Right then. Old people have no trouble telling the same story over and over again, so that’s not a problem.
For a two person interview that you can control, I’d use two lavalier microphones, one on the interviewer and the other on the guest. This has the advantage of being close to the voice and helping to isolate it from the room noises and echoes. I’ve been known to use the Radio Shack 3013 cheap lavaliers with XLR adapters into the Mixer Of My Choice and then on to the recorder/computer. Split the mixer so the two channels go down left and right. That’s very easy to control and you can mix down to a very pleasant show in post production with no problem.
Use good headphones on the shoot. Nothing like getting home and finding buzz on the guest microphone.
The microphone is not XLR, so an adapter must be made. I have the formulas for both creating one from wires and from common adapters in the store (more expensive). The microphone is $30.
If you’re interviewing two or more people, I would still use a 3013 microphone in Pressure Zone Configuration in the middle of the table between the people being interviewed. This is before and after the paint job.
http://www.kozco.com/tech/audacity/pix/3013PressureZone.jpg
http://www.kozco.com/tech/audacity/pix/3013PressureZoneFinal.jpg
The microphone is omnidirectional and the board doubles the volume of the microphone. A very good thing for cheap microphones. That’s about a 6" x 9" panel and about the smallest you can go without losing the effect. The effect gets better with panel size up to 30" square for a large conference room. Put a towel under it.
Never use a straight desk microphone that places the head of the mic 6 or 8 inches up from the desk (unless you have to). Table reflections give an odd tunnel, comb filter sound. Go up or down. The pressure zone goes down. In the illustration, ignore everything but the placement of the microphones. They’re both over a foot from the desk and I took the additional precaution of padding the table.
http://www.kozco.com/tech/audacity/pix/JMASoundShoot.jpg
That was a broadcast shoot and yes, that is the Peavey PV6 and a MacBook Pro in the shot.
This American Life uses a hand-held shotgun microphone and they got good at whipping it back and forth between the interviewer and guest as they were talking. It’s surprisingly effective at capturing voices and not anything else, but that’s only good for one guest. I’ve heard it done with two, but I strongly suspect they covered up any errors in editing. “Can you say that again? I didn’t get it (I had the microphone pointed the wrong way).”
I don’t have any recommendations for an actual three or more independent channel shoot. We have recommendations for multi-channel, but you have to be careful because different computers have different talents. I think all of our recommendations are for Line-Level, not Mic-Level. So yes, you do need a multi-channel mic mixer in addition to the digital converter and recorder. That’s probably not milk and newspaper money. That can run into serious bux.
There is an extensive publication about recording hardware.
http://forum.audacityteam.org/viewforum.php?f=27
And multi-channel.
https://forum.audacityteam.org/t/multi-channel-recording-in-audacity/15644/1
Koz