Well it seemed like a good idea. I bought a 64GB USB drive and converted a copy of my music library to all higher bit rate MP3 files, mostly 192Kbps, some up to 256Kbps. We're talking about 9000 songs by about 350 artists, all arranged in the usual folder structure that ripping yields. They all fit in about 52GB worth of space on the new drive.
The only problem is that when I load the USB drive into the Volt, I only see about 1600 songs by a hundred and some artists. The folder display shows 150. The really weird thing is that I had been using another smaller drive, 16GB, which the Volt is able to display about 230 folders and over 2300 songs, presumably all the music on the drive, although I haven't verified that. Both drives are FAT32 file systems.
I'm trying to test some different things now to get some kind of clue for what the problem or limitation is, but I thought I'd put it out to the group to see if anyone has any suggestions or ideas.
Another thing I determined is that when you copy MP3 files from the USB, they seem to get recompressed. Chevy doesn't specify the data rate it uses, but I can tell from listening to it that it's not as good as the 192Kbps files on the new drive. This whole music system could use some work!
It's difficult to create something totally universal here because different ripping tools can create somewhat different ID tag and folder structures. (What are you using BTW) But I ran into something like this recently on the Buick Regal, which uses a similar if not identical system to the Volt.
There' a recent corp bulletin describing the maximum files addressable in each folder, and perhaps you hit your head on that. Don't quote me just yet but IIRC the maximum is 256 files/folder.There's also a folder maximum for the root directory. So if you exceeded that you wont "see" some of the files. In the case I was involved with adding a genre level broke the folder structure down sufficiently to prevent topping out to these limits.My portal is closed for maintenance until tomorrow but I'll try and obtain and post the bulletin tomorrow. It also describes the various supported file formats and various incompabilities.
I finally determined that there is some kind of limit to the number of folders, just like WOT suggested. I made a flatter file structure on my USB drive and was finally able to hit the next limitation! And that appears to be that you can't have more than 7,000 music files on your USB. Granted, that's a lot, but my collection was actually over 8,000. So I pared down about 1500 tracks, which will eventually go onto another USB drive to keep in the car.