First of all to DickyD, not sour grapes - I'm just suggesting that you Brits open your eyes to other possibilities - you do have a tendency to latch onto just one thing and then have blinders on to anything else. RCMW are not the only guys on the planet, and to be honest I fell of my chair laughing when I first saw their sound module with a huge fan on it - they have just got to be kidding!! There are MUCH better solutions than using a wretched fan - like using a more efficient amplifier that doesn't generate the heat in the first place. Think outside the box guys - RCMW included!!
Now to reply to Bluebird. Actually, the total storage time is now more like 12 minutes. But the default behaviour of the sound module is to loop when it reaches the end of the sound clip from the start of the sound cip, so it will play indefinitely until the sound clip is switched off. Further, the loop point at which it starts to play from again does not have to be the start, it can be any point into the sound clip. For example, an engine sound with a startup sequence followed by an idle sound is all one sound clip and once its end is reached, it can be configured to play just the idle part, not the startup as well.
Any sound can be configured to either play once, or to loop, and either latched or momentary mode. Latched mode means you trigger it once and it stays on until triggered again, when it switches off -great for long sounds when you don't want to hold the switch all that time. Momentary means on only while the switch is activated - good for short sounds like horns and gunfire.
The minimum supply voltage is 10V so it won't work on less than a 12V battery unless you want to put in a second battery, which is always a good idea anyway for any sound system. And it will also work on a 24V battery. Note : Power is proportional to the square of voltage, so if you double the voltage to 24V, you can get 4 times as much power - 40Watts output!!.
The SFX4-2 can only play one sound at a time so one sound has to be switched off before another can be played. The SFX5.3 can play any two sounds at a time, and they can be connected together like a master/slave to play more sound simultaneously.
Hope this clarifies things.
Regards,
David