In Reply to: RE: Heard a reference level planar speaker last Saturday posted by josh358 on May 20, 2012 at 06:26:08:
A uniform shape (such as a Square) would be a real no no due to the very strong (high Q) modes that will be generated from the symmetry of the shape. A rectangular panel will have strong resonances as well and this is because when it is tight it will have refelctions, if it is loose then it will have a very low resonance that is likely never to be excited (eg. Apogees ribbon midranges have a resonance in the single digit Hz range while they crossover in the 300-500Hz range). Clearly the Magnepan panels have strong modes due to the shape and the tensioning.
Clearly this can be used to offset cancellation effects, but not entirely at the resonance itself. I heard this to some extent with my Acoustats (particularly the 1+1s and almost not at all with the 4400) and less so with the Apogees. If you lower the Q of the resonance by distribution of tension in the panel and by having a non-uniform shape it works generally better and in the case of the bigger apogees pushes the resonance almost below all music excitation (very little music at 30Hz).
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- It is also inherent in the panel shape - morricab 00:34:02 05/21/12 (8)
- RE: It is also inherent in the panel shape - josh358 06:17:26 05/21/12 (7)
- RE: It is also inherent in the panel shape - JLindborg 09:49:42 05/21/12 (6)
- RE: It is also inherent in the panel shape - Roger Gustavsson 22:53:08 05/21/12 (5)
- RE: It is also inherent in the panel shape - JLindborg 00:24:31 05/22/12 (4)
- RE: It is also inherent in the panel shape - Roger Gustavsson 02:44:41 05/22/12 (2)
- RE: It is also inherent in the panel shape - JLindborg 03:34:54 05/22/12 (1)
- RE: It is also inherent in the panel shape - Roger Gustavsson 22:01:08 05/24/12 (0)
- RE: It is also inherent in the panel shape - morricab 02:24:52 05/22/12 (0)