Quad ESL 57 Bass Panel

ESL Labs Quad ESL 55/57 refurbished Bass Panel.

The Quad ESL 57 Bass Panel

The Quad ESL 57 consists of three panels: one treble panel in the middle and two bass panels, one on the left and one on the right. Contrary to what the name might imply it does not only reproduce bass but also a large part of the low mid tones.

A properly functioning Quad ESL can produce a surprising amount of bass. Unfortunately the bass panels are almost always out of specification. It is not always necessary to refurbish the bass panels but often highly recommended.

Bass panel aging

The Quad ESL bass panel ages in two ways that work together and decrease the amount of low frequency output considerably. The most important is the stiffening of the diaphragm which causes the resonance frequency to rise. As a result most old panels do not produce much output below 80 to 90Hz. A second effect is the aging of the coating which causes a loss in sensitivity. This lowers the output of the panel all together. These two effects combined have earned the Quad ESL 57 to be 'bass shy'. Broken panels can also hum, rattle or tick.

The Quad ESL can't produce bass?

The Quad ESL has earned a name for not having any bass. Now you probably don't want to use them at a disco party (except for a triple stack perhaps??) but a refurbished Quad can play down to 40Hz without much trouble, which is quite acceptable. Most Quad aficionados that hear a proper Quad for the first time are surprised by the amount and quality of the bass. "Where is that bass coming from? Do you have a sub somewhere?" No, no sub. Just good Quads!

Quad bass panel refurbishment

A refurbished bass panel not only sounds like new but also looks like new. Refurbished stators, new diaphragm, new dust covers, wiring and hookup panel. In short a bass panel that will serve you well for a long time.