Great Article, minor comments...
Dear MRH fans,
Rich has put together a great article here, and I totally agree that background sound can materially enhance the overall presentation of a layout, whether in a home environment or for a "touring layout".
However, a few comments come to mind
- "Obviously repetitive loops" are a commonly cited issue with layout sound. The need for such obviously _short_ loops is often a response to the kind of limited-recording-length digital playback devices offered by some Model RR companies. As Rich notes, the "user loading" functions of even cheap MP3 players and similar animals allow the Modeller to deploy _exactly_ the kind of sound their _ears_ tell them suits _their_ layout, while allowing "loops" which can measure in the _hours_ of duration.
FWIW, a reasonable quality MP3 file eats around 1MegaByte per minute of Stereo audio. Therefore, even a "tiny" cheapo 1Gb MP3 players can handle up to 1000 minutes of audio, or over 16hours of audio!
- Overall volume (referred to by Pro Audio bods as "Gain") is indeed a key element to deploying Layout Sound.
It is entirely possible to recreate, for example, a HO scale warehouse dance party,
providing a tangible "doof doof" bass rumble to a viewer leaning into the model scene,
while _not_ exceeding 60dB SPL
(for the non Audio bods, that's quieter than you and I having a close serious conversation between ourselves in a quiet room),
and being _inaudible_ (or at least not peaking above "conscious level") for a person standing 2 paces away.
- I have to note that a "USB compatible" 5VDC supply is not hard to make, and for those modellers who dislike electronics at the best of times, there are some plug-n-play 5VDC USB-plug-type supplies available from RadioShack, Maplin, and Jaycar. I am unsure why Rich reccomends against USB-powered units, if you intend to deploy the LayoutSound systems on anything other than an occasional basis, replacing AAA batteries is going to get old. (If you only run the sound occasionally, you're actually _more_ likely to _not_ check the batteries on any regular schedule, and therefore discover that they are dead or have leaked within the MP3 player right when you _need_ them...)
Furthur, it can be a good move if you can find MP3 players that _automatically_start_playing_ when power is applied. This makes it easy to run a additional "layout sound power buss" which can be turned on or off with a single switch.
- Side-Note: When choosing an MP3 player for Layout Sound missions, if at all possible, perform the following test _before_ buying.
* turn it on,
* start a file/sound playing
* set the volume to a given level
(It doesn't particularly matter what level you choose for the purposes of the test, but probably best not to choose "full volume")
* turn the MP3 player OFF
* then turn it back ON again
The key point is, when you re-turned-ON the player, did it "remember" the volume setting you set earlier?
If it _did_, then you can buy and deploy them under your layout, confident that when you "power up" the players everything will be as you intended.
If not, every time you power up the players, you'll be resetting the volume to an appropriate level, which may wear thin after a while.
- Rich is correct, both PCs and MACs both come with applications within their Operating Systems which will allow basic Audio Editing to be performed. However, if you are reading this post, you are also likely online. This means that you are only moments away from downoading a _FREE_ dedicated Audio Editing app, such as Audacity
http://audacity.sourceforge.net/
Such apps are more powerful than Sound Recorder or Movie Maker (Win) and iMovie (MAC), and just as easy to use. (If you can drag and drop a sound file into any of the above, push a volume fader, and export a MP3, you can do it in Audacity, with better audio and exporter algorithms and more accurate control for a better audible result).
- Downloadable sounds from online are definitely a quick way to get _something_ up and running. However, be fully prepared that the downloadable sounds may
* be low (digital audio) resolution (to save space online, unfortunately to the detriment of the audio quality itself)
* have unwanted background sounds (a better-equipped Audio Editor such as Audacity will shine over MovieMaker and iMovie under such conditions... ).
* have unwanted/in-appropriate "ambinece" (think of a church bell which is physically modeled right at the edge of the layout, and thus up-close-and-personal to the viewer/listener, but the sound has an audible "reverb and delay" ambience which suggests that it's much furthur from the listener)
* oh, and just because it's online does _not_ mean it's free for the taking. Suggest starting at a bona-fide _freesound_ site, such as "the FreeSound Project"
http://www.freesound.org/
- Agree that "periods of quiet" help avoid ear fatigue in the layout viewers. However, make sure to fade the Heads (starts) and Tails (Ends) of each effect. A "sudden start" of audio is often just as jarring as a "constant rumble" (NB that in some environments a "constant rumble" at very low volume, such as in a city-scape, may be entirely appropriate! ).
- If at all possible, start and edit using WAV file format audio. This will give you _some_ fighting chance of producing a reasonable-sounding result. As above, audio posted online has filesize as it's _first_ priority,
and audio results second. Anything you can do to improve this situation, or at least "stop the degradation", has to be a good thing.
(As many Pro Audio bods have said for many years:
"you can make a good signal go bad,
but you can't make a bad (read:low resolution or degraded) sound come good...")
- Here's something that wasn't mentioned. If you edit your sounds on your PC, connected to your PC speakers, then when you play the end result back thru the speakers mounted in/on/around the layout,
the change in speakers will have a definite effect on the sound.
What to do?
Well, Pro Audio bods can only _wish_ that they could mix their audio (TV shows, pop songs, whatever) on the actual speaker system the End User will be listening to it on. Indeed, they spend deliberately spend significant time/effort/$$ setting up at least 1 set of "basic bookshelf speakers" (as opposed to High Fidelity ultra $$$ Studio Monitor speakers), in an attempt to "hear what it will sound like" on a "domestic home speaker system".
Hey, assuming you're using a laptop (or a machine dedicated to "model railroading" missions, as IIRC Joe F's surveys indicate a significant percentage of MRH readers have at their disposal),
why not
* download the "Raw sound files" you intend to create (kitbash?) onto the machine
* get your "basic edit" happening
* get the speakers at least "roughed in place" on the layout
* plug the Editing PC connected directly to the now-installed Layout Speakers
* and then complete the edit, _confident_ that the sound you are hearing during the edit is actually what you'll hear once it's all edited and deployed "for real"???
- As above, MP3 files eat around 1MegaByte / min of stereo audio. In comparison to CD-spec WAV files at 10MegaBytes / min of stereo audio, so absolutely yes, MP3s are indeed smaller. However, actually _creating_ usable MP3 files without compressing the life out of your carefully-crafted soundtrack is not quite as simple as just hitting "Save As MP3". If at all possible, suggest choosing 320kbps Constant bitrate and Normal Stereo compression in order to avoid un-necessary additional degradation.
I would also suggest considering:
* saving the _Project_ somewhere on your system, so you can come back and re-edit the soundtrack without having to re-build it from scratch in the future.
* once you're happy with your soundtrack, save a copy as a CD-spec (44.1Khz 16bit or better) WAV file, for _archive_ purposes. This means that, if in the future you change the playback hardware, and need to compress the soundtrack into some _other_ audio format, you will be starting with a _decent_resolution_ version of the final edited file. This is far better than re-compressing the already-compressed MP3 file version, and simply adding digital processing degradation to the process...
Again, Rich, Love the article!
Hope this helps...
Happy Modelling,
Aim to Improve,
Prof Klyzlr