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-   -   303 sound (http://forum.fulqrumpublishing.com/showthread.php?t=27771)

Sternjaeger II 11-11-2011 09:22 AM

Quote:

Originally Posted by robtek (Post 360477)
I can't follow you here, first a slight and then unprofessional common places which doesn't prove anything.

I answered to the opinion that the sound should increase eight-fold, and you?

Sorry man, but the answer you gave is not correct and misleading, hence my post. There is a lot of this going on in this forum, it would be better to keep things as accurate as possible for the sake of the sim and people's knowledge.

robtek 11-11-2011 09:39 AM

It would behave you well if you could point out which part you assume i've got wrong and how so.

Sternjaeger II 11-11-2011 09:55 AM

Quote:

Originally Posted by robtek (Post 360540)
It would behave you well if you could point out which part you assume i've got wrong and how so.

your assumption

Quote:

At first the guns don't fire synchronized, so the soundwaves sometimes add up, somtimes they cancel each other out.

It would be louder as a single gun, but a more constant noise, like ripping texture.
is simply wrong, soundwaves won't cancel each other out, they will just make things louder. Regardless of the synchronisation, the rate of fire is so high that the sounds will superimpose and create a concerto for .303, especially because they're sitting so close to the pilot.

winny 11-11-2011 09:59 AM

Quote:

Originally Posted by Sternjaeger II (Post 360537)
Sorry man, but the answer you gave is not correct and misleading, hence my post. There is a lot of this going on in this forum, it would be better to keep things as accurate as possible for the sake of the sim and people's knowledge.

OK then in the interest of correctness..

You said " I think you have a pretty confused concept of sound waves."
His understanding of soundwaves seems ok to me.
Soundwaves can cancel each other out if they are the same amplitude, if they are similar you get disruption to the waves which can mean either an increase or decrease in volume. I'm a sound engineer by trade. It's like when speakers are out of phase.

You also said.. "I personally don't know of any "don't fire synchronised" setup"
I'm pretty sure that British brownings were not synchronised. They were fired pneumatically which meant they couldn't synchronise them.

Aircraft with synchronised guns fired them electrically. I think the 109 was like this but my 109 knowledge is limited.

Skoshi Tiger 11-11-2011 10:36 AM

Quote:

Originally Posted by winny (Post 360544)
Soundwaves can cancel each other out if they are the same amplitude, if they are similar you get disruption to the waves which can mean either an increase or decrease in volume. I'm a sound engineer by trade. It's like when speakers are out of phase.

The wave forms need to be opposite phase (hope thats the right phrase) which would be extremely unlikely, So for every quiet spot there would be correstponding loud spot where the wave form built each other up.

Over eight gun I would think it would average itself out.


Quote:

Originally Posted by winny (Post 360544)

You also said.. "I personally don't know of any "don't fire synchronised" setup"
I'm pretty sure that British brownings were not synchronised. They were fired pneumatically which meant they couldn't syncronise them.

Aircraft with syncronised guns fired them electrically. I think the 109 was like this but my 109 knowledge is limited.

Even slight mechanical difference between the guns would cause a variation in the rate of fire.

Are the German guns fired on a pulse that would allow them to syncronise rounds or does it just opperated a solenoid that moves the shear that restrains the bolt?

Cheers!

robtek 11-11-2011 10:56 AM

As the guns don't fire synchronized there will be of course parts of the sound cancelled out, parts added up and parts filling the "free"spaces.
That is what i meant, the sound doesn't increase 8-fold, it increases, but without actual measurement one can't say how much.

pupaxx 11-11-2011 11:41 AM

you simply can't algebraically sum two sound pressure levels. a sound pressure level L1=50db + another sound pressure level L2=50db isn't equal to a sound pressure level of 100db.
The mathematics law governing this phenomenon is on logarithmic base.
The increment should be minor of 0,5db
Cheers

winny 11-11-2011 12:07 PM

Quote:

Originally Posted by Skoshi Tiger (Post 360546)
The wave forms need to be opposite phase (hope thats the right phrase) which would be extremely unlikely, So for every quiet spot there would be correstponding loud spot where the wave form built each other up.

Over eight gun I would think it would average itself out.



Even slight mechanical difference between the guns would cause a variation in the rate of fire.

Are the German guns fired on a pulse that would allow them to syncronise rounds or does it just opperated a solenoid that moves the shear that restrains the bolt?

Cheers!

Yeah, opposite phase is the right term :). To completley cancel out it would need opposite phase and the exact same frequency. If you've got 8 guns all firing at the same rate at some point in the room you'll get opposite phase somewhere. (Because the sound spreads out in a circular way, unlike speakers) but it would be hard to notice. But you'd get some cancellation, and probably some amplification somewhere else. In short, it would sound messy!


I have no idea about how exactly synchronised guns work, but they all recieved the same electrical pulse to fire at the same time, with pneumatics they just carry on from where they were in the cycle.

He111 11-11-2011 12:12 PM

I've noticed in the latest patch the 303s are quieter .. which i would assume means better efficiency?

When I open fire in a spit, i can barely hear the guns .. this cannot be correct! I suspect in reality if you opened up with 8 x 303 it would shake the plane, causing rattle n rollin.

The video shows a low pitched sound, 8 x such would probably be the same pitch but louder .. i would assume?

... more milk maid logic .. :grin:

.

reflected 11-11-2011 01:12 PM

I love when people start speculating about how it might have sounded from the cockpit to fire 8 brownings... (although I tend to do it myself)

Unless you've done it, you can't possibly know.

Yes, now it's quieter. and pretty high pitch. Then again, sitting in a cockpit of a warbird with a 1000 HP Merlin growling in front of you at 3,000 RPM...that kills pretty much every frequency and I wouldn't be surprised if only the higher frequencies came through. Then again, I might be wrong. We can only be sure of the rate of fire and it sounds correct.

The only reference I've read about it is that it sounded like "tearing calico" - that means 1) high rate of fire 2) high pitch - at least those are the conclusions I've jumped to.

All in all, I have no idea wether the sonud we have is correct or not, but it's not implausible (give nmy limited knowledge and experience)


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