Making A Low Cost Microphone Fun & Interesting
For video, audio quality is as important, or even more important than video quality. At least that’s my opinion now. In the beginning, I really didn’t care too much as long as I could be understood. And since quite a few of my videos didn’t (and still don’t) have any dialogue, it was never too much of a concern.
These days, I really want everything that I put into a video as good as it can be, and I’ve gone to great lengths to improve the audio quality. I did a lot of work in my shop to reduce reverberation and have tried several microphones. Indeed, at this point in time, I’ve spent more money in total trying to improve the audio than I have on cameras.
My latest microphone is the best solution so far, and the cheapest. It is a low cost electret capsule mic that I mounted in a wooden handle:
The bundle of polyfil stuffing is a home brew wind sock so that the mic can be used outdoors. I added that recently to film video building my back deck, and it works exceptionally well.
Before that, I made a simple mount for the camera, but it transmitted too much vibration to the mic and I changed it to the thin arm configuration shown below. This has it’s problems too, especially out in the wind. The large wind sock makes it sway back and forth and can rock the camera slightly.
While searching for the ideal wind sock material, I initially rejected the foam shown above, believing it was too dense, As it turns out, it is very well suited and if used correctly, can double as vibration isolation.
To get started, I soldered a new mic capsule to a lead wire with a 3.5mm plug on the end:
The mic capsule needs a small DC voltage to operate and I have one that came from a cheap lapel mic. These are very easy to make from scratch, and I’ll go through how to do it in an upcoming article.
Some cameras and most voice recorders won’t need this, as they will supply the DC voltage internally.
I cut the foam into a square block and made a slit halfway through. I then inserted the mic with it facing forward:
I made a simple holder for it using pieces of foam core, hot melt glued in place:
Trying it outdoors shows that it is very effective at eliminating nearly all of the wind noise, and it also dampens vibration very well.
Along with that, it’s lighter and more compact than the previous version.
At some point, after a bit more testing, I will make a more permanent version with a built in power supply and a bigger, more noticable on/off switch. Quality sound is only good if you remember to turn the mic on!
For those interested, the mic capsule I used is from Digikey: 668-1393-ND
Made by PUI, their part number: AUM-5047L-3-R
I made a video showing how I did it:
This is another version of the mic body, made only from wood. The capsule is in the front and I cut a slot down the length of it for the wire. The wind sock blocks most of the wind and also helps to reduce the high end frequency response, which I’ve found to be a little harsh with this mic capsule:
The holes and slots behind the capsule allow sound to enter from the side and rear, to maximize off-axis rejection.
A different, more compact version in a metal tube with rubber tube shock mount:
Same type of wind sock, just an ordinary foam sponge bought at the home centre and cut to size.
Here’s a video comparing the mic above to a $400 Sennheiser MKE 600: