I don’t know why this works but connecting my Reciva internet radio to SWYH http stream output gives audio which is pretty bad; however, if I stream the SWYH http output through vlc (which is also free open source software) and listen to the vlc http output stream on my radio it sounds excellent. I tried this with both SWYH 1.3 and SWYH 1.4 and got similar results.
I can’t account for why putting vlc between SWYH and the radio should make any difference but it does. It may be that other devices that don’t work well with direct http streaming from SWYH do work well if streamed from SWYH through vlc so I thought I would mention it.
The detailed instructions for using SWYH, vlc and a Reciva radio are here: http://iradioforum.net/forum/index.php?topic=1945.msg17669#msg17669
Adapt these instructions appropriately to your device.