Infinite baffle

Dear Knut,

...and here's the results, as seen by Izotope RX5

Notes:
- We're specfically focussing on the 24-46sec portion of the clip
- There appears to be a reasonably significant and constant Low-mid (most people would call it "bass") tone happening around 110-120Hz. This is the "engine throb" audible in the clip.
- There is significant 400 and 700Hz content evident, filling-out to a low-mid rumble as the locos pass by the camera (Who said HO onboard installs couldn't physically produce doppler?)
- The Bad News is that the vast majority of that "low mid" energy is swamped by a noticable co-incident-in-time increase in 1000Hz - 2500Hz energy. Indeed, the average person even listening on really accurate speakers would say that "the bass disappeared" (It did _not_ disappear, the higher-frequencies just became more pronounced and "shouted over" the lower-mid/bass frequencies).
- From 35sec onwards, one can track each individual "clickety" and "clack" of the wheelsets in the trailing cars,
these "clickety clacks" have a wide frequency spread covering 50Hz - 16000Hz. (Check the vertical lines of orange which _exactly_ match each "clickety clack" 4-hit sequence).
- The digitally-compressed and aliased "wheel<> rail rub" sound is contributing a significant ammount to the 50Hz - 2500Hz range, long after the loco consist has passed the camera, IE from 35sec onwards.

There's a number of things which can be inferred from this clip,
but with the limits of the camera mic, YT audio compression,
the effects of the train consist and track/roadbed acoustics,
and the train<> Mic relative-position changing thru the clip,

it's difficult to draw accurate or meaningful conclusions...

Happy Modelling,
Aim to Improve,
Prof Klyzlr

Wow-effect

Thank you, Prof! I got a wow-effect of your Isotop RX test picture.
The video was also quick and dirty shot with an iPhone 6. 

Your comments are interesting, but such analyzes is way out of my league. Still I appreciate the comments as I am always willing to learn. And I want the best possible sound.

I have not come around mounting the high bass speaker, nor tested with iPhone 5 speakers i have. But I think I adjusted the equalizer per instructions from the Soundtraxx blog.
Of course I should take my time an listen and adjust and listen.

Graphic equalizer tweaking

As a suggestion, set the Tsunami graphic equalizer CV 153 to a value of 7 to allow tuning CVs 154 through 160. I would start with 154 and 155 at 50, 156 at 190, 157 at 80, 158 at 20, and 159 and 160 at 128. Notice the difference in sound and continue tweaking from there. This speaker is likely not going to produce quality sound at the lower frequencies controlled by CVs 154 and 155.

As the Professor pointed out, the bass did not die but was merely over shadowed by the midrange frequencies as the throttle increased. Another possible factor, as the back of the speaker is open, does the Walthers body have open fans and sides? Maybe out of phase sound is impacting the sound reaching our ears?

Will try your settings

Thank you. I will try your settings and do some tweaking, but not tonight. They differ from the settings on the soundtraxx blog.

I do not think there are open fans or grills in the Walther Proto body. But will take an other look.

Values are install dependent.

Your speaker may have subtle differences from another of the same model. Your loco body may add "color", warmth if you will, which impacts what your ears transmit to your brain.

The Professor is a sound professional so heed any of his advice. I did and it made a huge difference in the sounds of my locos.  Good hunting.

Thank you

Thank you for reminding me that I need to adjust every loco.
And I know the Prof is a sound pro - and he is a modelrailroader! I sure will listen to his advices.