Duncan Taylor / Colorado Daily
A listening space like this will sound better than one where the couch is moved all the way back to the wall. The beige pieces on the wall also absorb reflections and further clarify the sound.

Ever see a skinny guy wear a polo dress shirt? In the South, it’s admittedly a more common dress staple. But in these days of graduations and dinner with parents, perhaps you’ve had a chance to see what’s going on behind a well-dressed, slender lad.


Traditional dress shirts in America are made with an extra healthy bit of fabric around the waistline — what I like to call the beer belly pouch. If you’re on the thinner side trying to look dressy in something like this, what do you do?

Tuck all the extra mess in the back and try to face your company head on, that’s what you do. You rock a back bunch bundle and try not to think about what it must look like back there.

When it comes to our home audio systems, many of us share something in common with our big-shirt buddy. Continuing our series of “symptoms of a serious audio system,” this week, we examine the oft-overlooked element in home listening that has just as much to do with the eventual sound as any piece or bundle of devices that actually make the music.

Many home music-listening setups neglect to address the walls or acoustic environments behind where most of the listening takes place, because what’s in front of us is what we are most aware of. I’ve seen more sound setups with the couch placed right against the back wall, and this is just plain wrong. And I’m here to tell you why!

Sound waves are easily reflected. That’s one reason why we cup our hands to our mouth to yell and be heard more clearly. We bring in the walls (hands) around the sound source so that more of the sound is reflected forward.

Our brains are set up to receive sounds information in two categories: important stuff and background stuff. We have specific regions of our brains devoted to sorting important from background, and it’s always engaged when it comes to hearing.

Sound travels at roughly 1,000 feet per second, or 1 foot per millisecond. If you’ve ever yelled in a canyon, the echoes you hear can help you determine how far away the reflective surface is that sends your voice straight on back to you. An echo like that is easy for the brain to recognize as an echo, because the first sound and the echo sound are very far apart.

Scientists have found that our brain needs between 6 and 11 milliseconds of difference between an original sound and a reflected sound to sort the latter into the “background” category. Remember the speed of sound? That means that, in practice, we need to move the listening couch at least 6 feet and as much as 11 feet away from the back wall so that reflections off of it don’t confuse the original direct sound, muddying it up and masking all kinds of potential goodness.

Obviously this isn’t ideal for most living rooms. But what’s great about sound is you can slow those waves down by placing foam or other absorptive materials behind you and simulate the distance without actually having it. Food for thought.

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