purist ESL proto

purist ESL proto at HighEnd2008 in Munic
purist ESL proto at HighEnd2008 in Munic


The big fully active ESL prototype at the HighEnd2008 show in Munic.


The setup consisted of

  • MusicServer HDR6-DA 
  • Preamplifier PRE
  • active crossover purist LMS

  • four mono power amplifiers KR-Audio Kronzilla DM and DX

  • loudspeaker system purist ESL proto


All in all a playback sytem that reproduced music on an extraordinary high level and with an unbelievable high grade of authenticity.


ESL proto in anechoic room of Aachen University
ESL proto in anechoic room of Aachen University

The picture shows the prototype of the ESL speaker sytem.

The dimensions of ESL-Panel are 60"x15", hence 930 square-inch.

It is crossed over at 180Hz. A new material is used as weakly conductive coating and a new manufacturing procedure shields and encapsulates the coating from environmental influences.

As a welcomed side-effect this technique also considerably reduces the effects of the acoustic phase cancellation. The amount of electronic equalizing required for amplitude linearization can be lower and a very thin shaped holding frame profile may be used.

Less power demand and a increased dynamic range add as bonus to this first-used and unique technology.



A casing is situated below the panel, that contains the electronic circuitry.

A special dedicated audio transformer with a transformation factor U of a low 1:50 connects between amplifier and panel. The HV-polarization-voltage is generated from a HV-cascade. A automatic music sensor senses if a music signal is on. It activates the electronic circuits and switches the -reduced to the half at standby- HV-polarization-voltage to their full level.


The Bass tower, fitted with eight pieces of bass drivers of the 9"-class, raises to a height of 76".

The drivers come with a stiff, black anodized aluminum-cone and a highly linear longthrow motor system. They feature attractive cast baskets and massive phaseplugs.

The slightly trapezioidally shaped bass tower casings are made from wooden high density fibre boards. The casing is chosen to be of open Baffle -to the backside- with a small footprint of 10"x 9".

The Bass tower and ESL-panel parts are situated with defined distance to each other on a common base plate.


Sonically this system leaves not much to wish for. However in large listening rooms -and the system requires large rooms- one might miss every now and then on the usual slam and weight in the lowbass region, which a dipole can´t produce by its nature.

The height of 76" can hardly be overseen in any room.

For the series wanted to change:

  • optically more pleasing, more compact appearance
  • adding a dedicated Subwoofer