Re: Securing your audio
 

Peter, you'll want the microphone centered on the speaker, and at least one foot (1/3 meter) up to a meter. . This allows the sound from all 3 speaker components to reach your microphone together for best sound.

After having been in a few tight spaces, and working with one DJ who had the bass rumbling, even in speeches, I'm glad I use the mixer feed or the XLR output on the back of the speaker ((only works if it's an active (powered) speaker)

Re: Securing your audio
 

As Robert mentioned, it has to be pretty close otherwise you pick up lots of ambient sounds as well. Level-wise it's also quite low as I have to set it to 100 on the H4N (although I'm recording a backup track at 75 through an XLR splitter).