MDF versus Ply for lower frequencies

[augerpro]

Yes I searched, and no this isn't just an mdf versus plywood debate. I'm only concerned about resonances under 1khz, maybe even a bit lower. For example I have a three way where the mid is a dome with its own enclosure. So only the woofer running up to about 800hz would actually excite panel resonances.

Given that which is better? I figure ply being stiffer and light would have higher Q, higher frequency resonances, while mdf would be lower Q, but also lower in frequency. Is the ply resonance high enough to be out of the woofer's passband?

[planet10]

Ply is stiffer, lighter, and better damped. Energy to excite a resonance is inversly proportional to frequency. Higher Q resonances also reduce the available energy to excite reasonances.

For really low frequencies, one is also interested in keeping the box from ballooning. Stiffer is good here.

Further, in a woofer, a significant amount of the box load can be actively cancelled with a push-push arrangement of woofers.

dave