Author Topic: Ummm about his new engine sound thingy (Read 4751 times)

ALF · « **on:** February 11, 2004, 10:47:05 PM »

Im really not sure I understand the purpose?

In AH1 I never bother with RPM....cause it doesnt seem to do anything that the throttle doesnt do....am I missing some key game feature....since beta 1 no less:eek:

The engine going more or less silent is freaky!

Citabria · « **Reply #1 on:** February 12, 2004, 02:25:55 AM »

rpm now does what it should very well.

big fuel savigns at low rpm and throttle settings

Waffle · « **Reply #2 on:** February 12, 2004, 04:51:58 AM »

RPM = revolutions per minute, Not decible or volume per minute....

It is very odd...I agree....even in a car your engine doesn't get quite when you reduce power. It's does loose some volume - guestimating around 6db, but it doesnt have the severe lose of volume as currently the case with new patch. A step in the right direction - guess you could say "right street - wrong address"

Imagine it would be hard to sync audible revolutions of the engine to correspond with throttle changes in the game..not sure - leave that stuff to the programmers...lol

But - Engine sounds should be more of "half-way doppler effect" Oscilating up with pitch as power applied (some volume) and decresing pitch as throttle released (with slight decrease in volume). Hopefully not to much pitch increase as to where the planes sound like ricers on a saturday night at taco bell.....

A prop plane flying at 1000ft is about 88 decibles - about as loud as a garbage diposal. I'm guessing due to proximity - that would equate to roughly 92-98db in cockpit. A jet flying at 1000ft is around 102 dbs. Currently if full power in AH is set to roughly 98dbs - when you throttle back, it sounds as if it drops 45 decibles to 53db - almost to the sound of a dish washer in comparison. It seems that it should only drop a quarter of that or less. (10-12db from full power to off)

Ghosth · « **Reply #3 on:** February 12, 2004, 08:11:32 AM »

Cars are insulated, tuned piped, mufflered, & catilytic convertered, & exit 12 feet behind the driver.

Airplanes are big growly radial engines with NO pipes, NO mufflers ohh & they exit within a few feet in front of the cockpit.

Ya think maybe they'd sound a bit diff?

Start up your lawnblower or snow mower.
Play with the throttle up & down. Hear the difference?

Eagler · « **Reply #4 on:** February 12, 2004, 08:13:41 AM »

stop flying ur lawnboy ghost

Waffle · « **Reply #5 on:** February 12, 2004, 04:16:29 PM »

Still a lawn mower doesn't have as much of a decible decrease with power as the throttle does with patch 13.

Currently as is - the throttle sounds like a volume control....not controling RPMs

Kweassa · « **Reply #6 on:** February 12, 2004, 05:11:54 PM »

On the positive side, you can now hear your engines overreving than the set amount during powerful dives. It's really cool!

Fangio · « **Reply #7 on:** February 13, 2004, 10:24:32 AM »

I race cars. A racecar has no mufflers etc..... just like a WWII fighter.

There is a HUGE difference in noise at different rpms. At idle the car is really not that loud. At 3k rpm its much louder... just starting to cause babies to cry. At WFU 8000 rpm.... small children are in a panic, wives are screaming for help and red blooded men have a grin from ear to ear.

It sounds like speaker volume should be adjusted. Make it normal at idle, pretty lound at cruise and so loud your wife is pitching a fit at full throttle. That will be closer to realistic.

Fang

Waffle · « **Reply #8 on:** February 13, 2004, 02:48:39 PM »

Not sure of all "racing" rules, but for eveyones benifit.....
If you've been to a sanctioned track, most have decible regulations on the cars. The rules that I found were that the nosie level / exhaust from the car can be no more that 96 db at 100 feet. Which roughly equates to being withing 5 feet of a lawn mower

I guess this is about SPL(sound pressure level) or "intensity" of the sound. When a engine is on idle - the engine is still emitting a certain db per "stroke" or "revolution". As the throttle is apllied, the revolutions increase and so does the frequency(time) that an indivual "stroke" db is produced. When you're at 200Rpm it will seem quiter than when you're at 3000rpm due to the fact that you have 3000 individual "stroke" decibles crammed into a minute rather than 200 "stoke" decibles.

Basically, If you shoot one round off in a gun - it's loud, but not that loud as compared to 3000 rounds firing off in one minute. Where as 3000 rounds being fired will pale in comparision to 8000 rounds in a minute.

What i'm getting at is a "percieved" loudness. The guns are all firing at the same db, just the frequency of fire makes it seem louder.

Granted there are other factors involved, coupling for one will make an engine running at a certain RPM seem lounder as well as amount of fuel burned per stroke.

WhiteHawk · « **Reply #9 on:** February 13, 2004, 06:32:30 PM »

I agree with waffle. The volume should change a bit but its the frequency that should be the dramatically tied to our throttles.
Very nicley put waffle, i was thumbing through my dust covered physics book looking for some equatiion describing a combustion engine operation when I got down to your post. Another analogy, is dipping your hand in hot water for 1 second then out for 1 second is completely different from dipping it in for 10 seconds, thenout for 1 second, even tho the water temp does not change.

Kweassa · « **Reply #10 on:** February 13, 2004, 07:26:04 PM »

Quote

The volume should change a bit but its the frequency that should be the dramatically tied to our throttles.

Why?

The momentary throttle up/down is not going to effect anything with an engine equipped with a CSU prop. The characteristic sounds and noises each engines makes is determined by its internal structure and engine revolutions, no?

If cutting the throttle drags the plane down to a really notieably slower speed, and thus, to a level where the CSU cannot compensate and hold the designated RPMs, it's then it should start revving down, isn't it??

Ecliptik · « **Reply #11 on:** February 13, 2004, 08:00:32 PM »

I always thought throttling down reduced volume because less fuel is being pumped into each cylinder per revolution, thus there is a less powerful combustion and hence less noise. It's not the prop blades whizzing through the air that makes most of the racket, it's the thousands of controlled explosions happening a few feet in front of you.

Waffle · « **Reply #12 on:** February 13, 2004, 08:19:18 PM »

ok - one more example....

Take remote control planes or gas powered R/C cars.....

When you're piloting them - you can hear your engine just fine at a slow speed...the engine emits a lower frequency audio pitch at a slower cycle. When throttle is applied the audio pitch increases as the engine cycles increase. But, there is very little audio difference in Sound pressure levels, or decibles. Some, but not as much as one would think.

pls note pitch here is related to acoustics, not aerodynamics.

I'm trying to clarify the engine volume thing - not worried about props cutting through air and other noise created by prop driven aircraft.

Eagler · « **Reply #13 on:** February 13, 2004, 08:56:04 PM »

seems like it gets too quiet when you throttle back..

Kweassa · « **Reply #14 on:** February 14, 2004, 12:19:02 AM »

cc Waffle, I think people more or less agree that the engine becomes to quiet when throttled back. The "sound pitch linked to RPM" part, I don't see any problem.

In FB, the engine does become a little less loud when throttled back, and emits a low pitch 'chugging' sort of growl when left to idel. It's definately not 'silent'.