways to improve the RSPM IV setup. Audio Research maybe....or to stick with the vintage theme I so obviously love with someting by Radford.....any suggestions
 
Hi guys, Im also new here.

I freshly own a Mint pair of ALS40.

I drive them with a fully modified Dynaco PAS2 tube preamp and a quad 303 fully upgraded and caps renewed.

They sound very good, the bass is very present, but miss some "punch". The response also looks a bit slow when I compare them to dynaco A25. I would rate them 8 out of 10. The sound detail is on my opinion very hard to beat.

I will try to change my tubes to Mullards and see if it can help the bass.

I will also try to drive them with a quad preamp 33 or 44 ( not tube ) to see if they sound better. I had 2 and sold them...I'll try to find another one..

Or even try a amp with way more power...my quad shoots around 45rms per channel...might not be enough to make my IMF happy..

Anyone had experience some caps renew with IMF ? Im pretty sure it would help them get some bass.

Thanks !
 
All this posting about eighties UK products that some people revere as new (!!) and this discussion about a once wonderful top end UK speaker manufacturer make me want to start up a vintage HiFi shop. I'd be right at home, but probably wouldn't have any customers.....

I have a vivid memory of playing ALS40's LOUDLY one Saturday morning with a master tape copy of Frankenstein by the Edgar Winter Group through a Crown/Amcron D150 (a good old power amp with tons of bass grip and a bit bright sounding) and possibly an IC150 preamp (not so well loved). The impact was staggering and I got a round of applause from the customers in the dem/show room when the track finished!! - We had customerS then, not one or two or none like today..

These dear old speakers need an amp with huge amounts of bass grip and a brightly lit, but not agressive (like Naim) top end. The little vintage Crown D60 was ample for general domestic use, but although the D150 was superb with IMF's it fares less well with the spitty, bassless "HiFi" speakers of today, although it should work a treat with any Spendor, Harbeth or old Rogers it bumps into...

Fond memories, great products (sorry PMC, your range just doesn't "do it" until you get to the MB2 and BB15 series......
 
I will try to find a Crown D150, I saw a couple on ebay.

I wonder how much it will cost to re-cap a Crown D150...
to make it sound like new.

Thanks,
 
One of my first experiences of the Sondek was at the local hi-fi store in St. Andrews. back in 1977..they had the LP12/SME2/Vms 20 with the Crown 150s pre/power into the JBL L200s as their reference system- it blew me away with the bandwidth and dynamics. The owner there made a couple of cassette dubs of some LPs (The Captain and Me being one of them) for a princely sum of 50p per LP, and they sounded fantastic, even on a friends Amstrad cassette deck. Problem is that the few students I knew who were monied enough to actually purchase the LP12 got them from either Russ Andrews or Robert Ritchie, as they were held in higher esteem than that local High Street Linn dealer.
 
Have been driving my IMF PMs with a Pioneer A400 for several years, anno domini has set in and I wanted a set up with a remote. Said IMFs now driven by an NAD355BEE they seem to have better damping and sound stage. Anyway Pioneer A400 for sale on e bay now. Any one for a starter Integrated amp?
 
bunny-blanc said:
Have been driving my IMF PMs with a Pioneer A400 for several years, anno domini has set in and I wanted a set up with a remote. Said IMFs now driven by an NAD355BEE they seem to have better damping and sound stage. Anyway Pioneer A400 for sale on e bay now. Any one for a starter Integrated amp?
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The Pioneer A - 400 is an amp 'that is made in heaven' if coupled with B&W's DM2A's , a model from the 70's. Have the same combo as one of my stereo systems...would'nt change it for the World. Who needs a remote control when you have this quality of sound available for modest prices? Tried out the same B&W speakers with the upgraded AX series of the same Pioneer amp. The original 'magic' was not there.
 
I would like to add if people are into IMF transmission line sound (I also have a pair of TLS 80MK2 by the way!) the B&W's DM2A's belong to the same 'transmission line' school as well as sharing many things besides being sold as let & right mirror imaged pairs. Big open soundstaging, pin point position of imaging and that uncanny 'surprise out of nowhere' of real bass.
 
I just acquired a pair of IMF Pro Monitor II and dont know much about them, any idea what they are like compare to TLS80's and Pro Monitor III & IV.
I understand they were quite expensive in the early 70's (~£1200), weighted about 100lbs and go down to about 19Hz. Are they worth hanging on to?
 
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