Microphone Isolation Shield - Isolation Bar




Introduction: Microphone Isolation Shield - Isolation Bar

Okay, so we all want to have a nice crisp, clean recording. Weather its for audio tracks, voice overs,youtube videos, exc. But decent audio equipment is EXPENSIVE. youve probably just dropped an entire paycheck on your microphone, and are now wondering WHY THE HELL DOESNT IT SOUND GOOD?! Well because noise. Ambient noise in the room. Google how to remove it in the program you're using aaannnnddd still sounds unprofessional. So what gives? Reverb. Reverb is what happens when your voice, hits the mic over the course of a few milliseconds. See, when you speak, your voice's sound waves hit the mic. They also hit everything else in the room. They also bounce off of - everything in the room. Which then comes back and hits the mic, a second time, and a third time, and so on, and so on. So for a fraction of a second, your mic is picking up the echos of your voice. You may not be able to hear it, but your super sensitive mic can. It causes the sound to be kind of fuzzy in a way. So now you need an isolation shield. A shield that catches your voice before it can go bouncing around like that little ball at the beginning of Men in Black. You know, the one that destroyed the whole main office room. You get all excited like, YEAAHHHH IM BUILDING A STUDIOOOooooooohhhhhh its $100. WHY IS IT $100???!! Well because they mark up the price because they know you need it, so you'll pay for it. Well Never fear, because you can build one yourself, out of the same exact material - for 1/5 of the cost, and heres how.

Step 1: Materials

Okay, so you'll need professional grade acoustic foam. You can get this stuff at Guitar Center. They sell the stuff for putting on the walls of your studio, but its the same material. They have a 2 pack of 12"x12" foam. Its the kind with ridges, the only problem is those ridges are pointed. So curving the foam, will cause those high pyramid shapes to close up, and there will be no more low points. You can cut off the tips of those points, low enough that the gaps wont be closed up when you curve it. If thats what you want, go for it. Its easier. What i did, was i got a 4 pack of 2"x2"x24" foam bars. These cost $9.99

You then need to go to walmart. Back in the paint section, next to the paint rollers, is some metal roller trays. NOT the kind you put paint in to get on your roller. These are metal mesh, and are meant for you to roll excess paint off your roller. These are what you need for the backing. They cost $2.50 each. You need 2 of them.

You now need glue. I would suggest spray adhesive. Its WAAAYYYY easier. I didnt have the money for it, so I used rubber cement, and super glue. You need the kind that works on metal and foam, and wood. If it doesnt say it works on metal, dont get it.

You will need these tools

A sharp Knife - only a few inches long. Too long will cause the weight of the blade to pivot on the foam and cause uneven cuts.

a Box cutter knife - Prefferably one with a blade that can be adjusted to only extend 1/2" or so out of the handle.

A ruler

A hard straight edge, that is long and wide.


Step 2: Making the Metal Backing

So, i decided to make an instructalbe AFTER i had done this step. So i dont have any pics. But i do have a link to the video that gave me the idea to use the metal paint roller trays.

You straighten the 2 supports that raise the tray off the ground, and then open one of them up, and clamp it around the straightened supports of the other tray. The video shows what i mean.

Now in this video he uses AC insulation, but thats becauase I think he didnt know you could get Acoustic foam for the same price or a bit less. It just takes more work with the foam. You can splurge and buy sheets of acoustic foam that will be like what he uses here, but those are more expensive.

Step 3: Cutting the Foam, Part 1

So for my version, I created 1 inch sections that changed between 1/2" thick and 1 1/2" thick. To do this we first need to cut the bars in half. They are originally 24" long. Cut them to 12" long. This will now give you 8 bars. You then need to cut the bars in half, long ways. You need to cut the 12" pieces that re 2"x2" into pieces that are 12" long by 2" wide, by 1/2" thick. And the pieces that are 12" long, by 2" wide, by 1 1/2" thick. To do this, you mark a line along the bar, half an inch from the edge. You then need to flip it over and mark the same line on the back side. Make sure the marks line up. To do this, i used a ruler. I propped up one end on a piece of foam, so that way it layed flush on the piece i was marking. I then marked 1/2" from the edge at the top, bottom, and middle of the bar. Then you need a straight edge. I used a clip board. The straight edge needs to be relatively thin. You then need to prop the straight edge up with a piece of foam, so that way it lays flush with the piece you are cutting. Otherwise it will be at an angle, and press into the foam, causing your cut to be off. Once you line your stright edge up with the marks you made, run the ruler down the edge to make sure the whole thing only sticks out 1/2". Foam can easily bend and can cause an uneven edge. Make sure the edge varies no more than 1/16 of an inch. If it needs to be pulled out in sections, press your index finger, WHILE keeping pressure on your straight edge, and push down on the edge of the foam in the area that needs to come out, You can do a little flicking motion, kind of brushing the corner down quickly. This will pull some of the foam out from under the straight edge. Do a little at a time. You then run your box cutter along the straight edge. Make sure the blade stays flush with your straight edge. When you cut, do a couple passes. Only cutting in a tiny bit at a time. Cutting too deep causes it to pull too much on the foam, and will pull it out of alignement with the straight edge. Do this for both sides.

Then you can take the foam, and squeezing the edge, see the two cuts you made. Now using your knife - cut accross the foam, connecting the two previous cuts. Now using the same knife, lay the foam flat on the table, and start cutting along the length of the foam. The two cuts you made with the box cutter knife, act as guids for your knife. Make sure the blade always sticks out from both sides of the foam. The tip should never be drawn into the foam. This will ensure that the cut is straight and doesnt deviate from the guides. Also, do not press down on the knife, keep it level, only pressing forwards along the direction of the cut. Pressing down on the knife causes the cut to curve downward. Using your hand, put pressure BEHIND the cut on the foam. This will kep the foam in place. NEVER push down above where you are cutting, as this will cause your knife to cut into the foam above the guides, and in essence will cause your cut to curve upwards. As you move along the cut, reposition your hand on top of the foam to stay just behind the cutting area. If your cut gets too far away from your other hand, the sawing motion will cause the foam to slide side to side.

Step 4: Cutting the Foam, Part 2

You now have your eight foam bars cut, into eight 1/2" thick pieces, and eight 1 1/2" thick pieces. These pieces are all 2" wide and 12" long. You now need to cut them in half again. The thickness remains the same, but they need to be cut in half width wise. From 2" wide to 1" wide. Use the same method in the previous step, to mark, cut guides, and then cut in half. Here however, for the 1/2" thick pieces, you only need to cut a guide on top, as they are thin enough to cut from this. You can then use a pair of scissors to cut them the rest of the way. Bend the foam to see the guide, and place the scissors in the guide cut. Now allow the foam to unbend, so as to close around the scissors, and then cut the foam. Now the foam is long enough still at 12" that your cutting into it will cause the pieces to need to bend away from each other, to make room for you hand and the scissors. This will ruin the cut. So, allow the foam piece closest to your hand to slide in between your index finger and thumb.

Alright, you know have 16 pieces that are 1/2" thick, by 1" wide, and 12" long.

And you have 16 pieces that are 1 1/2" thick, by 1" wide, by 12" long.

It is time to glue them onto the metal backing. You should have, from the videos instructions - attached the two metal trays together, and then bent them into a semi-circle shape. Make sure that the bends are even on the top and bottom, so that way the curve isnt warped. You can check this by setting it upright on a flat surface. if any part does'nt sit flush with the table, then it needs to be bent in order to do so. You can also check by looking at it from the top, downward to see if it stands vertically, or if it leans a bit.

Step 5: Gluing

So what I did was brushed rubber cement on the metal grid, and then put super glue along the metal frame around the edges. I did this enough for one piece at a time, so that way the glue wouldnt dry on me. I also put rubber cement on the sides of the pieces I had just placed, so that way the new piece would stick to the side of the previous one. Only brush on the bottom 1/2" of the foam, as that is all that will ever be touching the foam piece next to it. Obviously though, spray adhesive would be WAAY easier. But like I said, I didnt have the money.

If you are doing a table top set up, like infront of your computer like i did, you can use the few extra pieces of foam, to create a matt for the mic, and shield to stand on. This is so you dont get any reverb off of your table or desk.

Now all you need is a pop filter. Theres a few videos on youtube on how to make those cheap as well. Just get an embroidery hoop for $2 from joanns, or michaels, and then put some panty hose or nylone material in it.

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    Good idea. I need something like this for my audio recordings.