Is it beneficial to add a sound deadening sub-roadbed? I was planning to glue cork roadbed directly over plywood and I’m wondering if it’s worthwhile adding a layer of sound absorbing material onto the plywood first.
I’ve read of others using foam, ceiling tile and homosote, but wonder if it makes a difference once the scenery is in place and the track is ballasted.
I live in the humid southeast, model in HO, and plan to add sound to my steam locos. [?]
Hi. First, I have never actually tried this, but I have another hobby where dual-density foam has a beneficial effect in dampening vibration. If…if…we can generalize to a healthy extent, then it should also work for sound. So, I will say that it should work, and something like a lino or flooring underlay may do the trick. Experiment on a length on the plywood and see how it works with a heavy loco.
I would be interested in your findings. Maybe try with just the one layer, and see how the newer way turns out in comparison.
Here’s an article that arrived in today’s MRMag newsletter.
http://www.trains.com/mrr/default.aspx?c=a&id=631
I’ve been experimenting with a second layer of homasote attached to the first layer at very few places. The air gap and the minimal routes for the sound to travel to the wood subframe seems to help reduce noise when ballasting with the traditional white glue/water mixture.
I only recently discovered this so I don’t have a lot of information and it would be impractical to tear up my layout and redo everything but on my next layout…
Tom
On my last layout, I had sound deadener ONLY, and it worked great.
On a friend’s HO-scale layout that is built on styrofoam with cork roadbed, the trains make a lot of noise because the styrofoam amplifies the sound. On our club layout and my home layout, both HO scale built on hollow core doors with two half-inch thick layers of Upson Board (Sound Board) glued down with carpet mastic, and cork roadbed, the trains are much quieter. The only sound you hear, except in the case of a sound equipped locomotive, is the rush of metal wheels on the rail. When you glue down ballast, it also tends to amplify sound and will cause styrofoam to be even louder.
Even thick foam like 2" will amplify sound?
It depends on what’s under the 2’ foam. The thicker the sub base the quieter it will be. Foam glued to thin (1/4") wood or none at all will be the loadest.
Use matte medium or WS scenic cement instead of white glue. These never harden like wood glue and therefore don’t transfer sound as readily as wood glue. Tacky Glue works similar.
Finishing the rest of the scenery will also help quiet things down.
How about this one: once the wiring is done, add fiberglass insulation underneath in between the girders of the benchwork.
Good idea. All I have for my base is 2" pink foam board. SInce it’s a logging layout, I hadn’t planned on roadbed. Would it be worthwhile to even put down 1/8" cork? Thanks for your reply.
Plywood, Homasote, cork, track. Keeps things about as quiet as I can imagine. Also, the heavier the plywood the less sound. I am about to try oriented strandboard an the new layout in lieu of plywood. Cheaper and heavier.
Is the sound of running trains really big a deal?
What is wrong about hearing the clicity clack of the trains, i like it. When is the last time you saw a real train go by & not heard it. No sound seems sooo unnn prototypical for those rivet counters out there. PS i do not count rivets.
Larry
It isn’t the clickety-clack, but the loud roar that tries to hide the clickety-clack. In between the clicking, the wheels still generate noise along the length of the rails, and this is like scale thunder if you don’t control for it.
I found the quietest places on my layout, bar none, were over my wooden trestles. The trains fell dead silent except for the clicking.
My previous layout was 90% temporary, with Kato HO Unitrack placed (not attached in any way) on plywood trestle tables supported by collapsible sawhorses. This (temporary) portion of the layout was 100% quiet - just the clickety-clack over turnouts and the gentle, soothing sound of metal wheels on metal rails. I could even hear the increased friction when the trains went round the curves. I did have a small yard and terminus area that could easily be removed for storage, but the track itself in this section was not temporary. This section used 3/4 inch plywood covered by an 1/8th inch sheet of cork glued to the plywood, with the track spiked down. This was noticeably noisier than the temporary-track section but not bad. A removable bridge section connected the two afore-mentioned sections. It used 1/2" plywood (because I had a big enough piece lying around and didn’t want to blow money on another whole piece of 3/4"). I had Homabed homasote roadbed, and track spiked to it. This section was an incredible sounding board and drove me absolutely nuts - I hated having to run trains across it. Curiously, it was the only one of the three sections not mechanically connected via supports to the floor (it was connected at either end to the other two sections with carriage bolts); don’t know if this is relevant or not.
My current layout - a 6’ x 14’ HO one - is also temporary while I complete the finishing of our basement (a political requirement before I can start a permanent layout), but since it does not have to be taken down, I have glued down much of the track. This layout uses styrofoam (minimum 1" thick) on hollow core doors on sawhorses. It is 100% quiet.
This topic interests me greatly because (a) I’m nearly done finishing the basement and (b) I was planning to use 2" styrofoam on a plywood base. I’m very surprised to hear that people have found the styrofoam to be a sounding board.
It is if you have the plywood’s nether surface exposed to the floor. If it is glued to, say, 5/8" or thicker plywood, you will find it heavier, more expensive, but considerably more quiet than formerly.
In the case of the hollow door, their was a change in density between the roadbed and the door 's upper veneer, between the door and the hollow air-space, between the hollow air-space and the veneer, and between the nether veneer and the surrounding air.
That is why I stated, earlier, that dual-density eva, vinyl, open celled foam rubber, you name it, and cork or homasote should quieten things quite nicely. The sound waves will be refracted and diffracted in so many ways in the various media that they get dispersed.
Yes, much bigger deal than I would have ever imagined… What happened to make me see the light was a modular layout. When I hooked mine to another, during our coversations we suddenly noticed we where shouting at one another. Why? The train had moved off the modules with the sound deadening roadbed onto one that didn’t have any. When the noise is constant, one tends to ignore it, when it suddenly goes away; it is amazing how peaceful the train room becomes.
THE PROBLEM is the layout material acts as a ‘Soundboard’.
Motors and rolling wheels create vibrations. Easiest is to add a vibration-absorbing layer as insulation - especially if you want to hear more sound from those small speakers. CORK ROADBED is often the easiest.
With milled wood or plastic roadbed (trimmed) rubber sheeting works. Insulating track vibration from the soundboard is the key. BEWARE of nails transmitting the vibration.
NAILS and white glued Ballast transmit vibration, so now I use double thickness cork - HO GAGE ON TOP OF O GAGE - and a ‘soft’ glue such as Matte Medium for ballasting. The double ‘profile’ looks far more prototypical, and absorbs sound better than 1/2" Homasote. 3/8" nails won’t transmit vibration, and neither will the matte medium, plus it bends easily…
DON’T take my word for it. The Homosote (I’ve used) is 0.5"somewhere. A double layer of cork is 0.4", looks better, and is quieter under a 3’ section of operational Flextrack. TRY IT…
I haven’t tried it yet, but I have considered using Woodland Scenics foam roadbed on top of cork roadbed. To maintain the ballast slope, I would space the two halves of the cork apart about 1/4-1/2" which would place a channel of air beneath the center of the track. I’m not sure if that would deaden the sound or create an amplification chamber, but I though it would be an interesting experiment. Of course, even if it works, the major downside is that you’ve doubled the cost of your roadbed. Randy
I just purchased the WS foam roadbed. When I worked out the cost, it actually turned out to be less expensive per foot than cork roadbed.
I’m curious about the sound deadening properties. My last layout used cork over a foam base and it seems fairly quiet (but not perfectly).
-Tom
There are several issues that can lead to sound problems:
My layout has Homabed roadbed glued to 1/2" plywood(cheap carpenters yellow or white glue). The Atlas code 100 track is spike down with 1/2" brads. The scenery is ‘hardshell’. So far the sound has not been too bad. Ballasting is with real rock ballast and Matte Medium. This layout was started in 1987 and I really had no concept of how bad the sound would be at that time. If I were to start over, I would use a soft latex glue/caulk to secure the track to the roadbed. I am sure the track nails transmit the sound from the track to that 1/2" plywood. I ballasted about 6’ of track with white glue, and noticed the sound issue right away! Further ballasting was done with Matte Medium. Ballasting seemed to be the biggest sound issue.
A friend is building a layout with 2" foam glued to 3/16: plywood(stiffen the base, and provide a mounting pad for switch machines). It will be interesting to see what sound issues he faces…
Jim