# Soundtraxx 9 pin decoders



## Methodcaptain (Jan 12, 2013)

I was looking at Soundtraxx website, as I'm thinking of upgrading some of my locomotives to sound now that I see that Soundtraxx has decoders that will simply plug into my Athearn and Athearn Genesis locos.

I like this idea because in the past, having to add resistors to each light bulb was a pain. Being able to use the factory light board is a huge bonus to me.

My question is, are these decoders capable of using more than one speaker?

I have non sound athearn Genesis sd75ms, SD70aces, and rtr dash 9s, etc that I think would be able to hold more than one speaker.

Anyone have any photos of an install of these plug in decoders?

If this information is already on the forum, I apologize. I'm brand new here.

Thanks for any help!


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## BNSF 1 (Dec 27, 2012)

Methodcaptain said:


> I was looking at Soundtraxx website, as I'm thinking of upgrading some of my locomotives to sound now that I see that Soundtraxx has decoders that will simply plug into my Athearn and Athearn Genesis locos.
> 
> I like this idea because in the past, having to add resistors to each light bulb was a pain. Being able to use the factory light board is a huge bonus to me.
> 
> ...


Any and all decoders are capable of multiple speakers. It is contingent upon how you wire them. There are 2 ways to wire any speaker, series or parallel. Soundtrack uses an 8 ohm amplifier. If you plan on using 2- 8 ohm speakers than you will need to wire them in series. If you don't wire the in series it will cut the impedance in half meaning it will create a 4 ohm load on a rated 8 ohm amplifier. Shortly put you will fry your decoder. On the other hand if you are using 2- 32 ohm digitrax speakers you will want to wire them in parallel. Wiring these digitrax speakers this way will cut the impedance in half and you will be at 16 ohms, which presents less resistance, meaning a louder sound than the 32 ohm. Although I would not recommend using a 32ohm speaker for soundtrack 8ohm amplifier, the sound won't be as loud as using 2- 8ohm speakers wired in series. It's pretty straight forward, 8ohms has less resistance than 16 ohms therefore the sound will be loader. I'd suggest you do a google search on series vs parallel wiring, it will have diagrams that show you how to wire them.


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## BNSF 1 (Dec 27, 2012)

Methodcaptain said:


> I was looking at Soundtraxx website, as I'm thinking of upgrading some of my locomotives to sound now that I see that Soundtraxx has decoders that will simply plug into my Athearn and Athearn Genesis locos.
> 
> I like this idea because in the past, having to add resistors to each light bulb was a pain. Being able to use the factory light board is a huge bonus to me.
> 
> ...


I forgot a very important detail. When using multiple speakers you will need to pay attention to speaker polarity. Most speakers for sound decoders are not marked as to which is positive or which negative. If you you can't figure what is positive and what is negative you can take an AA or AAA battery and connect it to the speaker if the speaker moves outwards than the wire that is connected to the positive side of the battery is the speakers positive wire. If the speaker moves inward than the wire connected to the negative side if the speaker is the speakers positive wire.


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## NIMT (Jan 6, 2011)

I would like to clarify some points.
I'm a Soundtraxx dealer and Installer and have delt with just about any situation of an install.

Most engines will not have enough room to fit more than one speaker in it.
Remember you not only have to fit a speaker in there but also a enclosure around the speaker. Without a enclosure the speaker will sound week and wimpy, like the decoder is not putting out any sound volume. A proper enclosure will double the volume and depth of the sound coming out of the engine. I rarely use 2 speakers in engines, but I've had many a customer ask me how to turn the sound down , they were just too loud!

Soundtraxx decoders don't really plug in, most are replacement boards. You remove the existing interface/adapter board and install the Soundtraxx board in it place.

You mention not having to solder a resistor in for the bulbs. The GN-1000 (Genesis form) boards are made to drive the 1.5volt bulbs. But here's the cautionary side to that decoder it will not drive LED's so if you want to upgrade to LED's from lamps your out and will have to replace the board. On the other hand the AT-1000 (atlas form) board will run both the 1.5 volt bulbs and LED's so it's a much better long term choice. You will need to solder a resistor in line if your using LED's.

Check out my site or drop me a line if your needing the decoder or parts as I sell them for an excellent price and ship everywhere!


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