Portable MP3 Player with Tempo Control?

July 29, 2007 4:37 PM

Is there a portable mp3 player that can adjust tempo during playback without affecting pitch?
posted by irv4oh to technology (12 comments total)

I've used a program like this on a PC for learning guitar parts but never thought about it with MP3 players. I just found this discussion, though, which looks promising.
posted by monkeymadness at 4:45 PM on July 29, 2007

I had a cheapo no-brand 1gb player that could do this. Not well, certainly, but I suppose it was good enough for dictation.
posted by pompomtom at 5:07 PM on July 29, 2007

Creative Nomad Zens do this. Its in the EAX control section in the menu. I borrowed one and wondered why all the songs sounded slow. Turns out a fresh firmware install set it to default to slot. I did not noticed any change in pitch. From the page linked:

Customize Your Audio Playback with Innovative EAX Technologies

* Advanced EQ lets you customize your music playback with Equalizer presets or set your own using the 4-band custom equalizer
* Smart Volume Management adjusts the playback volume of all the tracks on your playlist so they will remain at the same level without you reaching for the volume control between songs!
* Time Scaling speeds up or slows down an audio track with no distortion
* Sleep Timer and Wake to Music Feature
* Environmental Effects simulate audio environments such as "Concert Hall" or "Arena"
* Spatialization Effects expand your soundstage

posted by damn dirty ape at 5:12 PM on July 29, 2007

err "slot" should be "slow."
posted by damn dirty ape at 5:13 PM on July 29, 2007

DDA: That looks about right, but I'm most interested in a small flash-player. Do all the Nomad Zens do this, or just some? Do you know which? The Zen Nano Plus looks good, and it would be a great choice if it had the "time scaling" feature.
posted by irv4oh at 5:24 PM on July 29, 2007

Just a heads up, MP3's sound like messy ass when time or pitch shifted due to compression. You'll get loads better results if you find a portable media player that will do this to .WAV's.
posted by knowles at 5:28 PM on July 29, 2007

re: Nomad speed
I have Zen Xtra from 3-4 years ago and it does the speed (slow and speed up factor of 2), though the 128 bitrate doesn't help causes.
posted by jmd82 at 5:47 PM on July 29, 2007

Lectures at my school are posted as MP3s, but listening to them a second time is pretty slow-going. I listen to them at 1.5x or 2x speed on my computer, but I'd like something portable. I thought I should say this in case people wonder why I'm looking for it.
posted by irv4oh at 5:55 PM on July 29, 2007

Of course, you can do this with audacity once you get the lectures and then just listen to the finished product on any media player. You can even time compress MP3's without much quality loss since you're just removing tiny slices of the data instead of filling new spaces. If you're feeling saucy, you could probably hack together a script to automate the whole thing.
posted by knowles at 6:20 PM on July 29, 2007

There are far better options listed above, but if you already have one, an iPod does let you do this. The "fourth generation" and later models have speed w/o pitch change settings -- but you need to convince it your files are audiobooks first (m4b file, you can convert to m4a in iTunes and then rename.) Definitely don't buy one above any of the other choices, only do this if you already have one and see if it fits your needs.
posted by neustile at 7:36 PM on July 29, 2007

many of the noname chinese mp3/4 players have this feature as in Asia many use them for language learning and kareoke. For a fact the "sumvision gio" do. They are usually sealed in plastic blisters; look for the feature "tempo rate".
posted by priorpark17 at 12:53 AM on July 30, 2007

Rockbox is an open source firmware replacement/upgrade, available for many mp3 players (usually, the best ones, since those have enough geeky owners to get the code ported).
The last version I downloaded (years ago) had tempo adjustment but did not maintain pitch. I know people were trying to implement a tempo control without affecting pitch, but I wouldn't know if anything came of that.
(AFAIK it would be done as a software/CPU manipulation, since mp3 decoding hardware doesn't support the feature, so it would be more likely to show up in the versions of Rockbox for mp3 players with beefy processors, like some of the ipods).
Actually, that's probably true regardless of Rockbox - I don't think you'll find the feature in something that is basically just an mp3 decoder chip + storage. Look for players that have signs of a processor :-)
posted by -harlequin- at 3:05 AM on July 30, 2007