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IMF CM3 Drivers

 
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mikeytheo
Intermediate Contributor 25+


Joined: 16 Apr 2007
Posts: 33
Location: Sydney Australia

PostPosted: Thu Aug 30, 2007 3:16 pm    Post subject: IMF CM3 Drivers Reply with quote

Hi,
Have just purchased a pair of IMF Compact Monitor 3 speakers with both mid range and one tweeter requiring replacement. Firstly trying to identify exactly what drive units were used in these models KEF or other? - yet to collect to check myself as they are presently 900kms away.
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ColinR
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Joined: 31 Jul 2004
Posts: 1175
Location: Staffordshire

PostPosted: Thu Aug 30, 2007 3:49 pm    Post subject: Reply with quote

No identifiers - Custom Dalesford - OR - Part numbers on magnet - Custom IMF/Elac.

The Midrange can probably be rebuilt for about A$60, the dome may cost more, depending upon the competence/confidence of your reconer.

Neither drive unit had a commercial equivalent, but the dome tweeter was an IMF specified or IMF/Elac evolution of the Peerless DT10HFC used in the mkI ALS40, TLS50 & Super Compact.
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T.O. Chef
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Joined: 31 Aug 2007
Posts: 150
Location: Toronto Canada

PostPosted: Thu Sep 06, 2007 10:02 pm    Post subject: Reply with quote

Be sure please to let us know how you make out with sourcing those replacements or repairs won't you? I have a real interest!
Collin, you seem to know something of IMF's. Any chance you'd be able to help with a blown super tweeter in my 50 MkII's? I know it's a Coles unit, there's a man using ebay in Australia selling lots of older Coles super tweeters at both 8 and 16 ohms. Should I take a chance on a pair of 8 ohm units and do both sides? Does anyone in the world work on this very tiny little tweeter (repair)?
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mikeytheo
Intermediate Contributor 25+


Joined: 16 Apr 2007
Posts: 33
Location: Sydney Australia

PostPosted: Thu Sep 20, 2007 3:27 am    Post subject: Reply with quote

Thought I would jump our discussion back to the IMF post. OK. SO this is the explanation re crossover from the chap selling them...

I didn't make any modify to the xover, what I mean was that
both the super compact and the tls50 used the same bass, midrange and
tweeter drivers, and the xover have the same divided points, but the super
compact is a 3way xover while the tls50 is a 4 way (tls has the super tweeter).
Between the tweeter and the super tweeter, there is only a 2.2 mfd
capacitor, so in my opinion, if you want use the super compact xover to
replace the tls50 xover, you may just need to add a 2.2mfd capacitor to each
xover.

So is his science correct?
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ColinR
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Joined: 31 Jul 2004
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Location: Staffordshire

PostPosted: Thu Sep 20, 2007 7:06 pm    Post subject: Reply with quote

Quote:
So is his science correct?


NO

The crossover points on IMF specifications are "nominal" which is good as using the same sized inductor with a 100uF capacitor in the TLS50 and a 60uF capacitor in the Super Contact will have different resonant frequencies.

So Physics wins over false logic in this case.
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mikeytheo
Intermediate Contributor 25+


Joined: 16 Apr 2007
Posts: 33
Location: Sydney Australia

PostPosted: Fri Sep 21, 2007 1:50 pm    Post subject: Reply with quote

Many thanks for the technical heads up on the cross overs. Will avoid. Am now in two minds whether to buy the cabinets (very reasonable condition) and start the ongoing search for drivers and crossovers. I notice a pair of TLS50s going on UK ebay but his info states that the supertweeter is the Coles 4001 - not the HF2000. My understanding was that the HF2000 ws originally used and is a superior unit. Unfortunately I cannot log onto the imf.electronics site - not sure if it is down or the problem is at my end.

Regarding crossovers, assuming that it would be near impossible to locate a pair for the TSL50s, I guess my only option is to attempt to locate a schematic of the original and have them built here in Aus.
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ColinR
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Location: Staffordshire

PostPosted: Fri Sep 21, 2007 2:35 pm    Post subject: Reply with quote

Why Rolling Eyes?

The only differences between the two crossover are the two components already discussed.

So, total up the cost in parts and labour of changing the 60uF capacitor to a 100uF one and base your own valuation on these and your percieved value of the IMF TLS50s.

Celestion HF 2000s were only ever routinely used in TLS80 and RSPM models, (very) few Studio models used it as a supertweeter with the KEF T15 as it cost £2 more than the Coles 4001G.
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mikeytheo
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Joined: 16 Apr 2007
Posts: 33
Location: Sydney Australia

PostPosted: Mon Nov 05, 2007 3:04 pm    Post subject: Reply with quote

Hi,
Eventually bought the TSL50 cabinets. Lucky enough to score a complete set of drivers and crossovers from the UK so am awaiting their arrival. They are from the first series while my cabinets are MkII, but it is a quick fix.
I did also get hold of the super compact crossovers when I initially bought the cabinets, but no longer need them due to the purchase of the complete driver/crossover set. Have sent a PM to R.C. who showed an interest in them. I have no problem posting them to the UK (wonder how crossovers will go if x-rayed on the way through - suspicious wiring and all!).

Still haven't brought the CM3s up from Melbourne as yet - waiting for work to take me there to collect - also have another pair of JR149s (red badge) awaiting me - gotta stop buying and start selling! M
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mikeytheo
Intermediate Contributor 25+


Joined: 16 Apr 2007
Posts: 33
Location: Sydney Australia

PostPosted: Thu Jan 17, 2008 12:55 pm    Post subject: Reply with quote

Update! Got the CM3s and put the replacement drivers in today. Very impressive sound.

The mid drivers installed were reconed by an amateur and while sounding 100% look really poor. The originals, which are blown, look the business so I may look into seeing if they can be repaired. Still small variations between drivers (typical IMF from my reading!).

Will attempt to identify them all as to their manufacturer. The removed mid versions have an IMF sticker and 4/200 - Elac I presume. The replacements are slightly different with a slight beveled edge on two sides of the magnet but no markings.

The tweeter removed is stamped IMF and marked TW/1500, while the replacements have no markings but look identical except for the positioning of the terminals and a lighter coloured cone.

Have been listening to my ProAc Tablettes of late and the 3-way CM3s with the better bottom end are a joy. Then connected my JR149s and have to say they were more detailed than the CM3s. Again, the CM3s go lower but the 149s are just so sweet in their mid range. See how I feel after more extended listening.
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mikeytheo
Intermediate Contributor 25+


Joined: 16 Apr 2007
Posts: 33
Location: Sydney Australia

PostPosted: Thu Mar 27, 2008 1:52 pm    Post subject: Reply with quote

Well my drivers and crossovers for the IMF TSL50s never showed up!
$220 down the drain. No response at all from the seller, even via PayPal - yet he lives on in UK ebay JAMSTAR1961. Hasn't sold since jan but all attempts to contact him just to even check the address have failed. So, back to square one re the drivers/crossovers. May pillage from the CM3s as I think the 50s are a better prospect.
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Rempstone
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Joined: 08 Jul 2011
Posts: 1
Location: Dorset, UK

PostPosted: Fri Jul 08, 2011 10:53 am    Post subject: I have some CM3 Reply with quote

Came across this old post while searching for info. on "IMF CM3". I have owned a pair of these since the ealry nineties. They are now gathering dust in my garage.

Are these speakers still of interest to enthusiasts?
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surv1v0r
Introductory Contributor


Joined: 23 Jun 2013
Posts: 9

PostPosted: Tue Dec 02, 2014 6:13 pm    Post subject: Re: I have some CM3 Reply with quote

Rempstone wrote:
Came across this old post while searching for info. on "IMF CM3". I have owned a pair of these since the early nineties. They are now gathering dust in my garage.

Are these speakers still of interest to enthusiasts?
I am certainly interested, do you know what drivers they use?

What do they / did they sound like?
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