SPEAKERS FOR DCC
This post combines new material with some hidden away in other posts. The photo below was of a common speaker such as those supplied with Loksound decoders. They are quite suitable for large body diesels and other larger models that have enough room.
This was the 25mm (1″) 4Ω 1.5Watt speaker and enclosure used for a 42 class diesel project. A silly but important point is make sure you solder the speaker wires to the speaker terminals before you seal it in place!
It is very important to make sure that the enclosure is fully SEALED around, and behind the speaker. The bigger the enclosure, the better but we are usually stymied by lack of space. See below for using Canopy Glue for sealing.
One of the best speakers I have used is the so-called “Sugar Cube” speaker. With even a small enclosure, they are remarkably compact combined with good sound quality. The ESU version is 12mm x 14mm and 5.5mm thick:
I prepare some styrene strips equal to the height required and use a small machined metal block as an aid to assemble the pieces using a styrene cement.
The next photo shows one of the best TIPs that I have. If you are using super glue for assembling anything, use a small piece of teflon bearing material (or even thicker plastic) and drill a small depression into it. Put a drop of super glue in to the recess and it will last up to an hour or more without going off! It also helps when applying styrene cement. [PTFE teflon sheet can be purchased on eBay by searching for ptfe sheet]
To seal the speakers into their enclosure, I prefer to use “Canopy Glue” as it is sticky and remains in place, plus, it dries clear. As with the super glue, the best means of applying it is with a thin applicator such as a T Pin or a tooth pick:
THINK OUTSIDE THE SQUARE:
The speaker enclosure doesn’t have to be rectangular – consider a cylindrical one to fit inside the smokebox of a steam loco. I have fitted them to brass steam locos including 30 class, 36 class and whitemetal 32 class. Like this:
|The curved part has been cut from a small section of plastic pipe which needs to be filed flat as in the previous photo. Two end plates have to be shaped to fit.|
The benefit of the smokebox speaker is that the sound is coming from the correct part of the loco. The photos below show a 25mm speaker fitted to a custom housing in the tender of a 36 class brass loco. The sound was brilliant – but it was clearly radiating from the wrong end of the loco.
Fitting the cylindrical speaker can be difficult. In my brass 30 class (small) loco, the smokebox door was loose so I was able to remove it. For the larger 36 class boiler, I was able to insert the speaker from the firebox end of the boiler tube:
THERE ARE OTHER OPTIONS
This is an iPhone 4S speaker purchased from eBay. In this case I have split the speaker to see what was happening inside. As I understand it the chamber on the right is an acoustic cavity to improve the sound. The port where the sound exits is shown with a pink arrow, just below the speaker itself.
Here we have a 40 class diesel look-alike modified from a Kato RSD4/5 model. I like this model as it is well engineered and very smooth and powerful with 2 large flywheels. The tight space in the narrow hood filled with mechanism and weights meant I couldn’t easily fit a sugar-cube speaker but and iPhone 4S speaker sat nicely on top of the motor.
A close up shows the sound port on the RH end of the speaker.
Here is a sound file using an iPhone 4S speaker with an ESU V4 Loksound decoder programmed with an ALCO 12cyl 244 (FT) #73401 sound file. The loco sound volume is quite low and would be deafening if run at full volume.
I note that iPhone 4S speakers are currently (24/3/19) available on eBay from as little as $1.58 ea (+ GST) and with free postage.
For an even smaller loco, consider other iPhone speakers. The first 3 work but you would need to experiment. The iPhone 5 speaker may be a good option for a small loco.
|Solder directly to the contact springs.|
iPhone 5 speaker showing the parts that can be removed.
If you have had any interesting success with speakers, I would be happy to post that on this blog (with acknowledgement). Rick