Video of the better sound as a result retrofit http://youtu.be/BXiGwaQ6ozA
I had picked up a couple of these disappointing decoders on eBay at a very reduced price…used. Perhaps I could play around with them. I found that others had very disappointing experiences with this decoder, which actually has some design flaws and has been discontinued as a result.
However, cheap is cheap. I had previously experimented with creating “sound cars” in which to place larger speakers for loco conversions with very little space. I like to use the large 28mm by 40mm ovals which I had bought many years ago. I had placed one in a small coal hopper and use it behind a three truck shay with a Tsunami decoder. This gives much better sound.
With the SDN144s, designed for N scale but good enough for HO switchers, I created a few sound cars with a variety of speaker combos. Below is the creation of a dual speaker car with wiring in series so the impedence is at 16 ohms. You don’t want to drop the impedence to 4 or the little decoders will probably seriously overheat and fail. 16 ohms seems even better than 8 judging by the results.
Here is the replacement speaker next to the original.
Create a nice box from stock plastic.
I found some 5 minute epoxy at the dollar store. Hope it works as well as the $7 stuff from the hardware. Seems to.
Now, as usual, the second effort is better. The second speaker box is tidier, better fit and ready to solder wires on.