Sure the HX9V has a better audio than the HX5 but what if you want a kick ass audio to the class leading video?
Maybe this will get you on the right track!
Stereo X/Y mic configuration captures perfect stereo images
Records Broadcast WAV (BWF) at 96kHz/48kHz/44.1kHz at 16-bit or 24-bit
Records MP3 from 48 to 320kbps for maximum recording time
Hi-Speed USB 2.0 port
Built-in reference speaker
Includes 2GB microSD memory card and one AA battery
One AA size battery allows 10 hours operation
Accommodates up to 32GB microSDHC memory cards
Track marker function
Low cut filter
Built-in tripod mount
1/8-inch external mic input
1/8-inch stereo line output
Auto record level
more info at: hx9v.blogspot.com