Sound on N scale

Discussion in 'N Scale' started by Frank Labor, Sep 24, 2001.

  1. Frank Labor

    Frank Labor TrainBoard Member

    Has anyone had any experience with Soundtrax DCC decoders with sound, for N scale steam and diesel engines?
  2. Harron

    Harron TrainBoard Supporter

    No, but I'm pretty sure it would be a near impossibilty in a powered unit, the trucks, mechanism, frame weight, and decoder take up too much space. Have to be done in a Dummy or a freight car.
  3. bmalonef45

    bmalonef45 TrainBoard Member

    Somewhere I have seen sound cars made from Con-Cor auto racks. Probably give the most room in any n-scale car. Sure would be cool.

  4. swissrhb

    swissrhb TrainBoard Member

    We fooled around with N-Scale sound options a few years ago and we concluded the following:

    Onboard sound is a waste of time due to physics. An N-Scale car is only big enough to hold the smallest of speakers. This means that when the train gets more than a couple of feet away from you the sound disapears completely because these small speakers don't have enough power to project any further than that.

    Static Sound (placing fixed speakers under the layout) is fine but in our humble opinion this is kind of cheesy because that's not how sound behaves. Sound moves with the train in real life and static sound always stays in the same place. After a while the static sound system became rather "toy like" so we ripped it out.

    In the end we decided to simply do without sound but others will disagree with that and that's OK. The choice of course must be made by the individual but we thought we would share our thoughts.

    [ 25 September 2001: Message edited by: swissrhb ]</p>
  5. ilitig8

    ilitig8 TrainBoard Member

    Swissrhb hit on several of the problems with N scale onboard sound, the main one is physics. There are several "decent" approaches to N scale sound:

    1. Onboard. The workings of this really depend heavily on whether you are trying to recreate diesel or steam engine sounds. Steam engines are far easier for two reasons; A. you have the tender to work in and B. most steam sound is higher than 1khz which makes it possible to reproduce with a very small speaker. The tender is often decent size and a speaker and decoder isn't a problem BUT the speaker size is; the limit to speaker size is the width of the N scale car! Even using an oval speaker one is still restricted to the 3/8 inch and possibly 1/2 inch speakers. Though I have access to lots of raw drivers (speakers) the ones sold by Soundtraxx are about the best I have found for the application. Most "better" speakers (all tweeters in this case) may have a very small radiating surface BUT have a larger support structure and magnet so they will not fit. Bottom line they most useful I have found is the 3/8 inch version sold by Soundtraxx, the 1/2 version is just a wee bit large BUT with some creative frame reinforcement can be used. They will produce "decent" volume when driven by the Soundtraxx modules. The reason they don't produce much sound has almost nothing to do with the surface area or overall size of the driver. I have some drivers with about the same radiating surface as the 3/8 inch Soundtraxx button but will produce 115dB. The issue is really three fold 1. amount of power the driver can take without giving up the ghost 2. the efficiency (sometimes called sensitivity which is similar but has different units and not quite the same) of the driver 3. the power delivered by the amplifier in this case the decoder/sound module. Though a speaker and amp combo can be had this small and produce very serious volumes the cost would be rather high. With all this said onboard steam sound can be decent!

    1B. Onboard diesel is a somewhat different story. One it will NOT fit in a powered unit, dummies are hard to come by in N scale unless you wanna gut a powered version, so my "fix" is a dedicated head end car. Autoracks and 89' box cars are good choices. My choice here would be to run one of the non-decoder units that Soundtraxx makes in the car. Again you have the driver size problem but it is worse for diesel sound for one big reason.....the low frequency rumble of diesels. Low frequencies are BIG waves and due to the physics of sound small drivers just can't make the rumble. My best solution so far is a pair of the Sountraxx modules one in a headend freight car which handles the higher freqs (and rolls of naturally though I may at some point try bloaking the lower freqs via a passive crossover) and a second Sountraxx module hardwired to the DCC signal,"MUed" with the onboard sound unit and feeding the speaker level inputs of a subwoofer. Since the low frequency sound can not be locallized by humans you get a rather seemless sound. The biggest problem here is the tiny speaker only handles down to maybe 500hz (more like 1Khz effectively) and humans can locallize sound above 100hz which does leave a gap. This may or may not be irritating to you depending on your ear for fidelity (If you are used to listening to DTS 6.1 with a Classe' front end, pre/pro and power running a sextet of Totem Mani 2s and a big ole B&W 15" sub this WILL drive you nuts. But, if the last sentence looks like its written in Greek or you own anything made by Bose chances are it won't). Bottom line this is the best I have been able to do with onboard/sub reinforced diesel sound.

    2. Finally there if offboard or static sound. The best shot here is a product called MaxTraxx by QSI. Check your Walthers catalog and I must say they are a great company based on my experiance with them. Two really neat things about them are 1. they sue what they call "atmospheric sound" or something like that, its designed to make static sound move around. Though it ain't perfect it does NOT sound static. 2. They also have a very neat Doppler horn function. I suggest using their system with two rather widely spread resonably high fidelity speakers with a high efficiency. Some of the smaller Klipsch speakers (not the computer versions) work very well in this capacity. Doing this and using a subwoofer with the Maxtraxx output going to the speaker level inputs of the sub and using a relatively low crossover point for the sub (~80hz) can give excellent results. I have basically reverted to using this system instead of onboard UNTIL someone produces a specialty speaker for N scale (don't hold your breathe) that is effective both in sound and price. The biggest drawback to this system is the fact it cannot be run via handheld or radio cabs, well not completely. The Maxtraxx is designed to be connected to track power so that the sound is calibrated to engine speed this and is easily accomplish by using a cheap loco decoder hooked to the DCC signal and outputting to the track voltage input of the Maxtraxx, this keeps the sound in sync with the engines BUT you wont be able to remotely control the horn et al functions, but ofcourse you can still contral them from the base. Actually my next project in this area is to pull one of the Maxtraxx apart and make a companion walkaround controller for it....maybe after that wireless...

    My final words (know your glad to read that!) are N scale sound is possible but there are extreme limitations which you must accept and work with/around, BUT sound is one thing that REALLY brings a layout alive. One thing I have not touched on is ambient layout sounds which there are good articles on in recent Mainline Modeler and N scale mags (basically a repeat maybe even word for word). I really do wish Bob had made it a multi-part feature instead of the gloss over that was presented, but in his defense it is part of an already multi-part layout feature. I think ambient sound along with a small portion of motive power sound used sparingly but executed well could be a real jawdropper. I am currently collecting old CD players (I figure I need about 15 which gives me 30 channels of sound BUT if I had a way to record in DTS or DD on DVD I would only need 6 DVD players!) to run my ambient sounds, not to mention amps, preamps (simple pots) and speakers! And the layout saga continues...


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