|Project by ferstler||posted 11-19-2011 06:11 PM||3175 views||12 times favorited||8 comments|
I am a retired audio writer and have had various subwoofers and other components installed in my home over the years, both as items to be reviewed and for personal use. I recently have had a pretty impressive pair of subwoofers in my main audio system (Hsu and SVS models), but while both worked just fine, they wer not visually complementary, and so I decided that I wanted a matched pair of subs that I built myself pretty much from scratch.
The new subs, like the classic Hsu Research TN-1220 (that I also owned for a while) and the SVS cylinder models, were made from 58-inch long, 14-inch diameter Sonotube sections. (Hsu and SVS models varied from 12 to 16 inches.) While Sonotubes are not exactly wood, I did use woodworking tools to build the subs and the top and bottom sections did at least involve the use of mdf boards cut to proper size and shapes.
With the end plugs, caps, and standoff plates (the standoffs and plates are 16-inches in diameter) the subs are each 68 inches tall. The enclosure volume of each is 5 cubic feet, and with the 20-inch-long, 4-inch-diameter, bottom-located ports the tuning frequency is 17.5 Hz. (The woofer drivers are mounted on top, facing upwards.) Each Sonotube interior surface is lined with 2 inches of fiberglass batting to simulate an even larger enclosure volume. I purchased most of the electrical and mechanical parts from Parts Express, with the Sonotube purchased from a local lumberyard and the mdf purchased from Home Depot.
The Sonotube is only available in 12-foot lengths, and it was easy to cut that item down to the two lengths I needed. The top and bottom plugs are mdf (glued and screwed into position just inside the top and bottom rims, and with larger plates glued and screwed to them. above and below. The bottom actually has double thick mdf plates, and then both the top and bottom have additional plates, each held away by three hollow standoff dowels that are secured to the plates by long screws. Each tube was painted flat black, and then standard black speaker grill cloth was wrapped around them and secured in back by Gorilla tape for removal should the cloth be torn or damaged by accident. To serve as hems top and bottom 50-inch long, black-leather belts were wrapped around the perimeters. The top and bottom plates were spray painted with several coats of satin-finish black enamel.
Outboard power to the subs is provided by the first new component I have purchased for some time: a Crown XLS1000 stereo power amp. The vintage (but still working just fine) Yamaha DSP-A1 integrated amp in the installation has both mono and stereo subwoofer outputs, and, well, I have the subs hooked up stereo style. It may not mean much to do it that way, but, heck, it is an offered feature with the Yamaha, so why not use it? The drivers are massive 12 inchers, and the pair, as driven by the 350 watts-per-channel amp, is able to generate 105 dB peaks at 20 Hz at the listening couch 17 feet away from each unit. At 30 Hz (where even most deep-bass music cuts off), even higher peaks are possible. However, most sane listening will never involve levels that loud. As a retired audio writer, I just had to run them up that high to make sure they were able to hold together.
The subs can easily match the performance of any commercially made subs I have auditioned in that room over the past two decades.