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IMF owners thread!

True mech, always something so little - and I feel such a fool on discovering the problem!

Attached is a pic of the speaker, the right hand foam rectangle in particular is damaged. I could easily find something similar but how important are these things? Just dust protectors or something more?

Roger

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An alternative to that foam is any similar filter foam typically used for some kinds of stove hoods or air filtering. very open pore film material can be used as its just a cover for the opening to prevent ingress. Both of my TLS50II's have no foam covering those openings.

Also, Foam Factory has a similar material that is filter media but also doubles for a speaker grill material, IIRC, one of our members used it for his RSPM Mk. VII. It is similar to the foam used in the sculpted JBL L100 foam reproductions, although I think there the pore size and density may be a little different - due to its need to be painted. One of the original repro-makers, Foam Trends, had a lot of difficulty getting consistent supply and quality from his suppliers.
 
Hi,I know on my Prof. Mk III, no air movement even at high volume, put a piece of paper on top of both bottom outlets,it does nothing. My line is stuff with pink fiberglass insulation ,an no deposit of these particules ever show on the edge. That's why they call it infinite baffle.
 
Yvan_donald said:
Hi,I know on my Prof. Mk III, no air movement even at high volume, put a piece of paper on top of both bottom outlets,it does nothing. My line is stuff with pink fiberglass insulation ,an no deposit of these particules ever show on the edge. That's why they call it infinite baffle.
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Thanks so much Yvan, mech. I get the impression the foam is not particularly critical, though it must provide some sort of baffle for the pipes.
Yvan_donald said:
Hi,I know on my Prof. Mk III, no air movement even at high volume, put a piece of paper on top of both bottom outlets,it does nothing. My line is stuff with pink fiberglass insulation ,an no deposit of these particules ever show on the edge. That's why they call it infinite baffle.
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Thanks again Yvan, mech, for all your help. I'll be able to source some foam from somewhere, though at the moment I'll leave well alone!

I thought I'd post some pics of my setup, I apologise for the poor lighting and my shaky hand (comes with advancing years!)

The first pic shows the whole system built into home-made units, a compromise to living in a domestic environment with these things. The speakers are at either end of course. The second and third show one of the speakers with and without its outer fabric covering. The next shows what drives these speakers, a pair of Hitachi Mosfet amps, each bridged for mono delivering 200watts to one speaker. The next shows the Sony pre-amp (middle unit) which controls both audio and visual sources. The last shows an array of various bits and pieces, the bottom is a Yamaha amp which powers the centre and rear speakers in a Dolby surround setup. There's no need for a subwoofer with the IMFs!

Roger

AMBA0855.JPG AMBA0858.JPG AMBA0859.JPG AMBA0868.JPG AMBA0863.JPG AMBA0877.JPG
 
Hi, big nice unit, IMF are pretty far from each other, so you are probably pretty far when you are listenning them. And usually the woofer goes outside,you're setting you have put the right speaker on the left side?
 
Yvan_donald said:
Hi, big nice unit, IMF are pretty far from each other, so you are probably pretty far when you are listenning them. And usually the woofer goes outside,you're setting you have put the right speaker on the left side?
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Hi Yvan

Yes, the room is 21 feet long, so I can get a good distance away. Far enough, in fact, to 'hear' a true standing wave of 40Hz (16 feet as I recall)

So why do I have the speakers the 'wrong' way around? Short answer: I prefer the sound that way!

Longer explanation! As I understand it, the main reason for the bass unit being on the outer side is that, when the speakers are placed in the corner, the bass is reinforced by the walls. The trouble is, that is simply reflections from the walls, very artificial. IMFs are very directional and I have gone to some lengths to damp reflections. You can't see it in the photos but the walls are covered with a cloth lining and the ceiling has acoustic tiles. When I first installed the IMFs, they were placed over a foot from the corner, and were the correct way around.

Then larger flat screen TVs came along and I had to move the speakers further apart to accomodate one which meant they were now in the corner. I found the bass reflections not to my taste, although the difference was subtle, hence I switched the speakers around. True, the mid and high frequencies reflect more but these are more easily damped by the wall covering.

Maybe you just think I'm mad!

Roger
 
No,no Roger I'M sure you know that this is the best answer for your situation. I'M a cabinet maker and I will have place the speaker in the second or third unit section from the wall ,and keep the IMF the way they have been design. Modified the unit in your case, but that's Just me. The most important is you like the way they sound,right. Best regards,Yvan.
 
Yvan_donald said:
No,no Roger I'M sure you know that this is the best answer for your situation. I'M a cabinet maker and I will have place the speaker in the second or third unit section from the wall ,and keep the IMF the way they have been design. Modified the unit in your case, but that's Just me. The most important is you like the way they sound,right. Best regards,Yvan.
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Fair comment, Yvan. I'm not a cabinet maker but I did build those units myself! Trust me, it was hassle enough just moving them all and modifying the centre unit to accommodate the new TV without adapting the other units to keep the speakers away from the walls. It also involved modifying the backlighting which is not obvious from the pics. I also have to keep my wife happy with the overall design of the units!

But the IMFs sound great as they are

Best wishes

Roger
 
rogermatthew said:
Fair comment, Yvan. I'm not a cabinet maker but I did build those units myself! Trust me, it was hassle enough just moving them all and modifying the centre unit to accommodate the new TV without adapting the other units to keep the speakers away from the walls. It also involved modifying the backlighting which is not obvious from the pics. I also have to keep my wife happy with the overall design of the units!

But the IMFs sound great as they are

Best wishes

Roger
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Happy wife, Happy life, and the ability to keep and use med-large to large IMF speakers in the house.
 
mech986 said:
Happy wife, Happy life, and the ability to keep and use med-large to large IMF speakers in the house.
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Nice one mech! Thanks also for drawing attention to changing the caps on the switch panel, I'll look into that after Christmas. After that I hope I can leave well alone - these bad boys are getting heavier as I grow older!

Roger
 
Hi, these FRIED R 4 look really good and sound surely wondefull, never listen one pair but will love too , maybe I will have my chance one of these days.
 
Just checking in... I'm ready to button-up these TLS 50's but I'm still curious if playing with the cardboard tube on the mid-range is worth the effort?

Roger, nice work finding the issue on your crossover board. It's been so long since I've listened to my 50's that it will be interesting to hear them again after getting used to my pair of 80's. And if you think the 50's are heavy, try picking-up and moving an 80, they're about 85 pounds/40kg each! Cheers!
 
Andy-roo said:
Just checking in... I'm ready to button-up these TLS 50's but I'm still curious if playing with the cardboard tube on the mid-range is worth the effort?

Roger, nice work finding the issue on your crossover board. It's been so long since I've listened to my 50's that it will be interesting to hear them again after getting used to my pair of 80's. And if you think the 50's are heavy, try picking-up and moving an 80, they're about 85 pounds/40kg each! Cheers!
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Thanks Andy. Yeh, I don't even wanna think about lifting an 80, let alone a Professional Reference! No question, though, the 80s are superior with their extended range.

Cheers

Roger
 
Just out of interest, has anyone compared an IMF with a Cambridge transmission line monitor? I've heard them, but not in a true comparison situation
 
Hi,for the mids you can use aquarium active carbon filter pad sold in pad like 10 inch. X 20 inch. 1/4 or 1/2 inch. thick for the tube 4 inch. And install it on the perimeter inside the TUBE, use the roll of foam there but install it all around on top of the active carbon ,cut the excess .With my professionnal Mk III this mod make my mids much more insulated, I have use the same fiberglass strips, but reduce the thickness in half, it improved the clarity of the sound. IMF should have use a bit bigger TUBE for this mid, 4 1/4 ,4 1/2 inch. It will have been better, it's too tight in the tls 50, even for your TLS 80 it will make a big improved by using active carbon.
 
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