One of Dagogo’s recent polls revealed that 38% of those responding had spent nothing on room acoustics. I found this both disturbing and thought provoking. Why would anyone totally overlook this area of our hobby (though maybe they have tried some free things). Still, most rooms need a little more than you can do for free. So, I’m going to take this column to talk about what I did with my room for the least money possible.
I confess I have no scientific knowledge or training in this area, yet I feel compelled to write about my experiences with room acoustics. Over the years I have tried egg cartons, hospital bed pads (both of these were in dorm rooms when I had no money), Sonex, ASC Tube Traps, homemade traps, diffusers, absorbers, rugs, tuning disc, and many more things I can’t remember right now.
The one thing I can say for sure is that everything you put in your room affects the sound of your system. Now I didn’t say everything makes a big change. I didn’t even say you could hear every change, but as the things you put in your room begin to add up they really do affect the sound you hear. Ted Denney, founder and chief engineer of Synergistic Research came to my home in 2009 to install his Acoustic ART Real-Time Analogue Room Treatment for review. The first thing he said when he looked around my room was, “they may not work as well with all the nicknacks you have in the room.”
Ted was saying what I’m trying to say, all the stuff in your room affects the sound. Some of the stuff deadens the sound, some of it reflects the sound, some diffuses the sound, and lots of things sing along with your system as it plays. Now listen! This means if you trust your own ears there are lots of things you can do to tune your room that cost very little if anything.I’ve been working on tuning my current room and getting the right equipment in that room for the last 10 years, though I have to admit that I ended up spending about $4500 on commercially-available acoustical products.
The two products I purchased were the Auralex Elite B24 Pro Panels for absorption, and the Synergistic Research Acoustic ART Real-Time Analogue Room Treatment for overall acoustical treatment. The ART may seem expensive, but I found it to be the best overall room treatment I have tried. While these two products are essential to the sound of my system there is much I have done in the room over the last ten years that has had equal or even bigger effects on my system’s sound. So the rest of this column is to share those with you.
Let’s start with the bass. I worked on the room when I had the Audio Note Es, and some other speakers that have bass below 30Hz, but my room works best with speakers that roll off above that. I have tried some pretty fast subs, but my room just doesn’t sound its best when trying to produce bass down into the low 20Hz area. One of the interesting things I have discovered about the quality of the bass in my room is that it is more affected by how far my listening chair is from the back wall than the placement of the speakers. I discovered this by accident, and it was a major breakthrough for the sound of my system.
The other things I have done that helps the bass is the use of an interesting version of Tube Traps in the back corners of the room. In the back left corner of the room I have a 1937 Philco radio that has a 15-inch field coil driver. It’s presence in the room tightens up the bass as well as allowing it to have more air and breath. In the right back corner of the room I have a large easel with a large painting on it. It sits in front of a big book shelf. Whether this combo acts anything like a tube trap I have no idea, but it seems to somehow break up the standing waves in the room. I don’t know why but removing either of these from that corner loosens up the bass and affects the specificity of the midrange.
Between the two back corners is a large brick fireplace. The bricks are not smooth and neither is the surface, so with a large painting hanging on it as well as some other knicknacks it hasn’t given me much trouble. I did find that placing the Synergistic Research Acoustic ART Gravatron in the middle of the fire place seemed to smooth out and quiet the spurious noise of my system.
Now, let’s talk about the first reflection points. They really do need to be dealt with, it’s not some myth to sell sound absorption products. Since one side wall of my room has sliding glass doors and a triple window I have chosen to use drapes, but this isn’t as simple as it seems. Heavy lined drapes deadened the midrange and just about did away with the top-end. It was so overwhelming that I actually preferred the sound with no window treatments at all. By playing around with hanging materials of different weights, I discovered that light weight pleated cotton drapes seemed to have the least effect on the sound of my system, yet still adsorbed and diffused any echo from the windows. The wonderful thing for me is I can open the drapes about half way and still get these benefits. The other good news is that this is one of the cheapest forms of window covering you can buy.
The other sidewall is very different in that it’s not a single wall but a staircase, a wall, an alcove, and a flat wall that faces the left speaker. This wall gave me a lot more trouble. I tried different thickness of foam, acoustical foam, and rugs. What I found worked best was two-inch ridged foam or two-inch thick acoustical panels. I used three of these on the flat, facing wall, but on the side wall at the first reflection point I tried several rugs. None of the Oriental or modern floor rugs worked at all, but I happened upon a modern looking alpaca rug that worked just as well as the foam. It also cost about the same but looked a whole lot better.
The back wall behind my speakers is the most unusual wall in my listening room. My house is a tri-level built in the mid sixties. My reference system is in the lowest level that was built to be a family room. The back wall has a staircase that comes down the left side of the room as viewed from the listening position. The back wall itself is only four feet tall with an iron railing that goes above it. This created an interesting acoustical problem.
I played with this a lot. I first tried doing nothing, but the music sounded like it was being played in an echo chamber. I then tried 4-inch foam; this really over deadened the sound. I settled on two-inch ridged foam and later changed the foam to the Auralex’s Elite B24 Pro Panels. Either the foam or the panels need a little help, so I tried a combo of absorbing foam and diffusing panels. This worked fairly well, but was expensive and looked terrible. So I came up with another idea; I had lots of books with no place to put them so I made erratic stacks of them along the back wall. None of the stacks are above two feet high, but they work great. They also give me somewhere to run speaker wire so that it’s not on the carpet.
I’ve shared all this to encourage you to play with your furniture, your rugs, and other stuff in your room and see if you can help the sound. I can tell you one thing though: nothing sounds worse than an empty room unless it’s an over damped room. You just can’t ignore the room, it makes too big a difference in the sound of your system. I’m not telling you what can get by for free, like I said, I’ve spent about $4500 on my room. If that’s too much for you try something to improve your room, but I bet most of you’ve spent more than $4500 on some of the components in your system.