Converting Lossless Mac

Currently I am converting my music collection (80 gigabites FLAC) to a source that can be synced to my ipod. The first go around I used MAX and converted all to 320 kb MP3 files, when I listened to the files the beginning of the song had a hiss in it. I would compare this hiss to the hiss you would hear when playing a record from the 50's or 60's. I was disapointed that it didn't sound good to me (I tested it on both my ipod and my computer and both had the same problem, different artists and songs). I deleted all the MP3 files and started towards a apple's FLAC alternative called AIFF, after reading that AIFF provided higher quality than the MP3. After around 10 hours of converting I tested the songs again to find that the same hissing sound was this. I was on the verge of and still might be buying a Cowan and get rid of my ipod.

So here's my question, what is causing this hissing song. What program can prevent this from happening to my music.

EDIT: After some fiddling around with the settings on MAX I have removed the hissing. MAX was set to go for bitrate and not quality. With the bitrate option turned on the music was only 60% of the quality. I changed this to 100% along with the audio being turned to stereo instead of mono. Once I listened to it again I am completely satisfied, now I can listen to my music without getting a headache from the hissing. A special thanks to: poikkeus. If it were not for this community I do not know how I would go about things, thanks head-fi.

Thanks in advance,

Abovetheair

Im going to convert 3 CD's tonight with MAX again. I noticed the encoder was targeting bitrate instead of quality, could this make a difference?
 

Quote:

Originally Posted by poikkeus 

I also use OSX, but do not have your problem transcoding. Instead of your current process flow, try this: jettison the MAX software, and instead use the equally free iTunes, and transcode to 320 (or whatever you want). I use the iTunes AAC encoder set at 320 (160 in each channel), and I've not noticed the artifacts you report. 

 

Before you defect to Cowan, see if this software fix solves your problem.