2 plus 2, New frames

Read more on the Acoustat 2 plus 2 in our home audio section

Ephraim Meyer2004-02-23 22:21

Hello, this a question for Andy Szabo. I would like to rebuild my Acoustat 2+2 speakers on a hollow aluminium frame (to be filled afterwards with lead shot or sand). I want to attach the loudspeaker sections directly to the aluminium, and of course use some type of damping material between the aluminium and plastic of the loudspeaker units.My question is if there will be any magnetic interference with the electrostatic field. There will be no wood on the speakers or frames. Thanks in advance, Ephraim Meyer


Andy Szabo2004-02-23 22:21

The electrostatic field is very localized between the stators, so it is unlikely that any sort of metal frame (even steel) would have an adverse effect. Aluminum, by its very nature, is non-magnetic, so I don’t see any problems in that area.

The biggest concern with a metal frame is shock hazard. It is vital that the panels are insulated from the metal, so that any potential leakage cannot energize the metal. Use some sort of insulating material between the frame and the panel on the mounting surfaces, and allow at least ½â€ between edges of the panels and the frames. You may also want to use some non-metallic (nylon?) screws for mounting the panels. The wires leading to the panel should also be double-insulated along their entire run inside the frame. PVC tubing is a good choice for insulating the wires. The metal frame should also be electrically connected to earth ground, to further safeguard against shock hazard.

Another concern is resonance. A metal frame will have a considerably higher resonant frequency than a wood frame. Even filled with lead shot or sand, you may have problems with resonance.

See Izzy Wizzy Audio to gain some more insight into the problems of using metal frames. Please note that I do not necessarily endorse the work represented there, but you may be able to benefit from his experience.

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