Believe it or not, audience members are more likely to forgive poorly captured video than poorly captured sound which means that capturing clear audio is an incredibly important task. But it isn't as easy as it sounds. The truth is, capturing good quality sound can be one of the trickiest things that a filmmaker ever has to do.
As such, we've decided to help you in your quest for quality audio by showing you how to make your very own microphone boom pole, shock mount, and windscreen using easy to find materials from any big box retailer.
With it, you can be sure that your audio will sound great no matter what nature decides to throw at you.
If you've ever had to shoot on a windy day, you've probably heard how detrimental it is for your audio. Though some people may just reschedule their shoot for a better day, you might not be able to afford that luxury. That's where a microphone blimp and windmuff come in. They can shield your microphone from wind while still allowing a majority of the high and mid frequencies in your scene to come through. In fact, some of the best blimps have been known to cut wind noise by as much as 25 db. As such, it's an essential piece of equipment to have. Before we make one of our own, we thought we'd show you just how well the finished product works.
So we took our blimp and windmuff outside to a windy location for some testing. Here's how our audio sounded without any protection from the wind, and here's how it sounded after placing it inside our do-it-yourself blimp and windmuff.
Though it may not have cut as much wind as a professional unit, it still did a great job without breaking the budget.
To make the boom arm, blimp, and windmuff you'll need:
A metallic mesh bird feeder for the blimp
Epoxy for bonding metal surfaces
Epoxy for bonding plastic surfaces
12 elastic hair bands for sound isolation
2 rolls of velcro strips for attaching the windmuff
A spool of black thread for sewing the velcro strips to our material
A paint roller to act as an anchor for our blimp and extension arm
An extension arm for a paint roller
Small zip ties
a furry fabric to act as a windmuff
a cloth measuring tape
12 small clamps
and 6 clothespins
The first thing we'll be assembling is the blimp. To do so, we'll need the mesh bird feeding tube, 12 elastic hair ties, some epoxy for plastic surfaces, newspaper, 12 small clamps, 6 wooden clothespins, a pair of scissors and a number of cotton swabs. If you've ever held a microphone before, you know probably know that even the slightest bump or tap will create an unpleasant low frequency sound. This sound might work well for beat boxing, but are usually less than welcome when recording dialog in a shoot. So in order to make sure that any bumps or taps on the boom arm don't get transferred to our microphone's diaphragm, we'll be attaching a network of elastic straps to our blimp.
Here's what it looks like. As you can see, our shotgun microphone fits perfectly between the criss-crossed mesh of the elastic straps allowing it to be suspended in the middle of our blimp.
The beauty of the straps is that they will not only minimize the contact the microphone has with the blimp, but they'll also absorb most vibrations before they can register in the microphone. A perfect combination. Before we place the straps though, we'll need to do some measuring.
First, we'll need to measure the length of our bird feeder. Ours is 11 inches long. Since we want to have three mounting points for our microphone, we'll want to divide our measurement by 4 in order to get three equidistant marks. Doing so gives us 2 and three quarter inches. With this number in mind, we'll measure our blimp again and make marks with a pencil at 2 and a three-quarter inches, 5 and a half inches, and 8 and a quarter inches. Lastly, we'll want to count how many holes are in our mesh going all the way around our blimp. Our mesh has 17. Make sure to write that number down
Once that's out of the way, we'll move on to mounting our elastic straps.
Take your 12 hair ties and cut along the glued connection point in order to break the loop. Next, take two of your elastic bands and tie them together at one end. As you'll see later, this will make it easier to thread the bands through the mesh in our blimp.
Repeat this step for all six hair ties.
Then, from the marking furthest back in the cage, thread one elastic band through a hole in the mesh, across to the opposite side of the mesh, then through an adjacent hole in the mesh back to the other side again.
It's very important to make sure that both ends of your band is at the opposite side from one another. To make sure, we'll take the number of holes around our mesh, which we found out earlier was 17, and divide that in half. What this should tell you is that one end of band should be about 8 holes away from where the band comes out at the other side. If this is the case with your band, then you're all set.
At this point, you'll want to stretch out one end of your elastic band, then place a small clamp on it to keep it in place. You'll want enough of the elastic band to be sticking out above the clamp for you to glue the two ends together later. Then while stretching the other elastic band, place another small clamp on the band next to the blimp's mesh. You can then untie the two hair ties, leaving you with a single tie clamped to one end of your blimp.
Repeat this process for all six elastic bands. Now it's time to mix up some epoxy in order to permanently attach the band ends together. Before you do, make sure you're in an open space that is well-ventilated and wear gloves and glasses. Epoxy can be both an irritant to the eyes and skin so it's best to play it safe when using it.
Take a cotton swab and coat it with epoxy. Then liberally apply epoxy to both ends of an elastic band. Carefully join the two ends together and clamp them down with a wooden clothespin. Do this with all six bands.
While the elastic bands are drying on our blimp, we'll prepare the paint roller.
The first thing we'll need to do is to cut off the washer on the end of the paint roller with a pair of metal shears. With the washer off, you should be able to slide the paint roller right off of the metal bar. Lastly, you may find if best to bend the metal bar at a 45 degree angle. To do this, place the paint roller handle in a vise at the bending point and put your weight against the handle. Once you have it where you want it, take it out of the vise and place it to the side.
Going back to our blimp, we'll take each of the clamps and wooden clothespins off of the elastic bands. Epoxy is very sticky so expect some of the wooden clothespins to stick to the bands. At this point, we're going to make a hole in the back end of our blimp in order to hook an XLR cable into the back of our microphone.
To do so, measure across the back of the blimp. The back of our blimp is 3 and a quarter inches in diameter. Then divide that number by half and make a mark both vertically and horizontally. This is the point where we want the tip of our drill bit to be. Next, use either a cordless drill or drill press to make an inch sized hole in the back of the blimp. You'll be drilling through metal so you may want to use a little oil when drilling this hole. Also, you should always wear glasses and gloves for protection whenever drilling into metal.
While you have your drill out, you'll also want to make a series of small holes with a quarter inch bit in the cover of the blimp so that sound can get through. Make these holes as close together as possible for the best results.
Now we're ready to attach the handle to the blimp.
To do so, use several zip ties to fasten the main bar of the paint roller to the bottom of the blimp. The more zip ties you use here, the better it should hold. Next, mix up some epoxy meant for metal surfaces and use a cotton swab to liberally apply it to both sides of the metal bar and the blimp. You may want to use a small object or block of wood to hold the handle up next to the blimp. Otherwise it could slip leading to a crooked attachment.
While that dries, we'll make our last piece for the blimp, the windmuff. This piece will allow us to cut down the wind noise by up to another 10 decibels. You can find material much like the kind we're using here at any fabric shop. As you can see, we'll be wrapping the windmuff around our blimp and attaching it with velcro at the bottom and the sides.
To make it, you'll want to take a cloth measuring tape and measure the circumference of the blimp. We found ours to be a little over 8 inches around. If we add an inch for each strip of velcro on our material, we have a new measurement of 10 inches. This is the first measurement. For our second measurement, we already know that our blimp is 11 and a quarter inches in length so we can start with that number, add another 2 inches for the velcro, and another inch to make sure both pieces of velcro can reach one another. That brings us up to 14 inches. So we'll want to cut a section of our material that is 14 inches by 10 inches.
With our material cut, you'll want to cut a strip of velcro hooks that can fit across the top of our material. Just to make sure it fits, we've cut our velcro strip an inch short at 13 inches across. Then make an identical strip using the velcro loops for the bottom. For the sides, we'll want to make both a hook and a loop strip of velcro. As such, we'll take our 10 inch measurement, and take off an inch for safety and divide that number by half. That leaves us with 4 and a half inches for each strip of velcro. Then attach all of the pieces of velcro using more epoxy or better yet, by sewing them to the material.
The very last thing we need to do is to put the whole thing together.
Take your blimp and handle and place a shotgun microphone through the crossed sections of the elastic bands. Then hook up the XLR cable through the hole in the back of the blimp. Attach your windmuff to the blimp and mount the painter's pole to the handle of your blimp for extra reach. Lastly, wrap the excess XLR cable around your pole.
With that done, you can take your new boom, blimp, and windmuff out to a windy location and listen as your audio goes from unusable to pristine.