I just read that this material called UltraLam is being used by Spatial in their new X Series.  Is has some really good density properties.  

I believe I actually heard about this material a while ago when I was searching for GluLam beams for a housing project, but I never thought of the audio application for it.  It's a German laminated, ply product and can be order in special lengths and densities.  I haven't checked pricing, but it could be a more consistent product than other materials and may also save labor costs if it can be ordered in certain thicknesses.  It also looks cool and can be tinted certain stain colors when ordered, etc.

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