iPod Hacking Adventures, part 1

In search of a new-old recording tool: iPod as digital recorder. In which we try to adapt an iPod, 2G to record using Linux. And fail. And learn some new things. Chiefly: This method only works for a 3G iPod only.

The chief advantage of a portable recorder that stores the recording in a digital format is that you can transfer the recording to the computer as quickly as copying any file.  Otherwise, you’re stuck with “realtime” file transfer: You’re transferring it to the computer at the rate of the recording itself. If your recording is an hour in length, it’ll take an hour to transfer to the computer because you’re “recording” it on the computer at the same rate as it plays back from the device. This works if the device doesn’t have icky copy-protection that prevents you from doing so. (The portable MiniDisc ususally suffers from this copy-protection malady.)

The iPod is a good candidate for recording and file transfer. It’s a popular device that already lives in the homes and pockets of many. Some models have the ability to record. The Griffin iTalk is an add-on device that will allow you to record from your iPod.

The Good News: You can record on some iPod models with the add-on connector device called the Griffin iTalk. It’s a small microphone and speaker that plugs into your iPod. With it (and accompanying software), you can use the iPod as voice recorder. It works with 3G and 4G and iPod Photo iPods

The Bad News: The recording quality is only 8khz, or about as good as what you transmit in a telephone call. For comparison, the recording quality of an audio CD is 44.1 khz. (see glazing detail, below for more about this).

The Good News: Thanks to a version of the Linux operating system that’s been developed for the iPod—Podzilla—you can install a second operating system, restart into it, and then use the Podzilla recording function to make recordings at a higher rate: 32 khz (same as FM broadcast quality) 44.1 khz (audio CD quality), or 96 khz (DVD audio quality, which is overkill for spoken voice recordings). 

The Confusing News: Podzilla works on earlier generations of the iPods: 1G, 2G, and 3G. How is this confusing? Because I hunted down the instructions on installing Podzilla, and saw the 1G, 2G or 3G requirement, and thought that a 2G iPod would be fair game.

It doesn’t work on a 2G iPod. I’ve tried it and can assure you it does not. My brother is upgrading his iPod, and agreed to loan me his 2G iPod to conduct this test. I loaded up the podzilla software. (I’ll spare the gory details of what exactly “loading up the software” entailed for now, since the outcome of this process was failure. But I’d like to do a part 2 of this with a G3 iPod, and will bore you with excessive detail then, assuming that you might want to use it as a guide to try yourself.) The iPod rebooted into Linux (ooh! look! lots of tiny text scrolling up the screen as part of the startup mode). Then I looked for the Extras menu, found the Record part, clicked Record, and saw a message that said that Recording didn’t work for this hardware configuration. Uh oh. Worse than that, once I decided to reboot back into Apple iPod, the iPod rebooted… and kept rebooting over and over again. Charming.

It was only later that I saw a FAQ  about the linux install that states, “Recording is not supported on the 1 and 2G iPods due to hardware limitations however if you are lucky enought to own a 3G iPod you can!” Okay, now you tell me. Which underscores the lesson: Technology is confusing. But I made this mistake so you don’t have to. And yes, I had a good visit with my brother. 

So what’s the big deal about recording rates, anyhow? The entire range of human-audible sound—as expressed in pitch (that is, high tone and low tone) is between 20 hz [lowest of the low] and 20 kHz [highest highs]. A brilliant audio/digital guy who’s got better brain cells than mine came up with the following “law:” In order to make a good digital sample of an audio recording, you need to make samples at a rate that’s twice the highest frequency. So. Highest audible frequency is 20kHz, so digital audio sample rate is 44.1kHz (don’t ask me about the leftover 4.1; like I said, he’s got more brain cells than I do, but I hope this gives you an idea). 44.1kHz is what you get on your standard Audio CD, the quality of which is pretty danged nice.

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Posted by Susan A. Kitchens on October 11, 2005 in • AudioAudio: Hardware
5 CommentsPermalink

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Comments

Susan,

I commend the work you are doing in the area of oral history, and best wishes and much success as you manifest your dream.  I am also very interested in the power of the spoken word, and being able to empower people.  Thank you for sharing your passion, and providing the kindling for enthusiasts like myself that have a yearning to go into our communities and take this to the next level.

Best regards,

Gary Victor
Dayton, Ohio

Gary Victor  on 07/17  at  11:02 PM

Hi Susan,

Just found your site. I’m in the planning stages of interviewing my Mom, Dad and maybe others and I’m happy to find you.

I’ve got a cowan iaudio x5l mp3 player. It’s got a built-in mic that records at 128kbs and 44.1khz, and a stereo line-in that records at 320kbs and 44.1khz. audio quality is really nice.

I suppose if someone’s already got an ipod that’s one thing, but if not then there are certainly better players out there.

Best regards
Daniel

Daniel  on 04/10  at  07:16 PM

Daniel,

I totally agree that there are better players out there. I have one of them myself. (It’s an Archos Gmini—records WAV files using a Line In connection. Has 20 or 30 GB disk. I use it in a special Otter Box case with a preamp built in to take a stereo mini mic and amplify it up to line level.)

But I also wish to cover the “If I have a [name of equipment], what can I do to record with it?”  question. The crazy thing is that I now have a microphone that will work with the video ipod, but I don’t have a video ipod/ ipodNano Gen 2 to work with it.

Is the Cowan the one that has an open-source model? (can’t recall offhand) And will the cowan record in WAV format as well as MP3? Never mind, just looked at the specs. I think that your model (or something similar) is what my boyfriend has—he’s a *nix geek, open source all the way, builds his own linux boxen, so he got a player that would play OGG files. Come to think of it, the line-in and record specs are pretty similar to what my Archos has. I should try it out with my Otter Box/Pre Amp case.

Susan A. Kitchens  on 04/11  at  12:39 PM

If your boyfriend is a geek then he can install, or dual boot, Rockbox for the x5 that will allow wav record. I was considering doing that but really I’m not an audiophile and to my ear mp3 at 320kbs sounds really nice. The only downside to the x5 is that you need to have a pre-amp between the mics and the unit, otherwise I think it’s great.

I’m starting to run into the same issues with this that I have with photography. I started with a point and shoot digicam, but soon decided that a needed an SLR, and really nice lenses, and an external flash, etc…

I can see how this could turn into a gear-centric hobby.

I’m really happy to find your site

Daniel  on 04/12  at  11:07 AM

This whole site is excellent reading, thanks for sharing.

David Murphey  on 02/16  at  10:32 PM

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