Most heavy wooden parts of a piano are structural but my upright has thick , heavy front panels held in place with a few springs and plastic turn buckles . The lower surface panel may protect against knocks and bumps but the top is in between the player and the sound source . Is there a logical reason for this arrangement?
On my upright the panel to which you refer is neither thick, nor heavy.
What make and model is yours?
They might be using composite material rather than just wood.
I think Joe is right.
Many fine older uprights had 'top doors' (front panels) made from nice hardwood as a frame with inset thin hardwood panels (like my 1930s Weissbrod) and they are lightweight.
Particle board panels made from composite materials like MDF (Medium Density Fiberboard) are heavy because they are thick, and made partly of glue, and in addition coated with thick polyester. Solid plywood panels were heavy too, though I think less so than MDF.
The old Victorian-era idea of the fretwork panel backed with silk, was a nice idea acoustically (even though use on lost of awful, cheap pianos) as it let the sound out.
For me it is often an improvement in sound to hear the piano after the cover is put back. Particularly Yamaha.
Oh yes, an interesting thought. I imagine that there might be a distinction between pianos where a heavy front panel is a deliberate part of the acoustic design, and cases where it's simply a matter of cheap production.....
I dislike the ones that have the front panel permanently attached to the fallboard assembly. This is awkward, heavy, and somewhat risky. I don't know why they designed them that way.
Pwg
This has me puzzled ... because my old Kawai US-50 upright sounded MUCH MUCH better with the upper panel removed.
This has me puzzled ... because my old Kawai US-50 upright sounded MUCH MUCH better with the upper panel removed.
Each piano is individual. Different pianos may be voiced differently. Preferred tone is subjective.
Edit;. Room acoustics vary.