I went to the local goodwill store and bought four old computer speakers for $5. I was looking for a two inch speaker to put in a USA Trains 44 tonner. I ended up with four excellent speakers, but all too big
I am building a sound battery car, and am looking for a good speaker, So, What are the specifications that we should look for to get good train sounds. Impedance, Ohms. I am not sure exactly what I should be looking for.
You want to look at the power handling capacity--how many watts does the soundcard put out? IMHO a speaker that can handle three watts is fine, I generally keep my sound cards turned down pretty low.
You also want to look at impedance--8 ohms is a safe choice, some sound cards can handle 4 ohms.
you want a wide range speaker designed for general purpose use
Some people will say to look for large magnets--IMHO the size of the magnets is meaningless, except to the degree that it might indicate power handling capacity. But by itself the size of the magnet says nothing about sund quality
The relationship between watts and sound volume is not what most people think. A 6 watt amp is not twice as loud as a 3 watt amp--to double the volume, you'd have to have a 30 watt amp. Doubling the wattage, from 3 to 6, will produce practically no perceptible increase in volume.
And it does not take much wattage to get really loud. Guitar players are always looking to get the sound of a cranked amp at apartment bedroom levels. You can buy micro guitar amps now that put out half a watt. I've tried them--they are much too loud for bedroom levels. If you crank up a half watt amp people need to practically shout to be heard. You don't need a lot of watts to produce a lot of volume
It will make a difference, though, in distortion--if a 3 watt amp begins to distort at, say, 20 decibels, and maxes out at 30 decibels, a 6 watt amp will get to let's say 25 decibels before it begins to distort, and max out at 32 decibels. I made those figures up--they don't express an actual formula, but they express the idea. If Phoenix is touting a 6 watt amp, the advantage will be less distortion at a given volume level, not more overall volume. That's a good thing. But you get in most cases a much bigger effect on sound if you change the speaker, rather than the amp.
The demand for more watts is almost always associated with bass frequencies. Bass frequencies take much more power to produce, which is why the bass player always needs a much bigger amp. Typically the bass player has much bigger speakers and cabinets as well, which is what large scale trains will always lack. You just can't make a G scale train with a 3 foot by 3 foot cabinet and four ten inch speakers. Bass frequencies are the thing that's missing, inevitably, becasue of the size of the speaker and the size of the enclosure
Speaking personally, I find that even very low wattage amps tend to be too loud, and when Im running outside I have them all turned way down. The neighbors don't really need to hear my trains running.
So I'm not really worried about massive speakers or lots of watts.
Now I can report some results--I had a small scale railways sound card inside an Aristo slopeback tender. it sounded very good in there, plenty loud and not distorted. I put it just the other day into an LGB powered tender, and it sounds terrible--hissy and irritating. Same speaker, same soundcard. It's the enclosure. The LGB tender is much much smaller and is emphasizing the higher frequencies, so the overall impression is of irritating hiss. I'mnot sure what I can do about it, other than try another speaker or alter the enclosure in some way, maybe taking the weight out to make the interior volume bigger
Are you old enough to remember when "Component Stereos" were the up and comming thing? The joke at that time was, "I don't know how many watts per channel I have, but when I turn up the volume, the street lights dim."