Professional-Grade Audio Recording With A PDA

matt-fu writes "For a long time, live recording has been consigned mostly to the realm of DAT recorders, Minidisc recorders, or laptop computers. On one hand you have subpar sound quality, on the other you have a bulky rig with a big 'steal me' sign attached. Thanks to the folks at Core Sound though, mobile recording is about to take a huge leap forward with their PDAudio project. By using a hardware card that allows recording via S/PDIF onto Compact Flash, you will be able to use your iPaq or Zaurus alongside a decent A/D converter to portably get field recordings at up to 24bit/192kHz. The site includes WinCE screenshots, and there are Linux clients in the works as well."

Comments

Size Limitations

[shepmaster]

So, who would be interested in nothing more than a high-quality sound bite? Most CF and similar products are small, and audio recording is big. Or are there multi-gigabyte flash cards in the making?

Re:Size Limitations

[jandrese]

I wonder if they're going to include some form of lossless compression (like flac) on the sound to squeeze more bits out of the 4GB CF card mentioned in the article. As it stand, you can only get about an hour of uncompressed 2 channel 192 Kilosample 24 bit audio on there. With compression it should be easy to get 2 hours out of the card. If you use a lossy compression (like ogg) it should be trivial to get many many hours on a 4GB CF card.

Re:Size Limitations

[soupdevil]

How far apart are your ears?

Can you hear two channels of audio at once?

Re:Size Limitations

[hackstraw]

Actually, some mikes that are used in audience concert recordings have different cartridges to change the reception pattern of the mike (cardiod, hypercardiod, shotgun, etc ). Why? For better stereo seperation at different distances from the stage.

A good stereo audience recording sounds excellent. They really have that "there" feeling. I've actually jumped listening to a recording when a balloon popped near the mikes!

Some people have meantioned using minidisc for shows. I have never had a recording come from a minidisc. I've seen "tapers" use minidiscs, but there not considered tradable, they are for personal use only.

Regarding the recording of music on PDAs in general, I don't see this happening. There isn't a need. A minidisc is about as small as your gonna get, if size is what your after. Also, many of the current tapers have a dat deck, a good A/D converter, and some even have separate preamps to give gain from the mics to the a/d converter.

Trust me there are plennty of excellent recordings out there for many taper friendly bands. Many of the recordings have detailed lineage of the source. For example:

FOB B&K 4006 omni's (in hat, 36th row left of center) > Lunatec 316> Panasonic SV-250 by Marc Nutter; Transfer: Sony DTC-A6 > Dio 2448 > SF 4.5 @ 48K, Resample, add fades> CDWAV> SHN

This is from a recording 8 years ago, taping is almost godlike now!

Re:Size Limitations

[dougmc]

192khz sampling and compression do not fit together.

As long as you restrict yourself to lossy compression schemes, you may be correct (it's still a controversial subject, of course.) However, you may not have noticed this, but the person you responded to mentioned *both* lossy and lossless compression.

(Of course, he did incorrectly suggest that lossless compression requires having the entire stream at once, which is patently incorrect. Obviously he's never heard of gzip or bzip2 -- both of which are lossless and compress streams block by block -- but aren't that great at compressing audio streams. There's more on various lossless audio-specific compression programs here.)

Note that even lossy compression is not always bad. mp3s and Oggs at 128Kbit/s may not be CD quality, but they're pretty good -- and yet it's compressed by a 12:1 factor! Increasing the bit rates will reduce your compression factor, but will increase the quality.

Jpeg files are lossy, yet with higher quality factors the quality is so high that you can't even tell the difference with your own eyes.

An audiophile may not be at all happy with 128Kbit/s mp3 files, but as you increase the bit rate, there's likely to be a place where he can't tell the difference between the lossy compression and the original. (Of course, depending on how strongly he hates lossy compression schemes, he may never actually admit it.)

At that point, what matters is the compression ratio compared to what you could get with a lossless compresser.

You wouldn't want to use a lossy compression scheme for compressing the studio masters (you should always do your mixing and such with no compression or lossless compression), but if the quality is good enough, it may be perfectly ok for the final distribution of the music, even for the audiophiles. 128 Kbit/s mp3s don't cut it, but that doesn't mean that `mp3 sucks!'.

Hello? A to D converter?

[PhyrePhox]

This is not an all-in-one solution. You'll still need an encoder, and frankly, a portable DAT or MD recorder is: smaller; a single finished piece; designed specifically for this purpose; and (at least in the case of the MD recorder) much cheaper than a iPaq/A-D converter/this funky card.

What about an Archos

[toxcspdrmn]

I can do pretty much the same with my Archos Jukebox Recorder and an amplified microphone. With on-the fly VBR MP3 encoding direct to a 20GB hard disc, space is not an issue. And it fits in a pocket.

Re:What about an Archos

[delta407]

Do you honestly think that audio professionals store data in 160-kilobit VBR MP3s?

Besides which, can your Archos do 24-bit/192 KHz sampling? Professionally, very, very few people use 16-bit/44 KHz for anything serious.

Woah there, hoss!

[bengoerz]

For a long time, live recording has been consigned mostly to the realm of DAT recorders, Minidisc recorders, or laptop computers. On one hand you have subpar sound quality, on the other you have a bulky rig with a big 'steal me' sign attached.

Subpar sound quality? The DATs that I've worked with have better resolution than CDs (48 KHz vs 44.1 KHz sampling), minidiscs are technically CD quality, and laptop computers can be equally sensitive given the right equipment. Given what I've heard of PDA sound, there's nothing subpar about the existing recording mediums. Also, it's hard to claim that a minidisc is "a bulky rig".

By using a hardware card that allows recording via S/PDIF onto Compact Flash, you will be able to use your iPaq or Zaurus alongside a decent A/D converter to portably get field recordings at up to 24bit/192kHz.

So to record in this way, I must buy a "decent" A/D converter and a bunch of Compact Flash. And, unless they are using some compression which will lower the sound quality, this thing will suck up more MB-per-minute of audio than a CD. Good thing Hitchai (formerly IBM) makes their MicroDrive, and I have a money tree in my yard.

So, bottom line as I see it? An interesting project, but one which uses expensive hardware and media that makes it prohibitively expensive. So if you want professional digital recording, get a professional digital recorder. If you want ad-hoc "pro" sound recording from a PDA, now you've got an option.

The CF card has windows and linux drivers...

[JoeMango]

...if you didn't notice. They won't be selling this stuff exclusively as a PDA kit.

The cool thing about this is not "Yay, you can record on your IPAQ!" but "Yay, someone is producing a digital audio interface in CF format with OpenSource drivers!"

I've thought that using the PDA to do my taping would be super-slick and would get me a lot of oohs and ahhs, but the PDA+4GB CF card+dual CF sleeve combo is WAY more expensive than a Nomad Jukebox 3, which I recently converted to from MiniDisc, and which I am ecstatically happy with.

Still, it's nice to see someone sticking their neck out and making a device that people want rather than need. Good luck Len!