Most of you probably saw my thread a couple weeks ago about my desire for a model railroading-related science fair project. (HERE if you didn’t see it) After pondering many excellent suggestions, I thought it might be neat to try and get “BIG SOUND” from DCC sound decoders. Most of the speakers for our models are tiny–about 1" diameter. They don’t produce much sound in terms of deeper tones.
Mostly, my idea would be finding a way to wirelessly transmit sounds from the decoder to a large, external speaker. (Yes, I know about the Surround Traxx system, but my idea is slightly different and probably cheaper…) This way, omni-directional sounds such as the prime mover, would have the full range of sound and wouldn’t sound so “hollow”.
My main question before I commit to this project is if there is anything similar already on the market, (other than the Surround Traxx)in which case I will have to choose a different idea.
This is sort of an ever-evolving idea, so if y’all have any suggestions or forewarnings about this endeavour, please don’t hesitate to say so! Hopefully I will have more time this weeked so I can divulge into greater detail about what I plan to do, etc.
About 25 years ago (before DCC) there was a system marketed that used a stereo speaker system for the bass sounds. If I recall, it had the normal little speaker in the tender, but those big base speakers made the whole deal. I first heard it as the NMRA convention in Dayton and when they turned it on you everyone looked for the freight train they thought was coming through the convention hall.
There have been more than several threads about sound and model railroading. One of the concepts that has stuck with me is the concept of keeping the sounds we hear with our ears consistent with what we see with our eyes.
In model railroading the size of the locomotives implies to our eyes that we are seeing a full size locomotive at a certain distance, farther away as the scale gets smaller. So, making your ears hear the sound from the same distance your eyes see it would provide the most realistic sound, IMO, than hearing a full size locomotive in your layout room. Although it might be more impressive at first, I don’t think I would try for “big sound” but, rather, “realistic sound” from realistic distances.
And I am no electronics or acoustics expert, but yes, the low bass frequencies from the prime mover AND ground vibration are the most difficult to replicate with small speakers.
And from the “distance” we percieve the train to be, we hear noises from the entire train, like rolling stock wheel clack etc, just as much as we hear sounds from the locomotive alone.
Part of the problem lies in the fact we just put a speaker in and don’t make a proper enclosure. Do you thing a regular speaker works well without a proper enclosure? I think not!
True enough. I put enclosures on all three of my Tsunami installs and found…it’s still a tiny speaker trying to sound like a while trainful of noise.
Don’t get me wrong. I love my Tsunami’s. But external low end speakers would make a big difference. My only issue with the idea is that it doesn’t seem compatible with putting multiple users in the room. Multiple subwoofers would probably not play as well with each other.
My personal belief,on the purpose of having sound on anything,that is on a layout,is the fact that it is in miniature,therein lies the purpose,sound coming from a model in miniature. If you had a couple of engines,sitting around running in stereo, I’m pretty sure that would lose it’s appeal,real quick,in your house.
It would me anyway,having done it most of my life,‘‘Silence is Golden’’.[:D]
I say go for it. The research you do and the results you obtain may give insights and lead into directions you (and we) don’t expect. Besides, you may well have some fun.
The idea of a small speaker in the engine / big speaker under the layout should work. Low frequency “bass” sounds are harder to pinpoint than higher frequencies, so you brain will process the sound as coming from the engine if the big bass speaker is in the general area the engine is running.
In theory, you could do it if you had two decoders for each engine, one in the engine with a 1" speaker, and one connected under the layout to a larger speaker. Both decoders would be set to the same ID no. so both would come on when you select that engine. You’d probably want to greatly reduce or mute the bell and whistle/horn on the under-the-layout decoder/speaker, so you would just be getting the deep ‘chug’ or ‘diesel rumble’ sounds from the big speaker, with the bell, horn/whistle and the higher frequencies of the chug/rumble from the engine speaker.
Yep, that’s the make-or-break to this working. Getting that cut-off point right, as well as nice and crisp in terms of it being low enough to be non-directional is the key to making this work in the audible sense.
There’s the possibility that the cut-off point needs to be adjustable, given that different sound decoders may behave differently enough in the audio range that this will be needed to get the level set right for each. If so, then making then easily user-adjustable will be another requirement.
I’ll leave all the fancy electronic stuff needed to implement it someone else.[:o)]
The scale sound should also be in scale and as such not a sound of “super immense presence” but that of what you would here at the scale distance of hundreds of feet between your ear and the, scale apparently, distant engine. As we look down upon our trains, it is as if we are on a hill overlooking the rail yard or main line.
At least that is my take on how I calibrate the sounds on my Tsunami sound in my Blackstone and Sound/DCC converted narrow gauge brass engines.
For the science project, you are not necessarily locked to real scale sounds. You can make it sound like you are in the cab or riding on the pilot if you wish.
I am an audio technician and thought of an idea…have never tried it but it might work
use a second decoder mounted somewhere under the layout rather than in a locomotive or in a piece of rolling stock & wired to the track bus
…use the “speaker output” of the decoder to feed a small audio amplifier that then provides the “Umph” to the larger speaker I don’t think the output of the decoder straight to the speaker would have enough umph to give you the sound you are looking for
I have used ‘under-table’ sound decoders for years. They provide ‘voices’ for my non-sound equipped locomotives whenever the need arises. In all cases, the decoder speaker outputs are connected directly to 4-inch speakers with enclosures.
The DSD100 or DSD101-LC decoders have their exhaust volume set (CV122) at 50 or below. Anything higher becomes annoying in a very short time. The one watt amplifier is more than adequate for my small layout/room.
There is a short demonstration video of my diesel under-table decoder installation on You Tube. Here is the link:
I have done something very much like this after Tony of Tony’s Train Exchange suggested it to me years ago. And was going to suggest here. One additional point, MU the two decoders of course. I do this for yards sometimes since the action doesn’t move more than say 10 to 15 feet and you can have a couple of so speakers there.
The problem is that for road engines it’s not very realistic, since the speaker or speakers are stationary. I like listening to them coming and going and so have started to enjoy a kind of “scale sound” if you will.
Doing it with RF would be interesting and different, opening up other possibilities. Kind of like a radio station.
The locomotive I was planning on testing this out on (Athearn AC4400) has a Soundtraxx Tsunami decoder… Since this would be way more effective if sounds like the horn and bell remained only on the locomotive, I’m thinking a second decoder with the same address would be a good option.
Does Soundtraxx make sound-only decoders? I looked around but didn’t see any. I can always switch to a different loco and use Digitrax decoders…
I don’t know about on the market today but the idea has been around for ever. My PFM systems (1983 vintage) have what they call a “stationary” module that lets one run the PFM sound output through the stereo and get “full, rich, high fidelity” sound from the PFM unit.
There have been many threads on this very topic over the last 7 years. Some of the threads are quite long. One fellow simply used a 2nd decoder mounted stationary off-layout to get the sound into stereo system instead of using wireless. He programmed it to the same channel to match the locomotive it was “sounding” for. Clever in its simplicity and low cost.
One thing I always added to these threads was a conversation I had with the Sound Trax people. At that time their decoders only generated sounds that could be reproduced on a 3" speaker. As you probably know lower and higher frequencies are harder to re-create electronically let alone reproduce physically with a speaker to make the sound. Anyway the point being even if you hooked up an enormous woofer to the system the decoders are not necessarily even creating the low sounds you are seeking to produce. It might sound better than the tiny speaker but it certainly won’t be a high-fidelity sound. Now having said that I have NOT talked to the Soundtraxx people concerning their new offerings. They might create a wider frequency output. When I did my research I found that Phoenix Sound processors offered the lowest frequency. Once again they have had at least 2 new product offerings since that conversation as well.
I think this video kinda shows that the sound IS there… I’m not sure how long ago you talked to the Soundtraxx folks, but this video is about 4 years old.