Spontaneous video interviews in crowded convention center w/o lav

Question

I regularly video interview comic artists and writers who are behind tables at comic and anime conventions. They are in large, open rooms with loud, packed chattering crowds, so lots of ambient noise. I am always behind the camera with the interviewee(s) in front. The camera (and mic) is usually pointed at the guest(s), but I often scan over their wares on the table.

I've had terrible audio quality--in terms of interpreting/hearing speakers over crowd--in the past and am just getting around to fixing it. I do not want to mic-up the guests as the interviews last 6-15 minutes and are usually performed within 2-5 minutes of meeting the guest and I'm off shortly afterwards. So handing a mic to someone, even if it's a wireless dedicated audio recorder lavallier seems a bit formal, but maybe I just have misconceptions about that. It seems like I would also need one for myself as well, though this wouldn't be as much of a hassle.

Given this, I've been shopping for camcorders to improve the video and audio. Specifically, it seems like it would be a good idea to get a camcorder with a zoom mic which has a super-parabolic recording area, which would be me and the guest right in front of me. Would a mid-range ($300-$600) camcorder with a built-in zoom mic be sufficient for this, specifically one has facial recognition to adjust audio properties to speech? I would also be fine with getting an external boom or shotgun mic for the camcorder, but I'm not sure if this would be necessary or if it would sufficiently reduce crowd noise.

A couple side notes, I have no idea if camcorders by default disable the front-mounted internal mic when an external mic is plugged in or if you can choose to leave it on. Further, I don't know if zoom mics are standard, in other words, I don't know if my junky Samsung SMX-F50BN camcorder has a zoom mic or just a generic single mic.

I've also tried to use some multi-speaker isolation algorithms about which I read in a few research papers, but could never get the MATLAB plug-in to give good results.

Any advice would be appreciated as to what I should be focusing on to best improve audio.

Answer 1

This is a common problem and is not best solved with a new camcorder, but with a separate microphone. If you are satisfied with the picture quality you get today, then a new microphone is what you need.

If you don't want to hand the interviewee a microphone then a camera mounted shotgun microphone could vastly improve the sound. During the interview the microphone has to be pointed at the interviewee at all times. You have to shot the wares after the interview.

If your camcorder has a microphone jack you could connect the microphone to the camera, but you will get the best sound quality if you record the sound with some kind of sound recorder and merge the sound and video during editing. This is not as hard is it may seem.

Answer 2

There are two major factors contributing to your problem here.

Firstly, yes you are using an unprofessional, in-built camera mic and need to find a more suitable one. The best kind for your situation would be one of the following:

1. Handheld Mic - This is most recommended, as by holding the mic in closest proximity to the speech, you can isolate it from ambient noise. You can also freely move it between speakers. This video (see caption as well) is a great demo of the achieved sound isolation. You won't necessarily need to use lavalier mics, although if you are confident later you could try wiring up yourself (or the interviewee) with one, for improved coverage, but will need a better way to monitor and record both signals.
2. Shot-gun Mic (Mounted on Camera or Boom) - These can still improve the audio but I list it as second preference to the Handheld. Due to the typical Condensor properties, the audio will be highly detailed but may still pick-up more ambient noise than a Dynamic mic. If you don't want the mic in-shot, you will still need to have it as close as possible to the sound source (have it positioned just out of frame). Additionally, a shot-gun mic is highly directional and suitable if you are recording 1 or 2 people simultaneously. A mounted camera mic like this one will be a great way to start on your own. However, there may not be a way to mount it to a camcorder, which brings up the second problem.

The second main issue is that you need a better way to record the audio from the mic. Your camera is evidently not designed to record audio, so you may look into upgrading to a better camcorder or DSLR camera with 1-2 XLR inputs, although that may be a significant upgrade since they are higher-end features. You can keep using your camcorder if you are willing to settle for the semi-professional Zoom H4n, which can record from up to 2 XLR Mic inputs. The batteries will last much longer by recording a Dynamic Handheld mic, which does not need to be phantom powered (in contrast to Shotgun/Condenser mics).

If you decide to upgrade the camera, a further option is to look into a portable field mixer as well, like the MixPre-D, which can pre-amplify the mic(s) before recording. It may work best to purchase a Handheld Mic and Zoom H4n recorder, and find someone to join your crew.