[ale] [OT] Help! burned cd playback wave clipped, original wave perfect

Mon Sep 9 20:16:32 EDT 2013

Hi Neal,

Thanks for the tip.  I was able to solve the problem I had using the mic input on the laptop, once I figured out how to set it. I'll keep the usb dongle in mind.  I have some really cheap ones of those from amazon (no name brand) for a few dollars each.  Those had mono inputs, and I needed stereo.  The one you mentioned might be better.

In terms of the equipment, I had a dual cassette deck line out hooked into an amp, then the line output of the amp hooked to the laptop.  The main problem was that, when I set the controls of the mic input on the laptop one way, it clipped even though the overall level was not too high, and when I set it the other way, it worked.  It was quite confusing.

Sincerely,

Ron

Neal Rhodes <neal at mnopltd.com> wrote:

>I just skimmed this sorry if I'm way off. 
>
>Laptops usually have hopeless audio input.    Even if they have
>line-in,
>it may be affected by noise on the system board. 
>
>Griffin makes an iMic USB dongle which can provide excellent audio
>input, either of MIC level or Line Level, and is not affected by all
>the
>strange things going on inside the laptop.  
>
>Also note that if you are coming from consumer grade audio, like a
>cassette player, its headset output may distort at full volume.
>Sometimes better to stick with 80% or less, and trim in incoming signal
>to top-o-the-green. 
>
>And unfortunately, digital inputs do not like to get clipped. 
>
>
>
>On Mon, 2013-09-09 at 14:28 -0400, Ron Frazier (ALE) wrote:
>
>> Hi Boris,
>> 
>> Thanks for the note.  I think this laptop just has the mic in, but
>I'll keep it in mind in case I run into machines with different
>configurations.
>> 
>> Sincerely,
>> 
>> Ron
>> 
>> 
>> 
>> Boris Borisov <bugyatl at gmail.com> wrote:
>> 
>> >You need boost for some type of microphones that are not very
>sensitive
>> >or
>> >if you speak far from the microphone. For record from any analog
>device
>> >you
>> >should use LINE IN -> LINE OUT
>> >connection with proper cable. LINE levels are well known and are
>> >standard
>> >(0db or little more than 0.7 volts). Most laptops/netbooks have just
>> >one
>> >input jack normally MIC but this input is switchable trough mixer
>> >control
>> >panel between MIC/LINE. Make sure you are using LINE.
>> >
>> >
>> >
>> >On Mon, Sep 9, 2013 at 11:17 AM, Ron Frazier (ALE) <
>> >atllinuxenthinfo at techstarship.com> wrote:
>> >
>> >> Hi all,
>> >>
>> >> Thanks for the replies to this message.  I know it's been a few
>days
>> >but I
>> >> wanted to follow up.
>> >>
>> >> Sometimes reality has a way of breaking through any delusions you
>> >have
>> >> about what's going on.
>> >>
>> >> The clipping turned out to be my fault, unknowingly, and it wasn't
>> >the cd
>> >> player.
>> >>
>> >> The audio controls for the mic input on this laptop have two
>sliders
>> >you
>> >> can move.  One is input level.  And the other is mic boost. 
>> >Originally, I
>> >> had the input level at about 70% and the mic boost at 10 db.  At
>that
>> >> point, I was getting good clean waveforms.  Later, I decided I
>would
>> >like
>> >> it better if the level control was closer to 50%, so I put it
>there
>> >and
>> >> raised the mic boost control to 20 db.  In that configuration, the
>> >waveform
>> >> is clipped, even though the total level coming into audacity is
>> >within
>> >> bounds.
>> >>
>> >> I don't know why less boost and more level is OK and more boost
>and
>> >less
>> >> level fails.  I don't know what's going on in the hardware.  I
>only
>> >found
>> >> this out after I burned another cd from cassette input, which had
>> >worked
>> >> before, and it sounded all muddy and fuzzy.
>> >>
>> >> So, if you're recording in audacity or a similar program, and you
>get
>> >a
>> >> wave like the bottom one in my picture, you probably have
>something
>> >wrong.
>> >>
>> >> I had to learn several other things too, like how to fix minimal
>> >clipping
>> >> in the source wave, how to boost up weak wave forms ripped from
>cd,
>> >how to
>> >> reduce down really loud ones from different sources (as I was
>making
>> >a
>> >> mashup), even how to somewhat remove a dc offset that infected one
>> >cassette
>> >> I had.
>> >>
>> >> Oh, and, if you're creating a cd from an audio book or something,
>> >DON'T
>> >> even think about just recording one hour long track on a cd.  This
>> >will
>> >> drive the person playing the disc crazy, if they want to go to a
>> >certain
>> >> section in the disc and have to hold the fast forward or backward
>> >buttons
>> >> down for 6 minutes to get 45 minutes into the program.
>> >>
>> >> Learned that the hard way too.
>> >>
>> >> In audacity, zoom into the waveform enough so you can see pauses
>> >between
>> >> words or songs.  Add a label at that point.  Then, when you're
>> >through
>> >> editing, you can select the entire thing and select export
>multiple.
>> >>  Select to break on labels in the dialog box, set to auto number,
>and
>> >> you'll get a number of little track files you can burn to cd.  You
>> >may wish
>> >> to export the full audio for editing later as well.
>> >>
>> >> Also, when I burned the cd, there was an option in the settings
>that
>> >I had
>> >> to check which said burn without gaps.
>> >>
>> >> For music, I made sure the waveform already had the gaps I wanted,
>1
>> >sec
>> >> before and after each song.  For spoken word audio book, I just
>let
>> >it run.
>> >>  Having the burning software insert 5 sec gaps in the middle where
>I
>> >didn't
>> >> want them, the first time, was very frustrating.
>> >>
>> >> I did not try the function that's supposed to automatically break
>the
>> >> tracks on silences, but did the breaking myself.
>> >>
>> >> I chose to put 1 hour of stuff on each cd and put track breaks
>every
>> >6
>> >> minutes.
>> >>
>> >> With the help of some stereo equipment that I bartered from Jim
>> >Kinney, I
>> >> was able to eventually create the music disc for my family's event
>> >and it
>> >> worked out very well.
>> >>
>> >> So, thanks to Jim and thanks to you guys for help with the audio.
>> >>
>> >> Sincerely,
>> >>
>> >> Ron
>> >>
>> >>
>> >>
>> >> Phil Turmel <philip at turmel.org> wrote:
>> >>
>> >> >Hi Ron,
>> >> >
>> >> >On 08/29/2013 01:14 AM, Ron Frazier (ALE) wrote:
>> >> >
>> >> >[trim /]
>> >> >
>> >> >> Look at this file.
>> >> >>
>> >> >>
>> >https://dl.dropboxusercontent.com/u/9879631/cd_playback_clipping.png
>> >> >>
>> >> >> The top waveform, titled ripped, is the file that was ripped
>from
>> >the
>> >> >> cd.  It looks very nice and there is no clipping or excursions
>> >beyond
>> >> >> the +/- 1 amplitude levels.  It's just like the master file.
>> >> >>
>> >> >> The bottom file, titled played, is what was obtained by playing
>> >that
>> >> >> same file (track) back and rerecording it.  Note that it is
>> >severely
>> >> >> clipped, BUT, its excursions are nowhere near the +/- 1 limits.
>
>> >This
>> >> >> proves I don't have the input volume too loud.  This is
>something
>> >> >that's
>> >> >> happening in the playback circuit of the cd player.  I've
>> >confirmed
>> >> >the
>> >> >> behavior on 2 cd players and observed the same thing on a
>> >> >commercially
>> >> >> recorded cd.
>> >> >>
>> >> >> Also, I've compared the audio playing back the ripped file,
>versus
>> >> >the
>> >> >> played file from the cd player.  The ripped version sounds
>better
>> >and
>> >> >> fuller.
>> >> >>
>> >> >> I wonder if they're doing some dynamic range compression on the
>> >> >output
>> >> >> of the dac.  Whatever it is, it's not stored in the raw cd
>data.
>> >> >>
>> >> >> Does anyone know what this is and if there is a way to
>eliminate
>> >> >this,
>> >> >> so that the true waveform on the cd, which is the same as my
>> >master,
>> >> >is
>> >> >> what comes out of the speakers.
>> >> >
>> >> >From what is visible in that screenshot, it is almost certainly
>the
>> >CD
>> >> >player's output circuit clipping at that output volume level.
>> >> >
>> >> >Turn the CD player's output volume down until you see no
>clipping,
>> >then
>> >> >turn your capture card's input volume up (if necessary) to
>achieve
>> >> >maximum sensitivity for that level.
>> >> >
>> >> >Clipping can occur in any amplifier circuit between the D/A
>> >conversion
>> >> >(in the player) and the A/D conversion (in your input card).  If
>the
>> >> >clipping is happening in the player's first analog stages after
>the
>> >D/A
>> >> >conversion, before it gets to the volume control, you won't be
>able
>> >to
>> >> >fix it.  Your only option would re-level the master WAV to within
>> >the
>> >> >CD
>> >> >player's capabilities.  (I'd toss the CD player if that's true.)
>> >> >
>> >> >Phil
>> >> >
>> >> >_______________________________________________
>> >> >Ale mailing list
>> >> >Ale at ale.org
>> >> >http://mail.ale.org/mailman/listinfo/ale
>> >> >See JOBS, ANNOUNCE and SCHOOLS lists at
>> >> >http://mail.ale.org/mailman/listinfo
>> >>
>> >>
>> >> --
>> >>
>> >> Sent from my Android Acer A500 tablet with bluetooth keyboard and
>K-9
>> >Mail.
>> >> Please excuse my potential brevity if I'm typing on the touch
>screen.
>> >>
>> >> (PS - If you email me and don't get a quick response, you might
>want
>> >to
>> >> call on the phone.  I get about 300 emails per day from alternate
>> >energy
>> >> mailing lists and such.  I don't always see new email messages
>very
>> >> quickly.)
>> >>
>> >> Ron Frazier
>> >> 770-205-9422 (O)   Leave a message.
>> >> linuxdude AT techstarship.com
>> >> Litecoin: LZzAJu9rZEWzALxDhAHnWLRvybVAVgwTh3
>> >> Bitcoin: 15s3aLVsxm8EuQvT8gUDw3RWqvuY9hPGUU
>> >>
>> >>
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>> >> http://mail.ale.org/mailman/listinfo
>> >>
>> >
>> >
>>
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>> >Ale mailing list
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>> >http://mail.ale.org/mailman/listinfo
>> 
>> 
>> --
>> 
>> Sent from my Android Acer A500 tablet with bluetooth keyboard and K-9
>Mail.
>> Please excuse my potential brevity if I'm typing on the touch screen.
>> 
>> (PS - If you email me and don't get a quick response, you might want
>to
>> call on the phone.  I get about 300 emails per day from alternate
>energy
>> mailing lists and such.  I don't always see new email messages very
>quickly.)
>> 
>> Ron Frazier
>> 770-205-9422 (O)   Leave a message.
>> linuxdude AT techstarship.com
>> Litecoin: LZzAJu9rZEWzALxDhAHnWLRvybVAVgwTh3
>> Bitcoin: 15s3aLVsxm8EuQvT8gUDw3RWqvuY9hPGUU
>> 
>> 
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>> http://mail.ale.org/mailman/listinfo
>
>
>
>
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--

Sent from my Android Acer A500 tablet with bluetooth keyboard and K-9 Mail.
Please excuse my potential brevity if I'm typing on the touch screen.

(PS - If you email me and don't get a quick response, you might want to
call on the phone.  I get about 300 emails per day from alternate energy
mailing lists and such.  I don't always see new email messages very quickly.)

Ron Frazier
770-205-9422 (O)   Leave a message.
linuxdude AT techstarship.com
Litecoin: LZzAJu9rZEWzALxDhAHnWLRvybVAVgwTh3
Bitcoin: 15s3aLVsxm8EuQvT8gUDw3RWqvuY9hPGUU