Slashdot Mirror
Computer Audio - To USB or Not to USB?
Tom asks: "The time has come for me to upgrade the audio on my computer. This was last discussed, here.My specific area of interest, is the sound card, in its various embodiments. Two cards that I am considering are Creative Labs' Audigy2, and M-Audio's Revolution 7.1. These companies also have USB counterparts to their products - the Extigy and the Sonica Theatre - and I can't decide if USB's portability and other various advantages justify its shortcomings. Experiences, anyone?"
From what I can tell, a lot of semi-audio professionals like usb sound cards because there isn't quite the interference with them, that one gets from a sound card sitting inside your case.
:-)
The only real downside(other than price), is that they use more cpu than traditional PCI soundcards. However, not enough to make a difference these days.
And of course, I want the extigy because it looks so neat. Too bad it's still $150 at Compusa, I'm waiting for it to hit $75 or so and then I plan to pick one up. Since I use a real amplifier and speakers connected to my computer(the only way to go), it will be nice to drop the 1/8" -> RCA adapter coming out of the soundcard.
I would expect such blatant racism on Fark, but on Slashdot? Mods please ban this asshole.
... and I find it works just fine for my needs.
... at which point I'll chuck my 16-channel mixer and have an extra 2U's left in the rack for ... something ... else ... fun.
... but yeah, USB works just fine.
-tiBook
-19" rack full of synthesizers and a 16 chanel mixer with 2 recording/send busses.
-external keyboard (indigo2 synth, not the computer)
-external 4x4 USB Audio interface
-external USB hub, with MOTU MTP-AV, keys, mouse, etc.
I lay down stereo tracks at a time, typically, or at least I only ever record two tracks at the same time as I'm playing (and digitally mixing on my laptop) typically about 6 to 12 other tracks, no problems. My USB Audio interface keeps up with everything I'm doing, no glitches, and I'm working at 44.1khz/16bit.
I also watch DVD's on this setup, quite comfortably, and never notice any sync/glitch problems with USB.
A Firewire audio interface would be better of course, because then I'd have lots more i/o and routing capabilities with soft control, and so I'm planning on getting one soon
16 inputs in my rack right now would be sweet indeed, particulary considering that 4 items have their own input/routing capabilities as well as multipe output channels, so a Firewire interface is pretty much totally in sight
(OSX, tiBook, lotsa RAM, smooth as silk USB audio drivers)
; -- the corruption of government starts with its secrets. a truly free people keep no secrets. --
The creative is nice, but it's been my experience that creative has a hard time supporting thier products (with the exception of their cambridge soundworks stores).
Chrisd
Co-Editor, Open Sources
Open Source Program Manager, Google, Inc.
I use the extigy and I must say it's great.
I needed something for my laptop so that I could record live mixes from my dj equipment, since my laptop only had a mic input (really horrible for recording from a device). I decided on the extigy because I found a linux driver for it (you need a separate driver for 2.4.21, and so far it works with 2.6.0 test3, at least for playback).
So far I can tell you it records great. It records at 48000Hz (which means you have to convert wavs down to 44100 before you can burn em, but it's easy with sox). I haven't tried the 5.1 capabilities yet since I don't have money for a 5.1 speaker set;) I also haven't had a chance to test the midi capabilities with it yet, but my dmesg does say the usbmidi drivers are working.
I think the coolest thing about it so far, aside from the fact that it just works well, is that if you know what you're doing, you can write programs to make the remote control do whatever you want. The linux-2.4.21 drivers I found came with an xmms wrapper example that works pretty well. You can use the volume controls, stop, pause, play, etc. and switch songs... I spent the first week I had it just watchin my xmms volume knobs move when I pressed the vol+ button haha.
The extigy is also super light if you want to carry it with you. I think the adapter might weigh more than the device itself. I'm not sure how the extigy works any other OS, but I guess it would perform well if you had the right software.
Chaos is Divine *
You haven't said what you want to do with said sound card. Here are some likely possible uses:
If you want high-fidelity field recording, USB is good (I use an Edirol UA-5 usb 'prosumer' audio connection, and am quite happy with the results). Really high level stuff requires a different interconnect, firewire, PC Card, USB2, etc.
If you want a gamer card, USB is a good choice for a laptop or other semiportable operation (LAN parties). Keep in mind, this environment may call for simply a decent pair of headphones. Moving 8 speakers around constantly is not fun, 2 or 3 (or headphones) are a better choice.
If you want a home theater setup (DVDs, DVB, HDTV) you're probably looking at a fairly static setup and might as well go with the standard expansion card. If you have a really high-end setup, (good amplifier, speakers, and room design) consider a good quality external solution to remove the EM noise from inside the computer's case. I strongly hestitate from describing any recent Creative Labs sound device as 'High Quality', but I have not in fact listened to the one you described.
Both USB models you chose are USB1.1, meaning low bandwidth, and will top out quite easily. Think 48k/24bit/2chan full duplex, a raw AC3 stream, or 96k/24bit/2chan half duplex.
"'Tis great confidence in a friend to tell him your faults, greater to tell him his." --Poor Richard's Almanac
Most PCI sound cards have noise and interference problems. Try turning up the volumn and listen with a good headphone, the noise is very noticable. I don't understand why many people buy expensive PCI sound cards while a cheap USB card does the job better.
I got an M-Audio USB unit, and I was amazed by the sound quality improvement over the built-in audio on my Mac... and Macs are known for having pretty good audio to start with.
No problems digitizing at 24 bit accuracy across USB 1.1.
GCHQ Quantum Insert installed. If only our tongues were made of glass, how much more careful we would be when we speak
> I'm assuming that sound cards use a decent amount of
> bandwidth...
You're actually assuming more than that.
A channel of CD audio takes ~1.4Mbps. (44100 samples per second, two channels per sample, 16 bits per channel.) So full duplex stereo CD-quality audio takes 2.8Mbps. Let's say we're hardcore audiophiles and want full-duplex 96kHz stereo audio: 6.1Mbps.
And yes, the bandwidth of the PCI bus is 133MBps or ~1064Mbps. So if you really need 98 channels of CD-quality audio, PCI's clearly the only way to go.
Now, there are of course issues with USB devices. The main one that comes to mind to me are lack of DMA and bus-mastering. A good PCI sound card can handle its own transfers in and out of RAM, preventing it from being buffer-starved (or at least making it more difficult). This isn't possible with USB (but -is- possible with Firewire, sort of).
You'll also wish to consider latency, but I suspect it'll be lower than your average high-quality software synth if they're using the USB isochronous channel.
I can't speak to multi-channel video games on the PC (are they doing DD5.1 in PC games these days?), but bandwidth isn't a problem at all for the other big multi-channel format, DVD. A compressed Dobly Digital six-channel (DD5.1) stream comes in at only 448 kbit/s. Since the Extigy can pass through and decode Dolby Digital, the USB doesn't have to carry the decoded/decompressed signal and the data rate above wouldn't stress a USB 1.1 connection at all - all depending on the driver and DVD player software, of course.
how many channels does he want for his 7.1 system?
I am assuming 7+ the bass being sucked off all of them. It is at least 4 channels with the others interpalated so that is about half of your USB bandwidth at a minimum 7 * 2.8 and you can't fit it all and yes, I want CD quality sould if I am watching a DVD on my $150.00 sound card.
Also USB may be doing other things. Can you watch a DVD while you print stuff out? How about the line in, for say voice chat in a game.
I don't think that USB 1.1 has the bandwidth to support a full sound system without some crazy stuff happening (for example a driver could be setup that sends three channels (triangulate) and the card could split it up, but sounds very costly to the CPU).
If I am totally wrong here speakup.
Wow, sent an e-mail as suggested when clicking on "use classic" banner, and got a fast response that addressed my msg
...is (~an order of magnitude) bigger with USB. This can be a real issue if you're doing (many) multitracks, where latencies add up.
Higher CPU usage and bandwidth limitation (recording standard 24/96 will "max out" USB-1 at full duplex) are other issues you (usually) don't face with PCI cards or Firewire stuff.
Price difference is not an issue usually - better ADC/DAC are expensive in every packing (PCI/USB/Firewire).
Yes, it is advantagous to have the ADC/DAC remote from the EM-noisy PC enclosure - but the max. (specified) cable length of ~1m (correct me here please if my memory is not right - yes, I know that usually longer cables beyond the max. specification still work with a number of devices) is a bit short for nice usage above the desk.
I bought a JVC reciever about six months ago ('cause the ex spilled a coke in the old one) and it happened to have a USB "input" (USB-B connector) on the front.
/dev/dsp1. Now I have mplayer set up to use that device for audio output, and everything else uses /dev/dsp (lame built in sound on my MB connected to lame speakers built into my display).
I didn't think much of it when I bought it, figured it'd be a windows only thing anyway. One day my system was off, for a hardware upgrade IIRC, and I plugged in the reciever on a whim.
RH9's kudzu picked it up and set it up as
It all works out really well, and the sound through the reciever is great.
The one downside to consider ist that you can only play audio CDs through a USB sound device by using CDDA, which is less than ideal. Uses a lot of CPU and IDE bandwidth and still skips from time to time. (For me, anyway.)
Good luck!
-Peter