I’m amazingly lucky in so many ways, and one of them is my good fortune in having a dedicated recording space. I can leave mics and guitars out, decorate to my preference, put speakers in the middle of the room, and best of all, hang broadband absorbers all over the walls and ceiling and stuff them into every corner.
I found that installing these panels made a lot more difference in the quality of my recordings than upgrading a preamp or a/d converter, or even buying a new microphone. By improving the sound in the room, the acoustic treatment made the whole recording process much easier and more enjoyable. So when people ask me how to improve their recordings, one of the first things I suggest is room treatment.
Minimum Impact, Maximum Result
Unfortunately many people don’t have a dedicated recording space. They can’t stuff a dozen panels into corners or lean them against walls, and they often ask how few panels they can use and gain any benefit. My standard answer is two, just two panels can reduce reflection in one small area, an area just right for recording acoustic guitar or vocal or many other acoustic sources.
There are a number of commercial products born out of this idea of a zone of controlled reflections. Some of these are rather small and thin, so I’m doubtful that they’re strongly effective. Some are fitted with frames and/or attachment hardware. This adds flexibility and a pro look, but also adds weight and cost. My preference is a pair of simple unframed panels, 2 feet by 4 feet by 4 inches of OC703 compressed fiberglass. I made mine with burlap and hot glue, but premade panels are available as well. Here’s the blog entry on building these panels: Building a broadband absorber (on the cheap)
I deploy the panels in a V surrounding the microphone(s), often by simply leaning them against the mic stand if it’s sturdy enough. If needed I lock the panels in place using a bent coathanger poked into the fiberglass to add a little stability. I’ve experimented with different positions for the panels and this arrangement has seemed the most effective to me. The sound leaving the guitar, or at least a lot of it, passes through the panels as it leaves, so it hits the microphone full strength, then gets attenuated by the panel. Then after the sound hits the wall it returns through the panels for further reduction before hitting the back and sides of the mics.
In order to evaluate this two panel approach I set up in our guest bedroom, a 12 x 14 x 8 foot space with no room treatment and only a futon for furniture. This is a fairly reflective room and seemed like a good place to test the two panel solution. I used the Zoom Q3HD as the “mic” and placed it about 24″ from the guitar, with the stick-on wide angle lens attached Zoom Q3HD with a Stick-on Wide Angle Lens then I setup the Xacti HD2000 for a wider shot.
Here’s the resulting video:
I hope you’ll listen and make your own judgment, but my opinion is that the two panels do a remarkable job of cleaning up the early reflections and reducing the “small room” sound. The direct to reflected ratio is improved with a couple of benefits. Since the reflected sound includes a lot of high mids, the sound with the panels is “warmer” with those reflections reduced. The other effect is to make the recording sound like it was made with a closer mic position or in a much larger room.
I’m pleasantly surprised by the effectiveness of this two panel approach. They’re small enough to be stored under a bed or behind a door, they’re light enough that they can be moved into position quickly and easily, and even purchased commercially the cost is under $200. It’s possible that one or two more panels might improve things further, but in my preliminary comparisons it seemed that the big improvement came from two panels, and one or two more panels did not provide much additional benefit. Your situation could certainly be different, of course.
This entry was posted on Sunday, December 11th, 2011 at 9:54 am and is filed under Acoustics, Recording, Tutorials. 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.