High Power Amplifiers

Giant Scale Models and Sound Systems

Giant Scale models have the payload capacity, battery capacity and power systems to support very high powered sound systems with amplifiers capable of producing hundreds of Watts of electrical power and the appropriately large loudspeakers to consume that power to produce extraordinarily high SPL (Sound Pressure Levels).

High Power Amplifier Suppliers

Model Sounds Inc. does not design, manufacture or sell High Power Amplifiers themselves. The development cost and low volume of sales of these simply does not justify such development when there are already a huge number of potentially suitable inexpensive amplifiers available from China.

However, High Powered Amplifiers potentially suitable for Giant Scale use can be purchased from these suppliers directly at very reasonable prices:

1. 160 Watts + 160 Watts - AliExpress (China)

Interfacing External Amplifiers to our ShockWave^® 3 Sound Module

The ShockWave 3 sound module has line audio output pins to connect to an external amplifier. The pins for these are documented in the printed quick-start guide that comes with the module and also in the PDF reference manual in the Manuals folder on the microSD card of the module. We can supply short 150mm screened audio cables with a male servo connector on each end to connect to these pins. Typically you would have to cut off the male servo plug from one end and make your own connections to whatever type of connector the external amplifier of your choice uses.

The output voltage at these pins is approximately 1 Volt RMS at full volume setting. There is a "left" pin and a "right" pin. However, these are not two channels of a stereophonic sound since all the sounds on the module are monophonic. Rather they are two distinctly separate channels to carry different sounds, e.g. engine sound on the right channel and gun sounds on the left channel.

On very large models you may like to place separate loudspeakers, one near the engine for the engine sound and a pair of speakers near the gun ports for the gun sounds. However such spatial separation of sounds will only be noticed when you are close to the airplane on the ground. When in flight, because of the distance involved, the sounds will not be spatially separated - they will simply sound as if if they are coming from the same place.

Beware of Claimed Amplifier Output Power!

Exercise caution and a healthy dose of skepticism when reading the claimed power output specifications of ANY audio Amplifier or the amplifier chip that they use. Manufacturers of inexpensive non-audiophile amplifiers such as these always state the output power rating at 10% THD (Total Harmonic Distortion) to get as much electrical power out of it as possible. However, that distortion figure is very high and borders at the onset of clipping. A much better target figure for distortion level is 1/100th of that or 0.1% THD.

If you can find the amplifier chip manufacturer's datasheet, they always publish curves of power output vs THD. At 0.1% distortion, typically the power output is 50% of that at 10% THD. But still, if you have hundred's of Watts of claimed output power at 10% THD, you'll still have a few hundred Watts at 0.1%.

Choosing Loudspeakers for Giant Scale

When choosing loudspeakers, such as car stereo loudspeakers for Giant Scale models, be very mindful of the speaker's sensitivity rating. This is measured in dB/1W/1m. For example, the 4inch 20 Watt speakers we sell are rated at 90dB/1W/1m. What this means is that with 1 Watt of input power and when measured at 1m distance, and on-axis, the speaker will produce 90dB SPL. SPL is a logarithmic scale so if a speaker had a sensitivity of only 80dB/1W/1m, it is 10 times less sensitive, so you'd have to pump in 10 times as much power to get the same SPL level as a smaller speaker with a 90dB/1W/1m sensitivity.

To put this into perspective using two of our 20 Watt speakers in series, i.e. 40 Watts total, you'd have to pump in 400 Watts to get the same SPL as the smaller speakers on 40 Watts. So choose your high power loudspeakers very wisely, otherwise most of that huge electrical power the amplifier is generating, and the loudspeaker is consuming, will go to waste as heat in that loudspeaker.

Disclaimer

Note: Model Sounds Inc. is in no way affiliated with or associated with any of the above mentioned companies or have any financial interest in any products on their web sites. We do not guarantee compatibility with our ShockWave 3 sound system with regard to input sensitivity levels, nor can we provide any information or support for any product you may purchase from them. The above amplifier sources are listed as suggestions only.