Good Article, some other options
Dear Matt, MRH team,
Good to see an article covering practical sound deployment. Very much enjoyed the read. However, there are a number of currently-available options which were not covered, and a minor few issues which may need to be addressed.
In order of appearance.
1 - the ITTC modules are very effective as "plug n play" sound modules. However, being ISD chip based, they do not allow easy adjustment of the sound to suit given layout situations. ("Ah, you've got the ITTC Yard sound module under your layout, I'd recognize that air-release sequence anywhere").
They are also limited in frequency response and total sound duration. Limited audio performance is already (unnecessarily) hamstringing the perception of Layout Sound and Scale Sound as "a toylike add-on to the 'serious' hi-spec 3D modelling on the layout". (check the "Video2" within the article. The distortion which can be plainly heard is not a factor of the camera/audio rig and online video compression, that's what as ISD chip actually sounds like. Some sound is more fun than NO sound, but that sound certainly won't fool anyone into thinking it's "Scale Sound").
It also can, if deployed badly, contribute to actually _unsettling_ a layout viewer. Excessive volume and/or distortion is known in Pro Audio and Auditory Studies circles to contribute significantly to the negative repose of a viewer/listener. Indeed, how many times have you heard a layout viewer complain that the excessove distortion of a hi-volume DCC sound decoder is giving them a headache? It's not strictly the volume that's the problem, but the distortion being introduced by pushing the poweramp and speaker that hard. ISD-chips limited sound specs introduce distortion _by_design_. When deploying layout sound systems, it's worth taking this into account.
Limited sound duration tends to make modellers ask for the "background sound" modules to loop-play. This is fine, but inevitably results in the complaint, "I hate sound loops, they get monotonous, and you hear the same sound every 90 seconds".
NB that both the sound duration and audio performance issues have been looooong since engineered past in the domestic audio world, so there is little reason beyond $$$ as to why modellers whould have to accept ISD-based solutions as "THE way to add sound to their layout". That said, the average modeller does _not_ have to add a PC to play sound either! keep reading
(I'd respectfully suggest that an ISD-based module would _not_ be able to live up to MRH's oft quoted "benchmark" for a model/scene,
"Yes, it's a model...")
2 - Using 1" thru 4" speakers is a very do-able solution for strategic layout sound deployments. However, without a suitable speaker enclosure, that speaker will be flapping it's cone in the breeze, and simply making "turbulent air", _not_ "pushing sound" towards the viewer. Given that the article is covering using the poweramp that is built onto the ITTC modules, which is not all that powerful, wasting it's limited wattage by not efficiently coupling the speaker driver to the air is a significant issue, not to mention a significant way to degrade what limited audio spec the ITTC mod is capable of giving.
3 - Agreed, mounting the speakers low and in front of the layout fascia _can_ work under some circumstances. However, such single-speaker "point source" situations often do not truly achieve "Scale Sound" reproduction. Similarly, given a number of these modules scattered around he layout room, the individual "point sources" will attemmpt to sum (or "mix") together in the air between the speakers and the viewer's ears. Just as with water, sound-travelling-thru-air does not "scale well", and the results of such an arrangement of modules/speakers is likely to be cacophany, not "scale sound".
4 - I like the idea of adding a looping "traffic sound" under/around highway overpasses and similar model scens. However, stop for a moment and consider
* a car driving by you on a street
sounds noticeably different to
* that same car driving over a bridge/overpass, under which you are standing
Why? technically it's called "Acoustic Ambience". It's the same phenomenon that makes a loco sound different when it's running accross a field, as compared to running in a cutting or tunnel.
ISD chips have _no_way_ or being tweaked to replicate such acoustic effects. Again, this is what makes the difference between "oh, there's car sounds around the bridge" and "wow, you can really hear the sounds of the cars on the highway" (Fun Sound VS Scale Sound)
5 - The Raritan River scene works well with the ISD modules, as the sounds involved are within the audio range of the module. It's not being asked to scream loudly, or reproduce frequencies beyond it's digital limits. However, wouldn't it be cool if you could actually "fly the seagulls" around the scene sonically? Maybe get different waves-lapping-on-the-shore sounds at either end of the bridge? Place a fisherman in a boat right about mid-stream? All of these and more are do-able _right_now_, with a modicum of "sonic kitbashing", and a different player.
6 - As well as the list of websites with downloadable soundbites,
(2 of the 3 listed are "sign up and pay for" options),
There is also the "FreeSound project", which as it's name suggests, is a similar sound-library site, with _no_ attendent costs.
http://www.freesound.org/
6a - While we're talking about sound sources, can we please make a small yet siginificant point?
That being, if you only ever think of layout sound in terms of "what hardware to use", the results will never be up to what your "mind's ear" says it should be. Hardware without a _decent_source_sound/soundfile_ is just that, a pile of $$$$ silent hardware.
I strongly suggest that it's better to:
* start with the _Sound_ first,
* work out exactly what _your_ "Mind's ear" says it should sound like,
* Then nut out what hardware is required to make the desired "Scale Sound" happen...
7 - I'd also note that if you're looking for something with a bit better audio specs than an ISD-based module,
has discrete "Trigger Inputs" to start sound playback,
discrete "Control Outputs" to enable animation/light/relay/motor <> sound control
and uses readily-available SD chips as upgradable/user-loadable sound storage
(2Gb SD chip can hold 200+minutes of CD-Spec audio!!!!
Long enough to "loose yourself" in a decent duration loop,
and a audio specification that most human ears will actually accept as "a real recording")
then you could do a lot worse than the DreamPlayer by FantaSonics/Pricom
http://www.fantasonics.com/scaledreams/player.html
(NB I am NOT involved with FantaSonics or Pricom in any way, except as a satisfied customer and fan!!!)
7a - while you're at Fantasonics, if you've been wondering what I've meant by "Scale Sound", have a read of the Fantasonics "Scale Sound Manual"
http://www.fantasonics.com/scaledreams/player.html
8 - There is also a Yahoogroup which has a lot of useful info re both Hardware and Sound-design approaches to LayoutSound. This may be of use to some readers of the article.
http://groups.yahoo.com/group/LayoutSound/
Have to say I loved the article, and am really glad to see more publicity for sound deployment in model railroading. It's easy to do, the hardware required has been available for a long time, and is really quite cost effective. However, there's a marked difference between "Plug n Play" sound which is definitely more fun than _no_sound_, and true "Scale Sound" which provides fully immersive supporting enhancement to our layouts, and aims as high in it's end result as our finely-detailed "3D models"...
Happy Modelling,
Aim to Improve,
Prof Klyzlr