OR and Sound Distortion or Loss - Cab only

[qballbandit]

Good day,
I've mentioned in a few posts that I frequently experience sound distortion, sometimes followed by loss of stereo sound, and often followed by total sound loss. With any of the aforementioned scenarios, sound may return fully at some point, or in "pieces".

I have an older Creative Labs Sound Blaster X-Fi XtremeGamer card (not a debate on card pros and cons). I've tried a couple versions of old drivers, but it didn't correct the issue. I tried on-board sound as a test, no difference.
This all said, the problem mostly seems to arise when AI trains spawn into an activity and are active until they vanish at the end of their path. I used to have this issue in MSTS until using the LAA tweak. Also, I only started having this problem over the last year of using OR, using it fully for about 2 years.
Furthermore, I found out the other night that only my cab sounds are effected, where my external sounds are fine. This makes the issue even more perplexing to me.
In one activity, I even have no AI trains or static trains as a test to see if this issue arises, and it will every time.

I am looking for suggestions on what things to focus on - sms files? Shape or texture corruption in trains or world objects?
Since this can happen on any route with any set of trains, it makes it very hard to find a starting point to troubleshoot.

All suggestions are greatly appreciated.

Thanks very much,

[advut]

Do you experience sound distortion only in cabview? I experience that more on the outside view specifically like when navigating through a curve. To test this just use a long train which has loud, prominent rolling stock sounds and drive through a curve at moderate to high speed but try not to accelerate or decelerate too much. It sounds like a jet in underwater or something and ruins high quality sounds.

However, I don't think it's just limited to ORTS because I've noticed this kind of distortion to be present in videos of DTG train simulator made by rich youtubers with good hardware. So, I don't think it's hardware related. I've encountered this issue for years but don't know how to solve it.

[baldwin]

Have you tried running with the F5 Debug page onscreen. This will show if the sound loader is being overloaded, or if one of the other loaders is peaking when the sound gets chopped. Are you using the LAA version of ORTS?.

[Erick_Cantu]

It sounds like a combination of phasing and a lack of respect for the need for headroom. The phasing is caused by the same audio file playing multiple times, but with each iteration delayed by a fraction of a second. That's what causes the "whoosh" sound. The lack of headroom is what causes the clipping. OR applies a hard limiter to the mix, so that can lead to interesting effects (see: loudness wars).

Most sound designers just maximize the volume of every clip and call it good. You can't have that many loud files stepping on each other without crossing that 0dB threshold. The problem is worse in the interior because exterior sounds will decay somewhat with distance, whereas interior sounds are right at the source (and are thus at full volume). The solution? The horn should be the loudest sound source in the environment, realistically. The volume of everything else should be set relative to that, and, even then, I still drop the volume of my SMS files by half to provide enough headroom for a large number of audio sources. Phasing can be solved by using multiple SMS files, with some SMS files specifying slightly different frequency curves or alternate, phase-shifted audio clips. This is why the GP7s shipped with four sets of SMS files.

The ideal solution is smarter sound designers who understand how to mix audio. Dynamic range should never be an afterthought, it should be the first thought. Make 'em record bands for a few years.

[qballbandit]

Hi Advut,
I experience it in both, but noticed that when in the cab and it goes wonky on me, or disappears altogether on me, that the external sounds are still playing fine. I notice this by switching a "matrix button" on my speaker system which enables the external sounds to be playing vs. internal - but, still heard from within in the cab. But, if I "go outside - key 2/3/4, etc.", and stay in external mode for too long, the same crap can happen. I know it sounds confusing, but the matrix button pressed in enables full interior sound, where depressed out enables all external sounds.

Hello baldwin, I shall look into the F5 debug (have to cycle through them to familiarize myself with which page you are referring to) and see what I come up with.

Erick,
Very interesting reading. That all said, I am surprised that I don't hear/read of more people having the same sort of serious issues with sound as I?

[Erick_Cantu]

It could be that you're having a separate issue, too. Generally, sounds that are too loud result primarily in crackling and fuzz, plus compressor pumping as sources compete for space.