Tunnel Effect with exported files only

I am on Windows 7, Audacity 2.0.0. When I record from internet streaming files etc. I was getting a tunnel effect. Using advice from this board I changed Edit/Preferences/Devices/Host from MME to Direct Sound. I also right-clicked on the sound icon on the task bar and changed the properties in Recording Devices/Stereo Mix/Properties/Enhancements to Cancel all sound effects.

That worked well and removed the tunnel effect when I play back what I just recorded while still in Audacity. The problem is when I export the file to an MP3 file and then play that file with Windows Media Player, I get the tunnel effect again. Any suggestions please? I have attached a sample.

MP3 is a “lossy” format. There is always some damage to the sound when audio is encoded to MP3 format. The damage may be minimised by using high quality settings, but there is always some damage. The damage is permanent - there is no way to fix it. The damage is “cumulative” - each time the data is encoded it adds more damage.

The sample file uses a high compression rate of 32 kbps - That will give a small file size, but more damage. I higher bit-rate will produce less damage but bigger file size.

I tried re-saving it at 64kbs but still get the funny metallic echo. I have done a lot of MP3 recordings before from ripped songs etc. and haven’t noticed that problem.

As an experiment, try exporting at 320 kbps. Does that sound better?

I didn’t listen to your file 'cause I’m at work. But it looks like way too much compression. Try a higher bitrate. MP3 is lossy compression and the lower the bitrate, the smaller the file and the more data is “thrown away”.

Do you have a file-size limit?

128kbps is probably the minimum for good quality music. That’s about 1/10th the bitrate & file size of an uncompressed CD, but it won’t sound like 90% of the information was thrown-away. A LAME VBR (variable bit rate) setting of V0 to V2 is usually identical to the original uncompressed file. The "best"MP3 setting is 320kbps CBR (constant bit rate), and use joint stereo in any case. (You can’t really say it’s “best” unless it sounds better than a lower-bitrate setting.)

It’s a voice recording, so while the amount of compression is quite high it’s not way over the top.

Forgot to say - 32 kbps is about the lowest kbps (highest compression ratio) for reasonable quality mono voice recording. For stereo voice recordings, either push that up to 64 kbps or convert to mono before you export (Tracks > Stereo Track to Mono).

Ok, that is much better thanks. I converted to mono and saved at 128kbs.