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Multi-Way Conventional loudspeakers with crossovers

Telefunken TFK6006 50ohm Lpads
Telefunken TFK6006 50ohm Lpads
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Old 22nd December 2018, 08:34 AM   #11
Lojzek is offline Lojzek  Croatia
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It is a shame a loudspeaker will lack such a useful function, as an Lpad is, or a rheostat for that matter.
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Old 22nd December 2018, 10:19 AM   #12
ICG is offline ICG  Germany
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Originally Posted by Raccoon1400 View Post
The customer doesn't want to spend too much on these, and I have to redo a bad refoam job too. So I think this is the way I'll go as it is also the cheapest way.
A voltage divider consists of two resistors. That's much cheaper than a new L-Pad of some quality and dimensions (wattage).

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It is a shame a loudspeaker will lack such a useful function, as an Lpad is, or a rheostat for that matter.
In theory, yes. In praxis - no. You adjust it one time and then it plays that way for years.
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Old 22nd December 2018, 08:04 PM   #13
Raccoon1400 is offline Raccoon1400  Canada
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[QUOTE=ICG;5640579]A voltage divider consists of two resistors. That's much cheaper than a new L-Pad of some quality and dimensions (wattage).

But since it is a potentiometer with only two wires connected and not an actual L-pad, it is even simpler and I only need one resistor. And I can try it with no resistor for max level.
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Old 24th December 2018, 03:47 AM   #14
ICG is offline ICG  Germany
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But since it is a potentiometer with only two wires connected and not an actual L-pad, it is even simpler and I only need one resistor. And I can try it with no resistor for max level.
That's correct and wrong at the same time. While that's the same behaviour like the original crossover showed, it's still a bad design since the crossover frequency is impedance dependent. That means with changing the resistor value you change at the same time the crossover frequency, drop off slope and response. It would be the same like with the l-pad but that's a design flaw of the original speaker aswell.
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Old 26th December 2018, 05:30 AM   #15
Raccoon1400 is offline Raccoon1400  Canada
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So I bypassed the breakers and mid level pots with jumpers and hooked my ohm meter to the main input terminals. Each speaker reads about 1.2ohms and the nominal rating is 8ohm... That's seems not right?
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Old 26th December 2018, 02:00 PM   #16
Lojzek is offline Lojzek  Croatia
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A schematic drawing of all the parts in the circuit would have helped in situation assessment.
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Old 26th December 2018, 03:30 PM   #17
Galu is offline Galu  Scotland
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Have you tested the functionality of each of the individual drivers when disconnected from the rest of the speaker components?

And, as Lojzek says, it would help to see the circuit.
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Old 26th December 2018, 03:39 PM   #18
Galu is offline Galu  Scotland
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I'm not even sure what these speakers look like.

Could you post an external and internal photograph?
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Old 26th December 2018, 04:21 PM   #19
Raccoon1400 is offline Raccoon1400  Canada
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Here are some pictures. There isn't a crossover board inside, there are caps soldered in line with wires. I guess I should map it out on paper and see what is going on.
I tested the drivers individually in one of the speakers, seemed okay.
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Old 26th December 2018, 08:04 PM   #20
ICG is offline ICG  Germany
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Originally Posted by Raccoon1400 View Post
So I bypassed the breakers and mid level pots with jumpers and hooked my ohm meter to the main input terminals. Each speaker reads about 1.2ohms and the nominal rating is 8ohm... That's seems not right?
No, that is in fact not right. I suspect you've shorted the wrong connections.

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Here are some pictures. There isn't a crossover board inside, there are caps soldered in line with wires. I guess I should map it out on paper and see what is going on.
I tested the drivers individually in one of the speakers, seemed okay.
Well, you took the photo from the wrong side (photo 4), it would really help to see the connection side of the pads and the capacitor(s) and the soldering points of them and the wires. The woofers are definitely not the original ones btw.

The Harman Kardon receiver is very nice!
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