Filed under: Audio, Cool tools, Podcasting, Friday Favorite
Friday Favorite: The Levelator, friend to podcasters everywhere

The Levelator is offered by The Conversations Network as a single-purpose tool: it takes uncompressed audio (WAV or AIFF files) and performs a small miracle. The file is leveled to a uniform loudness level, even if varying parts are recorded with different microphones, audio settings, or even in diverse corners of the world (if you've ever tried to record a podcast over Skype, you know what I'm talking about). While many audio apps have normalization or 'leveling' functions, in my admittedly amateur audio experience I haven't heard anything like The Levelator; those with more savvy in this area tell me that the output is akin to what you would get with a human engineer 'riding the meters' to adjust the sound dynamically as it varies.
The really nice thing about The Levelator -- and this is an odd thing to say about a Mac application -- is that it has, for all practical purposes, no controls. Drop a file on it, wait an appropriate amount of time and watch the blinking lights, then take your output file and continue on your merry way; the final file will simply sound way better than the original did. It's made my life much easier in editing the TUAW Talkcast, and if you have any hand in producing spoken-word audio it might do the same for you.
The Levelator is a free 48 MB Universal Binary download, and will work on either 10.4 or 10.5, as well as Windows and Linux. Enjoy!
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Reader Comments (Page 1 of 1)
will.kuhn said 9:12AM on 3-27-2009
How is this different from the Compressor plugin that's included with just about everything?
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Sean said 9:20AM on 3-27-2009
Is there a program like this that levels audio output? If I'm watching a movie on the MBP and there are lots of audio highs and lows and my daughter is sleeping in the room near by, then is there a program that will level the sound out so I don't have to keep adjusting the volume?
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Elias Krause said 9:29AM on 3-27-2009
Sean, you can get Audio Hijack Pro, hijack all system audio and put a limiter in the "effects" tab. A good, free VST Limiter is W1 Limiter - download it here: http://www.dontcrack.com/freeware/downloads.php/id/3092/software/W1-Limiter/
Play with it!
jake said 9:45AM on 3-27-2009
You can also do this with a Compressor and a Limiter. Hum... Maybe I should write a tutorial on beginning sound design.
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jetbass7 said 9:54AM on 3-27-2009
Yes a compressor and limiter can do this and from reading the creators site that's what they basically do. However this is more adaptive and deals with wide differences in levels. My only complaint is that it's a little too aggressive sometimes and pushes a little hard.
If the content is critical I certainly would do things by breaking varied leveled areas into separate tracks in my DAW and then applying appropriate plugins. Definitely never for music, but for voice tracks requiring fast turnaround it works well. I wish I could drop movies on it...
Stephen Lang said 11:50AM on 3-27-2009
The whole point of this FREE application is so you don't have to read a tutorial, or spend any time fiddling with settings. It also seems to be optimized for spoken audio, so it's obviously not a Swiss Army knife but probably works great as-is for its intended use.
teeth weasel said 9:58AM on 3-27-2009
compressor - > limiter -> normalize
it's not really rocket science (or that impressive.)
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Southpaw32 said 10:06AM on 3-27-2009
I would love to have a simple drag and drop program like this to run podcasts I download through. (MP3 & AAC)
Anyone know of any such programs?
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Harvey said 11:02AM on 3-27-2009
++ I just want a program that will do two things to an audio file.
1. Normalize/Range Compress
2. Ensure that all audio is at a certain level.
[Optional extras]
3. Correct ID3 tags.
4. Have setting presets on the side (like Handbrake does). The main window is just a drag-and-drop target that uses the selected preset.
My source of frustration: APM Marketplace's podcast has horrible highs and lows and is very quiet.
Stephen Lang said 11:53AM on 3-27-2009
I imagine you could work up something in Automator combined with this program to make a drag-and-drop script.
Doug Kaye said 2:42PM on 3-27-2009
Thanks for selecting The Levelator. It's an honor for the TUAW fans here at The Conversations Network.
There's a lot of confusion about how The Levelator works. Behind the curtain, it has relatively little in common with a compressor/limiter combination, and you *can't* duplicate The Levelator's results using those tools. The only way you could duplicate it -- and it would be very time consuming -- would be by making a large number of level adjustments combined with selective RMS normalization. Unlike compressors and limiters, The Levelator has infinite look-ahead; it processes an entire file, breaking the track into segments and operating in multiple passes.
The basics are here: http://www.conversationsnetwork.org/levelator/ and we've just added a new overview of the algorithms here: http://www.conversationsnetwork.org/levelatorAlgorithm
To the skeptics we have just one suggestion: Try it. Compare it to what you can do with your existing tools. If you still don't like it, you're only out your time. But after more than 100,000 downloads, we have many converted audio/radio professionals among our ranks of happy users.
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JK said 2:43PM on 3-28-2009
Professional's using it? Really?
You mean iPod hacks, don't you.
Your ad on here is despicable.
If, by saying it "looks ahead: that's even worse.
It is merely reading sound levels, that's real art.
John Lennon's "Mother" must now sound like John Mayer.
What a tool.
Michael Rose said 11:36PM on 3-28-2009
JK, the tool is meant for spoken word audio, not for music. Try using it before you slag it.
mickey said 6:18PM on 3-31-2009
Thank *you*, Doug, for joining us and cogently replying.
Thanks also for the app, with which I'll be playing with next week. From appearances it seems rather well thought-out.
Mickey
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Nick said 2:42PM on 3-28-2009
Compression is this generations HIV.
There is no life in compressed music.
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Yakov said 2:08PM on 3-30-2009
Actually, HIV is this generation's HIV. It is a serious problem affecting over 30 million people.
On the other hand, the Levelator is a free tool intended for fixing the volume level on spoken word files.
I can see the similarities
Yakov said 7:40AM on 3-30-2009
I have audio of an a capella concert that was recorded in the back of a room – on one song, the audience clapped along, and the claps absolutely demolish the (unmiked) vocals in the front of the room – if Levelator can fix that, and will do that for free, I love it
One day I'd like to see this as an iMovie '10 plugin… hey we can hope
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