Speaker Wiring

[Stephen K]

I'm just beginning my first Rail Pro installation.  Well, soon as it arrives.  I have an Atlas Ready to Run GP-40 that I am outfitting with 2 small sugar cube speakers.  I have the speakers fitted to the speaker cover and ready to solder wires.  My question is if this pair of speakers should be wired in series or parallel?  Simple as that...  Thanks.

[Alan]

Either. RP modules can drive a 4 ohm load. Series sugar cubes = 16 ohms, parallel sugar cubes = 4 ohms.

[Stephen K]

Thanks Alan.  Does one method yield more volume than the other?  Thus can operate at a lower volume "setting" and reduce the load on the module?   This question is coming from my (vague) recall of an article I read somewhere on line that suggested this idea.  Just don't recall which way was which.  Seems to me, based on your message "series = 16 ohms" that this would be preferable.  Or is this idea just too insignificant to worry about?

[Alan]

Member KPack has real world experience. Hopefully he will chime in. I personally do not use sound.

Fundamentally, the parallel connection will yield higher volume. Less speaker resistance = more amp power = more cone movement. Real world can be very different depending on myriad of influencing factors. Dangerous area to make broad brush statements.

I would not worry about working the LM amp. RP has very good internal protection. It will shut down the module before damage occurs. Or if you have death metal as the prime mover sound and the volume cranked to 11 

[Stephen K]

The whole amp and Ohm thing completely eludes me.  Overall I tend to believe this isn't enough of an issue for me to concern about much more.  Two small sugar cubes shouldn't cause any trouble no matter how their wired.  My layout won't be huge, more on the small side of medium, I can't imagine I need REALLY LOUD.  Think I'll just proceed with parallel wiring for now.  If future recommendations contradict that idea I'll always be able to change it.  Thanks for your help Alan. 

[nodcc4me]

When you are wiring the speakers, why not try both ways before you put the shell back on and see which you prefer? It's just two solder connections.

[Alan]

The whole amp and Ohm thing completely eludes me.

[KPack]

Parallel will yield higher volumes.  I typically will run my dual speakers in parallel when they are rated to handle the wattage.  With a 4 ohm resistance, the Railpro amplifier will output 2 watts of power.  Not every speaker is rated to handle 2 watts of max power, and if they aren't they can be damaged.  I have a few sugar cube speakers that have a max rating of 1 watt, so I did series on those.  They are definitely quieter, but I'm also not at risk of destroying them.

Really though, as long you aren't maxing out the volume you should be fine with things in parallel.  If it's too loud it can always be turned down.  It's easy to adjust the volume on Railpro, including the individual volume of each sound.  Very customizable.

-Kevin

[Alan]

Parallel will yield higher volumes.  I typically will run my dual speakers in parallel when they are rated to handle the wattage.  With a 4 ohm resistance, the Railpro amplifier will output 2 watts of power.  Not every speaker is rated to handle 2 watts of max power, and if they aren't they can be damaged.  I have a few sugar cube speakers that have a max rating of 1 watt, so I did series on those.  They are definitely quieter, but I'm also not at risk of destroying them.

Really though, as long you aren't maxing out the volume you should be fine with things in parallel.  If it's too loud it can always be turned down.  It's easy to adjust the volume on Railpro, including the individual volume of each sound.  Very customizable.

-Kevin

The amp output is double at 4 ohms compared to 8 ohms but you are driving two speakers. So each speaker sees one half of the power. Sugar cubes are 8 ohm if I am not mistaken. That means each dissipates 1 watt staying within its rated power.

[KPack]

Parallel will yield higher volumes.  I typically will run my dual speakers in parallel when they are rated to handle the wattage.  With a 4 ohm resistance, the Railpro amplifier will output 2 watts of power.  Not every speaker is rated to handle 2 watts of max power, and if they aren't they can be damaged.  I have a few sugar cube speakers that have a max rating of 1 watt, so I did series on those.  They are definitely quieter, but I'm also not at risk of destroying them.

Really though, as long you aren't maxing out the volume you should be fine with things in parallel.  If it's too loud it can always be turned down.  It's easy to adjust the volume on Railpro, including the individual volume of each sound.  Very customizable.

-Kevin

The amp output is double at 4 ohms compared to 8 ohms but you are driving two speakers. So each speaker sees one half of the power. Sugar cubes are 8 ohm if I am not mistaken. That means each dissipates 1 watt staying within its rated power.

I believe that's correct.  I had a set of sugar cubes I was trying out that were rated at 0.5 watts (didn't realize when I bought them) so I kept the wiring in series to keep them within range.

Either way, wiring in parallel typically works better and gives you more room for adjustment.  You can always turn down the volume.  On that note, if Scale Sound Systems ever gets speakers up and running again, you will definitely want the 4 ohm version of the Coeval (double) speaker and not the 16 ohm.  I have both and my 16 ohm is maxed out on volume to be on par with my other locomotives.  The 4 ohm version can be kept much lower.

-Kevin

[ON28]

What happened to Scale Sound Systems?

[Alan]

Supplier problem.

Due to a severely limited driver-supply, all Rectify and Coeval Series speaker production has been put on-hold until further notice. I am working hard to bring an even better performing speaker series to market that will also eliminate these supply issues!
Sorry for the inconvenience and thank-you for your support!

https://www.scalesoundsystems.com/rectify

[KPack]

What happened to Scale Sound Systems?

The speaker drivers he was using stopped being produced.  He tried literally every other speaker available and none of them met his specs to use.  They were all too inconsistent with poor sound qualities.  He is currently designing his own driver for production.  I believe he's getting close to having it wrapped up.

-Kevin

[Stephen K]

Thank you all for the many responses about my speakers.  I don't think, no, wait...I do think, and I am absolutely certain... I just don't understand this stuff.  Never have and at 64 this dog is probably too old to learn it.  But I believe I've gathered enough knowledge from this thread that I feel comfortable wiring these sugar cubes. 

My Rail Pro system arrived yesterday so today I sat down and started installation on my Atlas Master GP40.  It was immediately obvious there is insufficient space to mount this new LM3 on top of the existing circuit board.  So I unplugged everything and removed the board.  Manufactured a simple tray to replace the old panel so there is a platform to carry the new module.  I anticipated the need so I ordered a 9 pin connector harness too.  Snip snip and a few solder joints and I have all the red and black power wires connected to the red and black leads of the harness.  The motor feed wires on the Atlas are red and black, now connected to the orange and gray leads on the harness.  Wired my sugar cube speakers with the brown wires of the 6 pin harness that comes with the LM3.  Then came lights and I ran into my first real road block.  Again, electronics that I need help with.

This Atlas GP40 has a standard incandescent light for the rear light, no problem.  But...  The front light is an LED.  Hmmm.  Guess I need a resistor.  Atlas has this LED headlight (along with the ear light) wired to a plug harness on their panel and "apparently" some little part on that panel is the appropriate resistor for the LED headlight.  What do I do now?  I can get a resistor from Radio Shack if someone can tell me what I need.  Or, I could cut that old board apart and patch into the existing resistor if someone can tell me what part it is.  Any thoughts or recommendations?  Thank you.   

[Alan]

1000 ohm, 1/4 watt resistor will do fine.

The color bands are brown, black, red. The fourth color band is irrelevant in this application.

https://www.ebay.com/itm/1-4W-25-Watt-1-Tolerance-Metal-Film-Resistor-40-Pieces-USA-SELLER/324056971361?_trkparms=ispr%3D1&hash=item4b734cf861:m:mQgs6muWwaTM07bCE4wHfhQ&enc=AQAEAAACUBPxNw%2BVj6nta7CKEs3N0qVyiNCVGko3B9%2FnIG%2Bsft9UCaCjM5bQ4WraLgDazMn4QFIskFuTa8%2BhtH2GLZwlvFpcy0AgVw%2F3NaL6z1ZROtH3sJDQ%2BKOXWqxYgne%2F8oFX%2FEEqP0VZ69abcT%2BeklK0f%2F%2FeSV1VD4SOiL9oo9KOcXPSFmyvj4tMmiXEyez8%2BYjFI88MeXN8k6O51zEg10%2FRLtIPxwtaBZVTr3UaHZAm%2F8sEd6GqQujgu7UbZ78d89NtZwUStMA1OGY%2FQ5lh%2BL9aKb8RBSry09RkIN4p8xWtW0i9EkKy5lIvWYsL5L4FXpn%2FkoPCOhTv9ZpsXmywnpLa7SHUYokm4Ez8z0AkgCucyxO9x0O%2FY0B2QVq07b%2BtlZOL74vcNE0c0q16MBzOaN5JNs3W5LKpvJ370ympNSWNU%2BTCH3nCrycLz28sXtMkM8a%2FlXrK6MvchN0PCSk4ixeeD%2BJhu%2FKVM1cYgRex5PYbo0WgqjeAVVKYvgsBwUoi9dgSFYyi6IGrTB129PPwneuOOosVfXFq%2BBebNkoxAtm5up%2BCu%2Bfyk8fNWLiDke3KXTppYuaK4WmZom4eThnfpcuhHr1mA7W5%2FdQaFTPkEqlwvulek84XR2vjXHkP%2FuT5ajjRzWM6ManIEQnp16%2Bgqu5Cey%2F%2FDL4uVHEV5njkZq1appeAnDEPY1j1EqDCvN6%2FZ%2BOTNlEE%2FQQEZTKkDjlISF2KuYrCB3h7SdY8CLci0DxbHm5TVRtR0cJLtZZuDA2SctdORp%2FDG%2BV0MoahgrtfBwyoVrg%3D&checksum=3240569713619acf2c4b0b834689b9e1f91fada89a98