2 schools

Dear Brotha,

While I understand your logic, the "current wisdom" seems to suggest that a quiet, non-resonant roadbed is now _more_ critical then ever, with the growing rate of onboard sound-equipped locos. In short, the sound of a model train physically operating over "drum head" roadbed can easily, uncontrollably, (and noticably "out of scale" in terms of both frequency and amplitude) overpower the effect of a "scale sound" loco sound system.

I know that some modellers like the ethos of "there's no electronics, like _no_ electronics", and point to the fact that metal-wheels-on-metal-rails give a pleasing "clickety-clack" without the need for any onboard sound decoders. (funnily enough, such a "pure" sound generation also has _automatic_ speed, pitch, and doppler effects built-in! ).

If you can find a copy, (and if my memory serves correctly), check out the small "Modelling Track" booklet by Kalmbach. One of the articles covered a modeller's extensive testing of various roadbed materials, and their effect on percieved operational sound. The test methodology may not hold up against, say, a true Pro Audio test such as by Audio Precision or EAW, but it did provide some interesting insights regarding sound and track behaviour...

Happy Modelling,
Aim to Improve,
Prof Klyzlr

PS IIRC, the "gold standard" as suggested by the Kalmback article author, was a free-rolling metal-wheelset-equipped boxcar, on a 3' length of flextrack, sitting on a thick bathtowel...

PPS ask yourself first, are you looking for "the roar of a full scale train" from your not-12"/1' scale models,

or would you rather a "scale sound" which more-closely emulates the impression that the sound is emenating from the "miniature prime mover" itself?

NB try not to see the word "scale" and immediately think
"...oh, so I simply drop a prototype recording by 1/87th the volume, and I've got 'scale sound'..."
(it's both simpler _and_ simultaneously far-more-complex than that ),

However, Trust Your Ears, and you can't go wrong...

Oh for a quiet life

The stores is located a coupla hundred yards from busy tracks. We barely notice trains rolling past. The horns are noticeably loud but that's all. The motor sounds and the cars rolling (separate sounds) drop off very rapidly only a short distance away. You almost feel it more through the ground, than hear it. For a train that looks about the right distance for HO, the sound is almost gone. And I never hear a train that's far enough away that it seems "n" scale.

I'm all for making the roadbed as quiet as possible. And even sound deadening inside the car so they don't make that model "rushing" noise as they roll faster.

plastic boxes make great resonant chambers...

Kinda Like the track noise.

Even with todays sound decoders built into the locos i find that i still like to hear the wheel sets heading down the line. In fact, i find myself turning the volume down in my locos or they drown out the rail sounds. Kinda wierd, spend $300.00 on a sound equiped loco that touts the loudest decoder only to turn it down! lol.

Turning it down

Dear UP,

As a Pro Audio bod, I have to say I'm a little disturbed that some sound-equipped locos are sold/purchased based on "who's loudest". Apart from the fact that I've yet to see a sound-equipped loco put thru a truly rigourous audio test,
(I've got an anechoic chamber and Audio Precision tone-gen/analyser ready and waiting... ),

the power-amp in most decoders will actually have more headroom to "sing" if we do _not_ force it into overload by overloading the source audio signal (IE push the Master CV volume up to max).

Lower distortion and overall amplitude = more "breathing room" when that horn blast really needs to "hit home" and cut thru all other sounds.

Furthur, not pushing the source signal + not pushing the power amp = better chance of getting a clean, undistorted sound out of the little speakers we're obliged to use onboard,

_and_, surprise, by tweaking the EQ (Tsunami) or the frequency content of the sound files themselves (Lok), we can quite effectively compensate for both the lower overall volume (human ears are not as sensitive to extreme High and Low frequency sounds when played at lower volumes, Google "Fletcher-Munson curve"),

and for the anomalies of the speaker/enclosure itself...

As Andy noted, stand trackside and really listen to the passing of a train, the loco sound often drop-off rather more quickly than we might imagine. We can't change the law of physics RE propagation of sound thru air, speed of sound, etc, but we _can_ work them to our advantage...

Happy Modelling,
Aim to Improve,
Prof Klyzlr

PS despite our best efforts, it's critical to realise that "sound" has no concept of "scale".
(Just because the signal, power-amp, and speaker are mounted in a scale model,
does not mean the physics of the soundwaves hitting one's ears change in any way.
It's still full-size, albeit small, soundwaves travelling thru full-size air, to full-sized-ears...)

Lowered the volume

different strokes

I kind of like the track sound at the club.  We handlay right into wooden roadbed, so there is no sound deadening at all on our layout.  I actually think the whooshing sound, especially of plastic wheels, and the whimpy clicking sound at the rail joints on deadened track makes it sound more toylike.  The metal on metal sound is more appealing to me.  It doesn't sound real, it just sounds better, in my opinion.  Having some cars in the train making realistic rolling car sounds would be interesting, but I'm not sure I would want to pay for the sound decoders to pull that off.

Keeping the sound down...

I have my sound locos volume set in the 25 to 30 percent range. (much like Rick above) My shelf layout is in a tight area and running the locos at default volume does get irritating. Using JMRI to set up my decoders makes it a very simple task.

"rollingstock sound"

Dear Jurgen, Over the past year or so there has been some pretty intense discusion of "rollingstock sound" over on the LayoutSound Yahoogroup. The projects centered around using the Digitraxx Soundbug and Fred Miller's SPJHelper utility as a cheap (less than US$50) digital audio player, with "random occurance", DCC speed-step reactive, and "CAM input triggerable" capability.

Such units could concievably provide various combinations of the following, and many other "rollingstock sounds"

- tight-curve flange squeal
- wheel/railjoint "clickety clack"
- wheel flatspot "thunk"
- random occurance mech-reefer startup/run/shutdown
- Horns as found on RCL units
- triggerable "handbrake"
(get your "brakeman" to have an active audible part of the actual switching ops!)
- etc etc

Happy Modelling,
Aim to Improve,
Prof Klyzlr

Quiet Trains?

Trackspeed VS Throttle position RE audible volume

Dear Art,

...equally, there's plenty of examples where a diesel-electric loco consist heading away from the listener is all but in-audible over the sound of the cars following, once 2-3 cars have passed...
(search "railfan video" on Youtube...

Just one example here

...and a drifting/pacing steam loco can be darn quiet, until it blows it's whistle...

(

Remember, mechies don't refer to the accellerator/throttle as the "noise" or "volume" control without cause...

Happy Modelling,
Aim to Improve,
Prof Klyzlr

Shhhh!

You might be surprised!  A car rolling by itself on welded rail is nearly silent, especially in the snow.  I have been surprised by cars sneaking up behind me in a hump yard.

Jointed rail would, of course, be a good bit noisier.

With welded rail most of what

With welded rail most of what you hear is flat spots on the wheels more so than anything else.

Flatspot example

Dear MRHers,

Just because it was mentioned, one of the best YT videos of a live-fire flatspot IMHO,
(and how, what sounds devastatingly loud trackside may be completely inaudible in the cab)...

Happy Modelling,
Aim to Improve,
Prof Klyzlr

turning down the volume on the prototype

Modern welded rail mainlines sound much different than old jointed track.  I remember jointed mainline when I was younger and found the noise of the train's wheels slamming over the joints at speed very intimidating if I was less than 50 feet from the rails back then.  Now you just get the singing sound of the wheels on the rail, with the odd flat spot.  It's a lot quieter than it used to be.

Foam filler

One could try a spray of expanding foam filler taking care not to over fill.