I have an Alesis Studio 32 mixer that makes a "seashore" noise in the
right outputs of both subgroups and in the main output. The source of
the noise in channel-11, and it's there regardless of the position of
the mute and pan controls for that channel.

To further describe the "seashore" noise, its a hissy, static-y (like AM
radios during a thunderstorm) sound with occasional deeper rumbles.

Although the problem has also surfaced on channel-6, it's most
reproducable in channel-11. It will start a few minutes after the mixer
is turned on, then will quiet down for hours at a time before
re-occuring. No signal needs to be present on any channel for this
problem to manifest.

Before I open this thing (or send it out for repair), I'd like to have
some idea of what components are the likely culprits.

Any ideas?

On Fri, 10 Dec 2004 20:00:26 GMT, GaryMedia
wrote:

a "seashore" noise

Any ideas?

A can of freeze spray is very handy for this kind of
problem, sometimes combined with a hair drier. Often
these culprits are thermally sensitive.

Good fortune,

Chris Hornbeck
"Shi mian mai fu"

in article , Chris Hornbeck at
wrote on 12/10/04 12:29 PM:

Good fortune,

Chris Hornbeck
"Shi mian mai fu"

Do you play pipa or just like Chinese music in general?

Carlos

On Sat, 11 Dec 2004 05:40:28 -0800, Carlos Alden
wrote:

Do you play pipa or just like Chinese music in general?

Sadly, neither. Just a movie. Can you translate?

Thanks,

Chris Hornbeck
"Shi mian mai fu"

"GaryMedia"

I have an Alesis Studio 32 mixer that makes a "seashore" noise in the right
outputs of both subgroups and in the main output. The source of the noise
in channel-11, and it's there regardless of the position of the mute and
pan controls for that channel.

To further describe the "seashore" noise, its a hissy, static-y (like AM
radios during a thunderstorm) sound with occasional deeper rumbles.

Although the problem has also surfaced on channel-6, it's most
reproducable in channel-11. It will start a few minutes after the mixer
is turned on, then will quiet down for hours at a time before re-occuring.
No signal needs to be present on any channel for this problem to manifest.

Before I open this thing (or send it out for repair), I'd like to have
some idea of what components are the likely culprits.



** Had any spillages on it lately ??

Sometimes electro caps leak their juice and cause such noises.

Or, as others have said, bad op-amp ICs.




............. Phil

GaryMedia wrote:
I have an Alesis Studio 32 mixer that makes a "seashore" noise in the
right outputs of both subgroups and in the main output. The source of
the noise in channel-11, and it's there regardless of the position of
the mute and pan controls for that channel.

To further describe the "seashore" noise, its a hissy, static-y (like AM
radios during a thunderstorm) sound with occasional deeper rumbles.

Although the problem has also surfaced on channel-6, it's most
reproducable in channel-11. It will start a few minutes after the mixer
is turned on, then will quiet down for hours at a time before
re-occuring. No signal needs to be present on any channel for this
problem to manifest.

Before I open this thing (or send it out for repair), I'd like to have
some idea of what components are the likely culprits.

Any ideas?


If you decide on a low cost replacment I have two Behringer 3242's for
sale perfect condition 350.00
george

It's almost ironic that you'd offer the Behringer 3242's. This all
started because I had two Behringer MX3242X's and added a third for my
home studio. I fired up a mix that I had been working on thru my Alesis
Studio 24 (not a typo, ...just follow the story) and listened to it thru
the MX3242X.

I was surprised at the difference in sound. There had been all kinds of
impolite and downright degrading commentary on this newsgroup and others
about Behringer sound, but this was the first time that I had an
opportunity to do some A/B comparisons in a controlled and known
environment.

After about 2 hours of going back and forth between the Studio 24 and
the MX3242X, I concluded that it was the handling of low-level signal
information that causes the downfall in the Behringer sound quality.
That is, the little reverb tails and soft decay edges of a variety of
instruments don't fade into the noise floor as gently as they do in the
Alesis. There was a secondary effect in that the bass seemed louder
relative to the rest of the mix when played thru the Behringer even
though the EQ controls were bypassed.

I'm not sure of which specification would affect this phenomenon the
most (THD+N?) but that was the only arena in the spec sheets where the
products differed in any great respect.

The subjective effect of the "rapid fade" problem in the MX3242X is that
the music is "dry", and "loses dimension" and is "flat" and certainly
less emotionally satisfying. It is much the same effect as like losing
bit resolution. The overall intuitive effect is quite surprising and
for the first time I understood a lot more about the reactions of people
who prefer the analog world.

Just as people have different visual sensitivities to vertical scan
rates in CRT monitors (some can tolerate 60hz and don't notice the
flicker, while it absolutely drives me out of the room), I imagine that
people have difference emotional sensitivities to the low-level
information in audio recordings.

Going back to THD+N as a suspect, I took the time to translate the
traditional percentage specification into dB in order to get a better
feel for what numbers the relationships are.

Behringer MX3242X THD+N = 0.005% = -86dB
Alesis Studio 24 and 32 THD+N = 0.001% = -100dB

Checking through some of my other equipment and looking around on the
web *almost* convinced me that I was on to something in that the
Focusrite, dbx, MOTU 1224 all had this spec in the -100 dB or better
ranges ...even the Studio Projects VTB-1 was at -97dB.

The theory took a torpedo in the side when I looked at the Avalon
preamps. The AD2022 had a spec of 0.05% for distortion which is -66dB.

Either that figure is a typo, or just more evidence that clearly
something else is going on here in the world of audio. Anyway, I
thought y'all would like read about my little rabbit trail of research.
The best quote I've read on this topic is "Reading specifications will
make you deaf."

The rest of the story is that I bought two Alesis Studio 32's to replace
the Behringers, and one turned up with a bad channel-11, so that
prompted this thread.


George Gleason wrote:
GaryMedia wrote:

I have an Alesis Studio 32 mixer that makes a "seashore" noise in the
right outputs of both subgroups and in the main output. The source of
the noise in channel-11, and it's there regardless of the position of
the mute and pan controls for that channel.

To further describe the "seashore" noise, its a hissy, static-y (like
AM radios during a thunderstorm) sound with occasional deeper rumbles.

Although the problem has also surfaced on channel-6, it's most
reproducable in channel-11. It will start a few minutes after the
mixer is turned on, then will quiet down for hours at a time before
re-occuring. No signal needs to be present on any channel for this
problem to manifest.

Before I open this thing (or send it out for repair), I'd like to have
some idea of what components are the likely culprits.

Any ideas?



If you decide on a low cost replacment I have two Behringer 3242's for
sale perfect condition 350.00
george

thanks for your information
I only do live sound and none of this would ever come to light at a live gig
George

I agree that none of this would come to light at most live gigs, and so
my MX3242x is being sold to a youth group that does really loud live
rock. I doubt that gentle reverb tails get much attention in that
environment. :-)

George Gleason wrote:

thanks for your information
I only do live sound and none of this would ever come to light at a live
gig
George

Do you play pipa or just like Chinese music in general?

Sadly, neither. Just a movie. Can you translate?

Thanks,

Chris Hornbeck
"Shi mian mai fu"

Shi Mian Mai Fu ("Sure mien my foo") means "Ambush from all sides (lit. ten
sides) and is the name of a famous pipa (lute like instrument) piece
portraying a famous historical battle about 200 BC. Lots of percussive
sounds and wailing cries of dying soldiers. Didn't realize it was a movie,
or from a movie. If so, it'd be lot like "Hero."

Carlos

On Sat, 11 Dec 2004 18:19:17 -0800, Carlos Alden
wrote:

Shi Mian Mai Fu ("Sure mien my foo") means "Ambush from all sides (lit. ten
sides) and is the name of a famous pipa (lute like instrument) piece
portraying a famous historical battle about 200 BC. Lots of percussive
sounds and wailing cries of dying soldiers. Didn't realize it was a movie,
or from a movie. If so, it'd be lot like "Hero."

Thank you very much. I'm a big Zhang YiMou fan, and it will likely
be very much like _Hero_. The American release title is _House of
Flying Daggers_ and hasn't reached this far into the boonies yet.

I don't know if it'll have a Tan Dun soundtrack either, but worse
things could happen.

If you're a fan of Zhang or Chen Kaige, or even Ang Lee, it might be
worth a couple hours. For me, he's *the* cinematographer of my
generation. Who would Godard have been without Coutard? Who would
Hal Hartley be without Michael Spiller?

Thanks again very much for the translation. I thought that "ambushed
from ten sides" was a funny newsgroup sig. Maybe.

Chris Hornbeck
"Shi mian mai fu"

George Gleason wrote:

thanks for your information
I only do live sound and none of this would ever come to light at a live gig
George

That's for sure - LMAO ! ;-)

It's an interesting subject though. I'm tempted to post more regarding other
product comparisons.


Graham

"GaryMedia" wrote in message
...

Going back to THD+N as a suspect, I took the time to translate the
traditional percentage specification into dB in order to get a better
feel for what numbers the relationships are.

Behringer MX3242X THD+N = 0.005% = -86dB
Alesis Studio 24 and 32 THD+N = 0.001% = -100dB

Checking through some of my other equipment and looking around on the
web *almost* convinced me that I was on to something in that the
Focusrite, dbx, MOTU 1224 all had this spec in the -100 dB or better
ranges ...even the Studio Projects VTB-1 was at -97dB.

The theory took a torpedo in the side when I looked at the Avalon
preamps. The AD2022 had a spec of 0.05% for distortion which is -66dB.

Either that figure is a typo, or just more evidence that clearly
something else is going on here in the world of audio.

The latter, I'd say. THD, or THD+N, is essentially a meaningless number
without (a) information on the conditions under which it's being measured
(level, load impedance, settings, etc.); (b) information on what frequencies
are being measured; and, most important, (c) information on the harmonic
spectrum produced. A low level of 7th harmonic distortion is a lot more
audible than higher levels of 2nd.

Backing up for a minute, THD is just one way of mapping the nonlinearities
of an amplifier circuit, and for most modern equipment, not a very good one.
IMD measurements can sometimes be more revealing, but we still haven't found
a way to map these nonlinearities in a way that correlates perfectly with
audibility, except in extremely bad cases (e.g., somethiing that measures
30% THD under normal operating conditions is likely to sound distorted).

Peace,
Paul