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IMF owners thread!

Yvan_donald said:
Hi,I always ask myself why the Tls 50 didn't have a mid tube of 5" diam. instead of 4" who is really to narrow for the midrange ,even the MK II have the same.The prof. have a 6" tube for a 5" midrange,it's a more solid installation,it fit in a groove behind the baffle. Like we have seen many time the tube of TLS 50 became loose,very bad installation. Yvan
Click to expand...

One idea comes to mind to deal with the problem of the poorly constructed tube design.
I would replace your current tube with a PVC tube.

There would be far less resonances with a PVC tube compared to the current type of tubes used in the IMF designs.

One way to get a square cut would be to cut a PVC pipe on a table saw.
 
Hi Jim,not shure it's a very resonant material,it has to be cover , like in house before it was cast iron,the pvc every time you use the toilet it is more noisy,the wall have to be very well insulated.I am sure if it was a better material many company will have use it.Yvan
 
IMF TLS50 MkII

Hi Everyone.

I got around to replacing the caps in my TLS 50 MkIIs, and pic 1 is the old board. The second pic is the new caps from Falcon Acoustics (one speaker's worth)

Basically - what do I replace! There seems to be more bits on the board than new caps!

Any help much appreciated. Thanks

Roger
 

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The inductors are the ones with the cable ties and the white component is a resistor which all stay on the board. The old caps (have red on either side) have values marked xxxMFD on them that should match up with the new caps unless theres an upgrade which Falcon accoustics should have given you some sort of diagrams. You should have 2 sets of caps for both boards. Hope that helps.
 
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Ahhh, thank you Chevel, Donald, that's clarified perfectly!

Just a last question to check: the MFD ratings of the new caps don't match exactly, presumably the idea is that as long as the new rating exceeds the old, that OK?

It will be a week before I get around to having another go.

Thanks

Roger
 
rogermatthew said:
Ahhh, thank you Chevel, Donald, that's clarified perfectly!

Just a last question to check: the MFD ratings of the new caps don't match exactly, presumably the idea is that as long as the new rating exceeds the old, that OK?

It will be a week before I get around to having another go.

Thanks

Roger
Click to expand...

What are the MFD values of the original capacitors and the new ones?
 
Hi canuckaudiog

I can't easily get at the crossovers right now (the speakres are built into units, etc), but looking at the pic I posted, the larger caps seems to be 100, 40, 12, & 2 x 6 Mfds. I can't make out the smaller ones.

The kit includes 3 large caps, 100, 60 & 30, four smaller caps 2 each of 6 and 4 mfds, plus a smaller one 12mfds.

Thanks

Roger
 
rogermatthew said:
Hi canuckaudiog

I can't easily get at the crossovers right now (the speakres are built into units, etc), but looking at the pic I posted, the larger caps seems to be 100, 40, 12, & 2 x 6 Mfds. I can't make out the smaller ones.

The kit includes 3 large caps, 100, 60 & 30, four smaller caps 2 each of 6 and 4 mfds, plus a smaller one 12mfds.

Thanks

Roger
Click to expand...

Something is funky here. Is that a Falcon Kit? They should be exact replacement values! :yes:
 
Yvan_donald said:
When they demonstrate their tonearm and cartridge (Wright,Hayes).M.Fried talk about TL for the mid,but I have never see a Mid TL line in all of the knowing IMF until now except maybe these early version of studio monitor?Yvan
Click to expand...

Hi Yvan,

Have not totally opened my IMF Super Compact Mk II down to bare cabinets inside, but it has some minor version of a midrange transmission line. Per IMF documents on the Super Compact T-line, it's..."mid range is isolated in it's own short transmission line", and then regarding the bass - they further state..." critically tuned and optimumly damped reflex enclosure"..."resistive loading conditions".

The IMF diagrams show the rear of midrange tube exits into vertical chamber space at the back wall which looks to go downward, then to very bottom under woofer and out to front vent. I never took mine apart that far to look there. We went into discussion about it previously on the AK thread "KEF Concerto vs IMF Super Compact" (and KEFKit3/IMF Compact Monitor III), it brought up interest and I posted diagram in post #22 link - SC model is at bottom of diagrams. Not sure if foam or fiberglass is in that vertical space, or if it is mostly open. There is foam in the front vent of course & that maybe (?) may extend almost back to that cavity near the back wall - not sure.

Perhaps many here have opened theirs to bare bones & can comment on the original factory appearance of that rear wall chamber section going down & out bottom front. There may even be photos of it somewhere on AK threads too. Maybe the tube is sorta like a "line-tunnel" as done on some of the Fried brand models. Unless that mid range tube goes all the way back smack into the back wall -then the IMF document doesn't make sense. I still did not get around to replacing my mids, but have tested the new Monacors long ago (I despise working on gear, but that's just me, it's not my thing, do not enjoy it; having little time, I like to buy all mint units only) and someday will get around to it & look back thru the tube, depending on how much, if any damping is in the tube. Maybe it exits rear and channels into a segregated vertical chamber inside that back wall cavity & is a t-line. We need to ask someone who stripped their cabinets down all the way. Cheers ! :beerchug:
 
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If the tube used for the midrange driver is sealed it would be a closed box enclosure.
By looking at the photos it doesn't appear that there is any venting in the rear of the tube enclosure.
If there are holes in the rear of the enclosure it would be an aperiodic enclosure.

The TOTL IMF Professional Application Monitor used a closed box for mid bass driver loading and not a T-line.

sacm_mk2.jpg
 
Are there some photos somewhere of the IMF Super Compact 1st series or Mark II later series showing the inside cabinet stripped down to reveal the back vertical wall chamber down to the bottom and out the front ? If so, please share where photos can be viewed - site, thread, post #. Maybe there are some threads on AK with these photos, or even somewhere in this thread too. I guess IMF has some reason to print in their literature the Super Compact "mid range is isolated in it's own short transmission line", and a few of us are wondering about it.
 
luvmusik said:
I guess IMF has some reason to print in their literature the Super Compact "mid range is isolated in it's own short transmission line", and a few of us are wondering about it.
Click to expand...

I.M. Fried commented about the tube in one of the writings that SimplySound and I copied and paste earlier on this thread.

It is unclear to me if R.Wright used T-line loading for the mid bass driver in any of his TDL designs.

I.M. Fried did use T-line loading in many of his 6.5" mid bass enclosure designs as I previously stated with Fried Products.

An 18" tube theoretically could go down to 270Fs in a T-line.
There would have to be a line terminus opening at the rear of the tube.
 
Hi Jim and Luv's,like the als 40,tls 50 the tube is close and I think the compact to,probably John Wright made a tl for mid in very eariier model? which model?Jim the tube in the MK III is only 6"X14",that is the require size from Kef specifications (? liters),in seal box.Yvan
 
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