Can someone explain this without exploding my brain? and a bunch of
00001111111's and 000xx0000xx's

Really simple?? please???

Once a pro tools session completely turned into white noise on me, i
loaded all the audio tracks into AWave as Raw data manipulated the DC
offset to 1024, specified bit depth and data rate, and re-saved the
files as aif

I saved them and thank god, but it was all trial by error, with the
different settings, I lowered the DC offset in divisable incruments, and
magicly, my beautiful, long lost audio appeared.

I see the DC Offset removal plugin in pro tools, without any adjustable
parameters, in what circumstance would I use this plugin for? and what
would the result be ?(In sonic explanation not a drawing of the hex
symbols or binary data)

I know it's hard not to get technical with such a technical issue, I
understand frequencies, acoustics, the principals of inductance,
capacitance, and resistance, and the BASICS of sample rate and bit
depth, (enough to get a good signal to pretty much any format on the
planet, and sync between platforms) but binary, digital, extreme
technical information is way over my head, and you guys are Guru's with
all the xxx's 0000's and 1111's flying around here, I'm liable to try to
invent a game of sorts with the types of responces this thread could
generate.

I don't want to stare blankly, and smile and nod at the screen, can
some one help me to understand the basics of "DC offset removal" ???

I'd greatly appreciate it.

Bobby Longsocks

IMO, but the easiest way to see it is this:

Words: DC ofset shifts your 0 amplitude line for certain ammount, thus
eating dynamic range. DC offset removers put this line back in place.

Grahic: Amplitude vs time plot. Perfect Sine wave, but amplitude
unsimetrical to time axis ("to"). Draw new time axis, "t", paralel to
"to", so sine to appear symetrical arround it. Distance from "to" to
"t" is ammount of DC offset. Erase "to".

You should end with original sine wave and no DC offset.

Vladan
www.geocities.com/vla_dan_l
www.mp3.com/lesly , www.mp3.com/shook , www.mp3.com/lesly2
www.kunsttick.com/artists/vuskovic/indexdat.htm

"Bobby Longsocks" wrote in message
...

Can someone explain this without exploding my brain? and a bunch of
00001111111's and 000xx0000xx's

Really simple?? please???

Once a pro tools session completely turned into white noise on me, i
loaded all the audio tracks into AWave as Raw data manipulated the DC
offset to 1024, specified bit depth and data rate, and re-saved the
files as aif

I saved them and thank god, but it was all trial by error, with the
different settings, I lowered the DC offset in divisable incruments, and
magicly, my beautiful, long lost audio appeared.

I see the DC Offset removal plugin in pro tools, without any adjustable
parameters, in what circumstance would I use this plugin for? and what
would the result be ?(In sonic explanation not a drawing of the hex
symbols or binary data)

I know it's hard not to get technical with such a technical issue, I
understand frequencies, acoustics, the principals of inductance,
capacitance, and resistance, and the BASICS of sample rate and bit
depth, (enough to get a good signal to pretty much any format on the
planet, and sync between platforms) but binary, digital, extreme
technical information is way over my head, and you guys are Guru's with
all the xxx's 0000's and 1111's flying around here, I'm liable to try to
invent a game of sorts with the types of responces this thread could
generate.

I don't want to stare blankly, and smile and nod at the screen, can
some one help me to understand the basics of "DC offset removal" ???

I'd greatly appreciate it.


Well, I'm not a guru, but I do some software development and I've some interest
in this, so I can explain this a little bit more from that aspect. Since I keep
my bigger foot in the "normal world," though, this should be understandable. g

You know that sound comes from a moving wave. Recall the ubiquitous sinewave,
where there's a horizintal line, and a continuous line making rounded waves
above and below the horizontal line. If the average of the waves above and below
the line is the same, the audio is considered to have "zero DC offset." The
average of the swings establishes offset. In the real world, however, that
average is constantly moving with the program matter.

DC offset is not a good thing for sound; it reduces the available bandwidth and
a lot of DC offset is a very bad thing for the lifespan of an amplifier and
everything downstream from it (including voicecoils.)

In the world of digital, processing can sometimes introduce file segments that
are not offset properly, by returning an output file that has average peaks
higher on one side of the wave than the other. Bad math does this.

If the entire file was like this, the sound quality would suffer. Having bits
and pieces here and there with DC offset allows comparisons to the unaffected
portions of the file, and that becomes very apparent very quickly.

Fixing this in software uses a routine called "summing" which usually introduces
a signal that compensates for the DC offset and brings the average difference
back to zero. The quality of your results is dependant entirely on the quality
of the summing routine.

That's my quick shot at it. I'd be interested to hear from one of the mastering
engineers in this newsgroup. They're the final savior from DC offset.

John

In article ,
says...
IMO, but the easiest way to see it is this:

Words: DC ofset shifts your 0 amplitude line for certain ammount, thus
eating dynamic range. DC offset removers put this line back in place.

Grahic: Amplitude vs time plot. Perfect Sine wave, but amplitude
unsimetrical to time axis ("to"). Draw new time axis, "t", paralel to
"to", so sine to appear symetrical arround it. Distance from "to" to
"t" is ammount of DC offset. Erase "to".

You should end with original sine wave and no DC offset.

Vladan
www.geocities.com/vla_dan_l
www.mp3.com/lesly , www.mp3.com/shook , www.mp3.com/lesly2
www.kunsttick.com/artists/vuskovic/indexdat.htm


Excellent... I totally get it, Thankyou.

Bobby

In article ,
says...
Well, I'm not a guru, but I do some software development and I've some interest
in this, so I can explain this a little bit more from that aspect. Since I keep
my bigger foot in the "normal world," though, this should be understandable. g

You know that sound comes from a moving wave. Recall the ubiquitous sinewave,
where there's a horizintal line, and a continuous line making rounded waves
above and below the horizontal line. If the average of the waves above and below
the line is the same, the audio is considered to have "zero DC offset." The
average of the swings establishes offset. In the real world, however, that
average is constantly moving with the program matter.

DC offset is not a good thing for sound; it reduces the available bandwidth and
a lot of DC offset is a very bad thing for the lifespan of an amplifier and
everything downstream from it (including voicecoils.)

In the world of digital, processing can sometimes introduce file segments that
are not offset properly, by returning an output file that has average peaks
higher on one side of the wave than the other. Bad math does this.

If the entire file was like this, the sound quality would suffer. Having bits
and pieces here and there with DC offset allows comparisons to the unaffected
portions of the file, and that becomes very apparent very quickly.

Fixing this in software uses a routine called "summing" which usually introduces
a signal that compensates for the DC offset and brings the average difference
back to zero. The quality of your results is dependant entirely on the quality
of the summing routine.

That's my quick shot at it. I'd be interested to hear from one of the mastering
engineers in this newsgroup. They're the final savior from DC offset.

John


Even more descriptive, I understand completely. thanks for taking the
time, in fact now, I think I recognise some wav files I've seen, that
have needed DC offset removal, looking extremely lopsided, above, or
below the center line, without being out of phase.

Bobby

"Bobby Longsocks" wrote in message
...

Even more descriptive, I understand completely. thanks for taking the
time, in fact now, I think I recognise some wav files I've seen, that
have needed DC offset removal, looking extremely lopsided, above, or
below the center line, without being out of phase.


I don't think that's an indication of needing to use DC Offset removal. Many
waveforms are symmetrical aren't they?

Ricky W. Hunt wrote:
"Bobby Longsocks" wrote in message
...

Even more descriptive, I understand completely. thanks for taking the
time, in fact now, I think I recognise some wav files I've seen, that
have needed DC offset removal, looking extremely lopsided, above, or
below the center line, without being out of phase.



I don't think that's an indication of needing to use DC Offset removal. Many
waveforms are symmetrical aren't they?


Many waveforms are Asymmetrical (is that what you meant?), in fact, most
are.

In article , says...
Ricky W. Hunt wrote:
"Bobby Longsocks" wrote in message
...

Even more descriptive, I understand completely. thanks for taking the
time, in fact now, I think I recognise some wav files I've seen, that
have needed DC offset removal, looking extremely lopsided, above, or
below the center line, without being out of phase.



I don't think that's an indication of needing to use DC Offset removal. Many
waveforms are symmetrical aren't they?


Many waveforms are Asymmetrical (is that what you meant?), in fact, most
are.


Once I was mixing a session for the client, and the bass track wav file
looked as though it was ALL 90% on top of the center line, i'd never
seen anything quite that drastic... zoomed in, zoomed out, there was
almost no wav form below the center of the wav. so.... I though it must
be out of phase, I inverted it, and it was all 90% under the center with
almost no wav form ever appearing above center line.

I sounded like crap, I figure it was something he client did when
recording it, i'm wondering now, if somhow there wasn't DC curren in the
bass line as he was recording it????

The client thought all sounded great, and was smiling, all the tracks
were brual, so i didn't really brin it up that somehing wasn't right wih
the bass track, (you'd understand if you heard the recording)

I've never seen anything like it.... quite as bad.... to date....
could this have been a dc offset problem? visable to the eye???

Bobby

"S O'Neill" wrote in message
...

Many waveforms are Asymmetrical (is that what you meant?), in fact, most
are.

Yes. Sorry.

In article s writes:

Many waveforms are Asymmetrical (is that what you meant?), in fact, most
are.

Once I was mixing a session for the client, and the bass track wav file
looked as though it was ALL 90% on top of the center line, i'd never
seen anything quite that drastic... zoomed in, zoomed out, there was
almost no wav form below the center of the wav. so.... I though it must
be out of phase, I inverted it, and it was all 90% under the center with
almost no wav form ever appearing above center line.

I sounded like crap, I figure it was something he client did when
recording it, i'm wondering now, if somhow there wasn't DC curren in the
bass line as he was recording it????

The client thought all sounded great, and was smiling

Interesting that you thought it sounded like crap and the client
thought it sounded great. Perhaps this project wasn't your cup of tea.

Anyway, as far as the waveform is concerned, while the average DC
level isn't likely to be zero with a waveform that's this
assymetrical, it doesn't mean that there's DC offset. DC offset is
when there's no input and you have a constant output.

By putting it through a "DC offset filter" which is often a high pass
filter at 1 or 2 Hz, you could better center the waveform, and then
increase its amplitude without clipping the peaks, but this wouldn't
change the sound of the bass, only the maximum level that you could
bring it up in the mix.



--
I'm really Mike Rivers - )