sound How to get real prop sounds?

[CoolP 283]

This is not a special Carenado problem, but the current Carenado planes show a nice spread of the anomaly. Talking about the wrong prop sound on sim planes with constant speed props (the prop alters the blade angle and keeps rpm steady, to a certain extent).Now you may already got used to the wrong behaviour, which is that the rpm change on the constant speed prop does not alter the prop sound, only the throttle (or power lever on the turbines) does.Now some planes (in the sim) do it right in my eyes. As a matter of fact, the very latest Carenado releases are among them and if you jump into the JetProp (turbine) or the A36 (piston) and change the rpm, you'll instantly hear how it is supposed to be. Small rpm changes can instantly be heard.Now jump into older releases, perhaps the C208 (turbine) and do the same there. Noted the difference? The rpm doesn't give you a difference in the sound, but only the engine power does. You see that the rpm stay at 1800 for example, but the sound still pitches up as the engine increases torque.If you decrease rpm in the C208 (which should lead to a lower pitched prop sound), the torque goes up (due to the lower rpm) and you even hear a higher pitched prop sound. Wrong! To be clear, this wrong thing happens on a lot of planes, especially the default ones of course.So how could we achieve the correct behaviour in the sim?I've tried the rough approach again and just used the JetProp (correct behaving) sounds on the C208, which comes with a 'wrong' set in regard to the mentioned behaviour. By doing this, I've tried to check if it's a throttle gauge thing or 'just' some sound.cfg problem. As it shows, the simple exchange enables the correct behaviour on the C208. So where's the trick?I've looked into the sound.cfg parameters and the description of them, but those values are way above my head. The FSX SDK explains how they are meant to be written, but I have no idea on where to tweak to get that prop to sound right.Can anyone help?

[CoolP 283]

On the C208 (which now is great due to the new FDE), I've tried another rough approach and altered the complete prop section in the sound.cfg with the entries from the JetProp. Together with the corresponding sound files, this leads to a C208 where you can hear the prop rpm independently of the power settings.I may add that the planes with the free turbines like the PT6 should show the most noticeable change or improvement, so that C208 is a good one to start with. That's due to the nature of the free concept, where the turbine is able to increase its rpm, increase the torque, but the prop rpm stay the same. The piston folks or the geared turbines are different to that concept, their prop to engine connection is fixed, so the engine power change shows less obviously, so to speak.

Edited February 26, 2012 by CoolP

[Guest BeaverDriver]

You have raised a very good (and valid!) point here. I'd be very interested to see where this goes. Good luck with it and thanks for raising this issue.

[CoolP 283]

Thanks for the kind words, Glenn.I'm still tweaking a bit and looking for the actual values and parameters in the sound.cfg. I wonder if an addon soundset for e. g. the C208 would fix the wrong behaviour. Since I actually like the default sounds coming with the plane, it would be a sort of redundant investment though.The rough fix with the JetProp sounds works, at least on the sound behaviour aspect. Maybe I'll just refine that one.

[bliksimpie 1]

Turbine sound studios seem to have managed this to large extend for the C208. I immediately replaced the C208 sounds with that from TSS, why reinvent the wheel if it is already been taken care off.

Edited February 26, 2012 by bliksimpie

[CoolP 283]

Don't read the C208 example the wrong way. It's just that, an example. The issue on the wrong prop sound rpm dependency is a more general one in my eyes.However, I can see two C208 soundsets. One is from Arezone, the other one from Synchro-Soft and I don't know if any of them corrects the error on the C208 example or if it just enables some other and still wrong prop sounds. There a videos which don't allow a clear judgement or leave doubts on the correction. I can't find a TSS C208 set on their site. http://www.turbineso...s.com/index.php If you have a shop link, it would be appreciated of course.If I'm able to correct some errors in the sound.cfg and then receive proper sounds, there's need to buy an extra sound set though. Must admit that this is the solution I'm aiming at in the first place. The C208 runs like that so far.

[bliksimpie 1]

sorry my mistake just checked it was arezone

[CoolP 283]

Thanks for the correction, that makes sense.Now, from their video, the sounds are great (they simulate the muffled ones, with the pilot wearing a headset I guess) and there's no doubt on the quality. But, as far as I can see, the rpm error is still there.That's from the approach scene where the rpm are steady and he just adjusts the torque. The prop sound changes a lot, it shouldn't though. On the takeoff, there's a part where he grabs the rpm lever and the prop sound doesn't change at all. But it should. So it's throttle / power lever dependant, just like with the default Carenado plane.However, I may interpret the video the wrong way of course, but it doesn't convince me that the error was ruled out. As said above, I think that a lot of folks got used to that wrong behaviour and therefore relate to it as the real one, which it isn't.Some real behaving turbine planes in the rpm aspect are the JetProp, the T Duke and the Aerosoft Twotter for example. Set a torque and only alter the rpm. This should give you a huge prop sound change. Alter the torque and leave the rpm steady and notice the prop sound remaining steady too, while the engine 'internals' of course get a bit louder and more stressed, depending on the plane.A bit hard to explain, but e. g. loading the default King Air after this will show a huge difference. Same for the Carenado C208.

[andy1975 13]

Hi CooIP,I recently purchased the PA46T Malibu sound from Arezone. Normally I am totally happy with their products, but as there the RPM-behavior was NOT taken care of, I used it only for one flight and reverted back to the oroginal Carenado one and stays that way as they are absolutely correct!When decreasing prop rpm with Arezone´s you could hear the engines whine up as TRQ increases but the PROP sound seems to be alligned to it also and so the prop-sound pitch did not change according to lower rpm!Maybe there is hope for a patch from Arezone as the sound as it is in general is pretty good.For twinengined turboprops the TSS King Air Sound is pretty good and correct regarding Prop-sound-pitch and you will get pretty cool propfeathering- and flyby sounds plus sound-cones too!

Edited February 28, 2012 by andy1975

[CoolP 283]

Thanks for that input, Andy.A part of me wonders how many sound designers are aware of the prop rpm dependencies. As said, the flight sim offers a ton of wrong behaving planes and only few addon ones do it right, e. g. the JetProp. You know, you just have to hear wrong things often enough to start thinking that those are the normal.Once again, thanks for the HU. I was thinking about getting some sound set for the C208 as my tweaked default ones suffer from the engine sound part being recorded with a lot of prop sounds (means the prop part wasn't filtered out). So while my rough tweak with the JetProp prop parts enables a correct behaving prop, that engine part still spoils it. You sort of hear a second prop coming up with engine rpm.As shown, it's just about the way the entries in the sound.cfg are made. So it's not a thing of recording or sound quality, just some parameters are off and dictate the FSX sound engine to raise and lower the prop sounds together with the engine rpm. On the free turbines, this leads to the effects shown.But I'll tweak and fiddle some more. The audiocity freeware sound editor allows some sound editing and the JetProp prop entries in the sound.cfg allow a view on correct ones, so maybe there's hope.

[andy1975 13]

Tried to fiddle arround in the Arezobe´s cfg file to seperate the sound correctly but with now luck, I am no big sound-editor!Now I use the Carenado-Malibu sound set for the Carenado C208, working like a charm! Did only change the according flap, wind and door sounds to get a kind of variety and realism :( .

Edited February 28, 2012 by andy1975

[CoolP 283]

Now I use the Carenado-Malibu sound set for the Carenado C208.

Not a bad idea at all. Both are PT6A 'small' versions. To get the larger prop and lower rpm maximum on the C208 right, you could reduce the pitch on the prop sounds.For example, the JetProp runs some 2200 rpm max in continuous operation, the C208 is below 2000. So if you pick the JetProp sounds using the audio editor and pitch some 10% down, you should end up with a more realistic C208 prop sound. You only need to do this on two files, that's Prop.wav and XProp.wav. Then save them and load the plane. No sound.cfg change needed. Should be better on the sheer rpm aspect.You can reduce the pitch some more if you like. That C208 prop is really huge.

[CoolP 283]

I've just checked. That's some 2200 rpm on the JetProp and some 1800 on the C208. So pitch those two prop sound files some 20% down and check if it 'fits'. I will test that later.Correction, 1900 rpm on the C208, so 15% loss in pitch. Rough method! :(

Edited February 28, 2012 by CoolP

[CoolP 283]

Those sound pitch changes just reflect the different rpm ranges of the props. As said, rough method. The real thing may sound very different due to different blade angles and prop construction. Also, the larger C208 prop leads to faster moving parts on the outside, so those 1900 rpm don't come in the same way as on some smaller device.However, the idea of using the JetProp sounds completely and altering the rpm dependant ones (Prop.wav and XProp.wav) with a lower pitch works. Thanks, Andy, for leading the way.

[andy1975 13]

Those sound pitch changes just reflect the different rpm ranges of the props. As said, rough method. The real thing may sound very different due to different blade angles and prop construction. Also, the larger C208 prop leads to faster moving parts on the outside, so those 1900 rpm don't come in the same way as on some smaller device.However, the idea of using the JetProp sounds completely and altering the rpm dependant ones (Prop.wav and XProp.wav) with a lower pitch works. Thanks, Andy, for leading the way.

Thanks for the advice! Will give it a try with Audacity which I also allways liked to use! :(