Soundbox - Sound for the Un-Soundable

Model Railroader General Discussion (Model Railroader)
1

I have a web article about making a soundbox at:

http://www.pacificcoastairlinerr.com/1879/soundbox/

Harold

2

Harold

Thanks for the reposting of your early pages, and the under-the-table sound article. I had missed the old article on lowering Mantua boxcars - I may use some of the info on some Mantua Old Time gondolas I found on the junk table.

I planned on under-the-table sound in any case for my tiny HO/HOn3 steamers, so reading somebody else’s experiments is very beneficial.

Fred W

3

Would this system work with two identical sound decoders, one in the engine for direction and one driving an under layout sub-woofer?

I know there are guys with well developed acoustic skills in here who should be able to answer this.

4

Sure would. If you tuned them the same they should stay in sync. You’d want to add a low pass filter to the undertable one so only the lows go to the sub, or you could use the equalizer if using a Tsunami. In Harold’s example the capacitor is blocking the lows - this capacitor was included witht he old Soundtraxx LC and DSD decoders so that the rumbly lows would not distort the small speakers. For driving a large full-range speaker I’d elmininate that because the speaker being used would be able to reproduce the sounds properly.

–Randy

5

Perhaps you all might be interested in my stationary sound decoder project finished in the spring of 2008 and posted then.

http://cs.trains.com/TRCCS/forums/p/129436/1459187.aspx#1459187

I used six sound decoders of various types, a control box with LED indicators, and dual control circuits for programming the decoders and playing the decoders mu’d with various locos.

I use two amplifiers…one dedicated to subwoofers, two sets of speakers and an equalizer.

This is all shown in the photos.

I could find no previous plans so I had to make up the circuits as I went along.

Sounds great…thundering really.

6

Would you need a resistor across the motor leads of the soun decoder under the table? I blew a decoder, bench testing it with just power to it and no load on the motor leads.