ACOUSTICALLY aluminium is not great! It's very resonant, no dampening from the material. You can cheaply cast funny shapes. And yes, it feels better as plastic.
A wood/plastic compound could be made acoustically way better - that's for sure! It provides some dampening and is still leightweigth.
When you knock a KH120 and KH120ii you get the difference. I recorded sound samples here somewhere.
It's ok when you like Aluminium - but ACOUTICALLY it's not a great material, it needs effort to make it work. Bite the bullet - that's physics, you can't change it with your liking for a material.
(Plexi glas or iron would both be a better material. But both not cheap to cast or very heavy. There is also a pretty good material named "wood" ... but that is too expensive when you want rounded surfaces (which we WANT!!!))
p.s.: I did a lot of material test - don't discuss technical facts, they will not change. Coincidence frequency perfectly shown from 6mm ALU (no dampening from the material) and significant lower Q with Plexi. 6mm Alu is heavier, dampening at lower frequency depends on the weight. You would need to copare to 14-15mm Plexi.
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