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Old 05-07-2019, 11:43 AM   #1
MadMike
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Default Declassified Soviet Sound Signatures

A certain three letter agency has declassified sound signatures for a wide range of Soviet submarines. Original date of the document is 1969.

Operating levels considered "quiet" were 30-35 decibels in the low frequency band, and 20-25 db in the sonar band.

For the Victor class, these levels were-

Low freq, at 5 knots- 55-60db. At 14 knots- 65db

Sonar band, at 5 knots- 16db. At 14 knots- 22 db.

Yours, Mike
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Old 05-08-2019, 03:28 AM   #2
Kazuaki Shimazaki II
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So basically, the Victors are quiet in the audible band, but not quiet in the infrasonic sections?
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Old 05-08-2019, 03:14 PM   #3
Sub187
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A link to the documents?
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Old 01-22-2020, 08:36 PM   #4
AllQuiet
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Quote:
Originally Posted by MadMike View Post
.....
Operating levels considered "quiet" were 30-35 decibels in the low frequency band, and 20-25 db in the sonar band.
For the Victor class, these levels were-
Low freq, at 5 knots- 55-60db. At 14 knots- 65db
Sonar band, at 5 knots- 16db. At 14 knots- 22 db....
If I wanted to adopt these numbers, how can I find an average representation when all we have to edit are Self Noise and Sonar Reflection figures....not to mention user control of his boat and options presented in a given environment, ie- surface noise, vessel depth / speed ....

all while trying to keep a fairly level playing field so to speak.
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Old 05-22-2020, 06:15 PM   #5
Sheppard
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Quote:
Originally Posted by MadMike View Post
A certain three letter agency has declassified sound signatures for a wide range of Soviet submarines. Original date of the document is 1969.

Operating levels considered "quiet" were 30-35 decibels in the low frequency band, and 20-25 db in the sonar band.

For the Victor class, these levels were-

Low freq, at 5 knots- 55-60db. At 14 knots- 65db

Sonar band, at 5 knots- 16db. At 14 knots- 22 db.

Yours, Mike

Link to document?
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Old 05-23-2020, 05:04 AM   #6
steel shark
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Default Noise Values In cold Waters

Noise level’s play a very important part of cold waters so getting them right is a major chunk of realism for instance early soviet boats were very loud see pic.1 & 2

this was mainly down to a few factors 1 multiple propellers’ 2 not as well made propeller’s as in machine milling 3 twin reactors and 4 louder reactors made worse by the fact most soviet designs used 2 but they were more compact and powerful then western designs of the time but not as safe

a good example is the echo class ssgn this boat was basically a November class with large cut outs along its port and starboard sides for missile back blast this added drag and extra noise when moving through the water how ever since the boat it was based on the November class was all ready very loud this made this class loudest submarine in the game even the SSN version which was a echo class with missiles removed and the missile cut outs welded up was still loud tho a lot more quieter

but there are other factors too thermal layers / bottom bounce that’s when the sonar system hits the sea floor and bounces back up / shallow waters the sonar reverberates of floor targets / and sea state heavy rain can an add up to 30db cause of the large surface of the ocean the rain hits and waves all mask targets noise signature

also a problem is the noise value of a boat is single so a diesel boat doesn’t have a second noise value for its electric motors for instance see pic pic.3

also the noise of the oceans has grown because of more sea traffic has raises the Ocean Base Ambient about 10bd more so modern asw Anti-Submarine-Warfare is that much harder now

I spent much time on this and ive made a quite good detailed noise charts other problem is you have to make all vessels stack if you only did lets say subs then surface warships and merchants ships would be off

noise per knot that had to be reworked too which in turn i adjusted cavitation noise value and then in turn the vessels cavitation rating which boils down to three choices 1.propellers / 2.Low Cavitation Propellers / 3.Pump Jet Propulsion .

ill post my in game values at some point if any body wants them let me know

Last edited by steel shark; 05-29-2020 at 09:40 AM.
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