So i looking at this one made in Canada ShockWave 3-System 1 x 4 inch x 8 Ohm
SUPERB SOUND QUALITY http://www.modelsoundsinc.com/soundsystems.php
Here is what they said they can do for me
we can certainly supply you with a sound system for your Rheinwerft Düsseldorf fire-boat model.
We have a Mercedes V12 engine sound. We can do a twin engine sound set in one of two ways:
1. We can mix two engine starts on one throttle controlled sound track so that the second engine starts up a fixed time period after the first one, say 5 seconds. You can then use one throttle radio channel to control the engine speed. Engine startup, by default, uses the throttle stick, but it can also be configured to startup using a spare switched radio channel.
2. We can put a single engine startup sound on each of two independent throttle controlled RC channels so that each engine sound can be started up and controlled in speed by two separate throttle channels on your radio.
We have various horn sounds, some samples attached here, but I do not know what a European fire-boat horn specifically sounds like. I looked online and the only references I could see to the Düsseldorf fire-boat were of the Robbe models of it, not the real boat.
Similarly for the siren, we have only one siren sound.
I have attached some sound samples here.
All the sounds are controllable separately from different radio channels so which ever RC channel you use to switch on your lights can be Y-ed into the sound module input for the siren sound.
For model boats, we usually recommend our ShockWave 3 1x4x4 sound system kit which comes with one 4inch 20Watt 4Ohm loudspeaker and can be operated on a 3S LiPo or a 12V NiMh or lead battery
Has anyone used their products. I'm open to discussion about this they sent me sound tracks and the sound good just not European Siren sounds USA sounds