Improve Your Sound By Understanding Room Acoustics

improve-sound-understanding-room-acoustics
It’s nearly inevitable that when people find out I review audio and home theater equipment they ask me the same question: “Who makes the best speakers?” My reply is always the same: “Describe your room.” My room? What on earth does the room have to do with getting great speakers? As it turns out, it has everything to do with it. I have a degree in recording engineering, a field that deals with audio engineering and the hardware, software and techniques needed to capture, mix and produce great recordings in a studio. As I learned more and more about audio, and as I practiced my craft throughout the past two decades, I began to notice a consistent trend. Moderately good speakers could sound great in room that had good acoustics, and great speakers could sound downright awful in rooms that had poor acoustical properties. It was an observation that I was able to eventually apply mathematics to and understand a little bit more about why this is the case.

For now, however, let me explain a few basic principles of room acoustics and why the very room you listen in may have more to do with your experience of hearing great music and movie soundtracks than you might think.

Lots of Hard Reflections Muddy the Sound

Have you ever had difficulty understanding the dialogue in a movie you were watching at home? There’s a reason that happens—even when you have a really nice center channel speaker. If you have wood, tile or terrazzo floors, or perhaps there’s simply a lot of glass in the room—this might be windows, or it might be a coffee table in between you and the television—you have a recipe for lots of reflections. Reflections aren’t all bad. After all, we hear tons of reflections when we speak and listen to others, when we interact with the word around us…reflections are everywhere. You can’t really get away from them to be honest. In a home theater setting, however, you want to control reflectivity so that music and movie soundtracks are reproduced more faithfully to the original. When the same sound comes at you repeatedly from different locations, it does so at different times. One instance of the sound may be bouncing off a glass wall behind you, while another comes up from the floor only to meet yet another that ricocheted off the glass coffee table. When these sounds converge at your ears, the net effect is best described as “muddiness”. Much of the detail and clarity you should have received from the speaker has now been lost in the shuffle.

And this will happen with a $100 stereo system or with a $10,000 pair of speakers. And I’ve personally heard these effects with both.

Solving the Problem

If I’ve just described your system (and when I talk to people I often see approving nods and thoughtful gazes) you don’t have to abandon hope. There are solutions. Those solutions can come in the form of doing some minor redecorating, moving your speakers slightly, or even adding a few key pieces of room acoustics. The bottom line is that you can often achieve better sound in ways that aren’t going to: a) break the bank, or b) cause you to have to remove all your furniture and start from scratch. I’ve actually thought about this long and hard, and I’ve helped enough people to achieve improved sound in their rooms that I’m prepared to offer a few suggestions that you may find useful in your own home.

Suggestion 1: Consider Some Minor Redecorating

When I talk about “redecorating”, alarms and bells go off—particularly as my friends consider what their wives may say regarding moving around furniture (most of my discussions are with guys, though I suppose there are more than a few die-hard women who love home theater.) The truth is, the recommendations I make often work right into the leanings of the homeowner. A great example is this one couple who had some large glass sliding doors at the back of their room. I suggested they install some fabric-based shades to break up the reflections occurring there. As it turns out, the wife had wanted those shades for a good long time. It suddenly became a priority for her husband

Another time I was speaking with a couple who told me that they had moved, and the same sound system simply didn’t seem to yield the same results for watching movies. They complained of having to turn the volume up a lot just to hear the dialogue. When I asked about their former room and the new one, I found that they used to have a carpeted space, but now enjoyed a renovated terrazzo floor. I suggested a small throw rug for the terrazzo floor right in front of the television. This would cause some of the reflections from the center channel speaker to diminish greatly and improve the clarity of the audio. The wife loved the throw rug idea and jumped all over it.

Suggestion 2: Move those Speakers a Bit

I’m always amazed at how little people will do their own adjusting of speakers to achieve a better sound. Most simply set them up and never again touch them. Sound varies greatly with speaker positioning. In one example I can remember, the center channel was pushed way back on a glass AV shelf (which, as far as I’m concerned, should be outlawed). The sound from the tweeter was decidedly bouncing off the shelf and combining with the direct sound at the listening position, creating a less than idea effect. I barely sat down before I saw (and heard) the problem and was able to simply scoot the speaker forward so that it was firing past the edge of the shelf. It was a simple fix that did wonders for the sound.

In another home there was a combination issue. A subwoofer was placed in the front corner of the room, which created a bit of a bump around 60Hz. That bump was rattling dishes in the kitchen every time they watched a movie. It was a minor annoyance, but it was very real and happened quite a bit. The homeowner had turned down the subwoofer to try and alleviate the problem, but then their movies lacked the punch he wanted. I suggested spreading out the front speakers a bit more, and placing the subwoofer just inside the left speaker position, about 18″ away from the wall. Immediately, the bass smoothed out, and he was able to raise the volume back up to his desired level—this time, without rattling the dishes.

Suggestions 3: Add Absorbers for Enhancing Room Acoustics

While some of my more innocuous suggestions may work for many, there are some instances where you simply have to bite the bullet and purchase or build some sound absorbers. The good news is that you can do this fairly inexpensively, and you can also color match it to anything you need. Sound absorption panels don’t need to be ugly. They can also take on just about any shape or size. The traditional panels are either 2 ft x 2ft or 2 ft x 4 ft, but you can really and truly make them any shape you want. Absorption panels are simply fabric coated frames filled with dense fiberglass that “scrub” sound. They remove audio from the room and don’t give it back. That means that they eliminate reflections. The trouble is, they need to be used sparingly or you’ll end up with a “dead” room that sounds lifeless, or which requires a ton of amplification power and some tweaking to sound right. Movie theaters are “dead” rooms, but they are designed that way, and the sound systems are designed to compensate for how they are built. A home theater offers a more “live” sounding space.

So how do you go about getting room acoustics? Well, you can Google how to make your own, or you can purchase pre-made models and get them in the colors you need (I’ve done both). If you have a minor issue with reflective walls, then a few panels decoratively placed throughout the room will do a lot to reduce these reflections. The true way to do it right, however, is to actually have a room analysis done by a professional. Many companies offer these services for a very inexpensive fee (some even do basic evals for free) because they also offer solutions that you can then purchase. A good rule of thumb is to stick to less than 30% covering of any wall to avoid over-dampening your room. If that sounds too ridiculous, then recognize that even a few panels on a rear wall will significantly reduce reflections.

Good Sound = Good Room Acoustics

There really is a correlation between good room acoustics and getting great sound for your home theater or stereo system. If you don’t get the room right, it’s going to be nearly impossible to get good sound out of even the best speakers money can buy. Hopefully, some of these ideas will spark some of your own, and you’ll be off to improving your room—and consequently—your home theater listening experience.

Disclaimer: The opinions expressed in this article are as provided by the company’s PR agency. Regardless, I only publish reviews of products or services that I believe will be good for my readers. I am disclosing this in accordance with the Federal Trade Commission’s 16 CFR, Part 255: “Guides Concerning the Use of Endorsements and Testimonials in Advertising.

Related Posts

Newsletter

Subscribe to our free weekly newsletter so that you can receive useful tips and valuable resources directly into your mailbox. (No Spam)

About our Newsletter

Featured Deal

View All Current Deals