? about speaker wiring

[Josephbw]

I pulled the decoder out of a new BLI engine with 2 speakers in the fuel tank. I am hard wiring the RP LM-2S to the various wires. The instructions say it doesn't matter which wire you use for the speaker positive terminal using 1 speaker, but it doesn't say how to wire for 2 speakers. Any ideas?

Thanks, Joe

[William Brillinger]

Try here for some suggestions:

http://model-railroad-hobbyist.com/magazine/mrh-2014-01-jan/di_dcc-multiple-speakers
and
http://model-railroad-hobbyist.com/node/8242

[KPack]

Take both speakers and mark the same terminal on them....this will be your positive.  It doesn't really matter which terminal you choose as long as it is the same one on both speakers.

Next decide if you will wire them in series or parallel.  If you are using 8 Ohm speakers (you should be) then series will present a 16 Ohm load to the module, which will then output 0.5 watts of power to drive the speakers.  The sound will be quieter, the amplifier will not be working as hard.  If you wire in parallel you are presenting a 4 Ohm load to the module, which will then output 2 watts of power.  The sound will be much louder and the amplifier will be working harder.

See this link for explanations and diagrams: http://www.bustedgear.com/faq_Speaker_wiring.htm

Why would you ever wire in series if parallel is always louder?  The answer has to do with your speakers.  If the max watt rating on your speakers is 1 watt and have them wired in parallel, you have the potential of overdriving the speaker up to 2 watts which could damage or destroy the speaker.  If you have speakers that are rated for 2 watts then go for it.  If not, parallel is probably safer.  Plus it will be plenty loud. 

I go back and forth between the two methods depending on the type of speaker I am using in a particular install.  In the end I normally turn my sound down to a level that is not obnoxious.

-Kevin

[Josephbw]

I don't think I phrased my question properly, let me try again. I have a new BLI engine that I replaced the decoder with an LM-2S. The BLI engine has 2 stock speakers in the fuel tank that I am going to reuse. There are 2 wires from the speakers that plugged into the BLI decoder board, a red wire and a black wire. The speaker wires from the RP decoder are both brown with no polarity indicated. Does it matter which brown wire I use for the positive or negative, or should I use clip cords and try both options to determine which has the best sound?

Sometimes I have a period of mental density, hopefully this isn't one of them. 

Thank you,
Joe

[KPack]

Nope, it doesn't matter which one you use.  Either way it will be the same.

[Josephbw]

Thanks Kevin, I thought that was the case, but I couldn't find any corroborating documentation.

Joe