Audio Tip – Zoom H4 Boom Mic
While many photographers want to try their hand at shooting video with their DSLRs one of the biggest problems with shooting video isn’t the video…it’s dealing with the audio. (Why DSLR Audio Recording Sucks and What To Do About It). I have really struggled with getting good and consistent audio and after watching several tutorials recently, I hit upon the idea of rigging up a form of a boom mic from my old Samson Zoom H4.
Audio on a budget
Since most of the video work I have done so far is for myself or for small jobs, there hasn’t been much of a budget to invest in super good equipment. To that end, I have made some good and some bad choices along the way but we learn more from our mistakes than our successes and thus a few things have worked out pretty good. Some of the better equipment I have picked up over the last couple of years include:
- RadioShack Wireless Lapel Microphone System $49
This very inexpensive wireless lapel mic has worked pretty good but does have a tendency to add in a little noise that is easily fixed in post-production.
- Audio-Technica ATR-3350 Lavalier Omnidirectional Condenser Microphone $22.28
Probably the best sub-$100 lavaliere mic you can get and it has a 20′ cord on it
- JuicedLink DS214 Pre-Amp with AGC Disable $144
While not super cheap, at $144 the DS214 will give a super clean audio signal into your camera and can disable the AGC on the Canon 7D allowing for crystal clear audio.
- Samson R31S Dynamic Mic $6.99
Not the best dynamic range, but its under $7
While these solutions have all helped to solve some of my audio needs, they all have pros and cons. The dynamic mic needs to be very close to the subject. While this works on if you are standing on a stage given a presentation, if you are doing an interview or talking-head style shoot, you usually don’t want the microphone in the scene.
The lapel or lavaliere mics are less visible than a regular microphone but have the downside of a limited pickup range so if you are doing an interview you need both people wired up, the take either odd batteries or require AC power, and do not have a good signal to noise ration so there is often a higher noise floor that will require more post production.
Add to the mix more wires and setup time, and the small noise issue, as well as the times that you don’t want a microphone visible in a scene and these types of mics are not always a good choice either.
By taking these microphones into the JuicedLink DS214 amp (review) you can get a much stronger signal, which results in less noise, than from going straight from the mic into the camera. While this gives you a really clean signal, you still have the issue of adding more wires and complexity to your setup.
A Better Solution
Sometimes you make a good decision and forget about even doing it or why. One of my better decisions happened way back in 2005 when I bought a Samson Zoom H4 for recording podcasts. The Zoom H4, now replaced with the Zoom H4n, is a battery powered digital recording device with two built-in microphones as well as two additional ports on the bottom that support both 1/4″ jacks and XLR connections.
I have used the Zoom H4 as a secondary recording device before and then synced the audio and video in post production but it can be a real pain in the butt sometimes and with long clips the two might not always sync up properly by the end of the clip.
What I finally decided to try was to mount the H4 as an overhead boom mic. Since the H4’s case has a 1/4″ thread hole, I screwed in a standard stud and put that into a regular umbrella swivel mount on an overhead boom. The fuzzy thing on the end of the H4 is a ReadHead Windscreen.
Using the mics on the H4 as input, I then connected a 20′ 1/8″ cable to the headphone jack on the H4 and ran that to the Mic input on the camcorder. I was still getting a ton of noise so I went into the camera’s settings and turned off Mic Attenuation (also known as AGC or Automatic Gain Control). While this cut the noise down dramatically, it also cut the overall volume down as well. To solve this, I turned up the headset volume on the H4 until the audio meter on the camcorder was showing good highs without any clipping. This gave really good audio, so good in fact that I needed practically zero post production. Here is video I made with the new setup.
As you can tell the audio is quite good. I did no processing at all of the audio in that clip where usually I need to do volume leveling, normalization, and noise reduction. The key is getting a strong enough signal from a source with decent amp circuits and not relying on the relatively poor audio circuitry of the camera.
An Even Better Solution
While the results of this setup are extremely good, there is still room for improvement. The issue is that the amps in the H4, and even the newer H4n are not as good as a good pre-amp. Since I already have the hardware, an even better setup is going from the H4 to the JuicedLink DS214 and then into the camera. Since the DS214 has much cleaner amps than the H4, if we use the DS214 to push the volume we will get even less noise.
The right way to do this setup is to set the volume of the H4’s headset to a fairly low volume so it isn’t trying to amplify the audio and then let the DS214 do what it is designed to do.
Down the Road
What I am really hoping to do is to purchase some nicer microphones in the near future and upgrade to a JuicedLink RA333 or other higher end amp. While I am not an audio expert by any means, Robert over at JuicedLink is and you he has a bunch of tutorials that will help you learn everything from audio basics to advanced concepts. Robert also explains that while this setup is an improvement over what I started with, it still suffers from some major issues.
The biggest problem is that the H4 has a very broad pickup angle and even though the H4n has an adjustable pickup angle, the smallest is still 90 degrees which will allow for pickup of extra ambient and unwanted sounds.
By switching to a real shotgun microphone like the Audio-Technica AT875R you get much better side noise rejection. Combine a good mic with a great amp like a JuicedLink RA333 and you have an audio system that is absolutely top-of-the-line.