IMF tls 80 problem

[09mike69]

Recently acquired a pair of tls 80 speakers, bass and mid work but tweeter and super-tweeter do not, I removed the tweeter to test and it showed 6ohm, this is the same on both speakers.
Anyone had experience with these that could offer some advice.
Cheers
Mike.

[Macca]

problem is possibly the crossover then. Has it been rebuilt before or is it original?

[walpurgis]

The HF1300 tweeters are measuring about right if I recall. The supertweeters should be HF2000 I think and those probably measure slightly less.

[Lawrence001]

I used to own a pair a few years ago. Ani right in thinking there's a knob on the back for the treble level? Might be dirty, try turning it back and forth several times (or several dozen!) and see if you get some sound out of the tweeters.

Failing that could be a broken knob, loose wire or failed component on the crossover.

[09mike69]

I used to own a pair a few years ago. Ani right in thinking there's a knob on the back for the treble level? Might be dirty, try turning it back and forth several times (or several dozen!) and see if you get some sound out of the tweeters.

Failing that could be a broken knob, loose wire or failed component on the crossover.
No knob, and x,overs look original.

[09mike69]

problem is possibly the crossover then. Has it been rebuilt before or is it original?
X,overs look original, seems odd that it's not putting sound to the tweeters.

[Macca]

X,overs look original, seems odd that it's not putting sound to the tweeters.

Could be a broken trace on the board, or failed components. Mine were working but way out if tolerance so require a complete re-build, that's where you need to start.

Falcon Acoustics sell all the parts.

[walpurgis]

It is unusual for two speakers to exhibit identical 'symptoms', perhaps they have been tinkered with. If the tweeters and supertweeters show a reasonable DC resistance when measured, they may be OK and any faults could lie with the wiring or crossovers. I'd check everything for electrical continuity and check the crossover component values. Remaking all soldered joints may help.

[09mike69]

It is unusual for two speakers to exhibit identical 'symptoms', perhaps they have been tinkered with. If the tweeters and supertweeters show a reasonable DC resistance when measured, they may be OK and any faults could lie with the wiring or crossovers. I'd check everything for electrical continuity and check the crossover component values. Remaking all soldered joints may help.

That was my thought, also the positive wire going to the tweeter is wired to something on the back of the baffle then returns to the tweeter?!
Spoke to falcon acoustics and apparently this is not normal.
A bit more investigation when I get home.

[Lawrence001]

No knob, and x,overs look original.Odd the photos on the net show a knob between the banana sockets can you post a photo of the sockets?

[09mike69]

Odd the photos on the net show a knob between the banana sockets can you post a photo of the sockets?

these have the old style twist spade connector like on some of the old celestion speakers, no tone switch, i removed the unit as id read these have a cross over behind the speaker terminal but there was no X,over either. these have been tinkered with for sure.

[09mike69]

ok so, tested the tweeters and super tweeters and they all work fine, except when i connect them to imf speaker then nothing,
there also looks like there is a resistor in the positive wire going to the tweeter,
but when all speker units are connected there is only sound from the mid and bass speakers, kind of like when the jumper bar isnt connected on bi wirable speakers.
this is the same on both speakers.
there is also a sticker on the back of the speaker that says modified and tested by south coast speakers.
anyone shed any light.
thanks
mike.

[Macca]

have you located the crossover? Usually it's behind the bass driver.

[09mike69]

have you located the crossover? Usually it's behind the bass driver.

Yes, I can't upload photos tho it just keeps saying error.

[walpurgis]

Yes, I can't upload photos tho it just keeps saying error.

Try using ImgBB. It's a free third party image hosting site that's very easy to use and does not require you to sign up.

Here: https://imgbb.com/

[Macca]

Yes, I can't upload photos tho it just keeps saying error.

use link Geoff gave, download your pic then select 'BBC Code' from the list of options, copy the link it gives into your post on here.

All your drivers work, that's the main obstacle with these speakers so you're past that. Get them sorted and you have speakers that would retail these days at about ten grand.

[09mike69]

The single white cap or resistor is on the positive wire going to the tweeter and glued to the backside of the baffle.https://uploads.tapatalk-cdn.com/20220507/c8d3d2d85f7aefb98d55fdee35d026ea.jpghttps://uploads.tapatalk-cdn.com/20220507/e4a27def36e171384a11383db7ac6047.jpg

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[Macca]

They look to be the originals, or if they have been rebuilt/modded it was decades ago.

I'd just rip the lot out and build entirely new crossovers with brand new components. Which is what I need to do to mine.

[09mike69]

I'd like to find out why it won't power the tweet and super tweeter first.https://uploads.tapatalk-cdn.com/20220507/88dfafd86774cc39683e4c7aea9ae354.jpghttps://uploads.tapatalk-cdn.com/20220507/f377dfca06e9c0cc8518f08b98ac1ada.jpg

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[09mike69]

The serial number or model number on the back says mdict but its very hard to make out so I may be wrong on some of the lettering.
Thanks again
Mike.

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[09mike69]

Maybe younger eyes can make out the type better than mine.https://uploads.tapatalk-cdn.com/20220507/25ee8c2a23c65263a12e0db7f05a5ff9.jpghttps://uploads.tapatalk-cdn.com/20220507/a890fb4a7a60cea9d2ff344de5f6c8ed.jpg

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[Macca]

I'd like to find out why it won't power the tweet and super tweeter first.

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Assuming connections between crossover and drivers are sound then it has to mean that some part(s) of the crossovers are shagged. You know the drivers are okay so what else can it be? There isn't anything else.

[09mike69]

There is the unknown cap glued to the baffle. And the fact its the same on both speakers.
I agree with the shagged cap approach but because they have been messed with I'm concerned what may have caused the problem.
Why the inline cap on the baffle, spoke to falcon acoustics and they had not seen or heard of it on these speakers.
And no caps on the speaker terminal or tone switch.
https://uploads.tapatalk-cdn.com/20220507/f10e415b8aa22d7bda39ea6330c8d12f.jpg

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[struth]

caps would i guess be put there either to protect tweeter or to limit its response(or both)

[walpurgis]

There is the unknown cap glued to the baffle.

Looks like a resistor to me.

[Lawrence001]

That screw is where the knob used to be so it's be removed by the modders. Also I don't think they are TLS80s from the label they are probably the earlier Transmission Line Loudspeaker I think they were called.

[09mike69]

That screw is where the knob used to be so it's be removed by the modders. Also I don't think they are TLS80s from the label they are probably the earlier Transmission Line Loudspeaker I think they were called.My thought too, removed the tone switch and put an inline resistor on the tweeter,
Still can't figure out why the tweeters won't work in situ.
Cheers
Mike

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[09mike69]

Ok so I removed the resistor and both tweets are now producing sound.
Sounded a tad low but I'll get a better idea when I reconnect the speaker units and have a listen.
Thanks for all replies, and I'll post back when I've had chance to put them back together and had a listen.
Cheers
Mike.https://uploads.tapatalk-cdn.com/20220507/00b0854c958057c81437b13f99f62dd4.jpg

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[Lawrence001]

What's the value of the resistor? It's normally about 1-2 ohm to reduce the treble level (in series). Much higher would explain the issue. Although why anyone would want to add it in the first place is a mystery.

[09mike69]

What's the value of the resistor? It's normally about 1-2 ohm to reduce the treble level (in series). Much higher would explain the issue. Although why anyone would want to add it in the first place is a mystery.I don't know I'd have to measure it, there's no value marked on it.
I won't replace it.
Hopefully get time today to get them up and running.

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[09mike69]

Well had a chance to try them but unfortunately still the same, very low output from both tweeters.
Low output meaning inaudible.
Sent pictures of the crossover to falcon acoustics and it has been mucked about with.
Also the b110's are not, they're a seas look a like !.
These speakers are the early version of the imf tls 80 that were called transmission line speakers.
Falcon don't have a schematic for this x,over either.
Any help, suggestions.
Thanks again
Mike.https://uploads.tapatalk-cdn.com/20220514/e908e8ec75936ef371ec10fcd6caf09a.jpghttps://uploads.tapatalk-cdn.com/20220514/7437d64a407626614dacc051f337e06d.jpg

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[Macca]

Buy a DSP unit and run them active? You'll need multiple channels of amplification but you could use cheap chip amps for mids and tops.

Build an entirely new passive crossover based on that for the TLS80? It will probably work fine.

[walpurgis]

Have you looked at the TLS 80 crossover schematic: https://www.google.co.uk/search?q=imf+tls80+crossover&source=hp&ei=P3Z_Yo7hEcmigQbQha-YDw&iflsig=AJiK0e8AAAAAYn-ETzhvzQ4wSwurFbfrgmjNLo__IqX7&oq=imf+crossover&gs_lcp=Cgdnd3Mtd2l6EAEYADIGCAAQFhAeMgYIABAWEB4yBgg AEBYQHjIGCAAQFhAeOgsIABCABBCxAxCDAToOCC4QgAQQsQMQx wEQowI6EQguEIAEELEDEIMBEMcBENEDOgsILhCABBCxAxCDATo ICAAQgAQQsQM6CAguELEDEIMBOgUIABCABDoHCAAQgAQQCjoLC C4QgAQQxwEQrwE6CAguEIAEENQCOgQIABAKUABY8j1gkGhoAHA AeACAAXuIAZ0KkgEDNy42mAEAoAEB&sclient=gws-wiz

It should provide an idea of where things may have gone astray.

[09mike69]

I wouldn't know to use dsp.
the x,over board layout is different to the tls 80 so I can't use one to copy.
Falcon sell a x,over that will work in these I'm waiting for a reply from Jerry on price.
Also I'm starting to think that this problem could've been caused by the mod done by South Coast speakers. It seems odd that both speakers have the same problem.
If you look at the crossovers they have two parallel wires on the board, should there have been caps here ?
Mike.




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[Puffin]

I have only just come across this thread. Did you get the crossover sorted and the speakers working properly?

[09mike69]

I bought new cross overs from Jerry at falcon acoustics. They sound very good.

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