removing "hum" from an audio recording

Discussion in 'Electronic Basics' started by mrdarrett@gmail.com, Jun 20, 2006.

  1. Guest

    I'm sure you've come across this before.

    We had to tape-record a meeting (with real cassette tapes!) yesterday.
    I was planning on playing the tape as input to the sound card, and burn
    a CD of the meeting for all attendees.

    Unfortunately, we have this HUM in the background. Sounds like it's
    somewhere between 60 Hz and 120 Hz.

    How do I remove this?

    As a test, I tried the freeware program Audacity, asked it to produce a
    pure 60 Hz tone, then
    tried the "low pass filter" feature, cutting off everything below 100
    Hz. This just seems to reduce the amplitude of the sine wave.

    Then, when I looked up "low pass filter" on Wikipedia, I realized I
    might have gotten it backwards (cut off higher frequencies instead of
    lower frequencies), so I then ran a "high pass filter", asking Audacity
    to cut off everything below 100 Hz. No improvement.

    Any other suggestions?

    Michael D.
    , Jun 20, 2006
    #1
    1. Advertising

  2. Ban Guest

    wrote:
    > I'm sure you've come across this before.
    >
    > We had to tape-record a meeting (with real cassette tapes!) yesterday.
    > I was planning on playing the tape as input to the sound card, and
    > burn a CD of the meeting for all attendees.
    >
    > Unfortunately, we have this HUM in the background. Sounds like it's
    > somewhere between 60 Hz and 120 Hz.
    >
    > How do I remove this?
    >
    > As a test, I tried the freeware program Audacity, asked it to produce
    > a pure 60 Hz tone, then
    > tried the "low pass filter" feature, cutting off everything below 100
    > Hz. This just seems to reduce the amplitude of the sine wave.
    >
    > Then, when I looked up "low pass filter" on Wikipedia, I realized I
    > might have gotten it backwards (cut off higher frequencies instead of
    > lower frequencies), so I then ran a "high pass filter", asking
    > Audacity to cut off everything below 100 Hz. No improvement.
    >
    > Any other suggestions?
    >
    > Michael D.


    select part of the wavefile where there is only the hum.
    Click Effects/Noise Reduction/Noise Reduction
    click "Get Profile from Selection" and adjust the slider in the preview
    mode to the desired value.
    click close and select the whole wave, then call that filter again and
    click OK.
    --
    ciao Ban
    Apricale, Italy
    Ban, Jun 20, 2006
    #2
    1. Advertising

  3. Luhan Guest

    wrote:
    > I'm sure you've come across this before.
    >
    > We had to tape-record a meeting (with real cassette tapes!) yesterday.
    > I was planning on playing the tape as input to the sound card, and burn
    > a CD of the meeting for all attendees.
    >
    > Unfortunately, we have this HUM in the background. Sounds like it's
    > somewhere between 60 Hz and 120 Hz.
    >
    > How do I remove this?
    >
    > As a test, I tried the freeware program Audacity, asked it to produce a
    > pure 60 Hz tone, then
    > tried the "low pass filter" feature, cutting off everything below 100
    > Hz. This just seems to reduce the amplitude of the sine wave.
    >
    > Then, when I looked up "low pass filter" on Wikipedia, I realized I
    > might have gotten it backwards (cut off higher frequencies instead of
    > lower frequencies), so I then ran a "high pass filter", asking Audacity
    > to cut off everything below 100 Hz. No improvement.
    >
    > Any other suggestions?


    If the hum is at 120 Hz, you need to filter everthing below about 200
    Hz to get enough attenuation.

    Best is usually to use a notch filter at 60 or 120 Hz (or both).
    However, some hum signals contain harmonics that exists at much higher
    frequencies, these cannot be readily filtered.

    Luhan
    Luhan, Jun 20, 2006
    #3
  4. GregS Guest

    In article <>, wrote:
    >I'm sure you've come across this before.
    >
    >We had to tape-record a meeting (with real cassette tapes!) yesterday.
    >I was planning on playing the tape as input to the sound card, and burn
    >a CD of the meeting for all attendees.
    >
    >Unfortunately, we have this HUM in the background. Sounds like it's
    >somewhere between 60 Hz and 120 Hz.
    >
    >How do I remove this?
    >
    >As a test, I tried the freeware program Audacity, asked it to produce a
    >pure 60 Hz tone, then
    >tried the "low pass filter" feature, cutting off everything below 100
    >Hz. This just seems to reduce the amplitude of the sine wave.
    >
    >Then, when I looked up "low pass filter" on Wikipedia, I realized I
    >might have gotten it backwards (cut off higher frequencies instead of
    >lower frequencies), so I then ran a "high pass filter", asking Audacity
    >to cut off everything below 100 Hz. No improvement.
    >
    >Any other suggestions?


    How did you record it? Can you listen to the tape deck with phones plugged
    into the tape deck. How are you playing it back. What AC connections
    are made during recording and playback?

    greg
    GregS, Jun 20, 2006
    #4
  5. Joerg Guest

    Hello Micheal,


    > I'm sure you've come across this before.
    >
    > We had to tape-record a meeting (with real cassette tapes!) yesterday.
    > I was planning on playing the tape as input to the sound card, and burn
    > a CD of the meeting for all attendees.
    >
    > Unfortunately, we have this HUM in the background. Sounds like it's
    > somewhere between 60 Hz and 120 Hz.
    >
    > How do I remove this?
    >
    > As a test, I tried the freeware program Audacity, asked it to produce a
    > pure 60 Hz tone, then
    > tried the "low pass filter" feature, cutting off everything below 100
    > Hz. This just seems to reduce the amplitude of the sine wave.
    >
    > Then, when I looked up "low pass filter" on Wikipedia, I realized I
    > might have gotten it backwards (cut off higher frequencies instead of
    > lower frequencies), so I then ran a "high pass filter", asking Audacity
    > to cut off everything below 100 Hz. No improvement.
    >
    > Any other suggestions?
    >


    You really need what is called a "notch filter". In fact you'd need
    several because most hum isn't just 60 Hz but also 120Hz, 180Hz and
    maybe higher. This is due to dimmers, cheap motors, switch mode supplies
    and all that.

    I am not familiar with audio software or what filter features they have.
    However, you might want the ask the pros in this newsgroup:
    alt.audio.pro.live-sound

    Stay cool. Heard it's going to be 107F this coming weekend. Whew...

    --
    Regards, Joerg

    http://www.analogconsultants.com
    Joerg, Jun 20, 2006
    #5
  6. Guest

    GregS wrote:
    > In article <>, wrote:
    > >I'm sure you've come across this before.
    > >
    > >We had to tape-record a meeting (with real cassette tapes!) yesterday.
    > >I was planning on playing the tape as input to the sound card, and burn
    > >a CD of the meeting for all attendees.
    > >
    > >Unfortunately, we have this HUM in the background. Sounds like it's
    > >somewhere between 60 Hz and 120 Hz.
    > >
    > >How do I remove this?
    > >
    > >As a test, I tried the freeware program Audacity, asked it to produce a
    > >pure 60 Hz tone, then
    > >tried the "low pass filter" feature, cutting off everything below 100
    > >Hz. This just seems to reduce the amplitude of the sine wave.
    > >
    > >Then, when I looked up "low pass filter" on Wikipedia, I realized I
    > >might have gotten it backwards (cut off higher frequencies instead of
    > >lower frequencies), so I then ran a "high pass filter", asking Audacity
    > >to cut off everything below 100 Hz. No improvement.
    > >
    > >Any other suggestions?

    >
    > How did you record it? Can you listen to the tape deck with phones plugged
    > into the tape deck. How are you playing it back. What AC connections
    > are made during recording and playback?
    >
    > greg



    How did we record it? Co-worker also brought along two microphones
    (one UHF wireless, another wired), along with his video camera. Then
    we discovered that for legal reasons we couldn't videotape the
    conference.

    However, we found an ancient Sony tape recorder (with analog signal
    meter!) and power supply in a box. Plugged this right up. We did some
    tests - everything sounded ok. Then I had this great (horrible?) idea
    - let's move the equipment closer to the laptop, which was driving our
    Powerpoint presentation. Then we unexpectedly started right up - no
    chance to test. (No headset to monitor the input, unfortunately.)
    Then, after the presentation, re-wound, and... hum!

    Possibly from the power strip, or the projector, or the laptop... or
    maybe from the wired microphone.

    md
    , Jun 20, 2006
    #6
  7. Guest

    Joerg wrote:
    > Hello Micheal,
    >
    >
    > > I'm sure you've come across this before.
    > >
    > > We had to tape-record a meeting (with real cassette tapes!) yesterday.
    > > I was planning on playing the tape as input to the sound card, and burn
    > > a CD of the meeting for all attendees.
    > >
    > > Unfortunately, we have this HUM in the background. Sounds like it's
    > > somewhere between 60 Hz and 120 Hz.
    > >
    > > How do I remove this?
    > >
    > > As a test, I tried the freeware program Audacity, asked it to produce a
    > > pure 60 Hz tone, then
    > > tried the "low pass filter" feature, cutting off everything below 100
    > > Hz. This just seems to reduce the amplitude of the sine wave.
    > >
    > > Then, when I looked up "low pass filter" on Wikipedia, I realized I
    > > might have gotten it backwards (cut off higher frequencies instead of
    > > lower frequencies), so I then ran a "high pass filter", asking Audacity
    > > to cut off everything below 100 Hz. No improvement.
    > >
    > > Any other suggestions?
    > >

    >
    > You really need what is called a "notch filter". In fact you'd need
    > several because most hum isn't just 60 Hz but also 120Hz, 180Hz and
    > maybe higher. This is due to dimmers, cheap motors, switch mode supplies
    > and all that.
    >
    > I am not familiar with audio software or what filter features they have.
    > However, you might want the ask the pros in this newsgroup:
    > alt.audio.pro.live-sound
    >
    > Stay cool. Heard it's going to be 107F this coming weekend. Whew...
    >
    > --
    > Regards, Joerg
    >
    > http://www.analogconsultants.com



    No kidding... sounds like South Lake Tahoe is the place to be...

    Thanks,

    Michael
    , Jun 20, 2006
    #7
  8. Joerg Guest

    Hello Michael,


    > However, we found an ancient Sony tape recorder (with analog signal
    > meter!) and power supply in a box. Plugged this right up. We did some
    > tests - everything sounded ok. Then I had this great (horrible?) idea
    > - let's move the equipment closer to the laptop, which was driving our
    > Powerpoint presentation. Then we unexpectedly started right up - no
    > chance to test. (No headset to monitor the input, unfortunately.)
    > Then, after the presentation, re-wound, and... hum!
    >
    > Possibly from the power strip, or the projector, or the laptop... or
    > maybe from the wired microphone.
    >


    Oh boy. Could be direct coupling from the laptop power brick. Those can
    be nasty. I guess you really need software with freely programmable
    multiple notch filters. Google search the ham radio community, for FFT
    and sound card software. They often have similar problems to tackle,
    usually trying to fend off on-the-air noises that can be similar.

    --
    Regards, Joerg

    http://www.analogconsultants.com
    Joerg, Jun 20, 2006
    #8
  9. Guest

    Ban wrote:
    > wrote:
    > > I'm sure you've come across this before.
    > >
    > > We had to tape-record a meeting (with real cassette tapes!) yesterday.
    > > I was planning on playing the tape as input to the sound card, and
    > > burn a CD of the meeting for all attendees.
    > >
    > > Unfortunately, we have this HUM in the background. Sounds like it's
    > > somewhere between 60 Hz and 120 Hz.
    > >
    > > How do I remove this?
    > >
    > > As a test, I tried the freeware program Audacity, asked it to produce
    > > a pure 60 Hz tone, then
    > > tried the "low pass filter" feature, cutting off everything below 100
    > > Hz. This just seems to reduce the amplitude of the sine wave.
    > >
    > > Then, when I looked up "low pass filter" on Wikipedia, I realized I
    > > might have gotten it backwards (cut off higher frequencies instead of
    > > lower frequencies), so I then ran a "high pass filter", asking
    > > Audacity to cut off everything below 100 Hz. No improvement.
    > >
    > > Any other suggestions?
    > >
    > > Michael D.

    >
    > select part of the wavefile where there is only the hum.
    > Click Effects/Noise Reduction/Noise Reduction
    > click "Get Profile from Selection" and adjust the slider in the preview
    > mode to the desired value.
    > click close and select the whole wave, then call that filter again and
    > click OK.
    > --
    > ciao Ban
    > Apricale, Italy



    Thanks! That noise reduction trick removed my synthetic 60Hz sine wave
    tone.

    Will try this on the tape when my co-worker comes back in to work -
    unknown to me, he took Tues-Thurs off too. (And, he has the tape.)

    Michael
    , Jun 20, 2006
    #9
  10. On 20 Jun 2006 13:12:44 -0700, in sci.electronics.design
    wrote:

    >I'm sure you've come across this before.
    >
    >We had to tape-record a meeting (with real cassette tapes!) yesterday.
    >I was planning on playing the tape as input to the sound card, and burn
    >a CD of the meeting for all attendees.
    >
    >Unfortunately, we have this HUM in the background. Sounds like it's
    >somewhere between 60 Hz and 120 Hz.
    >
    >How do I remove this?
    >
    >As a test, I tried the freeware program Audacity, asked it to produce a
    >pure 60 Hz tone, then
    >tried the "low pass filter" feature, cutting off everything below 100
    >Hz. This just seems to reduce the amplitude of the sine wave.
    >
    >Then, when I looked up "low pass filter" on Wikipedia, I realized I
    >might have gotten it backwards (cut off higher frequencies instead of
    >lower frequencies), so I then ran a "high pass filter", asking Audacity
    >to cut off everything below 100 Hz. No improvement.
    >
    >Any other suggestions?
    >
    >Michael D.

    Try and download a copy of Cooledit 2000, its gat a notch fliter
    system that is rather excellent. Low pass is not the right tool for
    this sort of thing.

    For example my Canon XL1s produces shit sound, nice bit 150Hz hum, I
    just knock the fundamental down by 30dB, no problems


    martin
    martin griffith, Jun 20, 2006
    #10
  11. Wes Stewart Guest

    On Tue, 20 Jun 2006 20:37:48 GMT, Joerg
    <> wrote:


    [snip]
    >
    >Stay cool. Heard it's going to be 107F this coming weekend. Whew...



    Hello Joerg,

    What's the big deal about a balmy 107? It hit that in Tucson
    yesterday and summer doesn't start until tomorrow morning [g]. It
    cooled off today... only 102.9 at 3:50 PM.
    Wes Stewart, Jun 20, 2006
    #11
  12. Luhan wrote:
    > wrote:
    >
    >>I'm sure you've come across this before.
    >>
    >>We had to tape-record a meeting (with real cassette tapes!) yesterday.
    >>I was planning on playing the tape as input to the sound card, and burn
    >>a CD of the meeting for all attendees.
    >>
    >>Unfortunately, we have this HUM in the background. Sounds like it's
    >>somewhere between 60 Hz and 120 Hz.
    >>
    >>How do I remove this?
    >>
    >>As a test, I tried the freeware program Audacity, asked it to produce a
    >>pure 60 Hz tone, then
    >>tried the "low pass filter" feature, cutting off everything below 100
    >>Hz. This just seems to reduce the amplitude of the sine wave.
    >>
    >>Then, when I looked up "low pass filter" on Wikipedia, I realized I
    >>might have gotten it backwards (cut off higher frequencies instead of
    >>lower frequencies), so I then ran a "high pass filter", asking Audacity
    >>to cut off everything below 100 Hz. No improvement.
    >>
    >>Any other suggestions?

    >
    >
    > If the hum is at 120 Hz, you need to filter everthing below about 200
    > Hz to get enough attenuation.
    >
    > Best is usually to use a notch filter at 60 or 120 Hz (or both).
    > However, some hum signals contain harmonics that exists at much higher
    > frequencies, these cannot be readily filtered.
    >
    > Luhan
    >

    A comb filter might work, phase locked to the hum fundamental.

    --
    Many thanks,

    Don Lancaster voice phone: (928)428-4073
    Synergetics 3860 West First Street Box 809 Thatcher, AZ 85552
    rss: http://www.tinaja.com/whtnu.xml email:

    Please visit my GURU's LAIR web site at http://www.tinaja.com
    Don Lancaster, Jun 21, 2006
    #12
  13. Jim Thompson Guest

    On Tue, 20 Jun 2006 15:51:05 -0700, Wes Stewart <n7ws*@*yahoo.com>
    wrote:

    >On Tue, 20 Jun 2006 20:37:48 GMT, Joerg
    ><> wrote:
    >
    >
    >[snip]
    >>
    >>Stay cool. Heard it's going to be 107F this coming weekend. Whew...

    >
    >
    >Hello Joerg,
    >
    >What's the big deal about a balmy 107? It hit that in Tucson
    >yesterday and summer doesn't start until tomorrow morning [g]. It
    >cooled off today... only 102.9 at 3:50 PM.


    They're predicting 116°F in Phoenix on Friday. Time for you
    Easterners to drop by ;-)

    ...Jim Thompson
    --
    | James E.Thompson, P.E. | mens |
    | Analog Innovations, Inc. | et |
    | Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
    | Phoenix, Arizona Voice:(480)460-2350 | |
    | E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
    | http://www.analog-innovations.com | 1962 |

    I love to cook with wine. Sometimes I even put it in the food.
    Jim Thompson, Jun 21, 2006
    #13
  14. Luhan Guest

    Jim Thompson wrote:
    > On Tue, 20 Jun 2006 15:51:05 -0700, Wes Stewart <n7ws*@*yahoo.com>
    > wrote:
    >
    > >On Tue, 20 Jun 2006 20:37:48 GMT, Joerg
    > ><> wrote:
    > >
    > >
    > >[snip]
    > >>
    > >>Stay cool. Heard it's going to be 107F this coming weekend. Whew...

    > >
    > >
    > >Hello Joerg,
    > >
    > >What's the big deal about a balmy 107? It hit that in Tucson
    > >yesterday and summer doesn't start until tomorrow morning [g]. It
    > >cooled off today... only 102.9 at 3:50 PM.

    >
    > They're predicting 116°F in Phoenix on Friday. Time for you
    > Easterners to drop by ;-)


    Thats why I moved here from Quartzsite: normal mid-summer temps there
    peak at 130. No records are set, because there is no official
    temperature taken there.

    Luhan "The Desert Rat"
    Luhan, Jun 21, 2006
    #14
  15. Jim Thompson Guest

    On 20 Jun 2006 18:32:13 -0700, "Luhan" <> wrote:

    >
    >Jim Thompson wrote:
    >> On Tue, 20 Jun 2006 15:51:05 -0700, Wes Stewart <n7ws*@*yahoo.com>
    >> wrote:
    >>
    >> >On Tue, 20 Jun 2006 20:37:48 GMT, Joerg
    >> ><> wrote:
    >> >
    >> >
    >> >[snip]
    >> >>
    >> >>Stay cool. Heard it's going to be 107F this coming weekend. Whew...
    >> >
    >> >
    >> >Hello Joerg,
    >> >
    >> >What's the big deal about a balmy 107? It hit that in Tucson
    >> >yesterday and summer doesn't start until tomorrow morning [g]. It
    >> >cooled off today... only 102.9 at 3:50 PM.

    >>
    >> They're predicting 116°F in Phoenix on Friday. Time for you
    >> Easterners to drop by ;-)

    >
    >Thats why I moved here from Quartzsite: normal mid-summer temps there
    >peak at 130. No records are set, because there is no official
    >temperature taken there.
    >
    >Luhan "The Desert Rat"


    Does anyone live in a house there? All you can see from I10 is
    trailers ;-)

    ...Jim Thompson
    --
    | James E.Thompson, P.E. | mens |
    | Analog Innovations, Inc. | et |
    | Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
    | Phoenix, Arizona Voice:(480)460-2350 | |
    | E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
    | http://www.analog-innovations.com | 1962 |

    I love to cook with wine. Sometimes I even put it in the food.
    Jim Thompson, Jun 21, 2006
    #15
  16. martin griffith wrote:
    <snip
    > Try and download a copy of Cooledit 2000, its gat a notch fliter
    > system that is rather excellent. Low pass is not the right tool for
    > this sort of thing.
    >
    > For example my Canon XL1s produces shit sound, nice bit 150Hz hum, I
    > just knock the fundamental down by 30dB, no problems
    >
    >
    > martin


    Good choice but hard to get. After Adobe bought Syntrilium, they
    renamed CoolEdit Pro Audition and removed CoolEdit 2000. I have looked
    around for it but I haven't found it. Audition sells $349. Its a shame
    they got rid of the $69 2000. It was really good.

    GG
    Glenn Gundlach, Jun 21, 2006
    #16
  17. Luhan Guest

    Jim Thompson wrote:
    > On 20 Jun 2006 18:32:13 -0700, "Luhan" <> wrote:
    >
    > >
    > >Jim Thompson wrote:
    > >> On Tue, 20 Jun 2006 15:51:05 -0700, Wes Stewart <n7ws*@*yahoo.com>
    > >> wrote:
    > >>
    > >> >On Tue, 20 Jun 2006 20:37:48 GMT, Joerg
    > >> ><> wrote:
    > >> >
    > >> >
    > >> >[snip]
    > >> >>
    > >> >>Stay cool. Heard it's going to be 107F this coming weekend. Whew...
    > >> >
    > >> >
    > >> >Hello Joerg,
    > >> >
    > >> >What's the big deal about a balmy 107? It hit that in Tucson
    > >> >yesterday and summer doesn't start until tomorrow morning [g]. It
    > >> >cooled off today... only 102.9 at 3:50 PM.
    > >>
    > >> They're predicting 116°F in Phoenix on Friday. Time for you
    > >> Easterners to drop by ;-)

    > >
    > >Thats why I moved here from Quartzsite: normal mid-summer temps there
    > >peak at 130. No records are set, because there is no official
    > >temperature taken there.
    > >
    > >Luhan "The Desert Rat"

    >
    > Does anyone live in a house there? All you can see from I10 is
    > trailers ;-)


    The houses there are all north of I-10; about 1 square mile. I was in
    a 32 foot motorhome with no ac (the compressor was already in 'thermal
    cutout' from the ambiant temperature). I had a makeshift swamp cooler
    that put out 110 degree's if you sat right in front of it.

    Even most of the locals leave town for the summer. A few years before
    I was there, they had a 'hot one' - hitting 136 reqularly.

    Now the worst I have to deal with, is the walk to the mailbox on a hot
    day.

    Luhan
    Luhan, Jun 21, 2006
    #17
  18. Robert Baer Guest

    Joerg wrote:

    > Hello Micheal,
    >
    >
    >> I'm sure you've come across this before.
    >>
    >> We had to tape-record a meeting (with real cassette tapes!) yesterday.
    >> I was planning on playing the tape as input to the sound card, and burn
    >> a CD of the meeting for all attendees.
    >>
    >> Unfortunately, we have this HUM in the background. Sounds like it's
    >> somewhere between 60 Hz and 120 Hz.
    >>
    >> How do I remove this?
    >>
    >> As a test, I tried the freeware program Audacity, asked it to produce a
    >> pure 60 Hz tone, then
    >> tried the "low pass filter" feature, cutting off everything below 100
    >> Hz. This just seems to reduce the amplitude of the sine wave.
    >>
    >> Then, when I looked up "low pass filter" on Wikipedia, I realized I
    >> might have gotten it backwards (cut off higher frequencies instead of
    >> lower frequencies), so I then ran a "high pass filter", asking Audacity
    >> to cut off everything below 100 Hz. No improvement.
    >>
    >> Any other suggestions?
    >>

    >
    > You really need what is called a "notch filter". In fact you'd need
    > several because most hum isn't just 60 Hz but also 120Hz, 180Hz and
    > maybe higher. This is due to dimmers, cheap motors, switch mode supplies
    > and all that.
    >
    > I am not familiar with audio software or what filter features they have.
    > However, you might want the ask the pros in this newsgroup:
    > alt.audio.pro.live-sound
    >
    > Stay cool. Heard it's going to be 107F this coming weekend. Whew...
    >

    The three frequencies you mentioned will kill almost all of it; a low
    pass with 3dB point near (say) 5KHz will take care of the spikes which
    are individually not too energetic, but add up to most of the balance of
    the noise.
    This all ASS-u-MEs that the fundamental is 60Hz; modify the three if
    50Hz instead.
    Robert Baer, Jun 21, 2006
    #18
  19. On 20 Jun 2006 19:42:54 -0700, in sci.electronics.design "Glenn
    Gundlach" <> wrote:

    >
    >martin griffith wrote:
    ><snip
    >> Try and download a copy of Cooledit 2000, its gat a notch fliter
    >> system that is rather excellent. Low pass is not the right tool for
    >> this sort of thing.
    >>
    >> For example my Canon XL1s produces shit sound, nice bit 150Hz hum, I
    >> just knock the fundamental down by 30dB, no problems
    >>
    >>
    >> martin

    >
    >Good choice but hard to get. After Adobe bought Syntrilium, they
    >renamed CoolEdit Pro Audition and removed CoolEdit 2000. I have looked
    >around for it but I haven't found it. Audition sells $349. Its a shame
    >they got rid of the $69 2000. It was really good.
    >
    >GG

    just found this
    http://www.mpex.net/en/software/download/cooledit.html

    I dont know if it works, since I already have cooledit


    martin
    martin griffith, Jun 21, 2006
    #19
  20. Roger Guest

    Jim Thompson wrote:

    > They're predicting 116°F in Phoenix on Friday. Time for you
    > Easterners to drop by ;-)
    >

    With drop being the key word!
    Roger, Jun 21, 2006
    #20
    1. Advertising

Want to reply to this thread or ask your own question?

It takes just 2 minutes to sign up (and it's free!). Just click the sign up button to choose a username and then you can ask your own questions on the forum.
Similar Threads
  1. removing "hum" from an audio recording

    , Jun 20, 2006, in forum: Electronic Design
    Replies:
    36
    Views:
    828
    joseph2k
    Jul 6, 2006
  2. weedmonke

    RCA home theater rt2250 - no audio, 60Hz hum

    weedmonke, Oct 20, 2003, in forum: Electronic Repair
    Replies:
    3
    Views:
    370
    weedmonke
    Oct 23, 2003
  3. CL
    Replies:
    3
    Views:
    458
  4. Jax
    Replies:
    38
    Views:
    645
    DaveW
    Mar 14, 2007
  5. John Leister

    RFI Hum Problem. PC inducing hum in stereo

    John Leister, Nov 25, 2003, in forum: Hobby Electronics
    Replies:
    61
    Views:
    1,086
    Byron John Forbes
    Dec 9, 2003
Loading...

Share This Page