I recorded some clips of a concert on my digital camera, and the audio sounds distorted. How can I fix this?

Question

I think I need to bring down the bass levels.

Answer 1

Your camera recorded the music as presented.  As you can see the bass is heavily over modulated as far as your cameras microphone was concerned.

You may be able to build a cutoff filter for below 150Hz and clean up your signal, but what you may find it that the bass frequencies over pressure also effected the frequencies above 150 Hz and remnants of it will be found to some level as distortion or an underlying backbeat within the higher frequencies.  

If you want a cleaner sound track (and if you are not prohibited from recording the performance) you will have to use an external mic like a Shure or AKG with a crossover filter that drops the 150 Hz frequencies and lower by at least 6dB ... 12 dB down might be better, but could be overkill ... so you may have to have two mics with you one 6 dB down and one 12 dB down set at the 150 Hz aim point.