The Nth Degree Posted January 4, 2012 Share Posted January 4, 2012 I've been planning a fairly small layout and I'm thinking of a novel (?) baseboard construction method. From my days of seeking audio perfection (a very expensive child and partner preclude such activities now) I remember that vibrations cause sound. This is good in speaker cones and such, otherwise you'd hear nothing, but in cabinet construction it is attempted to be engineered out to avoid resonance distortion. I once recall a speaker cabinet made of concrete 15 or 20 years ago. With that in mind, I've been thinking of an aluminium sheet of about 5mm over a 1m span will be stable enough not to 'bounce' laterally, and therefore avoiding most or maybe all of the sound produced by locos trundling about. Lanscape items, such as hills, are also perfect for producing a drum-type noise amplifier, so securing these with a vibration-absorbing silicone or rubber sealant should eliminate that source too. As an added bonus, the baseboard will be incredibly lightweight. Has this been tried before? I can't see anything like this with a search. What are your thoughts? Link to post Share on other sites More sharing options...
Kallaroonian Posted January 4, 2012 Share Posted January 4, 2012 I recommend styrofoam with an underlay of camping mat foam. It is light, silent and very easy to work. I think what you have suggested might work but would rely on everything being 100% rigidly fixed and/or sealed to avoid vibration - any inadequacies in that regard and the vibration would be worse. I think 5mm aluminium sheet might be expensive as well so if you intend a large layout that might be a problem. There are various threads on here about the use of styrofoam rgds Link to post Share on other sites More sharing options...
trisonic Posted January 4, 2012 Share Posted January 4, 2012 It is mass that stops sound. Anything else is fudging the issue. Baseboard tops transmit sound well because they are like a drum skin. You want something underneath to deaden it like a piece of 4x4 glued (by a system of trial and error) in the right place, the centre is probably a good place to start. Best, Pete. Link to post Share on other sites More sharing options...
The Nth Degree Posted January 4, 2012 Author Share Posted January 4, 2012 Pete, I agree in your statement, but if sound were not generated through vibration you wouldn't have to absorb it, no? Your method absorbs vibration but mine eliminates the generation of vibrations. Link to post Share on other sites More sharing options...
RMweb Gold Re6/6 Posted January 4, 2012 RMweb Gold Share Posted January 4, 2012 I recommend styrofoam with an underlay of camping mat foam. It is light, silent and very easy to work. I think what you have suggested might work but would rely on everything being 100% rigidly fixed and/or sealed to avoid vibration - any inadequacies in that regard and the vibration would be worse. I think 5mm aluminium sheet might be expensive as well so if you intend a large layout that might be a problem. There are various threads on here about the use of styrofoam rgds I wholeheartedly agree. The only way to go for me from now on. Links and links to links here http://www.rmweb.co....182#entry463182 Link to post Share on other sites More sharing options...
Kallaroonian Posted January 4, 2012 Share Posted January 4, 2012 Or here : http://www.rmweb.co.uk/community/index.php?/topic/46161-knauf-pink-polyfoam-space-board-insulation-boards/page__fromsearch__1 here: http://www.rmweb.co.uk/community/index.php?/topic/34132-styrofoam-baseboards/page__fromsearch__1 and here: http://www.rmweb.co.uk/community/index.php?/topic/43834-styrofoam-gradients/page__fromsearch__1 Link to post Share on other sites More sharing options...
silverlink Posted January 4, 2012 Share Posted January 4, 2012 Interesting idea however, I have one big concern, electrics! if any layout wires should acidentally touch the alluminium would it not create a short circuit? silverlink Link to post Share on other sites More sharing options...
RMweb Premium Kris Posted January 4, 2012 RMweb Premium Share Posted January 4, 2012 It seems like a lot of effort to eliminate only a small amount of noise. Link to post Share on other sites More sharing options...
billbedford Posted January 4, 2012 Share Posted January 4, 2012 If you really want to reduce the noise of your train you have to make sure that all your stock has properly sprung suspensions. Link to post Share on other sites More sharing options...
buffalo Posted January 4, 2012 Share Posted January 4, 2012 ...Your method absorbs vibration but mine eliminates the generation of vibrations. It's the movement of rolling stock that generates the vibrations. If you want to avoid that, it's simple, just don't run any trains Interesting idea however, I have one big concern, electrics! if any layout wires should acidentally touch the alluminium would it not create a short circuit? Don't use the foil coated stuff, it is nothing like as solid as the extruded pink or blue poly foam. Nick Link to post Share on other sites More sharing options...
The Nth Degree Posted January 4, 2012 Author Share Posted January 4, 2012 Styrofoam is a good product and I've used it in my job but it seems to me like a big low frequency bass drum to me, unless you rib it and limit your access to the base. Sprung wheels on 2mm stock is not an option for me, I'm afraid... I may be able to get a sheet for next to nothing and I'd like to experiment, if only to provide an experiment for research. Electrical isolation is a concern but only as far as having good isolated electrics to begin with. I only plan to have the track DC electrified, everything else wil be controlled with levers or crank handles and for that I can use a non-conductive material. Link to post Share on other sites More sharing options...
Kal Posted January 4, 2012 Share Posted January 4, 2012 Hi Apart from Cost and ability to work AL with ease,( it is not a straight forward material to cut or shape especially at 5mm), you should consider the weight. Each of your 5mm sheets at 1m Square will weight 1.3KG. L (mm) x W (mm) x D (mm) x 0.00000026 = x Kg Regards TNT Link to post Share on other sites More sharing options...
smokebox Posted January 4, 2012 Share Posted January 4, 2012 Hi Apart from Cost and ability to work AL with ease,( it is not a straight forward material to cut or shape especially at 5mm), you should consider the weight. Each of your 5mm sheets at 1m Square will weight 1.3KG. L (mm) x W (mm) x D (mm) x 0.00000026 = x Kg Regards TNT Are you sure that your decimal places are correct? using this calculator it comes out at 13.5 Kilos Link to post Share on other sites More sharing options...
The Nth Degree Posted January 4, 2012 Author Share Posted January 4, 2012 Wow, that's heavy. How does it compare to ply box section? At least it will provide mass! Link to post Share on other sites More sharing options...
RMweb Premium Kris Posted January 4, 2012 RMweb Premium Share Posted January 4, 2012 It would be much heavier. A meter square box section even using thick ply will be circa 5kg Link to post Share on other sites More sharing options...
muddys-blues Posted January 4, 2012 Share Posted January 4, 2012 How about using an open baseboard method ? Link to post Share on other sites More sharing options...
westerner Posted January 4, 2012 Share Posted January 4, 2012 Thinking about trisonics comment about mass. I once read of some one who built his baseboards using kitchen work tops and apparently there was very little sound, not too good for a potable layout though. Link to post Share on other sites More sharing options...
Kal Posted January 4, 2012 Share Posted January 4, 2012 HI You are correct, my decimals are all over the place, should have read: L (mm) x W (mm) x D (mm) x 0.0000026 = x Kg Regards TNT Link to post Share on other sites More sharing options...
RMweb Premium zarniwhoop Posted January 5, 2012 RMweb Premium Share Posted January 5, 2012 It seems like a lot of effort to eliminate only a small amount of noise. I've got a test-track baseboard using 6mm ply for the surface - a drum skin is a very accurate description! Personally, I *like* the noise (especially with rail joints filed at the correct length), but with heavy models (e.g. Heljan class 33) it *does* get loud, even at scale speeds.Of course, on the narrower gauges (HOm and HOe/009 in my case, but N is the same) nothing is heavy enough to make a noise. ĸen Link to post Share on other sites More sharing options...
The Nth Degree Posted January 5, 2012 Author Share Posted January 5, 2012 That's a very valid point Ken, I didn't consider that. Link to post Share on other sites More sharing options...
34theletterbetweenB&D Posted January 5, 2012 Share Posted January 5, 2012 From my days of seeking audio perfection .. I remember that vibrations cause sound. This is good in speaker cones and such, otherwise you'd hear nothing, but in cabinet construction it is attempted to be engineered out to avoid resonance distortion. I once recall a speaker cabinet made of concrete 15 or 20 years ago. With that in mind, I've been thinking of an aluminium sheet of about 5mm over a 1m span will be stable enough not to 'bounce' laterally, and therefore avoiding most or maybe all of the sound produced by locos trundling about... There are a number of things to keep in mind. Just like hi-fi, source first. What creates the vibration?: answer the locos and stock moving. Quiet mechanisms and good quality wheels make a difference in minimising the input energy of the vibration. What turns the vibration into audible sound?: coupling of the vibration source to the air mass in the room. In OO there is an audible difference between the sound conduction from code 100 track as compared to code 75. The lighter rail attenuates the conducted vibration. Don't know whether a similar effect is noticeable in N. Decoupling the track (the vibration source runs on) from the baseboard by a compliant material (flexible at vibration frequency) layer will attenuate conduction of the vibration to the baseboard structure. (Similar material to the flexible suspension surrounding the loudspeaker diaphragm.) Baseboard structure: there are several ways of skinning the cat here. Reduce the excited baseboard area. A flat sheet couples any applied vibration pretty efficiently to the air mass, so a narrow track bed as opposed to a large plane sheet can help. (Your large flat sheet of ally is likely to be bad news, that's a good size diaphragm. Remember how the original acoustic gramophone worked? Needle rattles about in a groove, and to be room audible that needle was coupled as rigidly as possible to a large horn. The energy involved is probably about the same order as N gauge trains, and while your large sheet won't be as efficient as a huge horn, it will still go some o the way toward that.) Use compliant baseboard materials, that absorb well in the frequency band produced by your locos and stock. Use a high mass construction that damps the applied vibration Apply mass damping or compliant material selectively based on experiment. Have fun. When you want a real laugh, go and look at the DCC sound section. Do you think they are ready for cable sexing? Or should I wait a few more years before launching my six 9s pure mono crystal copper silver plated speaker cables for optimum transmission... Link to post Share on other sites More sharing options...
shortliner Posted January 5, 2012 Share Posted January 5, 2012 My Fiddlestick Switch Job has a pine frame 4" deep with an MDF surface - I don't have a problem with noise, because it has two speakers built into it, with an MRC soundbox supplying the engine sounds etc - If you can't cure it - work around it! Link to post Share on other sites More sharing options...
The Nth Degree Posted January 5, 2012 Author Share Posted January 5, 2012 34C that is a very technical response, and right up my street. Good to see another audiophile here! Isolating the trackwork from the box-shaped (drum) baseboard is probably the simplest method to eliminate most of the sound. Using a pliable glue to fix the track to the carrier (cork or closed-cell foam) and using the same glue to fix the carrier to either open framework or a dense (mass) base seems to be the way forward. Or do something similar to Shortliner and use noise-cancelling electrics! Link to post Share on other sites More sharing options...
Kallaroonian Posted January 6, 2012 Share Posted January 6, 2012 My comments are based on recent experience. I'm using styrofoam with closed cell foam as an underlay. It is a lightweight and easy to work combination. It is also virtually silent but this is highly dependent on the loc. As 34C said the locos and stock are what vibrates and this is transmitted through the air as noise. The question here then becomes one of whether the baseboards are making this worse or not (they cannot make it better since the coupling of the vibration to the air mass happens regardless. I have only got as far as completing the early stages but I was able to run some trains before Christmas. Yay. What I can tell you is that old Airfix cl31 + 8 coaches is quite audible. Using an old Hornby cl37 (ringfield motor) it is very noisy but using the A3 White Knight it is practically silent - just the "rush" of the coaches. This tells me i) my baseboards are working well and not causing any resonance ii) old locos will always sound like food mixers.... Rgds PS interestingly the performance of the Cl31 remains as excellent as ever. While the speed drops off on the areas that is gradient+curve it keeps going just fine and could probably pull a lot more than 8 coaches. The cl37 really needs to be driven because if the speed isn't maintained it will stop and end up stuck with the wheels spinning. The A3 experiences some minor slip but manages OK. Link to post Share on other sites More sharing options...
RMweb Gold Re6/6 Posted January 6, 2012 RMweb Gold Share Posted January 6, 2012 ........................old locos will always sound like food mixers.... Link to post Share on other sites More sharing options...
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