club have many locos with sound. Some seem too loud and anoying.
has anyone given thought about what a realistic sound level (~dB SPL at some distance) should be, in particular when there are multiple locos active at the same time?
greg - Philadelphia & Reading / Reading
Best answer is "it depends."
Size of the room, how the room is finished (wall, floor and ceiling materials), other noise (A/C or heating, onlookers).
I've never heard of a club with a specific rule. I would think a good rule of thumb would be that no loco should be much louder than the others, then consider overall sound.
I think a couple of my locos are a bit loud for others and there are a couple I have thought about turning up. I wear hearing aides, so do not hear some sounds as well as other folks.
Out of courtesy to others, all loco owners should be willing to turn down the sound at a club layout, so that no loco stood out and an overall sound level was not too loud.
Soounds like a club level problem and a consensus would have to be reached on how to monitor the sound levels.
Good luck,
Richard
I can't give an expert insight on that.
But a suggestion would be to have a group of folks get together as a panel. Put one loco on the track, near the group, and adjust the master CV up and down to put a range on the too loud and too soft "limits". Use a sound meter (like my Android phone app) that would be the agreed tool in the future. (Repeatability matters, not absolute accuracy to true dB levels.) See what the consensus level is for one loco, perhaps in the middle, and make that the loco target (using that tool). Anjust any new loco to that spec. Consider both high rpm and horn sounds.
Then go to a relatively large number of locos running simultaneously and scattered a bit, to see if the additive effect (sound works funny in terms of our perception or tolerance for increased loudness). If needed, lower the target a bit and ask everyone to tune reasonably close to that.
That would be one way to approach it. Realize that half the battle would be in different viewpoints / opinions of what various folks prefer, as there is no "right" answer. And it sometimes depends on duration. It can be nifty at a higher level for awhile, but then preferable to turn it down. And some folks don't like small scale sound reproduction as they think none is better than our compromise sounds.
Paul
Modeling HO with a transition era UP bent
First, as soon as I have set the cab # as the address, I get into the master volume of a new/newly reset decoder and halve the maximum value the manual says it can rise to. From that much more civilized cacophony, I adjust the individual volumes. I set injector, blow down, pop-off, hiss, and turbo-generator even lower so that I can just hear them. The bell is also low, but not as much, and the same for the whistle and chuff. I have to custom-fit each loco for the installation parameters of the speaker and the capability of the decoder. This takes maybe five minutes with each new/newly reset to defaults decoder. I have to do this perhaps twice a year. Once just for practice.
In an generally quiet room of any size where loud males aren't commanding all the attention, decoders don't need to compete at such a volume that they destroy any pleasure they may offer the person wanting very much to appreciate all their various sound capabilities. Imagine a busy restaurant, not even a 'family' one with kids and annoyed teenagers complaining that the service is slow...you have been there. You talk louder to hear above those who hear you talking louder, thus forcing an ever escalating cycle of auditory desperation.
On the face of it, if you are the only one put off, you are in trouble at this place. If no others have noticed, or attempted to negotiate a happy medium themselves (and obviously failed...), you have a tough row to hoe. Tough sledding. An uphill battle (infanteers will get this). You'll have to hope that some of them admit they know what you mean when you raise the matter at a meeting. If they do, maybe you can ask for some support to a bylaw or policy that all decoders have to be set to approximately half their maximum volume level as set in the Master Volume CV....or less. No more than half.
FWIW, I really liked the QSI feature when they were more popular that allowed one to customize the mute level. With mine, I could mute them to about 20% of the max value and they'd just barely be aubidle sitting there idling, waiting to be called to duty. Otherwise, locos are fully muted if they are not being used, or removed entirely from the rails. I keep only one working, usually, and one or at most two whispering out their neutral/idling sounds somewhere around the layout.
In the confined spaces of even large layouts, decoder sounds should not compete with locomotives more than about 12 feet away. They don't scale anyway, just like real water. If not, you get the strident competition of Ye Olde Tavern an hour before last call.
This is the practice used by the Edmonton Model Railroad Assoc. The locomotive and db meter are about a foot or so apart. The db meter is a cell phone app. Accuracy is not important for the meter just consistancy. The actual levels you choose is a personal preference but this works for us.
Sound volumes need to be low enough that the sound is for the most part isolated to the area the locomotive is in. People operating or working in other areas of the layout should not hear the locomotive. You may hear or read this referred to as the 6 foot rule.
The "Time-out" Configuration Variables (CVs) shut off the sound after a time-out period to units or consists not in use. In some cases all functions must be shut off first (Soundtraxx). "Sounds on Power Up" CVs configure when sounds will start. NOTE: Not all decoders have these features.
Yup - "it depends". At home, I like them fairly quiet, so I can hear them when standing next to them but not standing across the room. In public club displays, I turn them up all the wya, or as loud as they will go without distortion - in a big open venue with lots of people, you'd never hear them at ALL on my 'home' setting, plus the crowd wants to hear the whistle blow. Just like they want to see stuff always moving, realistic switching bores most common spectators.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
All,
To date, the SoundTraxx Bachmann Sound Value family of decoders do not support CV 113 - Quiet Mode Timeout Period.
RR Baron
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!
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.
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.
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.
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.
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.
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
Not quite true, while most don't support CV113 there are a few according to Soundtraxx documentation that do.
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.
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
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).
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
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.
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.
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 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.
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/
Website: http://bobfrey.auclair.com
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.
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)
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
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.
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
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
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.
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.
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.