Sound Design Stack Exchange is a question and answer site for sound engineers, producers, editors, and enthusiasts. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Zoom's H4N can vary speed of audio that it records, but often has trouble doing that to podcasts (from CBC, etc.). Is there a way to persuade it to work with nearly "any" MP3?

If not, what FOSS software can do the job?

share|improve this question

migrated from Jan 27 '14 at 15:07

This question came from our site for engineers, producers, editors, and enthusiasts spanning the fields of video, and media creation.

I'm not sure why you are having trouble stretching audio on your Zoom, but it may have to do with the fact that MP3s are compressed and the Zoom may have trouble manipulating compressed data. You may have better luck with uncompressed audio like WAV files.

Audacity is a great place to start. Although 1.3.x is in beta, I've found it to be very stable and a lot more powerful than 1.2.x. You will want to convert your MP3s to an uncompressed format like WAV before you start stretching.

If you want to get really crazy, give PaulStretch a try. If you are looking for something with more of a mid-90s sound, take a look at AKAIZER.

share|improve this answer
The Audacity team has been really conservative with lifting the Beta designation on 1.3.x. I've been using it for a long time without any problems. Time stretch works great. – Jon Galloway Dec 23 '11 at 0:08
Yeah, Audacity's Beta is more stable than apple's production releases. – ObscureRobot Dec 24 '11 at 6:18

I always get best results using raw wav files and encoding later. It's just easier all round - you end up with better quality sound as well, as you are only compressing/encoding once.

share|improve this answer
... and huge Class 4 SD cards are cheap! – scottc Dec 20 '11 at 22:20
I agree with using uncompressed audio for audio manipulation projects. Sometimes you'd like to listen to a podcast faster or slower. In that case, it is annoying to have to work with the much larger uncompressed data. – ObscureRobot Dec 24 '11 at 6:20

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.