Sound Survey

in article jXDZg.17745$ snipped-for-privacy@newssvr25.news.prodigy.net, Bruce Favinger at snipped-for-privacy@swbell.net wrote on 10/18/06 10:21 PM:

The main problem I have with sound (other than lack of fidelity due to 1" or less speaker sizes), is that if you have more than one sound equipped loco running at a time, you get cacophony: chuffing, churning diesels, etc. all over the place. Unless you are in a real "yard," one rarely hears more than one loco at equal volume. Train rooms in the home are generally smallish, so the loco's ore more or less equidistant and are all about the same volume.

If I am running more than one sound loco, I turn the loco motor and other continuous sounds OFF, and use the whistles, horns, bells, and maybe coupler sounds as needed. Except for young visitors who really, really like the chuff sounds of steam loco's, such reduction of the overall continuous noise satisfies my need for minor additional realism and fun. (everyone likes to blow the whistle!)

I don't have sound on my layout, but had the chance to operate on a fellow modeler's walkaround layout last Saturday, where he had several locos with sound. (We had about a dozen operators running about 30 staged trains or so on a fast clock). Several trains operated with sound, including me having a couple of GE thingamobobbies (don't ask which... I'm a 60's modeler and they sure weren't U-boats) on the head of one of my trains.

I encountered several other sound trains during the session, and the experience was pleasurable. The owner kept the sound volume down to where it didn't overpower the layout -- you certainly couldn't hear other locos when they were on the far end of the layout.

No doubt the sound was "tinny" compared to the prototype, as Roger is apt to say. But guess what? The momentum effects of switching cars weren't the same as the prototype, and the 3:1 fast clock wasn't the same as real time, and when I had to follow a sulfur train through the division yard it didn't smell like the prototype, and the RSD-15s I passed (yeah... I know *those* engines) didn't smoke like the prototype, and the dispatchers orders coming through the headset weren't entirely up to prototype standards, and the unpainted loco on the branch line didn't look very prototypical, and the bare plywood at the paper mill wasn't convincing, and we used car cards instead of full prototypical paperwork....

But the sound was an enjoyable addition to the overall effect, and it _was_ nice to hear the growl of another set of engines as you passed them at a siding. And it was intriguing to hear the quiet rumble of a train in the distance as you headed around the curve at the end of a scenery divider... indicating that you were going to encounter _something_, but known only to the other train operator, the dispatcher, and God. (Oh, sometimes that last two entities can get interchanged during an operating session!!!)

And you're right... I blew the whistle more than was necessary. Especially when I first took control of the sound equipped consist.

__________ Mark Mathu The Green Bay Route:

So you can't move your trains?

"Mark Mathu" wrote in news:%6Z%g.36522$cc3.30783 @tornado.rdc-kc.rr.com:

All that means is it's a lot easier to go locomotive tipping (it's easy, just go up to it and push) on a model railroad than it is a real railroad!

;-)

Puckdropper

"Mark Mathu"

Some people just try to be obtuse.

He's right, physics does not scale, as in friction and mass, both of which are to do with physics.

-- Cheers

Roger T.

Home of the Great Eastern Railway

"Mark Mathu"

I am? Oh yes, I am! It does sound like a 1960s transistor radio.

However, that doesn't mean you shouldn't use sound if you like it.

It's like smoke units, Lionel Tinplate, roundy-go-roundy, Thomas, mixing eras, etc., etc.

If it makes you happy, each to his own as in all things.

-- Cheers

Roger T.

Home of the Great Eastern Railway

We've all needed to use the "five-fingered locomotive" (0-5-0) to move cars once in a while!

Of course I can, ninny.

But they move according to the physics of the 1:1 world.

So, you're saying the sound of a whiny little electric motor on a 4-8-4 and with silent whistles and bells at grade crossings etc. is more realistic and preferable to current sound systems? Not to my ears! Ken

Back in the 50's, I remember an article in Popular Mechanics or Popular Electronics about building a speaker assembly using 4 small 4" speakers. The author claimed that if the 4 speakers had similar characteristics and were properly phased, the group would perform like a much larger speaker. I remember walking home from elementary school down the alleys to collect junked 5-tube superhets from which I could scrounge 4 speakers. I did finally build one, and thought it really sounded great, but I suppose a lot of that was youthful imagination after all the effort to build it. But I digress. Does a tender with 2 1" speakers produce measurably better bass than one with a single speaker? Should the designers be placing speakers over the truck bolsters too so they can squeeze 4 or 5 into a tender? Geezer

in article srSdnWk7cKQA0t7YnZ2dnUVZ snipped-for-privacy@adelphia.com, Geezer at snipped-for-privacy@adelphia.net wrote on 10/28/06 5:40 AM:

Actually, a 12" speaker is a bass speaker (subwoofer) component if properly baffled. I have a 10" Sunfire sub for my computer sound which goes as low as

A full range speaker system usually has at least two, frequently more drivers of differing sizes: low, mid, hi, super hi, etc.

The array of smallish speakers (the PE article referred to a concept called "Sweet 16", an array of 16 4" speaker, and the group of four described was an example project) was commercially built by Bose in the 901: 9 4" full range speakers. It has the approximate surface area of a 13" speakers, and with proper equalization has a -3dB point of 29 Hz. It had its own problems with being a proper hifi speaker (rushing are by the bass ports, vague directionality, etc.).

Just to give you an idea of an approximation of the air moving ability (not even counting excursion distances or amplifier power needed):

A 12" speaker if considered a flat surface (like a piston, but it has more area than that) is about 450 sq in. (pi * r**2); a 4: speaker is about 50 sq in, so it takes about 9 of them to move the same amount of air as a 12" speaker, assuming equal excursions.

It takes about 450 1" speakers to do the same and they cannot equal the excursion distances.

That's one reason why I like using any sound equipped locos I have for just bell and whistle and to turn the chug-chug (or whrrrrrr) off.

What about the discussion in October MR? Steam engines don't sound too bad but the Diesel sound has the problem of a high amount of bass which is reproduced poorly by small speakers that fit in HO equipment. The solution of directing the bass component to under layout woofers was under discussion. Since the bass is less directional than higher frequencies some people have used this successfully. According to the article Soundtraxx is working on a commercial application of this.

The bass component of diesels was brought home to me several years ago while standing on the platform in Swift Current Saskatchewan at 2 AM and -30 F waiting for the E/B Canadian. Three SD40-2s were trying to get 80+ loads of grain moving. It felt like someone was beating my chest with a carpet beater. A little too much for the layout room perhaps.

That's a sight you never forget, here in Ontario I watched on as 4 SD40-2's picked up a cut of about 30 or so covered hoppers and tried to lift a train that was about at max. for the units, never forget not only the sight, but the feel as well as the ground was just a shaking....

Alan