--> Loudspeaker Installation - Model Sounds Inc. - The Ultimate in RC Sound Systems

Loudspeaker Installation in RC Models

Here's a few tips on building loudspeaker enclosures for model planes. Much of this also applies to model boats and tanks.

What's New:

April 25, 2022

New Serial Bus Feature supports Spektrum SMART ESCs, Graupner SUMD, Futaba S.Bus and many more. Greatly simplifies wiring with a compatible Serial Bus Receiver.

February 15, 2022

New Learjet 35-70 executive jet sound set added bringing our total airplane sound sets
to 123.

November 06, 2021

New Shelley Foss Tugboat sound set added bringing our total boat sound sets to 75.

September 27, 2021

New RNL Tamar Class lifeboat sound set added bringing our total boat sound sets to 74.

September 05, 2021

Many Battleship/Warship sound sets added bringing our total boat sound sets to 73.

Loudspeaker Installation in RC Models

We cannot make specific recommendations for loudspeaker enclosures as they are so dependent on the individual model. Here's a few tips on building loudspeaker enclosures for model planes. Much of this also applies to model boats and tanks.

  • The whole point of putting a speaker in a box is to stop the sound pressure wave coming from the rear of the speaker cone from reflecting off nearby surfaces and destructively interfering with the wanted forward sound pressure wave. The rear sound wave is in anti-phase to the forward one, so if it mixes with the forward one, it will tend to destroy it and also mess up the frequency response as the reflection is frequency dependent.

  • The sealed box tries to emulate an “infinite baffle”, which is the ideal situation. If you can get some acoustic wool (insulation), put some in the box but do not stuff it too full. Failing that, use ordinary pink fibreglass insulation.

  • Based on that requirement, a speaker box should be as large as possible and it's walls should be as dense and as rigid as possible, given space and weight limitations. If they are flimsy and not rigid then they will vibrate and act as sound radiators themselves, thus reducing the effectiveness of the enclosure.

  • If the box is small. i.e. just large enough to fit the speaker in, it should be "ported" at the back or side to relieve "back pressure" which occurs when the speaker cone is pushing air backwards. If you leave a small say 1.5" - 2" diameter hole at the back, the whole wing or fuselage can then act as the speaker box which will improve efficiency and low frequency response.

  • So, based on the above, use aircraft grade plywood, not balsa, and make it as thick as you can tolerate, given the space and payload capacity of your plane.

  • You want to hear the speakers when the plane is in flight, so they should always face downwards or sideways. Placing one in each wing is a good plan, again given space and weight limitations.

  • Cover the speaker hole opening with a coarse open weave fabric, aluminium window screen mesh or other aluminium grill and paint it to match the wing.

  • Keep the speakers near the plane’s C of G to avoid upsetting the balance of the model.