Does recording "Stereo Mix" affect sound quality?

Hi people,

I have a quick query - if I am using a soft-synth, or VSTi, or any program that plays back samples or wave files on my PC, and I want to record the audio (ie convert my midi code to a wav file) - am I right in thinking that,

A) I am recording the digital data coming from the VSTi or drum machine program output etc STRAIGHT TO a wave file, unadulterated so to speak,


B) am I recording sound from that has been sent to my soundcard, and has been converted to audio, then is converted back to digital as a wav file when recorded?

I have reason to want to record basically anything that is going through my soundcard, and have selected Stereo Mix on the soundcard Recording mixer (I may use n-Track or another recording program). Basically I’m just wondering if recording from the Stereo Mix will result in a deterioration in sound quality, or is it essentially a transfer of data (sound prog) to data (wav file) with no loss of quality.

My soundcard is a pretty standard one that came with my PC. And recording from the Stereo Mix is all internal in practice I should note (i.e. no cord is needed to go from the output back into the input - which would result in B above).

Anyone care to clarify (what I think I know but just want to make sure) ?

Much appreciated


As far as I know, this will just grab what ever is at the analog output and dump it back through the digital conversion stuff.

I would imagine there is some degradation of quallity going on. If you’re just trying to get that sequenced stuff down to a recorded track I think it’s going to be good enough in most cases. Over the years I’ve recorded from the ‘Stereo Mix’ or ‘What You Hear’ tab bajillions of times and never once have my ears scolded me for it.

My setup is pretty low budget and run of the mill though. Not much in the way of pro audio here. Your milage may vary!

You’re probably right, especially since the Stereo Mix could include an analog Line In source also, so it must be an analog back to digital conversion.

I want to have some sound files, mainly drum tracks, saved on a digital device (as pcm/wav files on a minidisc) that’s basically portable and can then be taken with me and then recorded to a portable multitracker. If I do this though I’ll be introducing a further coversion stage than I would be if the sound files were played from source on the computer and recorded strraight to the multitracker (which isn’t as convenient for me).

I wonder if there is a utility that can extract the digital data being sent to the soundcard for playback (“Wave” playback) on the computer and save it to a wav file?


I think I’ve found the answer! Use Total Recorder. There is a function for recording directly using the digital output from software sources.

I’m not real sure what you’re doing, but this is what I understand what happens…

If you input midi into a VSTi, then record the ‘audio’ coming out of the VSTi with n-track, then it all happens in the digital domain.

I don’t think the soundcard is involved, and I don’t think there’s any conversion to analogue and back to digital again.

But I could be wrong. Ask me a question about setting up bias on a reel to reel machine next time, I’m better at that. :D


JW, I think you are a little confused as to what a .wav file is.

A .wav file is not an ANALOGUE AUDIO recording it is purely and simply a digital file.
As such it can be copied and manipulated in the digital domain, just like any other piece of computer data.
The ONLY time it is converted to analogue audio is when you send it to an analogue port on your soundcard. i.e. headphones, speakers or line out.

The “Stereo Mix” is nothing to do with your soundcard. It is a software application that mixes digital data.

Just like a real mixer, you can select where the data comes from and in what proportions by varying the sliders on the panel. You can also send the output of the mixer to several destinations, one of which might be the speaker output on your soundcard.

So, basically, if you have recorded sounds using your computer soundcard, you have turned them into digital data. If you copy that data onto another device (pendrive, dvd, cd, floppy disk etc.) you have not converted it to audio If you then import that data into another device (computer, multitrack HD recorder) you have still not converted it to audio so there are no "losses"

HOWEVER, if you copy the data to your minidisk from one of the soundcard outputs (headphone, speaker or line out), then you HAVE converted it to audio, with the corresponding losses caused by your soundcard and minidisk.


Thanks Steve. That’s what I figured happened. But the posts above had me starting to wonder. :D

Hi Steve

I understand what a .wav file is, I just wasn’t entirely convinced that one program recording another program via the stereo mix was doing so entirely in the digital domain, though it probably depends on certain factors and the type of soundcard one is using (mine is the ordinary Soundblaster type).

This tutorial page at the Total Recorder site shows several methods for recording the output of a program using their software, in this example an audio webstream being played via WMP / RealPlayer etc:

Several methods are detailed - method 2 is the one we have been discussing above. But can anyone say there is a difference between methods 1 and 2 as per this tutorial?

If not, then all well and good. But IF there is a difference, then perhaps method 2 is doing this: sound being played on the computer is being sent to the soundcard audio out (= an analog output signal, which can be heard through headphones/speakers etc). Selecting stereo mix to record then takes this analog output audio as an analog input source and re-converts back to digital. In fact in method 2 the tutorial refers to the soundcard’s ‘loop-back line’, without explicitly suggesting that this is a digital/virtual connection – seems to imply an analog connection.

If there is no difference between methods 1 and 2, why are they making this distinction?

(My intention when I have recorded the wavs will be to transfer them to my HiMD player, which pays wav/PCM audio files - ie. I’ll have portable ‘first generation’ sounds to play back).




Methods 1 and 2 are essentially the same and are DIGITAL recordings.

Methods 3 and 4 are also essentially the same and are ANALOGUE recordings.

Use either method 1 or 2.


Yes I think you’re right about 1 and 2 being the same.

Though method 1 is using Total Recorder’s own version of the Windows mixer’s Stereo Mix. I guess not everyone will have the Stereo Mix option, though most will. There can also be conflicts with more than one program using the same sound card - ie one program uses it to play sound, the other needs it for recording (I have found this), so method 1 is a work-around for this also.

Thanks all