SoundCar decoders :: not now

 photo CNR80-CNR1532-StW-Dark_zpsljohca1c.jpg
(They are safe – for now)

Last week, I wrote a post about the Soundtraxx SoundCar decoder. Today, I opened up the tender on a CNR 10-wheeler with an eye to installing one – but then I did some testing with the speaker I planned to install and decided that the SoundCar isn’t appropriate for this layout.

It’s a great little decoder – don’t get me wrong! – but what I really need is the occasional bit of flange squeal on a few key curves on the layout. These are:

– The main and siding in St. Williams
– The curve from the east end of the Lynn Valley to the water tank
– The curve between the Lynn Valley water tank and Port Rowan
– The S curve on the elevated coal delivery track in Port Rowan

One of the things I realized in testing the SoundCar is that, while Soundtraxx provides adjustments to acceleration and deceleration, it doesn’t provide an adjustment for top speed. That’s problematic for my layout, because I’ve created custom speed tables for the locomotives that severely limit their top speeds. I did this because I have a 20 mph speed limit on the line yet I’d like to be able to use the full range of the throttles. It makes no sense to have “rockets on rails”:

 photo TriangSpaceCar_zps3koezraa.jpg
(Flash Gordon need not apply)

Unfortunately, this means that the sounds generated by the SoundCar will quickly go out of synch with the action on the layout. I’ll be trundling along at a sedate 20 mph (at speed step 126 on my throttles), yet the SoundCar would generate flange squeal and jointed rail noises appropriate for the CNR’s Turbo Train at full throttle:

 photo 20120910-Turbo-VIAKingston_zpsycdzfrtm.jpg

So… no.

Instead, I’m looking at what Scott Thornton has been doing on his delightful Iowa Interstate – Milan Branch layout. As Scott writes in this blog post, he is using components from Iowa Scaled Engineering to add ambient audio to his layout – including flange squeal.

I’ve use ambient audio quite effectively on my layout already using components from Pricom Design:

Layout Sound - Pricom Dream Player Pros photo Audio-Pricom_zps65368eb5.jpg
(Click on the image for more information about my ambient audio system)

I’m extremely pleased with the Pricom solution. That said, it’s expensive – and since and I’m thinking about four or five discrete locations to add flange squeal effects, I’m attracted to ISE’s more economical, if less powerful, sound player for this particular application.

I continue to ponder this. I need to figure out a number of issues – including the trigger mechanisms (which could be reed switches, IR detectors or something else), the location of speakers, the appropriately “squeal-y” sound files, and so on.

But progress has been made – and I don’t have to add more electronics inside the tenders of may already-stuffed steam engines.

12 thoughts on “SoundCar decoders :: not now

  1. Hello Trevor,

    I’ll be using ISE’s IR sensors to trigger the random sounds – one on each side of a curve.

    Since I’ll only be running one train at a time on my layout, ISE also developed a custom Arduino module that senses the throttle speed to avoid flange squeal if a train stops between the IR sensors. I have yet to install it, but it’s an impressive piece of electronics and may be useful on your layout as well.

    Contact me if you’d like to learn more about the module. I’d be happy to send a photo.

    I also have some thoughts on developing the flange squeal sounds if you’re interested.

  2. Modelling a secondary main line, I’ve been wondering how to add the sound of track torpedoes detonating under the wheels of a loco. Rule 99, but also 1951 UCO Rules 41 and 44 come to mind as trackmen would set up flags and torpedoes to protect their doing track work.

    “41. On subdivisions or portions thereof specified in the time table or special instructions, rule 40 must be modified as follows:

    (a) By day place a red flag and, in addition, by night a red light between the rails 200 yards in each direction from the defective or working point, and place torpedoes on each rail to cause the explosion 200 yards beyond the signals, also:

    (b) Yellow over Red Flag. By day place a yellow over red flag and, in addition, a yellow light and red light at least 2000 yards in each direction from the defective or working point on the same side of the track as the engineman of an approaching train, and place torpedoes not more than 100 nor less than 50 yards apart to cause two explosions 200 yards beyond these signals.

    (c) Trains approaching the signals prescribed by clause (b) must stop, replace the torpedoes and proceed to the red signal prescribed by clause (a) and there be governed by instructions of the foreman in charge, and must not proceed until the red signal has been removed by the foreman.

    (d) When weather or other conditions obscure day signals night signals must be used in addition.”

    Maybe the SoundCar decoder might be just the thing for modelling this and improving operation on a layout?

    Following your blog on this with some interest,

    Steve Lucas.

  3. Dear Steve,

    SoundCar decoders are not user-loadable, so no “detonators” or “torpedos” to be had there. That said, sound-designing your own “signal torpedo” sound is not difficult, needs only a FREE audio editor app such as Audacity, and you to Trust-Your-Ears…

    The biggest issue would be the nature of the gag, “dets” tend to move where the trackwork or other obstruction is. If you layout “always has torpedos at X location”, then grab an IR detector and a CKT-SQUEAL or Pricom DreamPlayer LITE, and you’re ready to go. IF however, you want the sound to “trigger at random locations”, the solution may (need to) be significantly more complex…

    Happy Modelling,
    Aim to Improve,
    Prof Klyzlr

  4. Dear Scott, Trevor,

    If we’re going to get into “scale-model sound design”, I’m very interested.
    Let me know if I can help in any way…

    Happy Modelling,
    Aim to Improve,
    Prof Klyzlr

    • No worries Nelson: I’ll find a use for them.
      The instructions say the momentum (Cv 3 and 4) should be adjusted to match the locomotive. But there’s nothing about matching top speed. The steam engine speed curves top out about 60 (of 255) so I can use the full 126 speed steps without having a rocket. This means the engine will move at a sedate pace but the SoundCar will sound like an express.

  5. Dear Trevor,

    I understand the logic behind bailing on the SoundCar decoders due to “no speed matching”.

    However, I would ask if you’ve checked CV116,
    as noted in the SoundCar User Manual?
    http://www.soundtraxx.com/manuals/soundcar_usersguide.pdf
    (bottom of page 26)

    “… Moving Sound Scalar
    To further fine‑tune the clickety‑clack rate (as well as flat spots), use CV 116
    to set the proportion between the speed step and the scale speed in feet per
    second (ft/s). This CV can be programmed with any value from 0 to 255 to
    determine the frequency of the clickety‑clack rate based on the scale speed
    of the car and the distance between rail joints. A value of 1 corresponds to
    0.01ft/s. Higher values correspond to faster scale speeds, and a value of 0
    will disable the clickety‑clack and flat spot sound effects. …”

    According to the maths in the “Tech Manual”,
    http://www.soundtraxx.com/manuals/soundcar_techreference.pdf
    (See page 51),

    a value of 28 or 29 in CV116 should give you a max “clickety-clack” cadence of approx 25smph at SpeedStep 128.

    Max Scale speed (ft/sec) = (Speed Step x CV116-value ) / 100

    CV116 “28” = a calc’d 35.8 ft/sec,
    CV116 “29” = a calc’d 37.1 ft/sec

    where the target “25smph” is 36.6ft/sec…

    CV3 and 4 (momentum) do not affect the relationship between speed step and “audible cadence”, but CV116 might just do what you need it to… 🙂

    Happy Modelling,
    Aim to Improve,
    Prof Klyzlr

    • Hi John:
      Thanks for this. That might solve the problem of the rail joints. There’s also the flange squeal to consider. I may install the SoundCars in my CNR combines – which already have decoders and speakers, so it’s a straightforward swap – and see how they perform.
      Cheers!

  6. Dear Trevor,

    CV201 changes the probability/random-occurance of the flange squeal per (second?). It is not smart enough to “know” when the loco is negotiating one of the “tight curve” locations you would _expect_ a long-grind ringing/resonant “squeal” to occur,
    (no “truck yaw angle sensor” input 😉 ),

    but should give a plausible “flange bump-n-grind”/”rail joint hunting” occurance…
    (and allow the occurance-per-minute to be less if it gets annoying…)

    Happy Modelling,
    Aim to Improve,
    Prof Klyzlr

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