I am constantly surprised by the low prices of tech gadgets on eBay and other online shopping platforms such as AliExpress. I sometimes invest in what I consider to be intriguing cheap items just to explore their potential. One such impulse-buy was a couple of MP3 sound cubes.
Overview
Not only were they ridiculously cheap, they were compact and versatile, including an inbuilt FM radio receiver and, as it turned out, a fairly loud amplifier. A quick experiment revealed that, for garden railway purposes, they could easily be set-up to play sound clip files (both .MP3 and .WAV) as loops.
The unit is quite compact (50x48x52mm) and can presently be bought for less than £10 GBP on eBay (Search for MP3 cube player).
The controls are quite basic and similar to most gadgets of this kind.
The menu button allows you to choose between the radio and the mp3 player, and also to loop the playing each file on the micro SD card. Pressing the last or next buttons allow you to select the required files to be played and holding these down allows you to increase and decrease the volume. The start/stop button, as expected, allows you to play or stop playing a file.
Of course, it also needs a micro SD card but, as it will only be playing a single file, a 2gB card will be sufficient. These can be picked up for around £1.50 on eBay.
PS - I have since discovered a similar cube player on eBay (without the FM radio) for a third of the price - though I haven't tried it and so don't know how it compares.
Triggering effects remotely
I haven't yet taken one of them apart to figure out if it can be triggered remotely through one of my Deltang/Micron RC receivers but, given my previous experience of triggering a similar device (see How I used a cheap MP3 player as a loco soundcard), I would imagine these can be readily adapted.
Sourcing the sounds
I decided that I would use these cubes to provide ambient sound effects around the railway - more specifically, the sound of a sawmill in action for Peckforton timber yard and the sound of cattle lowing for one of my cattle wagons.
The first task was to track down sources for these sounds. I used a couple of sources, a free sound effects website (Freesound.org) for the cattle sounds and YouTube for the sawmill effects.
Freesound.org
A search for "cows" revealed 713 sounds.
Pressing the 'play' button on each file enabled me to hear each sound and so, after identifying three sounds which I felt were appropriate, I downloaded them. This required me to register with the website but, given the sounds are free, this seems to be only a minor inconvenience.
A search for "sawmill" yielded just fourteen files. Only one of them was, I felt, appropriate as it was recorded in a steam powered sawmill, so I downloaded that. I wanted a wider variety of sawmill sounds and so turned to YouTube.
YouTube.com
YouTube generally provides a wide range of files, but it's a lot harder to sift the wheat from the chaff.
A search for "Steam sawmill" revealed many more clips which were suitable.
After selecting a couple of videos which seemed to have a good selection of sounds, the next problem was, of course, how to download them. Rather than signing-up for a YouTube account, I decided to use AnyVideoConverter - a versatile little freebie program which not only enables me to convert a wide range of audio and video clips into different formats, it can download YouTube videos and save them - in this case I wanted them saved as MP3 files
To download the required video and convert it require six fairly straightforward steps:
- The format for the file was chosen from the drop-down list - in this case MP3 (it's towards the bottom of the list beside the musical note symbol)
- The Add URL tab was clicked
- The + sign was clicked to add a new URL
- The URL for the video clip was pasted in (using Control V) after having been copied from the YouTube Share tab
- Start download was clicked
- Once the file had finished downloading, the Convert button was clicked
Editing the sound clips
Although I could have simply just transferred the sound clips to the SD card in each player, I decided to mix them together. This has allowed me to overlay one sound on top of another and provide some variation. To do this, I used Audacity - a well established freebie open-source sound editing package.
Rather than going into detail here, I simply followed the same principles I had used to create the sound files for my previous MP3 soundcard mod - see How I used Audacity to create the sounds for my Ford railbus.
Conclusion
The sound effects certainly add a new dimension to the ambiance of the railway. The players are charged up periodically using a bog-standard USB charger and I find the batteries easily last for an operating session of a couple of hours - though I only tend to play the sounds when I am filming in their vicinity. The added bonus is that, if there is something interesting on the radio, I can switch one of the cubes over the Radio 4 while relaxing in a deckchair with a cup of tea.