Sound issues

[MikeK]

Ever since installing TS2012 I have had strange sound issues where it sometimes sounds like there is a jet flying overhead, or perhaps another way to describe it is that the train sounds like it is going down a long PVC plastic pipe. I always assumed it was something to do with the fact that I am using the motherboard's on board sound rather than a sound card.

I spent the day looking for various replacement sounds for things to try to improve the situation, and along the way I noticed a youtube video posted by another person showing that they are hearing the same strange sound. Listen to this video from 1:40 to 2:10:

http://www.youtube.com/watch?v=_2TycsuINyo

Since it clearly wasn't just me, I spent the day doing various tests trying to work out exactly what is going on. I think I may have worked out the issue finally, but I am wondering if someone who has an actual sound card can try the same test and see if they are hearing it too.

Here is what the game sounds like with a single loco:

http://www.youtube.com/watch?v=iS-qt2gvkDU

Everything sounds fine, right? But now add in multiple locos and listen what happens to the sound when the consist goes around a corner:

http://www.youtube.com/watch?v=5CxFB92B5mk

That same strange sound in the background. It seems that whenever a set of locos goes around a corner the game is trying to add in some whacky effect and failing.

I am the only one hearing this?

p.s. Thanks to simer4 for the excellent ES44 sounds :)

[Rich_S]

Hi Mike,
I think you are referring to that sound that kind of sounds like a jet flying past? This is a known issues, how it was explained to me is that is what happens when you have multiple sounds on the same channel or frequency. I'm not sure if there currently is a way to correct this problem, maybe one of the sound guru's can explain it better than I can? It's kind of funny that not very long ago we figured out how to make all of the engines throttle up and then this happened Some times it seems like it's never ending, but it really is getting better all of the time.

Regards,
Rich S.

[Kali]

If it's happening with two identical engines, then it's interference ( musicians use it deliberately if you want to look up phasing ) - you don't get that in real life because a) no two things are identical, and b) reverb. I used to cure it by driving trailing engine audio a few rpm out of sync with the lead one, but now they all drive themselves perfectly synchronised. You can still get round it by editing the audio files for whatever it is and adding PitchShiftVariation to each loop sample; that will throw them far enough out of synchronisation if it's big enough that you won't detect any interference effects. I tweaked the SD40 soundkit using 0.1, and it made a vast difference without making any of the engines sound noticeably faster or slower.

Technically it's when two samples are ever so slightly out of phase with each other, and they start cancelling different frequencies out ( the usual analogy is overlapping waves in a pond - they reinforce at some spots and cancel out at others ). I've considered the idea of using something similar in reverse to play with engine tone for different loads, but I've just never got round to it.

[arizonachris]

This discussion about phasing is also going on over on the Steam/ RW Forum. I can hear it even at the startup and first run in the first video you posted. To me, having a long electrical and mechanical background, it is definately phasing. I can hear two electric motors "beat" against other, out of sync. Same with two diesels. This all really (kinda) sounds normal to me. Ever hear a twin engine small airplane with it's engines slightly out of sync? I can hear a lazy pilot every time. (yes, I know DMU's are different but I still hear it in this sim).

[MikeK]

After playing around some more, deleting loco sound files one by one and listening to the result, I have realised that this issue affects ALL the sounds in the game that are being played more than once at the same time.

For example, even the freight car "wheel on rail sounds" will subtly do this in the background if there is more than one fright car in the train.

[Kali]

Yeap, just add a little randomness.

[Ghettofab75]

I've been having the same issue and its really annoying.

Where exactly do you add or modify the pitchshiftvariation? Is it in the audio.bin file or the engine.bin?

Thanks,
Kevo

[Kali]

It's in the proxyxml files, it's a parameter in the sample definition blocks that will be at the top ( or just search! ).

[MikeK]

Wow, thanks Kali, such a simple change and it fixed the problem.

I only changed the loco files, I didn't go looking for track or freight car sounds, but it was enough to cure the issue.