getting two channels of audio via USB to PC from interface?

C

canadave

New member
Hi,

I have a TASCAM US122-mkii USB audio interface hooked up via USB to a PC at our community radio station. I also have a standard SM58 mic hooked up to mic input 1 on the interface, to record vocal tracks.

When I try to record into our recording software, it only shows the LEFT channel as being recorded. Is there any USB audio interface that will let me record BOTH the left AND right channels of audio into the PC at the same time?
 
The interface is set up so that input 1 is left, and input 2 is right in a stereo recording.
You want left and right recording? Plug in 2 mics.
Want to stop it recording to left? Record as mono, rather than stereo.
 
That's what I thought, but when I enable the "mono" switch on the TASCAM, it doesn't seem to make any difference. And we don't have two mics to record with.

What if we used an XLR cable Y-splitter to send the mic signal to the L and R input? Would that be sufficient?
 
To create a true stereo recording you need two mics.

Still, you can easily duplicate the recording and then pan in your DAW instead of connecting a Y cable, which would be pointless.
 
I think you are better off recording on a single channel (turn one of your inputs off 1 or 2) then work from there with stereo for your mix down.
 
Bane01 said:
To create a true stereo recording you need two mics.

Still, you can easily duplicate the recording and then pan in your DAW instead of connecting a Y cable, which would be pointless.
Click to expand...

We're not using a DAW, that's the problem. We have to use proprietary radio broadcast software, which gives us no way to change the channels used.

To create a "true stereo recording...with two mics", if we don't have two mics, couldn't we just use one mic, and Y-split that signal out, and put one end into Mic Input 1, and the other end into Mic Input 2, and wouldn't that be basically the same as having two mics going into the interface?
 
canadave said:
We're not using a DAW, that's the problem. We have to use proprietary radio broadcast software, which gives us no way to change the channels used.

To create a "true stereo recording...with two mics", if we don't have two mics, couldn't we just use one mic, and Y-split that signal out, and put one end into Mic Input 1, and the other end into Mic Input 2, and wouldn't that be basically the same as having two mics going into the interface?
Click to expand...
Sometimes necessity is the mother of invention. It sounds reasonable to me. Sounds weird you can't select the inputs. But hey, who knows.

Is there a reason you "have"to use the software? You might look into other software, some with pretty good demos, some as cheap as demo (with nagware only/$40).

Good luck!
 
canadave said:
We're not using a DAW, that's the problem. We have to use proprietary radio broadcast software, which gives us no way to change the channels used.

To create a "true stereo recording...with two mics", if we don't have two mics, couldn't we just use one mic, and Y-split that signal out, and put one end into Mic Input 1, and the other end into Mic Input 2, and wouldn't that be basically the same as having two mics going into the interface?
Click to expand...

More or less, but this is more of a dual mono than a true stereo. More of a pseudo stereo of sorts. You should try the Y-split technique but make sure to pan each input hard left and right respectively. Otherwise just assign the inputs each to one of the two stereo outputs. It's hard to say without knowing the software.
 
EDITED AFTER LOOKING AT THE TASCAM MANUAL FOR A THIRD MINUTE AND REALIZING THE LINE OUT IS ON TWO RCA JACKS:

The best solution would be to deal with it in the software, but - since nobody here knows anything about the software - figuring out exactly what the solution (if any) would be is a bit difficult.

Here's a cludgy hardware solution, based on looking at the layout of the interface for two [OR THREE] minutes:
- Plug mic into "Mic in L"
- Take a RCA-1/4" (TS) cable and put the RCA end in the "Line out - L" jack and the 1/4" in the "Line / Guitar R" jack. I think it would be preferabl to set the little switch by the input to "mic/line" rather than "guitar."
- Turn the "Mon Mix" pot fully toward "Input"
- Adjust the "Input L" pot as usual; then adjust the "Phones / Line-out" pot and the "Input R" pots so they work together to get a matching signal level going into the right channel.
- Turn off phantom power, as you're using a dynamic mic anyway.

As a result, your signal path should be like this:
- Mic -> left channel, gets amplified to line level; gets encoded as the left channel sent through the USB connection
- Amplified mic signal -> Left Line Out jack
- Left Line Out jack -> tip (only) contact on Line R jack
- Line level signal gets encoded as the right channel and sent through the USB connection.
 
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Some additional detail:

Random Background
Having the same signal on the left and right channels isn't "stereo," it's mono. Traditionally, there's usually no good reason to bother recording the exact same signal twice. This gets complicated a bit by the fact that some digital recording protocols (S/PDIF, for one) are inherently stereo. That is: S/PDIF (for example) is a single datastream, but it sends two audio channels. If you want to send a single, mono signal as S/PDIF, you need to have the same data on both channels.

What You Really Want To Do
Get the software either to record this as what it considers to be a "mono" track from the get-go, or in some manner get the software to take the stereo track it records with a silent right channel, and turn it into a mono track or a stereo track with the left-channel data copied to the right channel. There should be a way to do this. Audacity, which is pretty simple, provides several way to accomplish this. In addition to designating a track as mono from the get go, you could make a left-only stereo track into a left-and-right-identical stereo track a few ways, such as:
A Tracks | Stereo Track to Mono
B With the drop down menu on the track, (1) Split stereo track; (2) Delete the blank right track; (3) Copy the remaining (left) track; (4) Designate the newly copied track as "right channel;" (5) combine the two tracks into a stereo track

What About Splitting the Mic?
This generally is disfavored, as it will drop the input impedance that the mic sees in half, and also drop the relatively piddly signal the mic puts out. It's possible this won't matter a lot, but it's not a good practice. Then again, the same is true of connecting the output jack of a device to the input jack of the same device, so go figure.

Some More About the Hardware Cludge
As described, you'd connect the left output to the tip (hot) input on the balanced TRS jack for the right line input. The ring (cold) input is connected to the sleeve, and ground.

You can also set the little switch to "guitar," which apparently makes the input jack unbalanced. The input impedance would probably be different, but that may not matter.
 
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canadave said:
Hi,

I have a TASCAM US122-mkii USB audio interface hooked up via USB to a PC at our community radio station. I also have a standard SM58 mic hooked up to mic input 1 on the interface, to record vocal tracks.

When I try to record into our recording software, it only shows the LEFT channel as being recorded. Is there any USB audio interface that will let me record BOTH the left AND right channels of audio into the PC at the same time?
Click to expand...

Most DAWs will let you play a mono track out of both speakers.
It sounds to be like you have created a stereo track and set the input as 1+2, therefore input 1 only populates the left side.
If you create a mono track and set the input as input 1, then you should have a pan knob available that's set down the middle by default.

If that's a no go due to limitations of your software, there's bound to be some option to split your track into two mono tracks, then just delete the unwanteds.

What software are you using? Perhaps you can use a mono aux track/send?

If you REALLY are limited by the software (which would amaze me since it's broadcast software), you could plug your mic into a little mixer and take L+R line outputs into your tascam, assuming it has line inputs.
I don't know about the Y cable thing. Might work; I've never tried it.
Seriously though, I'd be shocked if any broadcast software doesn't facilitate a single mic to a L+R output.

'True stereo' doesn't really come into it. It's a mono source into a mono mic played back through two speakers - No different to vocals through a pub's PA system.
You don't need two mics for what you're trying to do.
 
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