Sound Speculation

[SpaceMouse]

The biggest complaint about sound decoders is the lack of low frequency.

It seems to me that a sub-woofer would handle that problem like it does with the small speakers in home theaters. Low frequency signals could be trasmitted through the rails to a filtered amp and subwoofer under the layout.

[Anonymous]

That sound like a good idea. The only problem I can see with it is that the low frequency sounds would not be "moving" with the loco. like the other sounds would be. Low frequencies are non-directional, though, so it might not be that bad. [2c]

[SpaceMouse]

QUOTE: Originally posted by TA462

Imagine the room shaking when your little HO scale loco passes by you, lol. You would need to come up with some sort of detection system that would transmit the sound you want to the desired speakers as the loco goes around the layout.

I've got two home theaters and a subwoofer on my PC. As long as the high frequency sounds are moving the sub would not have to be moving. I remember watching Private Ryan and having bombs blow up behind me--with the sub woofer in front of me. You can't tell.

[ereimer]

i think what you'd have to do now is buy a matching decoder for each engine and wire it under the layout to an amplifier and subwoofer(s) . the 2nd decoder would be set to the same address as the one in the engine

problems ....
how would the 2 decoders be syncronized so the sounds are made at the same time ?
how much real low frequency output do todays decoders have ?
how good would it sound once you get 3 or 4 + locos going ?
how much is it going to cost ? [:)]

i'm sure it would be possible for one of the sound decoder manufacturers to build a box that would provide this function for a set number of engines . being able to download sounds into it would be almost mandatory . unfortunatly it would probably only work with decoders from that particular manufacturer

[SpaceMouse]

ereimer,

I don't know. I have an intercom system that works using house wiring to transmit. Why would you need a second decoder?

[Anonymous]

That's a great idea. Low ferquency sounds are non directional, so you won't be able to tell where they're coming from.

QUOTE: Originally posted by kevnbety

That sound like a good idea. The only problem I can see with it is that the low frequency sounds would not be "moving" with the loco. like the other sounds would be. Low frequencies are non-directional, though, so it might not be that bad. [2c]

[Anonymous]

QUOTE: Originally posted by SpaceMouse

ereimer,

I don't know. I have an intercom system that works using house wiring to transmit. Why would you need a second decoder?

I think Chip in order to feed the audio to the sub-woofer which of course wouldn't be on the engine, has to be sometype of physical connection. I think the dual decoder, sort of setup the way you might MU 2 engines would work, though the sync'ing may be off, not sure how you would cut the higher freqs out though unless you used sometype of electronic cross over, similar to what a 2-way or 3-way speaker would use.

Interesting idea [:)]

[SpaceMouse]

QUOTE: Originally posted by dthurman

QUOTE: Originally posted by SpaceMouse

ereimer,

I don't know. I have an intercom system that works using house wiring to transmit. Why would you need a second decoder?

I think Chip in order to feed the audio to the sub-woofer which of course wouldn't be on the engine, has to be sometype of physical connection. I think the dual decoder, sort of setup the way you might MU 2 engines would work, though the sync'ing may be off, not sure how you would cut the higher freqs out though unless you used sometype of electronic cross over, similar to what a 2-way or 3-way speaker would use.

Interesting idea [:)]

The physical connection would be through the track--the same way DDC signals get to the engine. It would send the signal back through the track to the amp. I would think the biggest technical problem would be fitting a transitter to the decoder.

[Anonymous]

QUOTE: Originally posted by SpaceMouse

QUOTE: Originally posted by dthurman

QUOTE: Originally posted by SpaceMouse

ereimer,

I don't know. I have an intercom system that works using house wiring to transmit. Why would you need a second decoder?

I think Chip in order to feed the audio to the sub-woofer which of course wouldn't be on the engine, has to be sometype of physical connection. I think the dual decoder, sort of setup the way you might MU 2 engines would work, though the sync'ing may be off, not sure how you would cut the higher freqs out though unless you used sometype of electronic cross over, similar to what a 2-way or 3-way speaker would use.

Interesting idea [:)]

The physical connection would be through the track--the same way DDC signals get to the engine. It would send the signal back through the track to the amp. I would think the biggest technical problem would be fitting a transitter to the decoder.

There is someone here on the forums that has done something similar to what you are talking about, off the top of my head I can't remember who it is. Hopefully he will pop in and give a link to his site. Though it may have been how to may sound move around the layout, though it is similar to your idea.

[Bob Hayes]

How about Soundtraxx SurroundTraxx?

Bob Hayes

[Anonymous]

If it ever exists. You 'just' need a decoder that will respond to more than one address (should be a snap), and knows what to make of the signals to the decoders. That's the tricky part, since the sound is determined in the decoder, and not in the controller. If you only used the stationary decoder, then you'd only have to tell it how to react to commands to each engine. I think that's the SurroundTrax scheme, with the addition of location info the move the sound around. The other way of doing it would be to have a second sound decoder for each loco, combine the outputs, but only amplify the low frequecies for the subwoofer. A box to do that might not be too bad, you'd just need two sound decoders for every engine. Hey, if anyone does that, I want the royalties!

[Texas Zepher]

QUOTE: Originally posted by SpaceMouse
It seems to me that a sub-woofer would handle that problem like it does with the small speakers in home theaters. Low frequency signals could be trasmitted through the rails to a filtered amp and subwoofer under the layout.

That only addresses the issue IF (and a big if here) the frequencies are even being created by the sound processor.

I don't have any of my references here, but I seem to recall off the top of my head a sub woofer re-produces sounds from signals in the 28-200 Hz range. Because the sound decoders have been manufactured with the knowledge they would be used with small speakers, by design they might not even produce any frequencies in that range. Hence a lot of effort would be expended to install a sub-woofer and it would just sit silent.

So step 1 would be to contact the vendor of your sound unit and get the frequency range that it produces. I was very disapointed in the low range numbers I got back from one vendor.

Generally, I think if this idea was even applied to a decent woofer (even a 6") the results will seem spectacular compared to the squeeks we get out of those on-board 1 1/4" speakers in the locomotives.

Someone had posted this same idea over in the "layout form" in the last couple weeks, and it was discussed at length in the "future of DCC" last spring, so there appear to be several people thinking along the same lines. In the "future of DCC" thread, people were talking about using transponding to know where the loco was and route the sound to the off-board speaker closest to it. Hence the sound would still follow the train.

[NZRMac]

My first decoder install was an old athearn diesel, I didn't have much track set up or a suitable speaker so I connected the soundtraxx decoder to an old stereo speaker, and ran the loco up and back a few feet. (dragging the speaker wire)

It sounded awesome huge bass response. I had my neighbour looking over the fence!!

Chip, if you wanted the loco decoder to transmit the signal thru the rails you would need that intercom circuitry in the loco as well!!

Two decoders is the way, set them up on decoder pro and they would be syncronized.

[2c] Ken.

[skiloff]

Just throwing out another suggestion. I'm no expert in DCC, haven't ever used it actually, but just going with the idea of how the wiring and functions might work, I'd say that perhaps the manufacturers would have a stand alone sound module that would contain ALL sound decoder sounds they manufacture. When the sound function is activated from the controller, the train AND the appropriate sound from the sound module would sound simultaneously. This could be wired in two ways - with only a bass out to the sub so only low fequencies are used from the sound module and the higher frequencies are heard from the train, or you could combine them and have a boost in your treble and bass if you chose. MRC I believe has a sound only module that runs out of those cheap little computer speakers (I haven't heard what they sound like, but I've seen them), so really, this is just an extension of that, combined with the DCC. I'm not sure I explained myself very well, but I definitely see possibilities for people with brighter minds than mine in this area.

[Don Gibson]

Gentlemen:

The problem is not the sub woofer, nor a black-box with a sound module inside. it's 'Synch-ing' of two independent sound sources.

IMAGINE if you will a Steam engine with 4 chuff's per rev. synch'd at only one speed (electrically) - or all speed's (mechanically )- competing with another.

II: HO's size and speaker's limit low frequecies to above 400 cycles - about concert 'A' on a piano. When they can produce modules that can be Synched, they can go with Sub woofer's.

[howmus]

QUOTE: Originally posted by kevnbety

That sound like a good idea. The only problem I can see with it is that the low frequency sounds would not be "moving" with the loco. like the other sounds would be. Low frequencies are non-directional, though, so it might not be that bad. [2c]

True, Low frequencys are quite non directional to our ears. The big problem is that I doupt that frequencies below 200Hz are found in the sound files in the decoders. With MP3s, that is where much of the file size is made smaller.

Hey Don, glad to see you back here. Hope you are well. I took so long to post on this that you beat me to it.... LOL

[Don Gibson]

Sound Module's can pass low frequencies.

Reproducing them with a 1 watt amplifier and 1" speaker , is another matter.
It's like trying to illuminate a barn with sunlight though a single knot hole.

[bogp40]

What would really be great is to have speakers placed evenly under the layout that would have sound follow the train. I don't know the electronics end of it, but maybe a transponding sound decoder could control the fade-in to full volume and fade-out while the next speaker would do the same. The weak signal of the transponding decoder could be amplified by the speaker system as imput. Who knows, this could already be in the in the works by one of the outfits out there.
Bob K.

[Anonymous]

This could be a good use of the new DCC standards (the bi-directional communication specifically) - hope they're released and adopted soon. Decoders could then send a command back to the control system to activate the bass sound module under the board when you turned the sound system on, they could also transmit information on how loud it should be based on their own volume settings.

[SpaceMouse]

Gentlemen, I was not proposing this as a do-it-yourself proposition, rather one that would take significant R&D, but seems to me to be technically feasible. I agree with Don that two decoders would be hard to sync. And I do not know if current sound decoders transmit low frequency sound waves,

What I would be proposing is a system in which the decoder was engineered with the sounds stored within the decoder along with a signal transmitter that used the rails to transmit the signal to the receiver /amp. It would have to have the signal programmable so that two locos would not compete.

I'm suggesting a complete redesign of current technology.

[howmus]

QUOTE: Originally posted by SpaceMouse

Gentlemen, I was not proposing this as a do-it-yourself proposition, rather one that would take significant R&D, but seems to me to be technically feasible. I agree with Don that two decoders would be hard to sync. And I do not know if current sound decoders transmit low frequency sound waves,

What I would be proposing is a system in which the decoder was engineered with the sounds stored within the decoder along with a signal transmitter that used the rails to transmit the signal to the receiver /amp. It would have to have the signal programmable so that two locos would not compete.

I'm suggesting a complete redesign of current technology.

Chip, when this new technology finally reaches the marketplace, I might actually invest in sound for my locos.... [:D]

[Anonymous]

seems to me that if we model in HO, which if 1:87 scale, the sound should be equivalent.. in other words, louder is NOT better, nor would it be more realistic. If the size of the model is 1/87th of reality, shouldn't the sound be 1/87th of real volume, too? I usually turn down the volume to allow the sound to be part of the total process. Do we operate our model empires for the sound, or do we have sound to add to the operating realism? Just a thought...
Dave

[SpaceMouse]

QUOTE: Originally posted by djs0405

seems to me that if we model in HO, which if 1:87 scale, the sound should be equivalent.. in other words, louder is NOT better, nor would it be more realistic. If the size of the model is 1/87th of reality, shouldn't the sound be 1/87th of real volume, too? I usually turn down the volume to allow the sound to be part of the total process. Do we operate our model empires for the sound, or do we have sound to add to the operating realism? Just a thought...
Dave

Subwoofers have volume controls.

[Texas Zepher]

QUOTE: Originally posted by howmus
The big problem is that I doupt that frequencies below 200Hz are found in the sound files in the decoders.

Yes, exactly along the lines of what I was saying earlier . And even if they were in the sound files the "sound procesors" on the decoders aren't designed to produce them to the output.

Below is the exact e-mail reply I got from one of the vendors (name withheld since people might decide they are garbage based on this which isn't true. This is not a bottom of the line cheepo unit either. I doubt ANY of the current systems are any better. )

QUOTE: From vendor X.
Radford,

Our decoders work in the range of 1kHz to 25kHz. Somewhat on the high side
of the amp. Speakers that we use are small.

Xxxxx Xxxxxx
Customer Service

This particular unit cannot even produce a frequency low enough for a sub-woofer to recognize. The sub-woofer would be worthless in this case.