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Post by atsfan on Sept 27, 2012 17:42:51 GMT -8
The thought of mounting some good speakers under a layout (versus the onboard sound in an engine) has been rattling through my mind. Of course there is much room inside to rattle in..........  Anyway, it seems I remember seeing some sort of product out there that could use these speakers to emit the sound and "move" the sound from one speaker to the other to give the doppler effect??? Has anyone heard of this or seen it? Or any thoughts on it? Thanks  |
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Post by alco539 on Sept 28, 2012 3:49:30 GMT -8
I know you may not want to hear this, but MRC has a system, the Symphony 77 (two speakers). I have no first hand knowledge, but the text says, "create the sounds of a locomotive moving closer, then fading away".
MRC's "on board" sound system has it's problems, or so many report. Maybe someone has experience with the Symphony 77 and it works good.
Regards Charley.
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Post by fmilhaupt on Sept 28, 2012 5:50:58 GMT -8
That would be SurroundTrax from SoundTraxx. See www.soundtraxx.com/surround/index.php for details. It can track up to six locomotives at a time, with output to six different speakers and will perform mixing when two locomotives it is tracking enter the same detection zone. It requires that you have detection set up using a Digitrax BDL168, a Digitrax transponder in each locomotive (separate transponder modules are available as an add-on for locomotives that have another brand of decoder installed), and Digitrax transponding receivers connected to the detection circuitry. This can be overlaid onto layouts that use other brands of DCC, since it doesn't have to connect to the layout's command station or throttle bus. |
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Post by alco539 on Sept 28, 2012 7:54:54 GMT -8
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Post by edwardsutorik on Sept 28, 2012 8:42:10 GMT -8
The biggest problem with sound as it is, in my opinion, is the "tinniness" of it. The speakers are too small to adequately reproduce the lower frequencies. If the low frequency reproduction can be moved from the locos to larger speakers for the low frequencies, much better sound will happen. BUT, since higher frequencies are much more directional than low, the highs should still come from the locos. The "following" that Soundtraxx uses is great, 'cause there's a limit to how far the "subwoofer" can be from the loco (ie: if the loco's on your left, the subwoofer shouldn't be on your right).
For this kind of system to work, you've got to have decoders that transmit the sound back to the central system for processing. I wonder how many decoders can do that. I would assume very few. Which means that this concept isn't backwards compatible. I hope I'm wrong about that, because it's a GREAT concept.
Also, the Soundtraxx system still needs refinement. I don't want to be limited in the amount of locos I can run, nor the amount of speakers.
This does appear to me to be a very promising start to a solution to the major deficiency of sound as we know it.
Ed
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Post by SantaFeJim on Sept 28, 2012 13:49:25 GMT -8
For the true "doppler effect" I believe one must consult Dr. Sheldon Cooper.  |
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Post by Paul Cutler III on Sept 29, 2012 6:48:28 GMT -8
One way to go about this on a small layout is to use stationary sound decoders hooked up to a good-sized speaker. For example, buy two identical Tsunami decoders (or whatever brand). Install one into an engine and the other under the middle of the layout hooked up to a large speaker. When you want to run, MU the two together. Tune the volumes so that you can hear what you want from whichever source sounds best. The stationary decoder will provide all the bass you need, while the loco decoder provides the bell and other higher sounds that moves with the loco.
The only problem is that you'd have to have a sound decoder & speaker for every type of engine you have: Alco 539, 244, 251; EMD 567, 645, 710; GE FDL, F-M, BLW, etc. But if all you have are, say, EMD 567's, then you're set.
Bass sound is not as directional as treble sounds, so it won't sound as odd as one might assume.
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Post by edwardsutorik on Sept 29, 2012 7:07:45 GMT -8
One way to go about this on a small layout is to use stationary sound decoders hooked up to a good-sized speaker. For example, buy two identical Tsunami decoders (or whatever brand). Install one into an engine and the other under the middle of the layout hooked up to a large speaker. When you want to run, MU the two together. Tune the volumes so that you can hear what you want from whichever source sounds best. The stationary decoder will provide all the bass you need, while the loco decoder provides the bell and other higher sounds that moves with the loco. The only problem is that you'd have to have a sound decoder & speaker for every type of engine you have: Alco 539, 244, 251; EMD 567, 645, 710; GE FDL, F-M, BLW, etc. But if all you have are, say, EMD 567's, then you're set. Bass sound is not as directional as treble sounds, so it won't sound as odd as one might assume. Since the decoders would not be synchronized, there's a strong likelihood of phase differences in the sound. To avoid this, you would have to have an absolute cutoff between the two frequency ranges, and this would probably sound pretty strange because there's the mid-range to deal with. Experiment almost always trumps theory, though. And the cost of the experiment in minimal. I look forward to someone's doing this and reporting back. Ed |
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Post by atsfan on Sept 30, 2012 5:18:53 GMT -8
Yes that was the product. But Paul Cutler raises an interesting thought.......
How could I use a sound trax decoder and connect it to an amp and then a speaker or two?
Without having to buy an expensive system and new decoders for each engine?
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