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.
There's the boxcar I'll use.
I made this template some time ago for drilling holes in the bottoms of sound cars.
Ok, all in and wires connected in series, then leads taken out to one end of the car down near the coupler.
I like to use the little Soundtraxx single pin connectors. Here are the male ends. The female ends are on the speaker leads coming from various locos that use sound cars......locos too small or narrow to accept good sized speakers.
Reweigh the car and add back some of the weight.
And the sound car is ready to go.
Here is the sound car connected to one loco.
Now, this is just done for a few locos with less than top end sound decoders in them. Using a Tsunami or better I prefer, of course, to fit the decoder in a top end loco, usually one with plenty of room or already designed to accept a good quality speaker. But this is a adaptation to make something better out of a few less than stellar decoders.
A video of a switcher using this sound car is here with some earlier videos http://youtu.be/BXiGwaQ6ozA
Hey, that really does make a difference compared to the little speaker. The video looks and sounds realistic. I guess I should avoid cheap sound decoders unless I want to go to those construction lengths.
The video seems like a big improvement in sound for that type of decoder. I know they are not very impressive right out of the box.