Hollow care doors, HCDs come in several standard widths the widest being 36 inches and all are at 80 inches long When properly supported they make great bases. I use 36 inch wide doors with the back 6 inches devoted to scenery not track. I adhere to the 30 inch reach rule.
I'm inclined to agree. I would expect a single flat sheet of ply or foamboard sitting on a large, open rectangular frame to vibrate/resonate much like a drum. Sounds produced by a train will likely be amplified by the "drum". OTOH, "overbuilt" layouts, and HCDs have multiple layers of material in them which baffle sounds. Well, that's my theory, anyway.
Jim and Massey, I replaced the 4 inch foam trackbed of my sectional layout with new 3/4 inch plywood and it is much quieter now. I agree that the Foam allowed a "drumming" effect. The foam is great for scenery. - Tonkphilip
Yes. It is a bit noisier with the MRC I was using. (Tech II Rail Power 1400.) I just did not feel like setting up my Track Glide, which is MUCH better.
I used 3/4 inch Birch plywood with a layer of 1/2 blue foam and on top a 1 inch pink foam. When carving the foam for a stream or other below track level scenery the blue foam will act as a warning on how deep you are. On top of the pink foam is Midwest cork roadbed and Peco code 80 track, most of the sound I hear is the motor in the locomotives The Boston Mountains Sub Division layout build thread will give you more information of my experience from the beginning. Joe
I played with cork on plywood vs the WS foam roadbed on a quad plywood TTRAK module (With center divider so essentially a double). The foam roadbed was much much quieter. I also tried mass loading the plywood from underneath (peel n stick is analogous to car sounddeadener) And that helps too.
I also have gone with: 3/4" ply and cork - However, in my yard, siding, spurs and industrial complex - the track is right on the ply. Sound/noise - ? Nothing out of the ordinary (what is ordinary-?). We are not running Lionel. I have a few sound locomotives - they sound awesome. A shot from 2016: Thanks, Wolf