hello,
I have a pair of active-studio monitors. I've realized that they sound
very different, the one is much brighter than the other. I've tested
all configurations, so it's not the console, cable, room, position
etc... ( I've checked all this) I've also put the electronics (amp
incl. cross-over I guess) from one box into the other, in order to
check if it's the speaker(drivers) or the electronics. the result is
that its always the box that I put the specified electronics in, that
sounds muddier than the other. so it seems obvious that the
electronics are the problem. I got those speakers used, the guy who
owned them before told me he has left the speakers switched on all the
time. I don't know how old they are, but maybe 10 years. so my question
is, what is most likely the part in an amp, that changes from his
original specs due to age which affects the sound?

thanks for any helpfull ideas.

by the way, I know it would be a good idea to bring them to a
professional tech, for some reason I don't...

The problem may be drivers rather than the amps. I'd suggest you try
swapping drivers back and forth to quickly check that; if the problem
follows a driver, replace that driver.

matiss wrote:
hello,
I have a pair of active-studio monitors. I've realized that they sound
very different, the one is much brighter than the other. I've tested
all configurations, so it's not the console, cable, room, position
etc... ( I've checked all this) I've also put the electronics (amp
incl. cross-over I guess) from one box into the other, in order to
check if it's the speaker(drivers) or the electronics. the result is
that its always the box that I put the specified electronics in

Are they bi-amped, i.e. with a line-level crossover and power amp for
each driver?
If they are, then it could be the HF driver amplifier that's gone.

Clue: are you getting any sound AT ALL out of the tweeter on the bad one?

Anahata

I think it just makes no difference, whether I swapp the drivers or the
electronics. I did swap the high frequency driver (because the
difference is mostly obvious on high frequencies) and in the one box,
any of the two high-drivers sounds brighter, and any of both sounds
dull in the other box.so I don't think it's the drivers, because the
same drivers sound different in one box depending on the electronics I
put in. or do I make a mistake in figuring out the problem?

matiss wrote:
hello,
I have a pair of active-studio monitors. I've realized that they sound
very different, the one is much brighter than the other. I've tested
all configurations, so it's not the console, cable, room, position
etc... ( I've checked all this) I've also put the electronics (amp
incl. cross-over I guess) from one box into the other, in order to
check if it's the speaker(drivers) or the electronics. the result is
that its always the box that I put the specified electronics in, that
sounds muddier than the other. so it seems obvious that the
electronics are the problem. I got those speakers used, the guy who
owned them before told me he has left the speakers switched on all the
time. I don't know how old they are, but maybe 10 years. so my question
is, what is most likely the part in an amp, that changes from his
original specs due to age which affects the sound?

Could be anything. Since you don't mention what model number it
is, we don't even know if the monitors are biamped. But a handy way
to track these things down is with a two-tone test tone, and a scope.
Just work from the front of the circuit to the back and see where
the levels of the two tones start changing.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Scott Dorsey wrote:
matiss wrote:
hello,
I have a pair of active-studio monitors. I've realized that they sound
very different, the one is much brighter than the other. I've tested
all configurations, so it's not the console, cable, room, position
etc... ( I've checked all this) I've also put the electronics (amp
incl. cross-over I guess) from one box into the other, in order to
check if it's the speaker(drivers) or the electronics. the result is
that its always the box that I put the specified electronics in, that
sounds muddier than the other. so it seems obvious that the
electronics are the problem. I got those speakers used, the guy who
owned them before told me he has left the speakers switched on all the
time. I don't know how old they are, but maybe 10 years. so my question
is, what is most likely the part in an amp, that changes from his
original specs due to age which affects the sound?

Could be anything. Since you don't mention what model number it
is, we don't even know if the monitors are biamped. But a handy way
to track these things down is with a two-tone test tone, and a scope.
Just work from the front of the circuit to the back and see where
the levels of the two tones start changing.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

well. they are triamped with active cross-over. it's a pair of atc
scm50, very heavy ones. the weaker one still produces highs, but not
that brilliant, and I repeat that I've already swapped the high-driver.

matiss wrote:
Scott Dorsey wrote:
matiss wrote:

well. they are triamped with active cross-over. it's a pair of atc
scm50, very heavy ones. the weaker one still produces highs, but not
that brilliant, and I repeat that I've already swapped the high-driver.

Okay. NOW we have some useful information. Put pink noise in both,
measure the level at the speaker terminals. Compare the two. Now,
get the schematic for the thing and the scope and start working backwards.
You're almost certainly going to find something goofy with the drive
amplifier for the tweeter... but it might still be something wrong
in the crossover. Without the scope, you will never know.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Scott Dorsey wrote:
matiss wrote:
Scott Dorsey wrote:
matiss wrote:

well. they are triamped with active cross-over. it's a pair of atc
scm50, very heavy ones. the weaker one still produces highs, but not
that brilliant, and I repeat that I've already swapped the high-driver.

Okay. NOW we have some useful information. Put pink noise in both,
measure the level at the speaker terminals. Compare the two. Now,
get the schematic for the thing and the scope and start working backwards.
You're almost certainly going to find something goofy with the drive
amplifier for the tweeter... but it might still be something wrong
in the crossover. Without the scope, you will never know.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

just one more detail. when you switch them on/off, the more brighter
sounding amp (or triamp) makes a loud "tshak" like many active
speakers. the dull sounding amp makes by far not such loud noise when
you switch it on/off. a while ago the manufacturer customer service
told me in a mail, that this is due to parts tolerance and isn't a
problem...

Scott Dorsey wrote:
matiss wrote:
Scott Dorsey wrote:
matiss wrote:

well. they are triamped with active cross-over. it's a pair of atc
scm50, very heavy ones. the weaker one still produces highs, but not
that brilliant, and I repeat that I've already swapped the high-driver.

Okay. NOW we have some useful information. Put pink noise in both,
measure the level at the speaker terminals. Compare the two. Now,
get the schematic for the thing and the scope and start working backwards.
You're almost certainly going to find something goofy with the drive
amplifier for the tweeter... but it might still be something wrong
in the crossover. Without the scope, you will never know.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

just one more detail. when you switch them on/off, the more brighter
sounding amp (or triamp) makes a loud "tshak" like many active
speakers. the dull sounding amp makes by far not such loud noise when
you switch it on/off. a while ago the manufacturer customer service
told me in a mail, that this is due to parts tolerance and isn't a
problem...