FourTrack, as its name suggests, is a 4-track recording application for the iPhone (and iPod Touch):
On the whole, the application works well. It’s very simple to set up and use (although I’m not mad on the clumsy navigation scheme). Recording quality is pretty damn good given the limitations of the microphones I used, which were the iPhone’s built-in mic and the one on the supplied headset (which are actually very similar in performance). The ability to transfer audio files onto a computer using wi-fi is very welcome and totally straightforward. To be honest, I haven’t done any serious multitracking myself, but Sonoma claim latency of less than 1mS so there shouldn’t be any problem in that department. You can get more technical detail here.
My first impressions were pretty favourable, then. Unfortunately, I’ve discovered a couple of quite serious problems with the program. These have been unearthed because of the (perhaps slightly unusual) way in which I was using the program. My first serious recordings were done at the SAND 2008 conference where I was trying to record a couple of the presentations to use as podcasts on this very blog.
So what I wanted was just a single track of audio, but lasting something around an hour (and the website claims that record times are “unlimited”). I recorded two separate presentations into two songs. What I found when I got them home and transferred onto my computer was that they would both play up to a certain point, and then iTunes would jump to the next track in the playlist.
The recording of the first presentation was about 46mins long, and it always ‘flipped out’ at exactly the same point, 32mins 5secs. The second recording was around an hour and 10mins, and would again always flip out at exactly the same point, but this time 38mins 1sec. I tried loading the files into Peak Express but it reported that both files were corrupt.
In work the next day I tried loading them into Pro Tools, with the same result. Eventually I got them to load into Sound Forge on a PC, and this is what I saw:
What it looks like is that FourTrack continued recording for the duration of the presentations, but in each case it lost the input signal at some point. However, I’m not sure it’s as simple as that: working on a rough memory usage of 5Mb a minute, the file size should be around 230Mb for a 46min recording. The file size is actually 162Mb, which is right if it stopped at 32mins. This suggests that FourTrack did actually stop recording where the audio signal drops out, but that somehow it logged it as continuing to record, which is presumably why I was getting a corrupted file message… Whatever: just to be sure, I recorded one of my own lectures the next day to see if I could repeat the problem and exactly the same thing happened.
Whilst going through this process, I also found what seems to be another quite serious bug in the program, insofar it seems to have a memory leak. Here is a screenshot from iTunes showing the memory of my iPhone with the two presentation recordings onboard:
And here’s the same thing with those two files deleted:
Now those two files only take up around 350Mb, whereas we can see from the above that there is a difference in the displayed application memory of approximately 1.25Gb! Whether this is actually a ‘memory leak’ I don’t know for sure. But I do know that memory management is one of the issues with Objective C, so I’m taking a semi-educated guess.
In summary, I’d say that FourTrack is basically a good program, but as yet it has some technical issues that need sorting out.