purist esl proto
The purist esl was the second, smaller model out of the ESL-series. It was a hybrid-system as well, but featuring integrated class-D power amplifiers and a DSP-Xover/Filter.
The smaller dimensions of the panel allowed for useage in smaller rooms and at closer listening distances. There´s no subwoofer integrated, but a dedicated sub may be added optionally.
Conceptually and in apearance the similarities to its big brother are obvious. "Honey, I shrunk the speakers". The panel measures 49" H x 10" W. The membrane area is just half at 484"².
A toroidal audio transformer with an U of 1:70 drives the panel. The electronics reside in a cabinet below the panel.
The woofer tower features the same height and number of bass drivers as the big model. The bass drivers are just one size smaller at 6.5".
The base plate is therefore also less wide. The shape resembles the larger model though.
The crossover is a digital IIR-filter, crossing over at app. 250Hz.
The bass is equalized down to 35Hz. The esl doesn´t play with the stupendous sovereignty and pristine bass power of the ESL. In all other aspects it mimics its bigger brother and allows for a supreme sound quality. Slight deductions in sound quality of the system are for most due to the sound quality of the integrated class-D amplifiers. The amps guide the esls and basses at a short rope, but also introduce a technical, lifeless note.
With largescale dynamical, loud music this sonic character provides alot of fun, for classic natural music it certainly is far from optimal. A fine tube amp is a whole different animal, but at much increased cost.
If one uses a dedicated Subwoofer the equalization curve of the bass drivers may be risen to a lower bandwidth limit of 50Hz.
This increases the dynamic headroom by a couple of dBs and lifts the small esl nearly to the big ESLs niveau.