I recently listened to a Broadway Limited E7 equipped with QSI sound and was disappointed in the effect. On departure from a station stop, the engine of a prototype locomotive would rev up in response to the engineer advancing the throttle position to perhaps run 3, then once clear of yard limits, advance the throttle to a higher setting. For each throttle position advance, the engine would rev promptly but the locomotive would gradually accelerate to speed. The E7 I listened to didn’t behave this way. The locomotive speed and the sound of the engine rpms varied most unprototypically with changes in applied voltage. In another example, a prototype engine’s rpms on an up-hill climb would be high, but the locomotive speed would be perhaps as low as 20mph depending on curvature and grade. The QSI sound system I heard did not replicate this effect. Is there a feature in QSI sound that would “decouple” engine rpm sound from locomotive speed?
I recently purchased a QSI sound-equipped USRA heavy 2-8-2 and added a Sidekick in the control circuit. Two disappointments: first, the quality of the sound suggests that it comes from inside a resonant plastic shell - a bit hollow and scratchy. For that reason, investment in a chip upgrade from QSI Solutions for an onboard sound system doesn’t seem to add value in the area I would most appreciate, sound quality. Second disappointment: whether operating upgrade or downgrade, the locomotive always sounds like it is working steam. There is no sound effect of the engine drifting downgrade.
What I think I would prefer in model train sound is an off-train system with two 10 - 20-watt speakers placed at opposite ends of the train room, a fader control that smoothly shifts the sound signal from one speaker to the other to simulate the passage of a train from one end of the room to the other, a diesel engine rpm control separate from the voltage control,
While I’m not too sure about the QSI sound decoder used in the BLI locomotives, I can tell you that there are many decoders that support manual notching which would give you the same effect of the prototype. There are also many other ways to duplicate the effects of load and grade in relation to engine rpm, but this usually requires more advanced programming than most do (as is probably the case with the BLI E unit you heard), and is not supported by all of the decoder manufacturers.
On a side note, I use Loksound v3.5 decoders exclusively in all of my 2-rail O scale equipment, and I have a couple of Atlas SW’s that operate and sound very prototypically when under loads and on grades. So I can tell you that from an operations standpoint anyway, you can get pretty good results. As for reproducing the bass and overall volume levels of the diesel prototypes, I’ve never heard any system (under table, on board or otherwise) that does them justice… [;)]
My friend & I built an under-the-table sound system with mini-speakers placed every few feet to “acompany” a locomotive as it traveled around the layout. Each speaker was activated by a series of relays tripped by motion sensors between the ties as the locomotive passed overhead. It was really quite interesting and sounded good BUT…
…doesn’t even come close to today’s onboard sound systems available from various manufacturers. Nothing under-the-table can beat hearing noises coming from the actual locomotive in my opinion.
Additionally, unless you only run one locomotive on the layout, lashups and mulitple units operating at different locations cannot be replicated by an under-the-table sound system, especially if you have a switcher working the yard, a passenger train slowing down for a station and a coal train winding through the mountains, for example. You can hear all of these in concert with individual sound systems.
All of our BLI & Athearn locomotives are equipped with factory sound and sure, maybe they don’t throttle up exactly like the prototype but…these are model trains with sound at affordable prices.
Maybe you could track down a train club somewhere and spend time listening to their various sound-equipped locomotives go around the layout before you make a final decision.
Onboard sound may not be exactly what you seek but it can be a heck of more prototypical than under-the-table sound.
By the way, large, under-the-table speakers tend to make the sound out of proportion. And by the time you have to turn down the volume to get closer to proportional sound, you’ve negated the reason to build large speakers in the first place. We spent a small fortune finding this out.
How can you decouple prime mover sound from train speed?
First off, you should understand that I know absolutely nothing about DCC, by choice. Folks warned me that the small layout I’m building for my son would not operationally challenge either of us for very long, and also that DCC would greatly simplify operations, so we decided to kill two birds with one stone and stick with DC. Saved about three grand too.
Answering the first q, if you’re willing to spend the money, you use both onboard decoders and an under the table sound system. You buy two decoders per locomotive, and one is installed inside the locomotive, and covers the mids and high frequency end, while the other decoder feeds a mixer and then a subwoofer system and fills out the bass frequencies. You MU the mobile and stationary decoders so both respond to one set of throttle/controller commands. You need a mixer with enough inputs to handle all the locomotives you plan to run at one time, and if that number is less than the number of sound equipped locomotives you own, you either need a larger mixer or else a patchbay/multi-plexer to handle all the inputs.
If you crossover at the proper frequency, you shouldn’t have a problem with the bass following the train, because bass frequencies below a certain threshold are omni-directional as perceived by the human ear. You will, however, have volume problems, as the bass frequencies will remain at constant levels, while the mids and highs will roll off with distance. In a perfect world, this will approximate reality, since air absorbs higher frequencies as a function of distance, but you are trying to get two curves to intersect at a perfect point, in systems which you have not designed, and which have not been designed to cooperate.
There is another potential issue with this system, a f
I’m convinced that in N scale, anyway, under the table sound is the way to go. What little I heard of PCM’s N scale E7s was not impressive, but then I was at a show and there was a lot of crowd noise. Nevertheless, the physics (and yes, I’m a physicist) doesn’t seem to be in favor of the tiny speakers crowded onboard an N scale engine. Now, mounting a small HO sound system in a dummy B unit for a diesel might be possible, as might doing the same in an oversized N scale tender (like the PRR’s “coast-to-coast” tenders) for steam. Not only do you need to have a little room for a speaker, you need a little air to move to generate the depth of sound you need. Anyone who’s installed a DCC decoder in an N scale locomotive will tell you there’s virtually no room (or unobstructed air) inside!
You HO guys are lucky; I do enjoy the depth of sound your on-board systems can produce. Us N scalers are a ways away from having that depth onboard. I’ve just installed an under-the-table system and love it. Sure, I wish it followed the train, but it still beats the pants off of silence!
I’m just getting going in N scale and have been wondering what to do about the sound as well. For me, I agree with Dave Vollmer. At this point (and on a relatively small layout) I’ll go with an under the table system. It will end up costing me more (double the decoders), but overall I think it will work best. If I was still in HO, I’d try the onboard stuff first and then move to under the table if it wasn’t the effect I was hoping for.
For example, I have a single steam sound system, and I consist it with any steam I’m running. I don’t doublehead steam (by the mid 1950s, most freights heavy enough on the PRR Middle Division to rate more than one M1b 4-8-2 would get a matched set of diesels), so this is like one decoder for several engines. You will end up with less decoders rather than more, so it should be cheaper, right?
I only have a cheapo DSD 100LC from Soundtraxx in the only diesel I own, and it does a marvelous job of doing the load vs. sound vs. notching and speed thing. If I crank the encoder to 50, the loco doesn’t move, and the diesel sound rises to simulate a good solid load. Then, because I have CV 2 set properly, the loco takes almost a minute to get up to that speed. That is a most gratifying effect.
I would be very surprised if the QSI didn’t behave, or have the capability of behaving, exactly the same way.
The problem with relatively simple under-table sound systems is that there is no auditory cortex disparity in distance. I can adjust my decodered locos to a volume whereby if they are furthest from me, I cannot hear them…only the ones close by. That is the way it should be. Further, in scale, an observer should experience the same effect. If you were to stand in the middle of a modest yard, would you be able to hear the pusher three hundred meters away over the two that were 60 meters away? Not vey likely. How would a system costing $300 dollars or less duplicate that in synch with the proximity of each of the locos with their individualizes sounds?
I would say I assumed a little more about what you are talking about because of what I was thinking and not realizing exactly what you were saying. I read David Popp’s article in the August issue of MR (Page 36-39) and Options 3 and 4 sound really good to me. I’d start with the “ambience” sound system and add the sound modules similar to David’s for the switchers. Then I’d decide how to do the mainline locos at a later time, but my layout will likely be fairly small (still working on a place to put it and final dimensions, but looking to be no more than 6’ x 9’). With the smaller dimensions, and likely only 5-8 mainline locos (in several years), I could play with cross-fading and automated sound mixing with a computer and block detection, but I don’t know if I have the will to go that far. Besides, by the time I get all that, there could very well be a better technology for onboard N scale sound (or an effect of that) that would take care of all that mess anyway. Regar