HydrogenAudio

CD-R and Audio Hardware => Audio Hardware => Topic started by: tuffgong on 2013-01-11 05:23:09

Title: How do I listen to two USB dac's at once
Post by: tuffgong on 2013-01-11 05:23:09
Hi folks, I currently use a software program called Virtual Audio Cable so that I can run two USB dac's out of my computer at the same time. I had read somewhere that XP was able to handle multiple audio outputs so, I borrowed a friends laptop with XP, but it turns out that you have to pick a default usb output source in XP as well (perhaps you can listen to the audio 3.5 out while the usb out is working in XP, I didn't check, which is what the XP people keep begging to have it put back in future releases). I read that Mac OS just recently added a feature in their audio screen called "multiple devices" so that one audio stream can be broadcast to multiple output devices at the same time (I need this as well for audio work). I'm not sure if "multiple devices" in mac works for two USB's at once, but would make sense if it did. Is there another way besides virtual audio cable to send sound to two usb outputs (dacs) at once? I'm afraid that virtual audio cable might add latency (I can't hear any latency, but don't know if I want to trust doing a mix with that assessment), and mess up any mixing I am trying to do. Someone suggested look into a DAW but that seems like an awfully complicated solution to a simple problem. Did apple address this problem, or does apple just do one digital and one analog out, similar to what I assume xp does? Thanks for any help, greatly appreciated.
Title: How do I listen to two USB dac's at once
Post by: saratoga on 2013-01-11 05:38:49
You'll probably have latency issues no matter what you do since the two DACs won't be synchronized. 

Why don't you just mix on the PC and output to one DAC?
Title: How do I listen to two USB dac's at once
Post by: tuffgong on 2013-01-11 06:02:32
You'll probably have latency issues no matter what you do since the two DACs won't be synchronized. 

Why don't you just mix on the PC and output to one DAC?


The mm-1's have kind of forced my hand (sorry I didn't mention one of the usb dacs in my first post was dedicated), since they use a usb port and become the default sound, and have an internal dac. Methinks i'm just going to live with it and not try to mix anything. If anyone else has any other suggestions i'd love to hear them. thanks.
Title: How do I listen to two USB dac's at once
Post by: saratoga on 2013-01-11 06:09:07
The mm-1's have kind of forced my hand (sorry I didn't mention one of the usb dacs in my first post was dedicated), since they use a usb port and become the default sound, and have an internal dac. Methinks i'm just going to live with it and not try to mix anything. If anyone else has any other suggestions i'd love to hear them. thanks.


I'm sorry, but what are you actually trying to do?
Title: How do I listen to two USB dac's at once
Post by: tuffgong on 2013-01-11 06:31:30
The mm-1's have kind of forced my hand (sorry I didn't mention one of the usb dacs in my first post was dedicated), since they use a usb port and become the default sound, and have an internal dac. Methinks i'm just going to live with it and not try to mix anything. If anyone else has any other suggestions i'd love to hear them. thanks.


I'm sorry, but what are you actually trying to do?


Trying to play a song with foobar, that will go to the mm-1 via one usb out, and go to another usb dac out to run a sub, but do it natively without running virtual audio cable. As people have said, it will never be perfect, two separate usb dac clocks can't be synched. I concede defeat on that, but just curious if there is a native way within an OS to send sound to two default usb outs at once. Sorry for any confusion.
I might be missing some basic computer 101 here as well. Can you not run two ASIO or WASAPI instances at once on the same clock? So can someone give me a few sentence explanation on why the audio driver can't handle two digital instances at once? Maybe if they were buffered to be in synch? I will still listen to my setup with virtual audio cable, I can't sense any latency, but I wanted to ask the experts if there was something better I might not know about.
Title: How do I listen to two USB dac's at once
Post by: dZeus on 2013-01-11 09:32:04
The mm-1's have kind of forced my hand (sorry I didn't mention one of the usb dacs in my first post was dedicated), since they use a usb port and become the default sound, and have an internal dac. Methinks i'm just going to live with it and not try to mix anything. If anyone else has any other suggestions i'd love to hear them. thanks.


I'm sorry, but what are you actually trying to do?


Trying to play a song with foobar, that will go to the mm-1 via one usb out, and go to another usb dac out to run a sub, but do it natively without running virtual audio cable. As people have said, it will never be perfect, two separate usb dac clocks can't be synched. I concede defeat on that, but just curious if there is a native way within an OS to send sound to two default usb outs at once. Sorry for any confusion.
I might be missing some basic computer 101 here as well. Can you not run two ASIO or WASAPI instances at once on the same clock? So can someone give me a few sentence explanation on why the audio driver can't handle two digital instances at once? Maybe if they were buffered to be in synch? I will still listen to my setup with virtual audio cable, I can't sense any latency, but I wanted to ask the experts if there was something better I might not know about.


isn't PulseAudio on Linux designed for these types of scenarios? I've never tested it though...
Title: How do I listen to two USB dac's at once
Post by: RonaldDumsfeld on 2013-01-11 12:45:30
Mmmh. I've got Vista,7 & 8 machines. All of them support multiple USB audio interfaces simultaneously. I don't understand your issue.

Ah. Sorry. Now I do. You want to send a single output from one application to 2 separate interfaces?  Yes? That would be a little more problematic. Depending on the specification of your existing gear.

The MOTU Ultralite, NI Audio 2 and M-Audio Fast Track Pro can all do what you would want but that's because they support multiple stereo programs output on multiple channels via ASIO drivers.  I'm not sure off hand if I could feed the same output from, say, foobar to two different devices without looping the signal back and therefore getting latency issues.

Anyway the simple answer to your question is yes you can output the same signal to 2 devices provided you have the right kit.


Title: How do I listen to two USB dac's at once
Post by: tuffgong on 2013-01-12 00:17:15
Thank you for suggestions to check out, i'll check those out tonight.