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Music Media Software

Normalizing Music? 136

Posted by Cliff from the medium-peaks-and-moderate-troughs dept.
Beans asks: "I have a couple classical music CD's which I listen to at work, and use for putting the baby to sleep. I can never find the correct volume, I can't hear soft spots, so I turn it up, only to have a rising crescendo rouse the baby, or at work, have co-workers glace over. What is a good way to normalize them (read on for what I mean by normalize)? All of the normalizing software I have seen uses the entire song for the window of normalzing. Basically makes determines a static value required to get the average volume of the song to the user defined level, then applies that value to the entire song. What I need is something that normalizes over a sliding window, or say 5 seconds, or whatever. In effect making soft spots louder, and crescendo's quieter. Not the way the music was intended to be heard, but perfect for music-at-work, or putting kids to sleep. Does anyone know of any software that does this? On a side note, I work for a Seismic processing company, and we do stuff like this all the time on Seismic waves, not sound waves. If I can't find any canned software to do this, I may modify some of our code to work with WAV files, but I don't want to reinvent the wheel."
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Normalizing Music? More

Normalizing Music?

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  • WMP9 or 10 (Score:3, Interesting)

    by WhatAmIDoingHere ( 742870 ) * <sexwithanimals@gmail.com> on Thursday March 10, 2005 @03:42PM (#11902757) Homepage
    They both have a volume equalizer option.

    • Re:WMP9 or 10 (Score:5, Informative)

      by DetrimentalFiend ( 233753 ) * on Thursday March 10, 2005 @03:59PM (#11902982)
      It sounds like volume equalization is what microsoft calls compression. Compression is where the amplitude of music is altered depending on the average amplitude of the last few moments of music. It's basically like the device/computer has its hand on the volume nob and tries to keep the volume comming out at the same level, which is exactly what the poster described. Any good sound editing program has compression effects and I would be supprised if many audio players didn't offer it as well. I know my creative nomad has the feature available. FYI, audio compression is also what radio stations use to make their station sound louder.

      • Re:WMP9 or 10 (Score:3, Informative)

        by Anonymous Coward
        > It sounds like volume equalization is what microsoft calls compression

        It's pretty much a standard term.

        > FYI, audio compression is also what radio stations use to make their station sound louder.

        It's what TV advertisers do to make their station ads louder. FM transmissions pretty much have to be compressed. Get too loud with AM and you'll just clip and distort. Get too loud with FM, and you'll bleed into a neighboring station. Radio stations don't really like compression all that much, as it

      • Re:WMP9 or 10 (Score:3, Informative)

        by Grab ( 126025 )
        Compression is a standard audio term, not an MS invention. Good description of what it does though. A compressor effects pedal is often used by guitarists because "turning up the volume" as the note decays away basically makes the note go on for ever (which is good for atmospheric guitar effects).

        For the benefit of the original poster, if you want quiet relaxing classical music, try picking quiet relaxing pieces. If you're looking for a low-volume piece of music, why not just put in Metallica "Creeping
    • All these technofangle solutions so far - isn't it easier to get a CD player with a dynamic range compressor? I have one in my portable. It works a treat. My expensive HIFI receiver has a dynamic range mode as well - max, normal, low. That works quite well but it's very noticible when it starts playing with the level. They advertise it as "night mode" in a lot of cases.

      You used to be able to buy little analog boxes that you plugged between the output of the player and your preferred electro-mechanical
      • my reciever has this as well, but i was under the impression that it didnt do what the submitter wanted, they instead block out/ reduce the harmonic RANGE of the sound.

        This would mean, less bass, less extremely high trebles, but not actually changing the volume at all

        its considered night mode because those really high frequences and really low frequencies are more likely to be annoying to others at night time

        • Re:WMP9 or 10 (Score:3, Informative)

          by thegrassyknowl ( 762218 )
          It's a dynamic range control on mine (and actually called that, except in the advertising) - just flattens out the levels so you can hear people talking at a reasonable volume and when explosions and other loud parts of movies happen they are dropped back to "people talking" level so they don't make a racket. It's described in the book for my receiver.

          I guess it probably depends on the receiver as well.

    • Re:WMP9 or 10 (Score:2, Informative)

      by slonkak ( 648358 )
      MP3Gain is the best program I've found. It doesn't normalize like other programs do. 'Instead, MP3Gain uses David Robinson's Replay Gain algorithm to calculate how loud the file actually sounds to a human's ears.' [sourceforge.net]

      This is what I use and it works like a charm...
  • This is a feature in the newer versions of Windows Media Player, but I'm not sure if it normalizes over the entire song or not. You might also be able to normalize the volume some by playing with the EQ and lowering the volume of higher pitched sounds.

  • Look up information about audio engineering, (Score:5, Informative)

    by MoOsEb0y ( 2177 ) on Thursday March 10, 2005 @03:43PM (#11902777)
    it seems the music "industry" has been doing a very good job of this. What exactly you want is dynamic compression, not normalization. click here for more information. [teamcombooks.com]
  • Doesn't iTunes also have this option? Ir is it as the article poster states, that it takes a value based on the whole song and uses that to scale back the volume?

  • Plugins (Score:5, Informative)

    by Noah Adler ( 627206 ) on Thursday March 10, 2005 @03:46PM (#11902811) Homepage

    I've used normalizer plugins in both XMMS and Winamp. They aren't perfect, but they're generally alright.

    Check out http://volnorm.sourceforge.net/ [sourceforge.net] for an XMMS plugin, or one of the many Winamp plugins here [winamp.com].

    • For WinAmp, I like "RockSteady" by Piettro Pro. You can tune the gain time and amplification levels individually, although the presets it comes with seem pretty good. (I'm on v2.1, don't know if there's a newer version.) You can also set it to control the left-right speakers together or independently, although independent control sometimes has problems on songs where they cycle the L-R balance rapidly, but that shouldn't be a problem with classical music.

      Good luck!

  • Dynamic Compression with Audacity (Score:5, Informative)

    by mbrubeck ( 73587 ) on Thursday March 10, 2005 @03:49PM (#11902852) Homepage
    What you want is a compressor. Audacity [sourceforge.net] (GPL software for Linux, Mac, Windows) includes a simple built-in compressor, and also works with compressor plug-ins like SC4 by Steve Harris [plugin.org.uk]. (You can get SC4 by installing the swh-plugins collection on Linux or Unix; it's also included with the Windows version of Audacity).
  • Many products do this in hardware. I have both wireless headphones and a MiniDisc player that does this. The MiniDisc player can be set to manual recording level, so it is fixed to one level, but the headphones can't be switched away from this automatic setting. So I don't use those headphones for classical music listening, for example.

    You might have a product that does this allready, that you could plug in between the computer, CD, player, etc and the amplifier/speakers.

  • That's not dynamics compression, not normalization (Score:5, Insightful)

    by waynegoode ( 758645 ) * on Thursday March 10, 2005 @03:50PM (#11902869) Homepage
    That's not normalizing, that's dynamics compression.

    Normalizing scales the entire file so that the highest sample is the highest value that can be represented. For many sound formats, this is 32768, for 15 bits. (1 bit left for the sign). This lets the sample use the full range. However, the volume of the file is based on the value of one sample.

    What you want is to amplify different parts of the file so that the level of the song is more consistent. For example, sample every 1/4 second and adjust the level based on the average of that sample. A typical value might be 2:1 compression above -10 db. In this case, if the volume is above -10 db, the amount above -10 db is cut in half. -10 stays at -10, but -6 is scaled to -8, 0 to -5. (0 db is the highest value that can be represented.) There is a lot more to it, including look ahead, recovery time, multiple levels, etc.

    It is similar to riding the voume control manually and turning it down for the loud parts and back up for the soft parts, but very quickly.

    After dynamics adjustment, you usually normalize the sample.

    I edit speech audio for my church and deal with this all the time. I use Cool Edit 2000 and it is great at this. However, it is no longer available. But most audio editing programs can do this. Try Audacity.

    • On the parent, I copied the subject from the message, rearranged it and go it wrong. I meant "That's dynamics compression, not normalization."
    • I use Cool Edit 2000 and it is great at this. However, it is no longer available.

      CoolEdit was bought by Adobe and is now available under the name Adobe Audition [adobe.com]. Perhaps you were referring to the lack of a budget version of the software, however, in which case, yeah, that kinda sucks.

      • Adobe bought the company and turned Cool Edit Pro into Audition. They dropped Cool Edit 2000. It sold for $70 or $100 with the 4 track plug-in. The audio cleanup plug-in was $50 and it was great. It could clean room noise, tape hiss, clicks, pops, etc.

        The program and the plug-in did more than everything I needed. But now I'm stuck. I'd like to buy another license for it, but I can't. Audition costs $300. There is no upgrade except the $170 upgrade to Audition, more than I paid to start with. So, f
        • You're right - it *is* annoying to be stuck in that situation. We use CEP (well, we recently went for Audition[1]) for exactly the same thing -- editing speaking recordings at church (and some editing of individual music tracks, too; but most of that is handled from inside our multitrack application).

          They also seem to have gotten rid of a lot of the "extras" that CEP used to have...like free downloadable clips and free plugins (or am I just remembering wrong?)

          Cheers!

          [1] - don't bother, Audition is pretty

  • Classical != Quiet (Score:4, Informative)

    by yasth ( 203461 ) on Thursday March 10, 2005 @03:51PM (#11902879) Homepage Journal
    Classical music with its large dynamic ranges is meant to be loud at times. People think classical is something nice and calm like a little old lady, but much of it is meant to be exciting, and brash.
    • True - you don't see scoring for a cannon even in the hardest Metal... but sometimes you want to be able to hear it over road noise and/or not scare the baby.

      You could also argue that we should all set our eq's flat, or at least only for equipment compensation because that's "how the music was intended." Me, I like to boost the mid-bass a bit and don't apologize for it.
      • Great line about the cannon.

        It is just that there is a whole section of classical/trad music just for lulling babies to sleep. It is called a lullaby. While some of them have disturbing lyrics the baby doesn't care.

        As for work music, hmmm dance music is probably best, waltzes, etc. Solid beat, and relatively limited dynamic range. Or marches, but marches have all sorts of connotations that you just don't want to get into most likely.

        It isn't so much I have a problem with people doing it, but not really t

        • It is just that there is a whole section of classical/trad music just for lulling babies to sleep. It is called a lullaby. While some of them have disturbing lyrics the baby doesn't care.

          Benjamin Britten had something to say on the subject (A Charm, Op. 41):

          Quiet!

          Sleep! or I will make
          Erinnys whip thee with a snake,
          And cruel Rhadamanthus take
          Thy body to the boiling lake,
          Where fire and brimstones never slake;...

          A few years ago my Mum was practising this before a concert (s

          • Hehe, and some parents wonder what the alternative to threatening spanking is. :-P

            Seriously this is why I like Slashdot. I mean anywhere else it would be "cradle will rock and cradle will fall...". So thank you for boosting my faith in it.

            Hmmm and Thomas Randolph is not so bad a tutor of children (Though On Sixe Cambridge Lasses... would probably cause way too much explaning.)

          • Benjamin Britten was a nut job, or at least set the words of a nut job to music. That would be Rejoice in the Lamb, the lyrics of which were taken from Jubilate Agno, written by Christopher Smart while in a mental institution. Strange indeed. I've performed Rejoice and A ceremony of Carols, both odd. Ceremony is hauntingly addictive to listen to.

      • FWIW, one of Ice Cube's solo tracks has the sound of a bomb going off. Aptly named, "The Bomb."

      • Re:Classical != Quiet (Score:4, Informative)

        by brunson ( 91995 ) * on Thursday March 10, 2005 @06:10PM (#11904548) Homepage
        False:
        AC/DC - For Those About to Rock
    • I find it great when O Fortuna comes on to crank the quite part up to a normal volume - then when it suddenly becomes loud my windows explode...

      And the looks from other drivers at a stop light are great when that happens in the summer with the windows down!

      Anyway...

      • Ain't it true?!

        That's probably a perfect example of classical music with a huge range of quickly changing dynamics.
      • I find it great when O Fortuna comes on to crank the quite part up to a normal volume - then when it suddenly becomes loud my windows explode... And the looks from other drivers at a stop light are great when that happens in the summer with the windows down!

        So, do your doors bulge outward when your windows explode when they're down? ;D
        • Unspecified fact - I'm Canadian - it's cold round here these days - I don't drive with the windows down all year...

          But yes I totally messed up the logic on that, it was a typed out train of thought - and I don't prefer to proofread...

          Oh well
    • But the post specifically says: "Not the way the music was intended to be heard, but perfect for music-at-work, or putting kids to sleep." The poster realizes classical doesn't equal quiet, that's why he/she is looking for a solution to change that.
    • Yeah, he knows that:
      Not the way the music was intended to be heard, but perfect for music-at-work, or putting kids to sleep.

  • Rock Steady (Score:2, Informative)

    by FreshlyShornBalls ( 849004 )
    Give this [lycos.de] plug-in for Winamp a try. It's called Rock Steady and I've been using it for a year or two at the office without a hitch.
  • That's the name of the feature you're looking for.

  • One word. (Score:2, Insightful)

    by Solder Fumes ( 797270 )
    Headphones.
    • My baby is not a big fan of your word.
      • Quit forcing your baby to listen to classical music, it probably just wants to get one fucking night of decent sleep. Or maybe your baby is more into rap, or Norwegian death metal.

    • One word. (Score:0)
      by Solder Fumes (797270) Alter Relationship on Friday March 11, @06:58AM (#11902972)

      Headphones.

      Someone mod 'Solder Fumes' back up as 'Insightful' please.

      To the original story poster: headphones are your answer. If co-workers can hear your music even faintly, it's not fair to them (unless you have the approval of everyone who can hear it).

      There is a level of irritation before co-workers get bugged enough to "glance over" - don't impose it on your colleagues. Silence is better.

      • I sometimes wear headphones at work (just a temp, though) but I think some people will consider that to be rude. It's just that headphones have this fuck-off attitude associated with them, like an in your face version of a DND label. I mean, that's not what I feel like when wearing them, I don't mind people interrupting me at all, but I know it's what it looks like. I often wear only one side of the headphones so that I at least notice people "sneaking" up to me and start the conversation myself if necessar
        • The fuck-off attitude is bad - I have experienced it too. The solution is to fix the attitude, not to impose music on others (as you point out below also).

          To better notice people, one could use loose-fitting headphones (so you can hear ambient noise), or not listen to music at work at all.

          > I'm not saying that imposing your music on others
          > is a good alternative, of course, but maybe they've
          > told him they don't mind as long as the volume is low enough.

          Even if the boss Ok-ed it, the low volume l
      • but he was told he could listen at a reasonable volume.
        • but the slashdot article makes no such claim.

          Even if his boss told him, it's still irritating to co-workers - as i said, there is a level of irritation that occurs before someone is forced to glance over.

  • Compression, not normalization (Score:5, Informative)

    by ChadN ( 21033 ) on Thursday March 10, 2005 @03:58PM (#11902976)
    What you want is 'compression', not normalization. I don't mean data compression (ie. making smaller file), btw.

    Music studio use "compressors" to reduce the dynamic range of sound. Ones that work in real time have to be a bit sophisticated (sliding window, like you said), but doing it offline is easier, since you can know the max and min sound values beforehand.

    I don't know what tools are out there in PC land, hopefully someone will answer. But I will mention that I used to have a portable CD player with a built in compressor (to help keep your music above the ambient background noise, espicially when driving) and it was GREAT! It is a feature that I don't see much in portable devices anymore, which surprises me...

    Anyway, hopefully this might give you a new term to google for, at least. Try searching for "dynamic range compressor", or something...

    Alright, I found some windows plugins that might help; Anyone with some Linux/MacOs/Unix equivalents?

    http://www.divx-digest.com/software/tfm_filter.h tm l
    http://www.divx-digest.com/software/dedynamic.h tml

  • (-1 Flamebait) (Score:5, Funny)

    by Knights who say 'INT ( 708612 ) on Thursday March 10, 2005 @04:00PM (#11902998) Journal
    You want quiet, listen to Enya. But don't go around raping the masters because of mundane utilitarian reasons.

  • Night Mode (Score:4, Interesting)

    by Wiwi Jumbo ( 105640 ) on Thursday March 10, 2005 @04:03PM (#11903038) Homepage Journal
    On my nForce 2 motherboard, the sound applet has a "Night Mode" which um... "compresses" the sound so you don't have to turn it up as loud to hear the soft notes...

    It's a pretty niffty feature to have, but I've never seen it anywhere else that I can think of...
  • Google for Audacity - it's a free multitrack recording program for Linux and Windows. It'll have a compression effect/filter that can accomplish what you are asking with minimal effort. I'm sure you can find other stuff that does the same thing though.

    I'm sorry to hear you can't listen to the stuff with their original dynamic intent :/ I am a huge fan of dynamic contrast.

    • Yeah, I settled on the same solution for remastering CDs to play in my car. Not an issue for rock, which is mostly just loud, but I also listen to opera. If you crank up opera CDs so you can hear the recitatives over the road noise, your ears drums will bleed when the fat lady belts out her aria.
    • ...Audacity is a solution for Linux.

  • Replaygain (Score:2, Informative)

    by phej ( 21792 )
    Have you tried using Replay Gain? [replaygain.org] It finds the psychoacoustic level of the music and calculates an appropriate gain correction. Replay gain is supported by foobar2000. [foobar2000.org] MP3Gain [sourceforge.net] is a tool that computes the replay gain for a track and changes the overall gain of the file.

    • Re:Replaygain (Score:3, Insightful)

      by Vaevictis666 ( 680137 )
      Replaygain does kick ass, and more people should use it, but as others have mentioned, this isn't what he wants.

      Replay Gain is designed to level all the tracks from a CD (and infact many different CDs if you do it to all of them) so that they all have a mean volume of about the same, but it works on the track level, not a 5-second floating window level.

      • While Replaygain isn't the solution, foobar2000 does have the ability to do 'dynamic compression' that is exactly this, called foo_dynamics. I don't know if it came with foobar2000 or not, but it would be easy enough to find if not.

        If you just want to kill loud sounds, there's also a 'soft clipping limiter' that will just not let sounds get any louder than a certain volume.

  • The Solution is MP3 Gain (Score:4, Informative)

    by Sangloth ( 664575 ) <MaxPande@nospam.hotmail.com> on Thursday March 10, 2005 @04:21PM (#11903272)
    Geez...I'm surprised nobody brought this up yet. MP3gain normalizes MP3's, but it NOT based on an average of the entire song. Read the site for more info. This is exactly the solution you are looking for.

    MP3 Gain at Sourceforge [sourceforge.net]

    Sangloth
    I'd appreciate any comment with a logical basis...it doesn't even have to agree with me.

    • Check out Replay Gain. In addition to the above mentioned MP3 Gain, Wavegain also exists. Also, if you use Flac, Flac can compute a Replay Gain as well.

      http://replaygain.hydrogenaudio.org/

    • Normalization isn't what's wanted here. This isn't a case of "I want all my mp3s to have the same volume", it's "inside a given file, there's too much volumne variation".
  • There is an XMMS plugin I stumbled on a while ago called simply 'volnorm' that you might find useful. Not exactly perfect, but it works for me... get it here [sourceforge.net]. Or emerge xmms-volnorm in gentoo ;)

  • Many Receivers & DVD Players have this.. (Score:3, Interesting)

    by cybrthng ( 22291 ) on Thursday March 10, 2005 @04:40PM (#11903534) Homepage Journal
    Some home theater receivers and tv's have "Night Mode" which is used to do this. Feature is great in that you don't have to crank it to hear all of the dynamic ranges of a movie thus not loosing too much when you watch at lower volumes. (perfect for those with kids..)

    I think even my DVD player does this.
    • most DVD players do this.... mostly so when you want to hear that wisper you dont blow your ears out when something explodes in the middle of the people talking :p

      also, audio CD burning progs do almost the same thing, they actually normalize the whole CD, so when you change tracks you dont loose your hearing either

  • Compression (Score:5, Informative)

    by ratboy666 ( 104074 ) <<moc.liamtoh> <ta> <legiew_derf>> on Thursday March 10, 2005 @04:41PM (#11903539) Journal
    http://trikuare.cx/code/AudioCompress.html

    Works with most players -- xmms plugin as well.

    Ratboy

  • Volume Logic with Automatic Gain Control (Score:5, Informative)

    by Michael.Forman ( 169981 ) * on Thursday March 10, 2005 @05:07PM (#11903853) Homepage Journal

    I recommend the Volume Logic [octiv.com] plugin for iTunes. It provides dynamic automatic gain control (AGC) over multiple bands. I find it really brings out the nuances in quiet music without blowing me away, when things get loud.

    Michael. [michael-forman.com]
    • I also give a big thumbs up for Volume Logic. I use it at home and at work and it is great. It has a so many settings that you can make the compression subtle or completely over the top. It evens out classical music very well and it also makes my ripped records sound good (they are very quiet without it). I also have some audience recorded live concert material (ahem) and it improves the sound of those by an unbelievable amount.

      Despite the above rave review, Volume Logic is not a panacea. It can significan

  • Use your stereo's natural clipping ability (Score:4, Funny)

    by Anonymous Coward on Thursday March 10, 2005 @05:32PM (#11904127)
    What you need to take advantage of is called "clipping" by sound experts.

    Let's say your stereo can play a waveform that varies between -1.0 and 1.0. If you send it a peak of +/- 2 for instance, it will clip to +/- 1.

    What you need to do is find the lowest peak in your music. Even the "silent" parts have a little noise.

    Let's assume that it goes +/- 0.01 in those parts. Find the recipricol (1/0.01) = 100 and set your gain to that.

    The quiet parts will range +/- 1, and the loud parts will be clipped to also be +/- 1. Voila! You've "expanded" and "compressed" without all that fancy professional equipment.

    Note: if you don't have an easy way to estimate the gain you need, just use a round estimate like 1000. You can find op-amps at your local Radio Shack that will amplify even higher than this! Just be sure to leave off the "feedback" part of the circuit. We all know that feedback is bad, right?

    And as an added advantage, your child will grow up with a love of music by the Japanese artist Merzbow. It's a win-win-win.
  • Package: cmt
    Priority: optional
    Section: sound
    Installed-Size: 232
    Maintainer: Anand Kumria
    Architecture: i386
    Version: 1.15-1
    Provides: ladspa-plugin
    Depends: libc6 (>= 2.3.1-1), libgcc1 (>= 1:3.2.3-0pre6), libstdc++5 (>= 1:3.2.3-0pre6)
    Filename: pool/main/c/cmt/cmt_1.15-1_i386.deb
    Size: 58704
    MD5sum: ccff75c4945cd4cf1e12bf37cb7b7930
    Description: Computer Music Toolkit (cmt) a collection of LADSPA plugins
    cmt -- Computer Music Toolkit -- is a collection of LADSPA compatible
    plugins that any conforming prog
  • I use the `normalize' Debian package. -m takes the average from all files specified. There's also normalize-mp3 and normalize-ogg.
  • The cmt plugins are used with the following audio editor programs: gnusound, beast, sweep, muse, and jack-rack.

  • man sox (Score:2, Informative)

    by rsw ( 70577 )
    see subject
  • The LADSPA plugin VLevel [sourceforge.net] seems to be precisely what you want.

    From the website:

    VLevel keeps your music from making you jump out of your seat, and it keeps you from having to fiddle with the volume constantly. It's different from other dynamic compressors because it looks ahead. You can think of VLevel as someone who knows your music by heart, and turns the volume up during quiet passages, but smoothly turns it back down when he knows a loud part is coming. It's great for making CDs to listen to in your c

  • http://www.foobar2000.org & http://replaygain.hydrogenaudio.org/

    'nuff said

  • This is called compression (Score:4, Informative)

    by c0d3h4x0r ( 604141 ) on Thursday March 10, 2005 @07:25PM (#11905204) Homepage Journal
    The audio processing algorithm being requested here is called "compression", and it's a standard feature of most audio editing package such as SoundForge. You can also buy hardware compressors for under $100 (dbx and Alesis make stereo compressors) that are good for hooking into a home stereo/theater system.

    I keep an Alesis digital stereo compressor hooked into my home stereo system so that when loud spots (commercials, action scenece, etc) come on it doesn't suddenly get orders of magnitude louder and drive my apartment neighbors nuts.

    Some DVD players have audio compression built-in as a feature. Some newer TV sets have it built-in also.

  • (read on for what I mean by normalize)

    Thanks for not making me RTFA, but you don't expect me to read the whole question do you?

  • Low tech (Score:5, Funny)

    by k4_pacific ( 736911 ) <k4_pacific@yah[ ]com ['oo.' in gap]> on Thursday March 10, 2005 @08:09PM (#11905531) Homepage Journal
    The low tech solution is to wire a small light bulb in series with your headphones. As you may know, electrical resistance increases with temperature. Thus, when the sound is louder, and more current is flowing to the headphones through the lightbulb, the filament gets hotter and glows brighter. This increases the resistance which limits the current flow and softens the louder sounds. Conversely, during quieter periods, there is less current, the lamp filament does not get as hot, and more current flows, making them louder.

    Similarly, you can increase the dynamic range of the sound by putting the bulb in parallel to your headphones. Loud sounds increase the temperature (and thus the resistance) of the bulb filament, which diverts more current through the headphones. Quieter sounds don'y heat the filament as much and allow more current to take that route, thus making them even quieter.

    You may have to experiment with different types of lamps to find which works best.

    • I was running sound a couple weeks ago, on a Sunday afternoon.

      We got pretty loud, and our speakers started glowing. I thought we had a fire, at first, but it turns out that these speakers implement exactly what you describe (and in-line light bulb) to prevent overloading (protection).

      Pretty smart -- we didn't blow the speakers... yet.

      S
  • it's called a compressor/limiter - it's accually 2 seperate processes, one that squashes the high volumes (if ya have any) and the other that boosts low volumes. you can find something like this in prettymuch any audio editing software. i cant think of any free programs that do this but on windoze you can use adobe audition or cool edit (96, 2000 whatever) - i used to use cool edit but they got bought by adobe and so i use that now. by far the best program for general audio editing. although, you may no
  • This [winamp.com] plugin for winamp [winamp.com] does what you are talking about. It automatically moved the volume up and down to maintain and constant volume. It works quite well, but I'm not sure how much you can fine tune it.
  • Not all CDs sound equally loud. The perceived loudness of mp3s is even more variable. Whilst different musical moods require that some tracks should sound louder than others, the loudness of a given CD has more to do with the year of issue or the whim of the producer than the intended emotional effect. If we add to this chaos the inconsistent quality of mp3 encoding, it's no wonder that a random play through your music collection can have you leaping for the volume control every other track. As the website

  • You want a compander. (Score:4, Informative)

    by klaws ( 66658 ) on Thursday March 10, 2005 @11:46PM (#11907000)
    What you want is a compander. (compressor/expander). It is so called because it compresses or expands the dynamic range of the input audio. Sox includes one, if you like command lines.

    For winamp, I've found Rocksteady [uni-sofia.bg] is beautiful, and does separate compression for several frequency bands (i can't begin to express how good this is for pop/rock).

    For XMMS, AudioCompress [trikuare.cx] does a sufficient job, although the windowing is somewhat stupid (not predictive == you'll get pops if things suddenly get loud) and it doesn't separate into multiple frequency bands, so it won't sound so good if you're playing something where the bass is really pushed (like Fiona Apple) next to something where it's not (classical).

    Neither allow you specify complex transfer functions (of input volume to output volume).

    For your purposes, sox is really the right thing, although it may feel a bit like "ack! drowning in sea of unexplained options!". You could start off trying:

    $ sox infile.wav outfile.wav compand .1,.1 -60,-10 0 0 .1

    will give you VERY hard compression. Change the .1s to specify how fast it changes the volume; change the -60,-10 (always negative) to more similar values to make the compression less severe.

    $ man sox
    will tell you something more.

  • SOX (Score:3, Informative)

    by Midnight Warrior ( 32619 ) on Friday March 11, 2005 @12:26AM (#11907194) Homepage

    SOX [sourceforge.net] has a compand operator that lets you tune this stuff and parameters that let you tweak how fast it responds, how hard it attempts to correct the sound, and how fast it "lets go." Put this in line with your CD RIP process after you run a few through a test bed.

    Don't forget to specify settings for each channel (normally two).

    If you're willing to forego ID3 tags, or can hack them in yourself with mp3info, you can use cdda2wav to do sox processing: cdda2wav -O wav -t 7 -D /dev/cdrom - | sox [sox options] | lame - foo.mp3

  • Do you really want to do this? (Score:3, Insightful)

    by gvc ( 167165 ) on Friday March 11, 2005 @12:56AM (#11907306)
    I acknowledge that not everybody (including me) is an audiophile, but the recording engineer went to some effort to make a recording that, when played, would reproduce the original performance as closely as possible.

    If you ride the volume control (or use automatic gain control to do it for you) or use dynamic range compression (a different animal from digital compression), you're compromising the music.

    I'd no sooner do this than bleach my favourite painting.
    • That's one reason that I rarely listen to music on the radio anymore. Commercial, and many public, radio stations use multi-band compressors, euphemistically called modulation optimizers, to eliminate all traces of dynamic range. The suits insist on 100% modulation, all the time.
  • Would you believe that there is a tool in Linux called normalize [columbia.edu]? It's a command line tool written by Chris Vaill. You may have to break up your wav file into different files. Here's the man page (sorry for the mashed-up text, but you get the picture):

    NAME normalize adjusts volume levels of audio files. SYNOPSIS normalize [ options ][-- ] file... DESCRIPTION normalize is used to adjust the volume of wav audio files to a standard volume level. This is useful for things like creating mp3 mixes, where diff
  • What follows is an incredibly shameless plug for my project...

    VLevel [sf.net] is exactly what you want. It works by continuously but gradually changing the gain throughout the file. It has a lookahead buffer of a few seconds, so unlike a compressor, it never has to change the gain too quickly. This preserves "contrast," so for example if a quiet part was being made loud, the gain will decrease a little while before the big bombastic crescendo, so you'll still get the effect.

    For Windows, the best way to use it i

  • ...embrace dynamics! Compression was invented by suit-wearing big-label whores! --- (I.e., I happen to run a home studio and my most-used digital effect is compression. *shrug*)
  • Just buy an Audigy card or any card that can do digital signal processing (has a processor on-board) and have it run a compression filter/effect all the time. It is trivial to do and it works without taxing your CPU. Furthermore, it does NOT alter your original music files (compression is not good for classical music--you are supposed to appreciate the range from pianissimo to fortissimo with all the intermediate steps). Otherwise, you may use an output plugin, such as these offered by foobar2000 (an excell
  • I know Cool Edit Pro would normalize the music how you stated in your post (find an average throughout the whole song), but I believe there is a way you can normalize in spots. I use Cool Edit Pro all the time to take out noise of my music files. If all else, you can NOT choose the normalize option (if in fact in will only calculate the average for the whole song, and not just a snippet) and manually normalize it by hand by adjusting the values for a small section of a song (which I know you can do).
  • What you want is a nice set of headphone. [audiogear.com]
  • If you don't mind a hardware 'solution', look for a 'limiter' at your local musicians equipment shop. I got one about 10 years ago (rocksonics -- appear to be out of business now) which works great. I think it cost about $100, plus I needed some 1/4" -->RCA adapters.

    On the other hand there's lots of software that does the same thing -- main benefit of hardware is you could hook it up in front of some powered speakers and use any audio source (e.g. plain cd player).

    One other problem with limiting/compre

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