How do I encode songs with an equalizer applied?

August 5, 2008 10:36 AM

Can I apply an equalizer or other effect to songs as they are encoded? Can I decode/re-encode songs and do this so they sound better on my ipod?

I have an Intel Macbook running Leopard, and have started listening more frequently to music on my ipod. When I listen to it on my laptop (with the same headphones), I like to use the equalizer and some subtle tweaks with SRS iWow to give the songs a better feel/sound. The equalizer settings on the ipod really don't cut it. Is there a way to permanently apply custom equalizer settings or other effects (similar to what SRS iWow does) to songs so they sound better on the iPod?

Can I rip CD's and apply equalizer settings or other effects? I like to use Apple lossless for my songs, and listen to them through a headphone amplifier/DAC coming out of the USB on my laptop or the line out of my ipod.

I know the songs can "take" the built in equalizer settings with them and use them when I play them on the ipod, but those settings don't do much (don't do enough for me). Any software suggestions? Thanks in advance.

Bonus points if I can also apply time shifted crossfeed to the left and right channels to improve the feel of the soundstage.

posted by kenbennedy to computers & internet (10 comments total)

If you have an iPod that supports Rockbox, you'll have access to at least some of those features. I don't have an iPod handy for reference, but looking over the equalizer settings on my Sansa running Rockbox, it seems more full-featured than the iPod's options. Rockbox also has crossfeed support.

I'm hesitant to recommend anything that actually alters the files themselves. Unless you keep a pristine backup, you may irrevocably alter the sound of a given song and later decide you don't like it.
posted by sinfony at 11:11 AM on August 5, 2008

I will specify: I have the 5g ipod video.

I don't mind actually modifying files, as I would do a test run first to check the settings, but I will check out Rockbox. Any other suggestions though?
posted by kenbennedy at 11:15 AM on August 5, 2008

Most of my experience with this stuff is on the Windows side. For instance, dBpoweramp has support for applying various DSPs and equalization settings when ripping CDs.
posted by sinfony at 11:24 AM on August 5, 2008

Have you tried Garage Band? It has most of what you need.
posted by bitdamaged at 11:30 AM on August 5, 2008

Don't decode and then recode MP3's; it's a lossy format that will degrade if you recompress it.
posted by jenkinsEar at 11:37 AM on August 5, 2008

Foobar2000 has plugins for both EQ and crossfeed, and allows these to be applied inline with the ripping process. Downside: Windows-only; upside: runs under DarWINE.
posted by rhizome at 11:38 AM on August 5, 2008

Rockbox looks cool, and I'm sure I will try it, I just dont want to have to apply a new EQ setting for every song. At least I can save the presets.

I will check out garageband too (especially since it was included on my macbook). I want to keep the audio quality as high as possible, so as long as I can keep it in apple lossless or keep it from compressing it when I am done (and still play it on the ipod of course) I would be happy. Last time I looked I couldn't figure out how to get the apple lossless files in and then save it as one, but I will look again.

I don't have a windows license to set up a virtual machine, so the windows programs are out, and I have tried my hand at wine before with such limited success that I am unlikely to try it again anytime soon (troubleshooting terminal commands I don't understand is a bit more involved than I want to get right now).

Keep it coming, and thanks.
posted by kenbennedy at 11:54 AM on August 5, 2008

It is impossible to decode and then re-encode an mp3 (or m4p/m4a, etc). Any change to the file itself (turning it into an mp3, for example) is destructive. You can convert an mp3 to Apple's lossless format, but the lossless file will only be as good as the mp3, not CD quality. Encoding with Apple's lossless format means the encoded file will be only as good as the file being encoded - as in, no loss. This is why you should never alter the file itself. Once changed, it can never go back to being as good, sound quality wise, as the original.

This is why adding a non-destructive EQ to the file's settings in a program like iTunes is the way to go. You're not actually recording the EQ into the file. You're just telling iTunes how you'd like the built-in iTunes EQ to be set up for that particular song, and you can remove the EQ setting at any time.

On the other hand, if you re-record the song with an EQ playing, the song will forever be changed. That might sound like a great idea now, but when you get a better stereo someday, the 'better sounding' song might sound like crap. Why? Because most people use EQs to make up for what their speakers lack.
posted by 2oh1 at 12:36 PM on August 5, 2008

This is why you should never alter the file itself.

...after you've ripped it from CD, I mean.
posted by 2oh1 at 12:38 PM on August 5, 2008

All the music I am hoping to work with now I have on CD's, which is where the apple lossless files came from. When I play them on my stereo, I use the CD's. When I play them on my ipod, I use the copies on my computer. I can always rip them from the CD again. I can also back up the file before I modify it. I don't have a problem "equalizing" one of my lossless files, I just want to try it out. I am looking for new avenues, and I'm not really talking about thousands of songs here. Maybe 200 or so... I appreciate all the help.
posted by kenbennedy at 1:12 PM on August 5, 2008