[Al Skierkiewicz]

1.5 Liters is still a lot of hydrogen if I read your post correctly. I don't want Bloomfield Hills to disappear off the map, I have friends out there. Remember, the hydrogen may not be dissipating but it may be gathering in high concentrations above your head. Remember the Hindenburg!
Most audio amps will go very low in frequency (some down to 8HZ) but only DC coupled amps will go to 0 Hz and you will only be able to offset the input waveform with a DC amplifier. You will need to be able to control the voltage input as the power amps will respond rather quickly to changes on their input giving you significantly more than 6 volts peak output.