In a 3 three deck layout room, you can operate with a diesel horn about 1 Ft. from your face. I am more of a 70 dB(A) at 2 ft. type of person. I think it should be more general as to how far is your Diesel horn from your visitors’ ear?
I am 5’ 6” My layout in places is 4’ high. Horn say 6” from the edge. I walk with my arm about 6” from the edge. This comes out to about two feet from the horn to me ear for me. Your visitor could be further back to say 3 feet?
Set sound parameters, based on feet?
Bob Frey
Website: http://bobfrey.auclair.com
pocovalleyI really don't want to hear a locomotive on the opposite side of the railroad room.
i believe this is an unrealistic expectation. The physics of sound does not "compress" way that we model our layouts.
In general, I think the measure of a sound being too loud at some distance is if at that distance someone would need to speak louder for the type of sound being generated.
Background noise above 71 dB SPL cause people to start speaking louder. This is 3 dB lower that the average talker level of 74.
Based on the noise level of a coal train I previously posted, this would be between 1 and 2 ft. Assuming this noise level is the same for steam chuffs and prime mover, it means that you would not need to talk louder if you stood next to the engine and were more than 2 feet away from it.
However, a prototype whistle could be 30 dB higher. I don't think it's realistic to model this, but it suggests that a whistle might disrupt someone speaking (~)10 ft away. This translates to 77 dB at 5', 83 at 2.5' and 89 at 1.25'.
at 3 ft, whistle/horn would be ~85 dB SPL and steam chuffs/ prime mover 65 dB SPL
i recently measured the background noise level of ~~55 dB SPL in a layout room about 20 ft from some people talking. So while the prime mover level of 65 may seem low, it should be noticable 12 ft away, 12 dB lower level of 53.
i think using the disruption of someone talking 3 ft away from you as a measure is reasonable starting point for evaluation.
greg - Philadelphia & Reading / Reading
Our club, Pacific Southern, Rocky Hill NJ, is about to set some sound parameters, using a small sound meter, so your figures are quite valuable. Our proposed approach is to test a variety of locos running on the RR with the meter at a 3' distance for chuff/prime mover, bell snd horn/whistle. Once the values are recorded, we would select units that displayed an "acceptable" volume level and use those sound levels as our reference. The owner would need to tone down the louder units before they could be run further. We are mostly interested in steady state noise; the louder chuff of a steam loco at startup would not count. A steady rod clank would.
Should be a challenging endeavour.
With a walk-around railroad, I've always felt that the loco should only be as loud as to be heard when you are near it. I really don't want to hear a locomotive on the opposite side of the railroad room.
The club I belong to has an accoustic meter and sound standards. Most locos are at or below the max sound sandard out of the box. However knowing what your whistle/air horn sounds like is a quick way to find out where your train has run off to. We have a lot of visitors with a lot of questions. Our layout is loosely based on EsPee's Donner Pass line. We have more varities of cab forwards than any other steam locomotives. Although we run just about anything on occasison. Bet ya didn't know G-1's ran on Donner didja?
I'd keep the sound volume low or in the middle.
That way it's not super loud.
The threshold of hearing is generally reported as the RMS sound pressure of 20 micropascals, or 0.98 pW/m2 It is approximately the quietest sound a young human with undamaged hearing can detect at 1,000 Hz. The standard threshold of hearing at 1000 Hz is nominally taken to be 0 dB.
The first research on the topic human ear was Fletcher and Munson in 1933
https://en.wikipedia.org/wiki/Fletcher%E2%80%93Munson_curves
International Standard The IEC 61672-1:2013 mandates the inclusion of an “A”-frequency-weighting filter in all sound level meters. In almost all countries, the use of “A”-frequency-weighting is mandated to be used for the protection of workers.
“C”-frequency-weighting is for music. (Flat over a large frequency range.)
dB must be reported at a distance When distance doubles is a -6 dB change.
1. Background Noise If the level difference between the absence and presence of the sound is 10 dB or more the influence of the ground noise may be disregarded.
2. Reflection The microphone should be placed well away from reflected surfaces. Hold meter at arm’s length. This will help to avoid reflections from your body.
3. Exposure to 85 decibels or more for 8 hours is hazardous.
U.S. Department of Transportation Federal Railroad Administration
The Use of Locomotive Horns https://www.fra.dot.gov/ Page/P0105
Under the Train Horn Rule (49 CFR Part 222), locomotive engineers must begin to sound train horns at least 15 seconds, and no more than 20 seconds, in advance of all public grade crossings. If a train is traveling faster than 60 mph, engineers will not sound the horn until it is within ¼ mile of the crossing
Sound of train horns compliance
Title 49 → Subtitle B → Chapter II → Part 229 → Subpart C → §229.129 Locomotive horn
Each lead locomotive shall be equipped with a locomotive horn that produces a minimum sound level of 96 dB(A) and a maximum sound level of 110 dB(A) at 100 feet……..
(3) Each remanufactured locomotive shall be tested in compliance with paragraph (a).
(8) Background noise shall be minimal: the sound level at the test site immediately before and after each horn sounding event shall be at least 10 dB(A) below the level measured during the horn sounding.
(9) Measurement procedures. The sound level meter shall be set for A-weighting with slow exponential response ……..at least six such 10-second duration readings shall be used to determine compliance.
http://atsf.railfan.net/airhorns
The Prime Manufacturing Corp. of Oak Creek, WI produced a horn identical to the S-3L which they called the PM-920. Factory tuning for both was: B inverted 7th (B, D#, A) or 493, 633, 880 Hz tones.
At ¼ mile to the crossing, the minimum horn sound is 74 dB(A)
I have now reported what you should hear standing at a railroad crossing. Sound can be measured and reported by you. http://www.amazon.com sound level meters
Enjoy, it took me some time to find all this information.
I'm about 10 blocks from the tracks - lots of houses in the way but I am also up hill from the tracks. I hear horns all the time. Rarely a prime mover. Heavier trains, that's about it, as there is an upgrade coming away from CP Wyo and I can hear when they throttle up.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
wjstixA diesel airhorn is many times louder than the diesel engine sound of the locomotive.
A steam whistle can generate 110 dBC at a 100'. This is 30+ dB louder than a diesel train 88' away (from data I previously posted). I live about 3 miles from the Northeast corridor (New Brunwick) and can hear train whistles at night and maybe the rumble of a train.
One thing I notice with sound-equipped engines (as someone who has lived their whole life within earshot of a railroad) is that many decoders have the horn or whistle the same volume as the steam 'chuff' or diesel rumble...and that's wrong. A diesel airhorn is many times louder than the diesel engine sound of the locomotive. When the Soo Line owned the line that ran in front of my house, you could hear the BLAT airhorn a mile or so away, but you didn't really hear the engine until it was within a block or two.
I work as an acoustical consultant so this discussion is of interest to me. First, several responses mention using a sound level meter phone app to perform measurements. This is fine since they also correctly state to use a single designated phone to perform ALL the measurements. This must be done because there is no convenient way to field calibrate a smart phone so the same SLM app on different phones could (and usually do) report differing sound levels.
One response mentioned a dBC or "C weighted" reading. Never use the "C weighting" to make sound measurements meant to control the way people react to sound. We can't hear all the frequencies the way the "C weighting" network does. Always use the "A weighting" network as it is meant to measure sound the way people hear it.
It has been my experience that is it nearly impossible to set a sound limit that everyone can live with. Some of us are overly sensitive to sound while others are deaf as a post! Most of us like certain sounds and hate others. Depending on the task we are pursuing at the time, a sound can be perfectly acceptable at one time but totally unacceptable at another time. Say there is a big game on TV Saturday afternoon but you have to mow your lawn. You get up early and spend a couple of hours three feet behind a lawnmower putting out around 85 dBA. Didn't bother you in the least! Come game time, you've got your pizza and beer ready for the game to start but your neighbor chose that exact moment to fire up his lawnmower to mow his lawn 100 feet away. Now that same sound (but at only around 55 dBA if your windows are open) is driving you nuts!
It has also been my experience that a person complaining about a specific sound source won't be happy until that source is completely gone. Reducing the level of that source, even significantly, tends to have no effect for such people. If Joe doesn't like the sound of your Peanut whistle on your 0-4-0 switcher, he will likely complain it is too loud. Yet the Steamboat whistle on his J Class will sound great to him, even if he has it set so loud that others have to cover their ears.
As already noted, multiple sound equipped locos running in an enclosed space add together and can cause operators to have to raise their voices. If loco volumes are increased to be heard over people's voices, those same people have to further raise their voices to be heard again.
Everyone at an ops session needs to be aware of the limitations of operating with sound and should be willing to adjust (or turn off) the sound volume(s) when requested to do so. While it can be fun to run with sound, communication during an ops session is more important than whether you blew the correct whistle to call back your flagman. Oh, and the correct sound level range for "normal" conversation at a distance of three feet is only 60-65 dBA. Raised voices at three feet are 70-75 dBA and shouting is around 80-85 dBA. If operators are already speaking at 75 dBA, the background sounds are already too loud.
Hornblower
I'm sure there is a reason for turning up the sound in a club setting.
When operating alone in the confines of the train room, I like the sound set no higher than 25%.
I live near a class 1 mainline (inescapable since it runs through the middle of town). I hear the rumble of the train long before it blows its whistle. The rumble gets louder as it approaches the crossing and as it approaches my location, then the whistle blows.
The problem with onboard sound locos is that the sounds don't model scale distance very well. What I hear 3 feet in front of me tends to be exactly the same as what I hear 20 feet.....aka about a half a mile in real distance...away. That lack of difference in rumble sound as the train approaches is not captured well with our models. That's why I prefer to hear low level engine noises until the model train is very close to my space, when they then dominate the few feet in front of me as they should. Hearing them across the room seems unrealistic to me.
- Douglas
As a club member, we have challenges when it comes to sound. We have a 6300 sq. ft. room with a 12' ceiling. We have blown HVAC and two industrial dehumidifiers that run in the summer, not to mention all the cooling fans on our DCC power supplies humming away. When we're running trains alone in the layout room, it can be relatively quiet, but throw several hundred people in there for a train show, and you can barely hear the loudest engines.
Sound is also time sensitive When the SIW operates at 11:30 at night (as many prototypes do because non rail traffic is minimal)sound is banned no need to wake up the family but at 11:30 AM the sound is going full blast which in my case is about 40% of maximum.
Joe Staten Island West
Happily, this is all of academic interest to me. I am not a club member (and my present health problems will keep it that way) and I am not pleased with on-board sound in HO-size models. So my own locomotives all wear dolphins - the silent service.
Actually, they all sound like catenary motors - metal gears and open-frame traction motors. Of course, a good percentage ARE catenary motors. So I have some realistic sound without on-board electronics. I can live with that.
Chuck (Modeling Central Japan in September, 1964)
I was told many years ago that the only one who should smell your cologne is someone that is embracing you. I feel that model locomotive sound should be restricted to a similar distance.
I have the right to remain silent. By posting here I have given up that right and accept that anything I say can and will be used as evidence to critique me.
Sound level is a logarithmic measure of the effective sound pressure of a sound relative to a reference value. It is measured in decibels (dB) above a standard reference level. The commonly used "zero" reference sound pressure in air is 20 µPa RMS, which is usually considered the threshold of human hearing (at 1 kHz)
http://www.digitrax.com/tsd/KB994/decible-measurements-on-sdh164d/
I totally agree, hearing rod clank before you even get in the room - too loud. Hearing a loco in a tunnel, 15 feet away - definitely too loud. Tunnels open another can of worms - a real train in a tunnel is separated by a lot of dense rock and earth from an observer, a model tunnel, maybe a liner of some sort plus a big open space covered with a thin layer of plaster and other scenery materials. The trick, if all decoders used F8 for mute, would be to broadcast F8 starting just inside the tunnel mouth, and ending just before the tunnel mouth at the opposite end. Or we will have to put sound insulation in our tunnels to muffle the locos.
rrinkerTrying to calculate out 'scale' sound levels will likely result in values below the background noise in the room, maybe even below human threshold despite your ears being only a foot or two away from the sound loco. An interesting mathematically exercise, but one I fear yields impractical results.
An interesting mathematically exercise, but one I fear yields impractical results.
Randy,
the values i posted are all above the threshold of hearing (> -9 dB SPL), certainly above what I measured in a quiet hallway (46) but not above typical speech (74) unless you lean down (1 ft).
I hear locomotive clanks as I walk down the step to the club. That can't be right. Or chuffs 15' away in a tunnel competing with people's voices.
I don't know that you can actually 'scale' sound, like other physical phenomena it doesn't really scale. Simulate the scale distance, perhaps. Some sounds would have to either be completely ignoored or exaggerated to some degree because at the scale distance you would be standing from the model, you wouldn't hear those auxiliary sounds from a real loco. Trying to calculate out 'scale' sound levels will likely result in values below the background noise in the room, maybe even below human threshold despite your ears being only a foot or two away from the sound loco.
An interesting mathematically exercise, but one I fear yields impractical results. For my purposes, a reasonable sound level that does not overwhelm the room and allows the loco to become audible as it becomes visible around the bend, and then trail off as it disappears into the distance a train length or so away, some manual tweaking is all it will take. And unless I have two exactly idenctical locos with the same body shells, same modeal speaker, same exact speaker enclosure, same decoder, and same sound file, any settings used on one will only be a suggestion for any other loco. 30 out of 255 might be plenty for the prime mover on Loco A, which fits a nice big speaker and has open radiator grills for the sound to get out, but Loco B might need 100 out of 255 with its smaller speaker and more closed up body shell to get the same sound volume at the same distance.
CNR378 RR Baron All, To date, the SoundTraxx Bachmann Sound Value family of decoders do not support CV 113 - Quiet Mode Timeout Period. RR Baron Not quite true, while most don't support CV113 there are a few according to Soundtraxx documentation that do. Peter
RR Baron All, To date, the SoundTraxx Bachmann Sound Value family of decoders do not support CV 113 - Quiet Mode Timeout Period. RR Baron
All,
To date, the SoundTraxx Bachmann Sound Value family of decoders do not support CV 113 - Quiet Mode Timeout Period.
RR Baron
Not quite true, while most don't support CV113 there are a few according to Soundtraxx documentation that do.
Peter
Peter,
Has the documentation for a Sound Value decoder showing it supporting CV 113 been verified as accurate? Too many known discrepancies between some Sound Value decoders and their documentation on SoundTraxx Bachmann webpage for me to trust documentation.
gregcA steam whistle is reportedly 110 dBC (C weighting) at 100'.
I can personally attest that if your pop-up camper is about 30' from the Durango & Silverton track centerline, you are sound asleep and the steam loco approaches in the early AM while you are still soundly sleeping, that (a) the approaching chuffing may not wake you, but (b) when the whistle is blown within 50' of your camper you will come close to hitting your head on the ceiling! You will be instantly wide awake.
One of those memorable experiences (quite a while ago).
Paul
Modeling HO with a transition era UP bent
this topic is obviously subject to opinions.
so i'm wondering if it's possible to "scale" prototype levels.
he's a paper that compared diesel and electric locomotive noise measurement. It provides several measurements, one of which is for a diesel pulling a coal train: ~80 dB SPL at 13.5m.
sound measurements are always reported at some distance. Double the distance and the level should drop by 6 dB in an open field and increase by 6 dB if the distance is halved. The following attempts to scale the measurement.
SPL m ft scale-ft 80 13.5 44.3 0.5 74 27.0 88.6 1.0 68 54.0 177.3 2.0 62 108.0 354.6 4.1 56 216.0 709.2 8.2 50 432.0 1418.4 16.3This data suggests a level of ~68 dB SPL at 4'. This is for a diesel locomotive, not a horn/whistle as the table posted earlier described. (still looking for info on a steam locomotive chuffs). A steam whistle is reportedly 110 dBC (C weighting) at 100'. As I said earlier, I measured ~46 dB in a quiet carpeted hallway. I believe the Bell System used a value of 74 dB for the average speaker (person) level a meter away, which is what they targeted the level coming out the ear piece of a phone.I think this is what to expect if you were listening to a train these distances away. The train would be noticable (above background noise) but not loud enough for someone standing next to you to have to raise their voice (74 dB).And as just mentioned, while these values may be realistic, it may make sense to use a lower level if you're constantly exposed to them for a period of time.
SPL m ft scale-ft 80 13.5 44.3 0.5 74 27.0 88.6 1.0 68 54.0 177.3 2.0 62 108.0 354.6 4.1 56 216.0 709.2 8.2 50 432.0 1418.4 16.3
If any of my locomotives had sound, I'd keep the noise level around low/medium.
Keep in mind sound can be annoying after awhile.
Greg,
I may be out on the distance, might be a bit more (but no more than 2 feet). I'd have to measure.
As I said these values work for us, using the app on a designated phone. You'll need to change these values to what sounds good to you and your members. Others sounds would use the 55 value.
CGW121 Off. The sounds are all tinney and when you get several people it sounds like fingernails on a blackboard. I am not a fan of sound. I only have one sound loco, a steamer. I would like to reprogram it so all you could hear is the whistle.
Off. The sounds are all tinney and when you get several people it sounds like fingernails on a blackboard. I am not a fan of sound. I only have one sound loco, a steamer. I would like to reprogram it so all you could hear is the whistle.
I believe that is easy to do if you find the CVs for the various sounds plus the master volume CV. It depends on the decoder, of course. Easiest to do with JMRI Decoder Pro, where each sound could be adjusted with a slider. Simply dial down the ones you don't want to function, such as chuff and steam release (whatever called), and set items like the horn and bell plus master volume to uyour liking.
For a Tsunami, I believe if you hit F8 it will silence the sounds you want to kill but also the whistle/horn and bell. So you may have to do what is described above.
On the LokSounds, which one usually sit silent when the layout power is activated, one hits F8 to start the motor and related intermittent sounds. But the horn and bell are functional withhout activating the motor with F8. So a LokSound I believe (working from memory) would not need any special attention to behave as you prefer.
CNR378The locomotive and db meter are about a foot or so apart.
CNR378 Sound Settings Volume Sound Level Overall (at idle) 45 +-2 dB Horn 55 +-2 dB Bell 55 +-2 dB Locomotive centered at Point 1 on Test Track Sound meter at Point 2 on Test Track Miscellaneous Brand Function CV QSI (Ver.7) Automatic Mute Time-out Value CV 51.5=30 QSI (Ver.7) Sounds on Power Up CV 56.0=0 Soundtraxx (DSX) Quiet Mode Time-out CV 53=1 CV11=18 Soundtraxx (DSD) Quiet Mode Time-out CV 113=3 CV11=18 Soundtraxx (Tsunami) Quiet Mode Time-out CV 113=255 Soundtraxx (Bachmann Sound value) Quiet Mode Time-out CV 113=255
the distance and the upper part of this chart is what I was looking for.
where did this come from? are there values for sounds other than bell and whistle (e.g. chuffs)?
i'm a bit surprised by the idle value of 45 dB. This is what I've measured in a quiet carpeted hallway at work.
I agree with Richard and Randy. At home I have the sound levels set to about 30% of max., but at public shows I put the sound up as high as possible. None of my sound equipped locomotives seem to suffer from distortion thank goodness.
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!