For Sale SD Acoustics SD2 Bookshelf Loudspeakers

Further Information

These are very rare speakers designed by SD Acoustics, a UK company in the 80's named after its Danish founder, Steen Doessings. He designed several models from the SD1 up to the SD5. This pair are the SD2's, a model with virtually no online reference. So excuse me as I don't have any original specs or information!

They sound really good. Everything about these speakers screams attention to detail, from crossovers and wiring to driver selection to cabinet quality, and the sound quality reflects this. I recommend having an audition if you can.

Physical attributes:

• Extremely solid cabinets with solid wood corners, extensive internal bracing and comprehensive foam dampening
• Two-way design featuring large, soft dome Audax tweeter and Audax bass driver
• Sophisticated crossover
• Dimensions: 560mm (H) x 380mm (W) x 320mm (D) (without grills)
• Stands 450mm high

My restoration:

Crossovers

I replaced all the electrolytic capacitors with Jantzen cross-cap film-type capacitors. It was a struggle fitting everything back on the boards but I did so, also replacing the seals on the boards for an airtight fit with the cabinets and replacing the binding posts with Dayton satin nickel-coated types. I kept the original ~8AWG solid core copper wiring.

Cabinets
 

The front baffles had cracking where the side panels and corners met the front panels so I sanded them right back. But before I filled the grain for finishing I implanted magnets for new grills. Before applying the veneer on the sides I used the raw cabinets as templates in order to route new grill frames. I then applied two pack epoxy filler on fronts and rears and sanded back until ultra smooth and ready for painting.

The seams in the original mahogany veneer had lifted away from the solid mahogany corners so I had to tackle a complete re-veneering. I desired to veneer it in a single sheet of veneer and, after looking for a long time I came across a guy in WA who had cut consecutive sheets of thick silky oak veneer from a whole log that were wide enough and long enough to cover the whole cabinets.

I sanded back all the original veneer and filled gaps etc with two pack epoxy filler. Then I bent the veneer around the entire cabinets using steam to facilitate the bending (the veneer was brittle and liable to split and crack).

Finish

I filled the extremely dimpled silky oak grain with about 6 applications of Aquacoat. After fine sanding, I applied 3 coats of Norglass penetrating timber oil. After more sanding I applied 6 coats of Norglass marine-grade gloss polyurethane with minimum 2 weeks between coats for maximum de-gassing and hardening.

Then I orbital sanded the finish down to about 500 grit then hand polished with compounds all the way down to ultra-fine and swirl remover. Because of grain dimpling I was not shooting for a mirror finish but it is an ultra-fine, scratch or swirl-free gloss finish with an incredible depth to the grain. The pictures look good but the reality is even better.

The front baffles (and rear panels) were in black and I preferred something else to contrast with the silky oak veneer. I tried several greys and landed on Dulux Wind Spray Metalshield, which would provide a hardwearing finish on the cabinets but also adhere well to the metal stands. I carefully removed the original 'SD' badges then glued them back in place after I finished the front baffles.

Stands

I acquired some solid steel stands that were probably used for 70's style chairs and repurposed them for these speakers; the round shapes matched the rounded edges of the speakers. I fashioned a plinth and bolted it onto the top plate of the stands so that the speakers would be more stable. I finished the stands in the same paint as the front baffles and rear panels of the cabinets.