PARIS, Feb 13: British engineers are on the way to devising ultra-thin, cardboard loudspeakers that will make cereal packets and detergent boxes blare out advertising jingles and cut-price offers to passing shoppers.

The breakthrough in so-called flat-pack loudspeaker technology has been pioneered by a Cambridge company, NXT, New Scientist reports.

The firm is already putting the finishing touches to its first cardboard product — a pair of speakers that stand 70 centimetres high and are likely to retail for about 45 dollars.

The speakers comprise a three-sided pyramid assembled out of a single, creased sheet of tough corrugated cardboard which folds flat after use.

Attached to the rear of one of the pyramid’s sides is an electro-magnetic “exciter,” a gadget about 2.5 centimetres thick which converts electric signals into acoustic waves.

Hooked up to an amplifier, the exciter causes the whole pyramid to flex like a diaphragm, producing sound. Millions of dollars have been invested to find a material that is light, stiff yet cheap and conducts acoustic waves.—AFP