Marias SB 18
Before my boyfriend spent his summer vacation almost fanatically building his own high-quality speaker boxes, it had never for a moment occurred to me that you could improve the listening quality of your favorite music by yourself. As a supportive girlfriend, I closely observed the process of building the Duetta that finally arrived at our house after long hours of research, and I helped out here and there too. Then, on my birthday, there was suddenly a big heavy package on my desk. No… could it be…? …yes, it was! The box contained the components for the SB 18 – a Blues class assembly kit. Now I had my own construction project – I couldn’t wait!
The first challenge was choosing the materials to build the cabinet. My design ideas were very simple: the box would be made of 21 mm multiplex, with the body coated in black wood lacquer, to provide some coverage but still leave the wood structure visible. I would leave the front its natural color. To keep it from being too easy, the side pieces would be mitered so that the edges could be glued together as sharp corners. So after calculating the new dimensions, I ordered the wood from my local lumber store and had them cut it to size. Finally, I had the front made by a cabinetmaker, who cut the openings very precisely. The only disadvantage is that you have to wait a good long while for your piece to be finished. After that, a long time passed because I was relying on my roommate’s workshop for the “miter-cutting” and “edge-beveling” steps and he was gone for part of the summer.
Meanwhile, though, I was able to start soldering the crossovers. My boyfriend had all of the necessary tools handy, so I had an expert guide to help me explore this new territory. A little bit of dexterity is important if you want to make the connections look good, but other than that I have to say that the soldering was much easier than I expected (if you don’t let yourself get too confused, and make sure you think through the crossover diagram ahead of time!). After two evenings, I was very satisfied with the results of my work. Now I “just” had to take care of the cabinets.
Once the boards had been cut to size and were ready to glue, we spent an evening gluing the two boxes together with good old joint glue. I had heard it was a good idea to attach the mitered parts with adhesive tape on the ground first, and then to glue them together; that worked pretty well.
Unfortunately the side panels weren’t mitered very cleanly, so they stuck out a couple of millimeters. We spent a long time thinking about the best way to position the slight projections so that they could be sanded off later. In all of our pondering, we ended up forgetting something essential right at the end (but fortunately we remembered it just before gluing on the front): the upper limit for the bass reflex channel. That meant another delay for my process, because now the slats I had originally prepared couldn’t be glued in with enough tension and had to be cut to size again. But once that was taken care of too and the boxes were completely finished, it was a good feeling, and I couldn’t wait to hear how they would sound. I could have installed everything at this point and had a test listen, but they still needed to look decent. I chose OSMO decorative wax in black for the back sides and linseed-oil varnish for the front. After two coats and one intermediate sanding step, I had the desired results: a beautifully even surface that still subtly showed off the wood grain.
The “moment of truth” came on the Thursday before Christmas. A cozy atmosphere in the room, wires welded to the crossovers, insulation wool cut to size, chassis installed and the terminals attached: check! Now all that was left was to turn them on, put on some music and go! The sound absolutely met my expectations, and my roommates were also very impressed. I’ve been listening to it for a while now, and I’m always pleased about the super sound quality. I also have to confirm the much-lauded “live feeling” of the SB 18.
Naturally, in the end I was also very proud to have put together this “acoustic wonder” by myself. I recommend that all of my female friends try warming up to their boyfriends’ building mania too, and I recommend that all of my male friends try surprising their girlfriends with a heavy box for their birthday. :) I learned a lot and had even more fun, especially because the results were so great !
The SB 18 kit with SB Acoustics speakers is available from Intertechnik