Has anyone added speakers to their engines?

[FJ and G]

In Feb05 MR, there's an article that states that while bigger speakers are preferable, more than one small one will do, due to size limitations within the loco shell.

Has anyone here ever added a second or even a string of speakers, with great sound effects resulting?

What I have in mind is using a dummy loco and attaching a removable tether to the primary mover, and putting numerous speakers inside the dummy attached to the powered unit.

Actually, I'd just add one at a time until the point of diminishing returns.

[Anonymous]

F J and G,

don't know, but You have an excellent idea, STEREO !!!
dummies, boxcars could be used, i'd certainly be interested
in a schematic,,,anyone,,,????
by the way, have been 'sailini' the bay, if anyone needs a horn
kit , here you go... go to site, punch in Item number: 5949348289....
see my next post for another SURPRISE !!!!!

driver8
on the BNSF mainline in IOWA,USA!!!

[cnw1995]

Funny you should bring this up, I am musing about something like this - but a bit lower tech. In the past, I have used steam and diesel sound CDs to add some ambience when running trains. Recently, I saved the speakers from some small children's toys before they were thrown out. I want to use them with an old Soundmaster 8000 machine from MRC that requires you to build a speaker box. This thing was designed to work with HO trains. I am planning to install two of these smaller speakers in small boxes around the layout to give me some surround sound. I find it more fun to manually adjust the steam chuff or diesel sounds. And it has a great slide bar for a whistle or diesel horn.

[SPFan]

Bose became a multimilllionaire based on the idea of using an array of small speakers to make one large speaker (901's). Just remember to keep the speakers phased. That is all the cones should move out with a positive signal and vice versa. If you wire them is series they would be wired plus to minus of the second speaker. If you wired them in parallel then all the plusses would be tied together. If they are not phased then you will actually decrease the bass that is supplied by one speaker alone instead of augmenting it. If the speaker is not marked +/- then you can connect a 1.5V battery across the terminals briefly and watch which way it moves.

Pete

[mcattardo]

Something else to consider, if you put too many in parallel, you might cook the output amp of the sound board. Too many in series might not sound very good and possibly have less volume.

[Anonymous]

I have 4 ,8 ohm speakers in my MTH Santa Fe F3's.
I tried it as a experiment as to how robust the QSI 2+ system was for QSI.
I have an ABBA set with a speaker in each one. The prime A unit with the sound system has its normal speaker in fuel tank, but I covered up all the open grill work with clear Window material on the inside for a good baffle.
I then put a 2 inch speaker in a paper towl cardboard roll and cut to length to fit in each dummy.
The sound is massive. The paper tubes act as subwoofers and the powered shell with the enclosed shell acts as the high frequency tweeter so to speak.
This is all wired in parallel yielding approx 2 ohms load.
I have use this system for 5 years now and no problems. I have to be careful on volume as I can easily get to 120 db at 3 ft if I turn it up just half way.
It is neat as it slowly goes by as it sounds like a real train with each engine having sound.
I got small two pin connectors at a model airplane shop to join each engine.
Dave.

[ben10ben]

Two eight ohm speakers are no problem for Railsounds. I did try one time to install three .4 watt 8 ohm speakers in a boxcar connected to a steamer with a single .5 watt 8 ohm speaker in the tender. The sound was incredible, but would overload the audio driver after a few seconds, and it would shut down before self-destruction. I tried it again with one of the boxcar speakers disconnected, and got the same results. Only one additional speaker worked great, though. My set-up was a bit crude, so I restored the engine to its original configuration after a little while of experimenting.

I have no QSI or MTH electronics to experiment with, so I won't comment on them.

[lionelsoni]

You can keep the speaker impedance constant and not damage the amplifier by using a series-parallel connection. For example, two 8-ohm speakers in parallel are 4 ohms. Two such parallel pairs in series get you back to 8 ohms.

[FJ and G]

"Something else to consider, if you put too many in parallel, you might cook the output amp of the sound board."

Is there a way to run a test on this?

--------

Driver8,

IMO the best car for this would be a modern-era autorack, enclosed but with vents. The tallness of the car would allow for a pretty hefty speaker.

If you are going for the older era, I suppose a stock car would work, as there are slots for the sound to come out and you wouldn't notice the speaker inside (maybe arrange some pigs around it).

I'm going to do it with an RS-3 (Lionel), which I'll convert to a dummy (it's a cheap one from construction set); and an MTH A dummy.

Before actually going thru with the procedure, I plan to simply open the shell and attach the wires and see how it sounds, taking some of your advice on how to connect it (I plan to download this post for reference after any additional comments, if any)

And yes, I do own BOse, got them in Okinawa in 1978 or 79. Still using them. As for the train thing, I plan to use different type of speaker and position them in different directions to see what pans out. I would love to hear a deeper throbbing sound with the diesel, as well as certain steam locomotive sounds. Would be neat if they had a mini equalizer to adjust the pitch and stuff.

[TurboOne]

Being newer, I cheated and added MRC sound station 312 under the table. Same great sounds and it works on all trains. Not quite the same as individual speakers in each train, but my kids love it. My six year old loves it too much, he likes to listen to a train crossing for 10 to 15 minutes. aaaaarrrrrrggggghhhh

Tim

[FJ and G]

Would be neat, Tim, if there were a way to establish a "wireless" system between the train's sound output and a hidden woofer/tweeter under the layout (or even above the layout hidden behind a valence.

This is definitely an area for future performance improvements.

[Anonymous]

Get the QSI soundblox and you will have fantastic sound and the same effects as a 3000. It syncs to the motor just like a engine mounted one but sends it sound to a external speaker. You can only get them from Walthers.
Dave.

[mcattardo]

"Is there a way to run a test on this?"

You can use an ohm meter. There is a math formula, speakers in series add, but I'm drawing a blank for parallal right now.
For better bass response a tuned enclosure is best (think bose wave radio) , or paper tubes as Dave stated.

[lionelsoni]

The resistance of resistors (or loudspeakers) in series does add. The conductance of resistors (or loudspeakers) in parallel adds. The conductance is one over the resistance. So, to calculate the resistance of resistors in parallel, just divide one by each resistance to get that resistor's conductance, add up the conductances, then divide one by the sum to get the resistance of the combination.

See my posting above for how to connect 4 similar speakers in series-parallel so as not to change the resistance.

Here is an electrical model for a dynamic loudspeaker, for those who are into electronics and want to understand them better:

The speaker looks at its terminals like a parallel combination of an inductor, a capacitor, and a resistor. This combination is in series with a resistor and an inductor. These last two, the series resistor and inductor, are electrical and are the dc resistance of the coil and its inductance. The resitance is virtually equal to the nominal impedance of the speaker, that is, an 8-ohm speaker actually has a series resistance of 8 ohms. The inductance is not very important for the frequencies that the speaker can handle and can be ignored for most purposes.

The parallel inductance, capacitance, and resistance represent respectively the springiness of the speaker cone, the mass of the cone, and the "radiation resistance". They comprise a resonant, "tank" circuit. Below resonance, the speaker puts out very little sound. Above resonance the output is approximately flat with frequency.

The radiation resistance accounts for the sound power that the speaker radiates. It is an unusual resistor in that its resistance is inversely proportional to the square of frequency. This compensates for the fact that, above resonance, the voltage across the tank is dropping inversely with frequency and keeps the radiated power constant.

At some high frequency, the wavelength of the sound becomes comparable to the dimensions of the speaker. Above that frequency, the radiation resistance stops decreasing; and the speaker's output drops off.