Elac’s new series 400 has been available at the dealers since october 2012. It closes the gap between the series 500 with Jet coax chassis and the bestselling series 200. Looking at the loudspeaker range from Kiel, one can splendidly start a controversy if such a broad diversification like Elac’s is really necessary. There are indeed arguments in favour of it: Each development of or merely tiny improvement on chassis, crossovers and cabinet designs requires a new classification. And in the case of the series 400, they’ve even redone everything.

The creative machinery at Elac’s never stands still. From the JET tweeter to the crystal cone of the low/midrange chassis everything was put to the test. And the technicians did indeed find room for improvement. JET stands for a tweeter design which Elac has perfected. Based on the principle of the legendary »air motion transformer« by Dr. Oskar Heil, Elac has constantly refined this design over the years. Its sound is markedly different from that of the otherwise ued dome tweeters.

Innovation in series

The folded foil diaphragm with is lamellar construction is driven by an extremely strong magnet system of neodymium rods. Contrary to diaphragms that move like a piston and merely compress the air, this diaphragm which is folded like an accordeon squeezes the air out of its foldings. In addition the diaphragm surface of the JET tweeter is about ten times larger than in a conventional 25 millimetre dome tweeter.

The kicker

Although the thin foil has an unfoldeded diaphragm surface that’s several times larger, the effective radiating surface is small which results in a high efficiency with exceptional dynamics and a low directivity. Therefore the JET tweeter can take even high dynamic peaks in theory without complaint. In its fifth upgraded version the JET is able to reproduce the incoming electrical signals with even greater precision – and practically no inertia at all.

The production of this tweeter in Kiel is run partly automated. Especially the glueing of the diaphragm is done by robots in favour of ultimate precision. Today a large percentage of the Elac speakers are equipped with this exceptional tweeter. Another asset of the new tweeter: the frequency crossover could do with a simplified layout which is supposed to further enhance the resolution behaviour.

Neither does the low/mid woofer look as if it came from the shelf of well-known chassis suppliers. No, Elac insists on their freedom to design the drivers just the way they want them to be. Hence only an in-house development can do it. This is exactly what sets Elac apart. Countless innovative chassis owe their existence to the art of North German engineering. And so does the AS-XR cone.

The black anodised, concave aluminium cone with its crystal-like embossing yields an extremely high stability in the low/midrange and, owing to a damping sandwich construction and beading design, very low partial resonances. The high rigidity of the diaphragm is provided by the pulp cone glued on the reverse, the diamond embossing produces defined partial vibrations. The manufacturers have deliberately gone without the otherwise usual dust cap and moulded the cone concavely from a single form instead. Hence there is no break in its rigidity; rather do we see fluent transitions, which renders the cone breakup more controlled and thus ensures a more continuous radiation behaviour. The spirit and purpose of this intricate construction is a transmission with as few resonances as possible, especially of the midrange. Precision and the absence of colourations are the result of the sandwich drivers. In the BS403 both precious parts are used.