Our famous Bass reflex speakers are now available to suit the new Loksound V4.x decoders.
Custom designed to enhance low frequency locomotive sounds (ideal for either Diesel or Steam).

The speaker impedance has been designed to match that required by the Loksound V4.x range of sound decoders (4 ohm), and can be used to directly replace the standard speakers without any other considerations.

Initially available in three sizes, all with attached wires.
This unit is based on a 40 x 20 speaker, measures 58mm x 22mm overall, and is a slim 9mm deep.
(ESU Loksound sealed speakers measure 44 x 22 x 12 in comparison.)

As the developers of this product, we offer full technical information, which is published below.

Bass Reflex, Technical theory of operation.
In contrast to placing a chamber on the back of the speaker which is (almost) air tight, a bass reflex system has a port or vent engineering into the case, which consists of an opening, generally backed with a pipe or duct of circular or rectangular cross section. The air mass in this opening resonates with the "springyness" of the air inside the enclosure in exactly the same fashion as air in a bottle produces a low frequency sound when a current of air is directed across the opening (try it, it's fun!). The frequency at which the box/port system resonates, known as the is determined by the cross sectional area and length of the duct and the volume of air inside the enclosure.

This permits a lower frequency sound to be produced by a smaller speaker than could otherwise do so. The design type augments the bass response of the speaker, and can extend the frequency response of the speaker/enclosure combination to below the range the speaker would reproduce in a sealed box. The enclosure resonance has a secondary benefit in that it limits cone movement in a band of frequencies centred around the tuned frequency, reducing distortion in that frequency range.

Technical specifications