For those interested, here are some pictures & comments about the recent crossover, binding post, and interconnect upgrade on my SDA 2’s.
My intent in this upgrade was twofold. First, I had have not soldered anything in years so it was a chance to re-learn things. I have a pair of SDA 1C’s that are currently my main speakers and chose not to practice on them. The 2’s have four crossovers so I figured that would be a lot of practice. Secondly, I was curious about the “sonic” differences between the before & after and thought the “dimensional tweeter” added a nice twist.
Just so we don’t get into component quality, my basic goal was an inexpensive upgrade. Not cheap, mind you – just less expensive given the four crossovers and the inherent value of plain SDA2’s versus SDA 1C’s. For that reason, I chose Solen Caps and Mills Resistors along with parts I had laying around (banana plugs, wire, etc.). Not the cheapest upgrade but definitely not the most expensive. The goal was to cost-effectively modernize 21 year old speakers that I will eventually use as surrounds.
Yes, I will probably upgrade the tweeters next but wanted a comparison of each upgrade so it’s a one-step-at-a-time and listening thing.
One thing I did not get done (yet) is to put in a toggle switch to turn the dimensional tweeter on and off. I’m having trouble finding a toggle with a long enough shaft. I’ll get to it eventually.
My thanks to all those upgrade contributors and posters that inspired me to take a shot at this. The soldering video links from Ricardo were handy, as was the upgrade project post from DarqueKnight. A special thanks to avguytx whom I could not have done this without. He in fact even offered to “do it for me”, helped me get the right parts, and bailed my out of a couple of soldering mistakes. Also thanks to nspindel for moral support, a couple of spare tweeters, and help in getting the pictures uploaded.
Here’s basically what I did:
1. Replaced all the basic caps & resistors and eliminated the Mica’s
2. Eliminated the Poly-switches and replaced them with wire jumper
3. Replaced the Input connectors with better jacks
4. Added a set of banana jacks into the binding post cup and wired them into the SDA interconnect jack. That way I could upgrade the interconnect cable quality but still maintain the usability of the original blade/blade connector
5. Replaced a few suspect connectors, wire runs, etc.
6. Eliminated a few vibration rattles (hot glue)
There are two other posts with parts costs, and basic methodology.
Speakers in question
Close-up after removal
After pulling the right cabinet crossovers, I added the new Binding Posts for the Interconnect Cable. The new jacks allow cable experimentation but still leave the IC jack intact. New jacks get 14-gauge to the crossover.
Inside View Right Speaker (Left would be reversed)
Back to the completed Stereo crossover
Poly-switch now replaced with wire jumper
SDA crossover complete
Assembly begins, completed bind post cup
One mounted, One ready to mount
Testing and Checking for Fires