I am attempting my first DCC install so I don’t quite know what I’m doing, treating this is a learning project. Hopefully these questions are easily answered. I’m trying to install a decoder and a speaker into a Stewart F3.
Question: How do I connect wires to the sugarcube speaker shown here? It looks like it has 2 springy connectors on either side. Do I just solder a wire to each one of them?
Do I then place the speaker into the enclosure? Curious what the enclosure is for - protection vs acoustics or both?
With a single speaker you need not worry about polarity. Connect a brown wire to each post, being careful to not get solder on the speaker body. The case is for acoustics, the deeper the better. Good luck!
Correct. Solder one brown wire coming from your sound decoder to each metal tab. And, with a single speaker, it doesn’t matter which wire goes to which tab.
The enclosure is your baffle and the sealed space is what will physically amplify the sound waves coming from the speaker. Otherwise, it will sound tinny and be barely audible.
Place the speaker facing downward into the baffle so that the metal back is level with the top of the baffle lip; the speaker wires facing upward. It should press fit into the baffle and stay in place. If you want you could seal the top edges with a thin bead of Testors Clear Parts Cement.
Chirs, where are you going to place the speaker in your F3?
The enclosure is for sound quality, not protection. Sugar cube speakers must have an enclosure to make them work properly. If you don’t have an enclosure the sound is horrible.
As was mentioned, the bigger the enclosure, the better, but your enclosure looks plenty big enough for decent sound. It is important that the enclosure is sealed tight or the effect will be lost.
You are correct. Just solder the brown wires to the spring contacts on the speaker. You may have to make a small hole in the enclosure to put the wires through. Seal the hole with some glue.
If you want more information on sugar cube speakers, have a look at these:
As noted earlier, if you are installing only one speaker, it doesn’t matter which wire goes on which connection. It will work and sound the same, either way.
That’s the “aren’t”.
However. If you have two speakers right next to each other, and you want to feed them the same signal, polarity matters. What you don’t want is one speaker cone going in, while the adjacent is going out. They should both move in the same direction at the same time.
While you are doing the soldering be sure you have your speakers restrained in a clamp or, what I do is lay a piece of double-stick tape down and put a weight on the board. The magnets in the speakers are strong enough that they will jump right to the iron tip of your soldering iron.
The discussion is about whether the polarity of a speaker matters. It doesn’t, electrically speaking.
Of course DC power is polarized. Sound is not. The speaker converts DC electrical signals to purely analog air movement. The polarity affects the phase of the speaker diaphragm although I remain interested in the actual effect out of phase locomotive speakers may have on the listener experience.
Noise cancelling headphones exploit the phase effects of speakers.
Ed is absolutely correct. This exact thing happened to me with a recent speaker installation in a brass 2-6-6-2 Mallet. Even the smallest sugar cube speakers have a very respectable magnet in them.
From the other thread, a page with a discussion of polarity as it concerns multiple small speakers in the context of model railroading. Answers lastspikemike’s questions and a great deal more without having to type lots of salad. Scroll down to the relevant section…
If the speakers were in line with each other then the phases would cancel (or at least seriously diminish) the sound. If the speakers were at right angles to each other, or in separate baffled compartments…?..?
If the speakers were not inside the locomotive but facing out into the room then the sound waves shouldn’t overlap precisely enough to make much difference. Mind you I notice speaker outputs on my ARCAM are red and black as are the inputs on each speaker.
Locomotive sound files are not stereophonic, or at least the speaker reproduction cannot be.
Look at some discussions on noise-cancelling headphones and some of the techniques used to implement the effect.
At the scale of these little speakers, the effect of antiphasing can be substantial. This is unlikely to create perceptible ‘imaging’ artifacts (which in this case would perhaps manifest as lower volume at particular off-axis angles for different frequencies) but generally quieter and ‘deader’ sound quality.
The photo in my earlier reply shows two identical speakers so you can assume the polarity are the same. Quite often I fit speakers of different sizes and I “audition” every one before making the installation permanent:
I also try both series and parallel wiring to see what gives the best sound output at a given input. The inexpensive amp shown above has both bass and treble pots along with a tone-flat button. These are handy for evaluating what kind of range to expect. You can usually tell when soundwaves are canceling eachother out. I play a familiar piece of music while quickly switching the wires. One way usually sounds better than the other.
I generally check the impedance of the finished wiring to be sure I’m not too far out of range but with the recent offering of sound decoders from ESU and Soundtraxx I have not had any problems. I usually have to cut the sound levels to about 25-35% of max.
Now a good EE or sound engineer might know how to make a crossover to feed higher/lower frequencies to the prefered speaker but I’m pretty happy with the results by guessing and tweaking.
I will place some sound absorbing material inside the shells if there’s room. I don’t know much about “standing waves” and such but I do know that my engines sound better, and it reduces rattles, if I use a few pieces of “fuzzy tape” or, sometimes I use the fuzzy half of Velcro hook & loop appl
Over the years I’ve gathered quite a few little MP3 players. Simply make a hookup using a 1/8 (3.5mm) phono plug from old ear buds or such.
Just enough wattage to hear the sound so you can evaluate things. The little amp I use helps since it has easy to reach tone controls. Some MP3 players have an EQ function, too.
I’ve had some real dud DCC speakers. So glad I tested them before going through all the trouble it would be after installation.
