«
»

Fix Acoustics Problems in Your Mixing Room

Now that you know all about what frequencies are out of wack in your studio (How to Test Your Mixing Room) you can start to worry about how to fix the problems.

You probably noticed that certain frequencies were louder than normal and some frequencies were quieter than normal. If you’re in a smallish room probably most of the frequencies below 500 Hz or so are pretty wonky. Low frequency sounds actually are made up of longer song waves and as the frequency increases you will see that wave length decrease. Think of a car with a sub-woofer pumping out side of your house. Most of the time, the low sounds are actually louder outside of the car, than inside of the car. It can take 20 feet or more for a low frequency sound to make a complete sound wave. You can figure out how long the sound wave is by taking 1130 ft/sec (The speed of sound in average humidity and temperature) and dividing it by the frequency you want to measure. Let’s take the example of 55 Hz which is a VERY low ‘A’ note commonly heard in songs with deep thumping bass.

1130 ft/sec
55 Hz

You get 20.5454… feet.

That’s how long that sound wave is. You need that much distance for the sound wave to finish one full cycle. Unless you have a stretch hummer, you’re not in the car at 20.5454 feet from the sub woofer. That’s why everyone OUTSIDE of the car gets to enjoy your sub so much!

So…What does this mean for listening in your room?

Let’s say when you were doing your frequency testing you noticed that 220 Hz was significantly louder than the other frequencies around it. You could get this kind of behavior if 220 Hz is a resonant frequency of something in the room. Or even the room itself! So let’s figure how long the wavelength is for that frequency:

1130 ft/sec
220 Hz

Or 5.1363… feet long. If your room is that wide or double (10.2727 feet wide) then your room is sympathetically resonating with the sound. The sound comes out of your speakers and then bounces around in the room. The harder and smoother the walls are, the more the sound bounces around before it runs out of energy. The frequencies that wavelengths are multiples of the dimensions of your room will get messed up in all likelihood.

So you either new to buy some bass traps or build some bass traps. So here’s the scoop in general about acoustic treatment products. The most cost effective products are usually not the ones that have the most advertising in stores or in magazines. The best article on building bass traps is written by Ethan Winer as is located at http://www.ethanwiner.com/basstrap.html.

Interestingly enough he is one of the founders of RealTraps, a company that builds bass traps based on his original designs and then improved over the years. So not only does his company make the best rated bass traps out there, he teaches you how to make your own! If you’re not already making a good living with music, then build your own traps. If you have some bread buy them. The pricing is EXTREMELY reasonable for what you’re getting!

Mid and High range frequencies are much easier to contend with. Soft materials like acoustic foam or even fire-rated blankets absorb mids and highs very well. They do deaden the sound very well, so you may find that your room doesn’t sound like a room anymore.

This entry was posted on Thursday, May 31st, 2007 at 5:12 pm and is filed under SPL meter, acoustic treatment, acoustics, audio, music. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

Leave a Reply