Balancing Loco Sounds.

Bruce Petrarca  www.Mr-DCC.com wrote on 31 Jan 06

 

John -

 

You've hit on a favorite subject of mine.

 

MOST sound decoders are not set up right. In fact, if you set one up to mimic reality, most folks will be unhappy.

 

For example, I spend summers near Flagstaff AZ, where BNSF moves about 85 freights a day, mostly with GE diesels. I can tell you from first hand knowledge that, as they move through town (up grade) at 35 MPH, the horn is AT LEAST 10 dB louder than the prime mover. Also, most bells are hardly louder than the prime mover at an idle.

 

Various SoundTraxx decoders let you set different sound levels, ranging from the complete control of every sound individually in the Tsunami to the groups in the LC series.

 

When I can, here is what I like to do. It is the best balance between reality and loco operation. Most customers seem to like it, too! I'll explain diesel, but the same, except for dynamic brakes, works for steam. This is for decoders where you have complete control. Your mileage may vary! I use a dB meter - about $50 at Radio Shack. I set the loco on rollers, so that the distance between the speaker and meter doesn't change.

 

I set the loco to an idle and read the dB level. I activate the bell and adjust its level until the reading is 3 dB more than the idle - indicating that the idle and the bell are about the same level.

 

I turn off the bell and turn on the dynamic brakes. Again, I adjust for 3 dB more than the idle.

 

I turn off the dynamic brakes and run the loco to top speed. I note the sound level reading. The horn is adjusted to be 3 dB louder than the prime mover at top speed. While this is less than the 10 dB or so I estimate reality to be, it gives a noticeable horn and fits within the dynamic range of the limited speakers we have available.

 

When set up this way, multiple locos can operate on a layout without driving everybody up the wall.

 

The above settings can be made by ear, just by adjusting the one sound to seem to be the same level as the prime mover.

 

My observations are that folks run the prime mover sound too loud and the bell WAY too loud.

 

Bruce Petrarca www.Mr-DCC.com Arizona, USA  YOUR dealer for:DCCS, Digitrax, ESU, Lenz, NCE, SoundTraxx, Team Digital, TCS and Zimo YOUR DCC installed here with Richmond Controls Golden White LEDs! Newsletter LitchfieldStation-subscribe@yahoogroups.com

 

John Lauterbach wrote:

> Okay, I don't expect to get any sympathy here.

>

> Tonight's local freight on my railroad has an Atlas Trainmaster and an LL GP-7 for the motive power.  I have throttled down the sound on from the QSI system on the Atlas Trainmaster so that you can hear the GP-7 (Soundtraxx LC series).  Somewhere there must be some data on engine noise in decibels versus throttle setting so that sound balancing can be done correctly.

>

> Also, what we desperately need from QSI is a firmware upgrade so that the Trainmaster will do the series-parallel transition on first generation diesels.  Soundtraxx LC decoders have their problems, but they do that transition so well.

>

> John