Unconventional Room Treatments: Copper

Unconventional Room Treatments

The listening room. One of the three pillars that make the foundation of any great audio system. Some say it is accountable for up to 33% of your audio system's performance. Yet many of us neglect optimizing our listening environment. There are of course legitimate reasons; aesthetics, space, and lack of knowledge of where to begin or what to do. Less legitimate are laziness, lack of patience, and "I can just buy more gear and/or tweaks as a bandaid".

Getting a room and system to sound great takes time, patience, and a lot of experimentation. For those that take the time and are curious enough the reward is enveloping, engaging sound that is relaxing and exciting at the same time.

Room treatments that used to be large, unsightly and heavy are at least getting lighter and better looking. Offerings from GIK Acoustics, Stillpoints, and ArtNovion have a pleasing aesthetic, and won't make your listening room look like a Naval radar testing facility. The costs are far less than what many would spend on a component or cable upgrade as well.

There are also unconventional products that are worth a listen as well. They work on the room in unconventional ways, take up less space, and visually can be quite appealing, or non intrusive.

This is part of my journey  on using the conventional and unconventional methods of turning a typical listening room with it's usual problems of too many flat, reflective surfaces, bass nodes and other sonic ugliness into a room that now allows me to hear more accurately, enjoyably, and listen more deeply to the music I love.

Sonex Whisper Wave Acoustic Absorbers. Lightweight and very effective. The ceiling rail
system from Picture Hanging Systems allows me to hang, move and remove the acoustic
treatments anywhere the rail is installed. Even over a window!

Terms: 

Conventional Room Treatments

I have posted on room treatments before, with details of how I installed conventional treatments in my listening room via a rail system. This system has been extremely helpful in dialing in the right amount and types of treatments. The rails allow me to add, subtract, move, and replace treatments rapidly and painlessly. It also allows one to hang art on the walls in the same manner. Making the room aesthetically as well as sonically pleasing. 

Anyhow, on to the definitions...

Absorbers - Usually foam or fiber filled panels that should absorb sound uniformly throughout their bandwidth.

Diffusers - Diffusers do not necessarily absorb sound, they scatter it. Much like a light diffuser in photography scatters light for more even coverage of the object being photographed, an audio diffuser scatters soundwaves evenly over it's rated bandwidth. They come in many shapes and sizes and are made of wood, styrofoam and MDF.

Bass Traps - Bass traps are more like low frequency absorbers. Often larger than standard absorbers, and also often shaped to be placed in corners where bass frequencies can build up. My advice is use effective speaker placement first, bass traps second.

Unconventional Room Treatments

Unconventional Passive treatments - Passive simply means unpowered. These devices use materials, mechanical resonance, or are activated by movement of air to absorb/scatter soundwaves.

Resonators - A perfect example of an unconventional passive acoustic treatment. Resonators are devices whose resonant properties enhance the spatial etc. aspects of the sonic presentation. This is nothing new. I've seen gold, silver, brass, platinum and copper resonators. I've seen these resonators take the form of small cups, bowls, and quasi-plate shapes. How they work is a bit of a mystery. But there is no doubt on their effects when placed carefully in a room. My take is that they resonate sympathetically to reflected sound, thereby cancelling the smearing effects of room. With cancellation there is more of the correct phase information reaching the ear, which in turn creates the effect of a larger soundstage.  Different metals have different resonant frequencies and therefore different bandwidths that they affect. In addition to the different metals, the way they are shaped and their thickness can also effect their properties. You can see that this can get rather complex rather quickly. This, coupled with the mystery of how they work exactly has kept them from the mainstream of audiophilia. But not from Tweek Geek. :)

The Dark Side - I didn't know what else to call these treatments. They are occasionally similar to the Active Unconventional Treatments, but are unpowered. Crystals, Pebbles, and other materials are sometimes used in raw form or suspended in epoxy, paint, or other mediums to affect sonics in a room. Strange things indeed whose effects can range from awful to glorious depending on their implementation and makeup.

Super Sonic Tonic consists of wooden cylinders filled with proprietary materials that are placed
strategically in the listening room. The net result is a wider soundstage, fuller, warmer, richer tone
and enhances low level resolution and phase coherance. Definitely a Dark Side room treatment.

Unconventional Active treatments - These are products that work on the room need power to work. Stein Harmonizers, Bybee Active Room Neutralizers, and Tweek Geek's forthcoming powered Super Sonic Tonic are prime examples of unconventional active room treatments. The Harmonizers claim to actually work on the air in the room, making it more pliable and viscous. Much like a bubbler in an olympic diving pool works, they put the air molecules in a state of momentum, thereby making them easier for soundwaves to propogate through. The proof however, is always in extended listening.

Using Copper As A Passive, Unconventional Room Treatment

If you have been reading my blog, you know that  I have been experimenting with copper and it's influence on room acoustics for quite some time. Experimenting with different shapes (bowls, cups, sheets and rods) as well as thickness of materials and gauges can produce a more spacious and dynamic sound presentation. Opening up the room so to speak. My extensive experimentation has lead me to find just the right diameter, purity, shape and process of copper that allows me to disperse the material across the room without over doing the effects. My past experiences have taught me that Too small a gauge/diameter of rod/wire and the sound can become too bright very quickly. Too large a diameter and the midrange can become harsh and thinned out. The copper rods that I use are 1/2" in diameter and are oxygen free. I polish them, then heat treat them for a beautiful visual effect. The last stage is to cover them with a clear lacquer to protect from further oxidation. They are beautiful to look at and really add to the listening experience.

I found that tiki torch stands make a perfect copper rod stand. One rod per stand holds the rod steady, and is light enough to allow me to move it around the room to find the right placement. Once I have the placement, I can then find a more permanent, aesthetically pleasing mounting solution for the rod.

The Tiki Torch Stand. $11 plus shipping.

Opening Up The Room
As mentioned in previous blogs, with the copper rods properly placed transparency is improved as well as the clarity of high frequencies. Micro and macrodynamics also improve. Vocal richness and midrange layering seem to be "de-veiled" as well. Musical decays, be they ambient caused by the recording venue, or electronic from reverb all seem to sustain longer and sound more 3D.

Placement
I start with placing one or two rods along the side walls a foot or so in front of the plane of the loudspeaker baffles.

Secondary is the wall behind the speakers.  I place one rod along the wall, centered behind the speakers. When you do this, two things happen. One, the center image is more focused. Two, the sense of depth that the speakers are producing also becomes greater. This effect increases with more rods.

Third, if not using Shakti Hallographs, I place them in the corners of the room behind the loudspeakers.

Mitigating "Room Boom"
The copper rods can also mitigate "room boom" to a degree. That midbass/midrange overloading of a room. For example: Your room is small to medium sized, and for aesthetic reasons you might not be able to place your speakers far enough from the sidewalls to get rid of a nasty speaker/room interaction. Placing one or more of the copper rods along the side wall and in front of the speakers can help to reduce the sense of too much bloom/boom. Another trick I use is simply playing some music with bass and walking close to the side walls, listening for the room nodes. I place rods along the wall where the bass energy seems strongest.

Copper rods with mounts, Stillpoints Apertures, Sonex Whisperwave absorbers, and Shakti Hallographs.

So far I have 4 rods along the wall behind the speakers, 1 each to the outside and just in front of each speaker, 1 each to the  side of the listening position and 2 more behind the listening position. The overall effect seems to be a more live, dynamic, more transparent and open sound. The system is now better at capturing nuance and texture as well as portraying those non musical elements that make reproduced sound appear more live.

Where to buy?

I get copper from onlinemetals.com  - Specifically I use the 101 oxygen free copper rod.  They are about $50 for a 4 foot 1/2" raw copper rod. I clean, polish, heat treat and clear coat them for use in my room. If you do not clear coat them, the finish will oxidize and become dull. My polishing and heat treatment makes each piece of copper a unique work of art.

The tiki torch holders are from a restaurant supply store for around $12 each. Not the best looking, but work well and won't tip over easily. Great for temporarily placing the rods until you find their best locations.

I am working on a stand that will make use of a rectangular vase (about 31" long x 6" wide x 16" tall) that I will fill with decorative stones and be able to place 1 to 4 rods in. This will be used on the side walls in my room. Pictures coming soon.

As for the wall mount holders, my machinist makes those for me and I can have them made upon request for $35 each.

It's my hope that some of you might be adventerous and curious enough to try the copper for yourself. For me it's another tool I can use to address acoustic issues in the listening space while being a bit artistic at the same time.