Home |
Search |
Today's Posts |
#1
Posted to rec.audio.tech
|
|||
|
|||
subtract one WAV file
What is the easiest way to subtract one WAV file from another?
I want to compute the amount of noise over a comm system. |
#2
Posted to rec.audio.tech
|
|||
|
|||
subtract one WAV file
|
#3
Posted to rec.audio.tech
|
|||
|
|||
subtract one WAV file
What program will add them?
|
#4
Posted to rec.audio.tech
|
|||
|
|||
subtract one WAV file
wrote in message oups.com... What program will add them? What one won't? You need to import 2 mono files into a new stereo file, invert one channel, then add the channels to make a mono file. (Obviously the files also need to be time aligned) MrT. |
#5
Posted to rec.audio.tech
|
|||
|
|||
subtract one WAV file
Mr.T wrote:
wrote in message oups.com... What program will add them? What one won't? You need to import 2 mono files into a new stereo file, invert one channel, then add the channels to make a mono file. (Obviously the files also need to be time aligned) I use Goldwave as it's free. Load 2 stereo files, invert one, copy it and mix it into the other. All in stereo. You should also tweak the volume of one file, in fractions of a decibel, to get the minimum signal, as the level may have changed between your two measurement points. If there is a high-frequency roll off on the noisy signal, you really should match it by lowpass filtering the clean wav file to match. -- Eiron No good deed ever goes unpunished. |
#6
Posted to rec.audio.tech
|
|||
|
|||
subtract one WAV file
wrote in message
oups.com What is the easiest way to subtract one WAV file from another? I want to compute the amount of noise over a comm system. Fire up Cool Edit Pro or Audition and do a Mix Paste Inverted. |
#7
Posted to rec.audio.tech
|
|||
|
|||
subtract one WAV file
wrote in message oups.com... What is the easiest way to subtract one WAV file from another? I want to compute the amount of noise over a comm system. I'd use a sound editor like Audacity. Jeff -- Remove icky phrase from email address to get a valid address. |
#8
Posted to rec.audio.tech
|
|||
|
|||
subtract one WAV file
When I invert a WAV and mix it with itself, I don't get silence.
Anyone know why? |
#9
Posted to rec.audio.tech
|
|||
|
|||
subtract one WAV file
|
#11
Posted to rec.audio.tech
|
|||
|
|||
subtract one WAV file
On Thu, 11 May 2006 10:50:32 -0700, David Nebenzahl
wrote: spake thus: wrote: When I invert a WAV and mix it with itself, I don't get silence. Anyone know why? Sure. Unless the inverted copy is EXACTLY in sync and EXACTLY the same, sample-for-sample, you WON'T get silence. Yes, but if the OP is inverting a file and mixing it with itself, that means it *should* be an exact inverse copy, and hence the mix should result in silence. Your reply in no way addresses this mystery. I assume the mixing is being done immediately after inversion, which should eliminate any differences between copies as you're postulating. Just tried this with Audition and the result is as expected; a perfectly straight line without a single bit out of place. d -- Pearce Consulting http://www.pearce.uk.com |
#12
Posted to rec.audio.tech
|
|||
|
|||
subtract one WAV file
Mr.T spake thus:
wrote in message oups.com... What program will add them? What one won't? Sound Forge, apparently; I looked high and low, but can't find any function that adds two signals together. (There is an "invert" function, though.) Anyone who can prove me wrong? It'd be nice to be able to do. -- Pierre, mon ami. Jetez encore un Scientologiste dans le baquet d'acide. - from a posting in alt.religion.scientology titled "France recommends dissolving Scientologists" |
#13
Posted to rec.audio.tech
|
|||
|
|||
subtract one WAV file
David Nebenzahl wrote: spake thus: wrote: When I invert a WAV and mix it with itself, I don't get silence. Anyone know why? Sure. Unless the inverted copy is EXACTLY in sync and EXACTLY the same, sample-for-sample, you WON'T get silence. Yes, but if the OP is inverting a file and mixing it with itself, that means it *should* be an exact inverse copy, and hence the mix should result in silence. No., read what the original poster actually said, please: "What is the easiest way to subtract one WAV file from another? I want to compute the amount of noise over a comm system. " He is NOT "inverting a file and mixing it with itself". He clearly states is taking a WAVE file, sending over a comm system and wants to compare the output with the input. Only if you take a WAV file, simply copy it with no intermediate loss or delay, then do what you're talking about, will you end up with silence. Be all that as it may, the invert-and-sum is NOT the way I would do what the OP wants. What I would do is probably a whole lot more sophisticated than he wants. I would take the two WAVE files, cross-correlated them, which would give you the impulse response of the COMM channel. Take the complex FFT of that, and you have the transfer function of the COMM channel, complete with noise. Or, if he just wants to know how much noise the comm channel is adding, assuming the noise is signal-independent, then simply ship silnce over the comm link, and the result IS the noise added by the comm channel. |
#14
Posted to rec.audio.tech
|
|||
|
|||
subtract one WAV file
|
#15
Posted to rec.audio.tech
|
|||
|
|||
subtract one WAV file
It works with Cool Edit Pro, but not Blaze Media Pro.
|
#16
Posted to rec.audio.tech
|
|||
|
|||
subtract one WAV file
David Nebenzahl wrote:
Mr.T spake thus: wrote in message oups.com... What program will add them? What one won't? Sound Forge, apparently; I looked high and low, but can't find any function that adds two signals together. (There is an "invert" function, though.) Anyone who can prove me wrong? It'd be nice to be able to do. You didn't look hard enough. Look in "process" for "channel converter" or you could use the Mix+ function with one of the data sets inverted. Later... Ron Capik -- |
#17
Posted to rec.audio.tech
|
|||
|
|||
subtract one WAV file
Ron Capik spake thus:
David Nebenzahl wrote: Mr.T spake thus: wrote in message egroups.com... What program will add them? What one won't? Sound Forge, apparently; I looked high and low, but can't find any function that adds two signals together. (There is an "invert" function, though.) Anyone who can prove me wrong? It'd be nice to be able to do. You didn't look hard enough. Look in "process" for "channel converter" or you could use the Mix+ function with one of the data sets inverted. None of which are present in my software. I've got Sound Forge XP 4.5, which I suspect is "crippleware" (it was bundled with my sound card). What version do you have, and where is the "Mix+" function? -- Pierre, mon ami. Jetez encore un Scientologiste dans le baquet d'acide. - from a posting in alt.religion.scientology titled "France recommends dissolving Scientologists" |
#18
Posted to rec.audio.tech
|
|||
|
|||
subtract one WAV file
David Nebenzahl wrote:
Ron Capik spake thus: David Nebenzahl wrote: Mr.T spake thus: wrote in message oups.com... What program will add them? What one won't? Sound Forge, apparently; I looked high and low, but can't find any function that adds two signals together. (There is an "invert" function, though.) Anyone who can prove me wrong? It'd be nice to be able to do. You didn't look hard enough. Look in "process" for "channel converter" or you could use the Mix+ function with one of the data sets inverted. None of which are present in my software. I've got Sound Forge XP 4.5, which I suspect is "crippleware" (it was bundled with my sound card). What version do you have, and where is the "Mix+" function? Don't think XP4.5 could be bescribed as crippleware, or if that function is available in that limited version (under Edit | Paste Special), but SoundForge is version 8 now .... The bundled versions of most software are often reduced capability wrt the full version, but fully functional. Crippleware is software that lets you do all sorts of things then prevents you from completing what you did, like not enabling saving. geoff |
#19
Posted to rec.audio.tech
|
|||
|
|||
subtract one WAV file
David Nebenzahl wrote:
Ron Capik spake thus: David Nebenzahl wrote: ...snip.. You didn't look hard enough. Look in "process" for "channel converter" or you could use the Mix+ function with one of the data sets inverted. None of which are present in my software. I've got Sound Forge XP 4.5, which I suspect is "crippleware" (it was bundled with my sound card). What version do you have, and where is the "Mix+" function? -- The XP 4.5 version may not have the channel converter tool (though the 4.5 full version does) however the mix+ should be there. Look for a clipboard + icon on the tool bar. There is also a "past special" function in the edit menu that will call that function. [Note: I believe Sound Forge 4.5 came out in the mid 1990's ] Later... Ron Capik -- |
#21
Posted to rec.audio.tech
|
|||
|
|||
subtract one WAV file
Arny Krueger wrote:
wrote in message oups.com What is the easiest way to subtract one WAV file from another? I want to compute the amount of noise over a comm system. Fire up Cool Edit Pro or Audition and do a Mix Paste Inverted. No need to invoke the automatic "a-word' Arny. He said he has SF. That does it fine. geoff |
Reply |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
what are multi tracks wrt a MIDI file | Pro Audio | |||
Voluntary Collective Licensing of Music File Sharing | Pro Audio | |||
File Sharing, in case you haven't heard... | Pro Audio | |||
AUDIO FILE EDIT: HELP PLS! | General | |||
unknown audio file format | General |