Audacity Forum

Hi,
Whenever I try to record stereo mix or mono mix input eg. to record an online radio stream, I am getting an annoying hollow echo effect on the recording which means the recording is basically useless to me.

The sound is fine while I am listening to it live but the recording is infected with that unwanted echo.
Recording from the microphone is OK.

I have tried unsetting all options that might be related to this, and other things, as per the following list:
1. Going to the preferences tab: Edit/Preferences/Audio-I/O and making sure the setting "Play other tracks while recording new ones" is disabled
2. Making sure "Software playthrough" is disabled, in the same preferences tab
3. Pressing "Mute" on the Audio track window while recording.
4. Trying different combinations of Playback and Recording devices (in same tab as above)
5. Playing around with different "latency" settings (same tab as above)

None of these things make any difference at all. What else can I try?

EDIT: I get the same result with the stable version of Audacity btw.

If the microphone is "live" when you are recording from "Stereo Mix", it could be picking up sound from your speakers.

Go into your sound card control panel / mixer and make sure that all inputs and sound sources that you do not want to record are muted.

Thanks for trying but no, it isn't that either.

I just tried it again with the mic muted, the mic cable disconnected and the speakers switched off as well.

The result is exactly the same, with the annoying hollow echo on the recording.

Any other ideas?

I suspect that it is a sound system set-up problem rather than Audacity.
To test if that is the case, try recording with Windows Sound Recorder and see if you get the same problem.

Thanks, and yes, I would also not be surprised if it is a general sound system setup issue.
Still, I was hoping somone in this forum might have been up against the same thing in the past.

Windows recorder records OK from the mic, as does Audacity.
However I can't find a way to get it to record the stream I am listening to. Is it possible in the first place, and how?
It doesn't seem to have an option to select "stereo mix" or "mono mix" as input as in Audacity.

dahaiou wrote:It doesn't seem to have an option to select "stereo mix" or "mono mix" as input as in Audacity.

Ah ha - we may be getting toward the root of the problem.

The source selection in Audacity is not always reliable as it depends on the sound card driver "playing by the rules", which many recent drivers do not. This is particularly a problem with many recent on-board sound cards, laptops and Vista.

In Audacity, go to "Edit > Preferences > Audio I/O" and set the recording and playback devices to "Microsoft Sound Mapper", then go to the Mixer/Control Panel for your sound card - this is usually accessed through a loudspeaker icon near the system clock. Use this Mixer/Control Panel to set the audio inputs and outputs as you require (there are usually separate sections for "recording" and "playback" - explore all the tabs and buttons for any hidden settings).

To record "stereo mix" with the Windows Sound Recorder", you do not make any changes to Windows Sound Recorder, you simply select "Stereo Mix" from the sound card Mixer/Control Panel.

Thanks again for the suggestions. It might be that we are getting a little closer to the root of the problems here.

I did already have "Microsoft Sound Mapper" as input and output devices, though I briefly tested changing there too.

It is an on-board sound card all right "Realtek AC97 Audio", but not recent and not a laptop. It is a four-year-old HP Pavilion mini-tower PC with XP-SP2.

I was now able to record stereo mix with Windows Sound Recorder thanks to your instructions, and the result is exactly the same there. I get the same echo on the recording. Apparently the fault is not with Audacity then, but I'd still be grateful for any advice on how to go about solving this.

It would seem that an audio output is somehow getting back into an audio input.

My "most likely" guess is that there is still some input / output combination in the Mixer/Control Panel for your sound card, or you have some sort of "Environmental Effect" enabled in your sound card. Check these possibilities first.

If still no joy -
Do you have any virtual audio devices installed (such as Total Recorder)?
Try closing down all non-essential applications and processes using the Windows Task Manager and see if the problem persists.

!!! SOLVED !!!

Thanks so much for your patience and suggestions. It was just what I needed to get me pointed in the right direction.

You mentioned sound card drivers, which in my case were the original ones that came with the PC when it was new in 2004.
So I hunted around on the web a little to see if there were any updates available, downloaded and installed the latest set, from oct 1, 2008, and lo and behold - problem solved - the recording is working perfectly now.

Once again BIG THANKS ! And a BIG SMILE from this end

And everybody keep up the good work with Audacity btw. It's a great application !