Five years ago my audio components sat stacked on top of a JBL speaker. Later I moved them onto a ¾” MDF shelf, hung on heavy-duty brackets, above my large projection screen TV. As my system progressed further, so did my need for space…my current preamp has a separate power supply and I added a 2nd power conditioning component, while the other power conditioner is pretty big. I had invested too much in my system to go back to using things like milk crates, cinder blocks and MDF and stacking components was out altogether. The time had come for a real audio shelf, but my budget was only in the range of repurposed Ikea furniture.
I first learned about acrylic as an audio material from Gary Koh, of Genesis Loudspeakers. Gary explained that acrylic has a very low resonance point, which makes it an excellent material for a high-performance audio shelf. After some Internet research about acrylic, I decided this would be the best performing option in my budget range, and decided to build one.
Getting the materials you need is the first step. I purchased three sheets of 1” clear acrylic, measuring 12×24” and eight 9” tall acrylic rods, 1.75” in diameter. Make sure to use cast acrylic, rather than extruded. With 24” sheets you’ll have about 20” of space on the lower shelves, which I find adequate for most gear. Were I to build another shelf, I might use 14” deep sheets and have the corners rounded off. I chose clear acrylic, but black was available and other options, such as smoked clear, are available, at a premium.
I purchased my materials from Commercial Plastics, in South Seattle; I mention their name, because I called nearly every plastics company I could locate, between Seattle and Tacoma, and found that they had the best prices (by as much as 50% in some cases) and the owner, Greg, was very much focused on customer service. The material cost was about $300 with tax. Had I wanted the shelf to be completely finished and assembled, it probably would have only cost me another $300, but if you’re like me, you’ll want to save that money, so you can spend it on another part of your system.
Before finishing, the sides of the sheets will be white and translucent. Finishing the sides of the sheets is purely for looks. It’s a lot of hard work, but finishing will bring out the crystal prism look. Do the finish work before assembly, while the sheets are easier to work with. Acrylic scratches very easily, so keep the protective paper on the sheets, until you’re ready to glue them up (or flame-polish them). You’ll want to start with 350 grit wet sandpaper and move up to higher grits, then buff with a buffing wheel on a heavy duty drill (if you don’t have a specialized buffer). At least this is how I did my finish work and it was tiring. However, there’s a faster, easier way…smooth the saw-cut ridges with the 350 grit sanding, then hit the surface with a MAPP torch to bring out the shine. There are videos on YouTube that instruct on flame polishing acrylic.
Now you’re ready to start the assembly. Before picking up the materials, I suggest asking your supplier to quickly hit the ends of the rods with a buffer, to give you a flat surface for a solid bond (they didn’t charge me for doing this). First, build a template to position the rods on the sheet. I took two pieces of ¼” thick, 2” wide wood strips and fastened them in a 90 degree angle, then I glued two pieces, ¼” thick, 1” wide strips on the inside, creating a stepped template that lays on the corner of the sheet, which will position the rod ¼” away from each side of the corner.
Your acrylic supplier will sell you a small can of liquid adhesive to glue the rods. Assembly must be done is a well ventilated area. The glue will melt the acrylic pieces and bond them into one. I threw out the little applicator bottle they gave me. With the applicator it’s difficult to apply the correct amount and keep the liquid from dripping on the surface. Instead, I used a small syringe (like an insulin syringe). Position the rod on the sheet, then put something under, such as a very thin gauge sewing needle, to create a small crack between. Squeeze the liquid glue into the crack with the syringe and it’ll wick toward the back. Don’t fill the gap completely, because when you remove the needle, it will spill out. If you don’t use enough glue, the bond won’t be complete and there will be air bubbles in the space between. Have tissues on hand to soak up any excess glue. Let the rods sit for at least 40 minutes, before you add the next layer or move the shelf. YouTube also has some simple videos on how to glue acrylic.
As a final touch and to get to the next level of performance, add some resonance control devices or damping material under the shelf. Stillpoints, Sorbothane, isolation platforms or butcher block are just a few options, depending on the remainder in your budget. Keep in mind that the ability of any audio shelf to improve your sound is entirely dependent on the extent to which everything else in your system will let it. If you’re willing to put some time and effort into it, a nice audio shelf is only $300 away.