IMF owners thread!

Hi all,

I am joining the IMF club. Recently picked up a pair of what I believe are very early "The Studio" speakers. Started thread here....
http://audiokarma.org/forums/index.php?threads/found-my-next-project-imf-the-studio.795656/

I will document the restoration process there. However, I just discovered this thread and will be visiting to ask very specific questions.

Here's my 1st question:
What is going on with this KEF driver? This is the working bass driver that I pulled. As you can see there is some kind of PVC tube/ring glued around the magnet. Has anyone seen this before? Did IMF do this, or was it a mod that someone did?

In the meantime, I will start reading through this thread from the beginning.
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Hi, never see this cover before, but who knows,could be an experience from IMF to eliminate the back wave of hitting the magnet?no idea,but they didn't kept this idea on the later models.So long tlme ago to tell us the real purpose.
 
Yeah, never seen that either. Maybe somebody was trying to reglue the magnet and make sure that everything was aligned.
 
Man those are pretty speakers. Very classy looking, and what a difference the Howard's made! They look awesome in your room there. When I see them I think to myself, "Now that's a speaker!"

Those staples I believe were for a sheet of paper to cover the vents up so dust didn't get in there during transportation. I just took a look at mine however and no staples or holes where the staples would have been - I've seen it before on other IMF's, so I'm not sure why some would have it and some wouldn't. Hmm, something to figure out it looks like. Maybe Jerry might know?


The paper was only put onto the export units as it was designed to keep crawling critters out while in transit to their destination via Sea Freight.
 
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The original "IMF Electronics" Signage was mounted on the building brickwork just to the right hand side of the recessed corner windows. It was smack bang in the middle area next to the white divider panel that's between the top and bottom windows.
 
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As far as that "Studio" driver is concerned I think that this may have been and idea done by John Wright. Most of the later IMF Elac drivers had black electrical tape placed around the magnets. I feel, and don't hold me to this but I'd say it's got to do with stopping the wiring from wearing against the magnet due to bass impulses and rubbing the insulation bear off the then really thin and cheap wiring used. Back then there was not much research done on the benefits of better wiring like it is more widely accepted today.
Also it was a way of making the sound waves travel backwards in a straight line without any obstructing magnet surfaces in the way. Remembering that "The Studio" was the original R&D speaker that John Wright developed before anything else for the commercial market.
 
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Thanks, I'm very happy with them!
I will construct stands from hardwood, found the dimensons on the IMF-Electronics group on Yahoo.
I investigated recapping and I was tempted to use MKP's instead of the Elcaps but after some reading it's clear the (frequency dependent) ESR of the Elcaps was part of the filter design so I will order the Falcon Alcap kit which should keep the voicing original.

The cosmetics of the set is really amazing, hardly a scratch on the veneer and the units look new.
I will post my progress in a few weeks!

regards, Peter


Hi Peter,

The image you've found on the IMF Yahoo Groups of the Mk IV stands is actually my handy work as I have the later Mk IV Factory "Improved's" (effectively a Mk V but not officially named that) with the "P" prefixed serial.

I copied the stands to a T so if you make them out of hardwood and not softwood pine you'll find them to be very good. They are originally painted in satin black and you wouldn't tell the difference between them and the earlier steel ones.

They were made out of timber for two reasons and that's the Export weight when sending to the USA and Australia, the metal ones will add about an extra 10 kilos to the shipping weight. Secondly and most importantly the cost as the British Hi-Fi industry was really struggling to stay viable in the late 1970's and the early 1980's.

BTW I'm enjoying your recapping images and the staggering of the caps as I'm about to do my Mk V's (Mk IV "Improved's" utilising Elac/Celestion, Mk VI's are full Elac) followed by the then totally redesigned Mk VII RSPM.

Cheers,
M.
 
Hi Peter,

Cheers,
M.

Hi M.,
Thanks for your reply.
As a matter of fact I just finished spray painting my stands!
A colleague of my brother offered me to weld some stands, I made a drawing and some two weeks later I got them.
Welding at the sides was rougher than expected, I used polyester putty to flatten to make the sides completely flat.

Fresh in the house:
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Sides:
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After polyester putty, some serious elbow grease and of course some paint:
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With speaker:
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both speakers (with a cd to show off the size of these giants):
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After these photos were taken I treated the wood to some layers of bee-wax stuff that really improved the looks, I will make some good quality pictures with a better camera in the near future.

Overall I'm really happy with my RSPM's!

regards, Peter
 
As far as that "Studio" driver is concerned I think that this may have been and idea done by John Wright. Most of the later IMF Elac drivers had black electrical tape placed around the magnets. I feel, and don't hold me to this but I'd say it's got to do with stopping the wiring from wearing against the magnet due to bass impulses and rubbing the insulation bear off the then really thin and cheap wiring used. Back then there was not much research done on the benefits of better wiring like it is more widely accepted today.
Also it was a way of making the sound waves travel backwards in a straight line without any obstructing magnet surfaces in the way. Remembering that "The Studio" was the original R&D speaker that John Wright developed before anything else for the commercial market.

Interesting take. When I get these rebuilt in other areas I might go get a couple pieces of PVC pipe and try recreating that on my replacement drivers. Will see if it hurts or adds anything.
 
Hi dogwan,

I'm not sure if the original "Studios" ever came with grilles or badges for that matter as they were the first IMF that was made before they really had a name, just remembering that it was Bud Fried that came up with the name for the New York Hi-Fi Show to showcase a new Decca Cartridge and using a un-named Professional Monitor for which he took sales orders for while demonstrating that cartridge. If it ever had anything it would have been the same as in the image below.

Cheers,
M.
 

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Hi Petervv,

Those stands look totally the real deal. It's amazing what a bit of Automotive filler will do, especially when using matte or satin black as the surface finisher.

Every time I see those photos of your crossovers it reminds me that I must do mine and order those kits from Jerry so that I get them before Christmas which is rapidly approaching.

Cheers,
M.
 
I forgot about the Metal stamped badge, both the images above come from around the same era. The metal ones were run for a really short time, as you can see it was much cheaper to just stamp a metal plate than have a moulded plastic unit made up. As you can see the grille material was the same ribbed product for both the above images before they changed away to a thinner more transparent cloth.

Going back to Member dogwan's plastic magnet cover, I don't think it really would've had much of an effect as if it did then they would've continued that concept. If you could hear the difference then you really must have the best ears in the world.

John Wright was always trying new things to improve the product, he really was a Pioneer in more ways than one. Maybe he should've worked for "Pioneer Electronics" or "Fukin Electronics" as they were first named. You can see why that name never lasted as a worldwide marketing brand name. Incidentally it was their first product, a loudspeaker, that was named "the Pioneer" and that's where the name came from and stuck.

Cheers,
M.
 
Hi dogwan,

I'm not sure if the original "Studios" ever came with grilles or badges for that matter as they were the first IMF that was made before they really had a name, just remembering that it was Bud Fried that came up with the name for the New York Hi-Fi Show to showcase a new Decca Cartridge and using a un-named Professional Monitor for which he took sales orders for while demonstrating that cartridge. If it ever had anything it would have been the same as in the image below.

Cheers,
M.

Mine definitely have grills and you can see the glue spot where there used to be badges.

Hi,that is suppose to be the badge at the timeView attachment 1058349

That looks like the same grill fabric on mine. Thanks, I will start looking for badges like that on the Da'Bay.

On a side note; my grills are stick built with what looks like Pine, which means they will survive a bath. They're very dirty and have one rip (but no fraying) that I am hoping I can discretely repair. Just in case, does anyone carry this same cloth?
 
I realized today that I've missed my window to start working on these until spring. At least as far as the cabinets go. It's just too cold out in the garage for stripping and refinishing work. I think I may just use as is until then. I could work on the crossover. But, since I'm going to have to strip everything out of the cab's I might as well wait until then.
 
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