SUBSIM Radio Room Forums



SUBSIM: The Web's #1 resource for all submarine & naval simulations since 1997

Go Back   SUBSIM Radio Room Forums > Modern-Era Subsims > Dangerous Waters > DW Mod Workshop
Forget password? Reset here

Reply
 
Thread Tools Search this Thread Display Modes
Old 01-13-06, 06:44 AM   #1
OKO
Commander
 
Join Date: Jan 2002
Location: Solar system, mainly on earth
Posts: 476
Downloads: 62
Uploads: 0
Default KILO vs KILO improved with LWAMI

Hi all
well, I wanted to tell about it for some times, but it's not a real problem at this time for gameplay, maybe usefull for this instead ...
But I feel like I must say it :
in LWAMI mod (I don't know for stock, I didn't checked as I always use LWAMI), the KILO improved is much more quieter than the KILO.
the KILO make 266% of the sound level of the KILO at every speeds.

I hardly believe that the KILO could be 2,6 times louder than the imporved version at every speed.
real values are more probably around X 1.3 to X 1.8

this cause the KILO to be quite easily detectable by the improved KILO when the KILO won't be able to counter detect (with passive) except at VERY close range.
Improved KILO is virtually indetectable for the KILO, when the improved KILO will easily detect the KILO at range from 10 to 15 miles.

Improved KILO make the same noise at 12 knts than the KILO at 4 knts, and KILO imp make the same noise at 19 knts (close to max speed) than the KILO at 11 knts (combat speed).
This can be true IRL, of course.

But I have to admit, this give you 2 very different ships, and that's quite nice for scenarios.
Maybe, anyway, a reduction of the sound gap beetween these 2 platforms could be made.
evry 3 dB, there is twice the sound level.
So, instead of X 2.6, near 3 times the sound level, maybe KILO could be change to be only 3 dB more (instead of 5) compared to the improved version ?
This time the KILO will be only twice louder than the improved.
I think actual values are quite to big at this time, I could chek it in a scenario where a HAN and 2 chinese KILO KLUB (so improved)escort a XIA, with 2 russian kilo attacking the XIA.
Russian never detect chinese KLUB with passive, when chinese always detect both 2 russians standard KILO with passive.
quite nice for the scenario, but maybe a bit far from realism.

what do you think about ?
OKO is offline   Reply With Quote
Old 01-13-06, 07:55 AM   #2
Stowaway
 
Posts: n/a
Downloads:
Uploads:
Default

Hm. This difference really seems not to be true. But the qustion is - should we increase the stealth of Kilo, or to decrease the stealth of Kilo imp?
  Reply With Quote
Old 01-13-06, 10:55 AM   #3
LuftWolf
Ocean Warrior
 
Join Date: May 2005
Location: Free New York
Posts: 3,167
Downloads: 2
Uploads: 0
Default

The Kilo and Kilo Imp are 5 PSL away from each other.

At 0 kts, the Kilo is 60 PSL, a bit louder than a Akula Imp I (59), and the Kilo Imp is 55 PSL, which is equivalent to the SeaWolf (the SeaWolf stays quieter at speed than the Kilo Imp of course).

The difference between the Kilo Imp and the Kilo is roughly the difference between the Akula II and the standard non-playable Akula I.

These figures come from real world data that Amizaur compiled from Russian data and projections, so they more or less are what they are.

Of all the things in the mod, I think I am most comfortable with the relative platforms sound levels, since SO much work had been done on it before I became involved by jsteed, finiteless, and Amizaur. I have seen their working graphs and they are quite impressive.
__________________
LW
LuftWolf is offline   Reply With Quote
Old 01-18-06, 07:06 PM   #4
OKO
Commander
 
Join Date: Jan 2002
Location: Solar system, mainly on earth
Posts: 476
Downloads: 62
Uploads: 0
Default

so ... the KILO make 266% of the noise level of the improved KILO ...
only 1/3 of the KILO sound level, with the improved KILO
Still looks quite strange to me ...
and this make huge difference in game, of course.
OKO is offline   Reply With Quote
Old 01-18-06, 07:32 PM   #5
Kazuaki Shimazaki II
Ace of the Deep
 
Join Date: Jan 2006
Posts: 1,140
Downloads: 5
Uploads: 0
Default

Quote:
Originally Posted by OKO
so ... the KILO make 266% of the noise level of the improved KILO ...
only 1/3 of the KILO sound level, with the improved KILO
Still looks quite strange to me ...
and this make huge difference in game, of course.
Is 5 PSL really 5dB difference, or 10? I ask this because IIRC the estimated noise levels of those subs in dB are very roughly 2x the PSL value - the Akula is about 115-130dB (dependent on variant and source data) for instance IIRC.

Anyway, with the sub technology having advanced something like 15 years b/w the standard Kilo and the 636, I'm not exactly surprised even if the 636 is indeed 10dB quieter. Supposedly the 688I is also 10 times quieter (10dB) than the original 688, which corresponds roughly to the current PSL in the game (PSL*2=approx dB)
Kazuaki Shimazaki II is offline   Reply With Quote
Old 01-18-06, 08:58 PM   #6
LuftWolf
Ocean Warrior
 
Join Date: May 2005
Location: Free New York
Posts: 3,167
Downloads: 2
Uploads: 0
Default

It is a compressed scale.

Generally speaking, 1 PSL= 2 db.
__________________
LW
LuftWolf is offline   Reply With Quote
Old 01-18-06, 09:20 PM   #7
Kazuaki Shimazaki II
Ace of the Deep
 
Join Date: Jan 2006
Posts: 1,140
Downloads: 5
Uploads: 0
Default

'bout what I thought. IIRC, the 636 is supposed to be about 50% quieter than the 877EKM, which presumably in turn had some significant quieting improvements over the oldest 877 models so a 10dB difference overall sounds fair.
Kazuaki Shimazaki II is offline   Reply With Quote
Old 01-18-06, 10:46 PM   #8
RedDevilCG
Watch
 
Join Date: Jan 2006
Posts: 26
Downloads: 0
Uploads: 0
Default

You sure about that? 10dB means that that the 636 is 100x quiter than the 877.

For comparison purposes, if one sound source is 50% quiter than another, it is 3dB quiter, or louder depending on which way your are comparing (quite to loud / loud to quiet).

Lets say that you do a further 50% reduction on the first one. You once again reduce it by a further 3dB.

So a 50% reduction, and another 50% reduction? A total savings of 6dB.

Cheers.
RedDevilCG is offline   Reply With Quote
Old 01-19-06, 04:32 AM   #9
Kazuaki Shimazaki II
Ace of the Deep
 
Join Date: Jan 2006
Posts: 1,140
Downloads: 5
Uploads: 0
Default

Quote:
Originally Posted by RedDevilCG
You sure about that? 10dB means that that the 636 is 100x quiter than the 877.
That's 20dB. 3dB is 2x, 5dB is about 3x, 7dB is very roughly 5x IIRC and 10dB is a mere 10x, 13dB is 20x and so on.
Kazuaki Shimazaki II is offline   Reply With Quote
Old 01-19-06, 07:07 AM   #10
OKO
Commander
 
Join Date: Jan 2002
Location: Solar system, mainly on earth
Posts: 476
Downloads: 62
Uploads: 0
Default

LOL
this thread become a lesson about dB

The only simple thing I know about dB is : each more 3dB, you have twice the sound level
So, 10 dB is a bit more than 10 times the sound level

But in DW, it's NOT 10 dB beetween KILO and Improved, it's 5 dB (with LWAMI) just take a look at the graphical chart.

So the Improved KILO, who is always 5dB less than KILO at same speeds, is around 3 times quieter.

But what does it mean in the game :
you can detect a KILO with another KILO at ~12 miles, but you won't be able to see any improved KILO on passive sonars of a KILO.

I have one question for Luftwolf : are the conformal and cylindrical the same on KILO and on improved KILO in DW ?
I ask this because improved KILO are supposed to have improved sonar suit IRL.
OKO is offline   Reply With Quote
Old 01-19-06, 09:04 AM   #11
Kazuaki Shimazaki II
Ace of the Deep
 
Join Date: Jan 2006
Posts: 1,140
Downloads: 5
Uploads: 0
Default

Quote:
Originally Posted by OKO
The only simple thing I know about dB is : each more 3dB, you have twice the sound level
So, 10 dB is a bit more than 10 times the sound level
Actually, 3dB=2x is the approximation and 10dB=10x is the exact version. What most people forget with decibels is that it is really a variant of the bel, which is a logarithmic measure of intensity. The "deci" is a prefix which means 0.1. 1 bel (10 decibels) therefore means 10^1=10x the intensity of 0 bel, 2 bel (20 decibals) is 10^2=100x the intensity of 0 bel.

Quote:
But in DW, it's NOT 10 dB beetween KILO and Improved, it's 5 dB (with LWAMI) just take a look at the graphical chart.
No, the difference is 5 PSL. I remember seeing those charts and they are measured in the game unit PSL. Each PSL = roughly 2dB, as LW confirmed up there, so it is 10dB = 1 bel = 1 order of magnitude = 10 times quieter.

Quote:
But what does it mean in the game :
you can detect a KILO with another KILO at ~12 miles, but you won't be able to see any improved KILO on passive sonars of a KILO.
The Kilo's passive sonar was never very good (small, cylindrical...) - my question would be whether it is appropriate for a KILO to detect another (presumably slow moving) Kilo at 12 miles.

Quote:
I have one question for Luftwolf : are the conformal and cylindrical the same on KILO and on improved KILO in DW ?
I ask this because improved KILO are supposed to have improved sonar suit IRL.
The upgrade AFAIK is mostly software and processing. You can check that one for yourself by downloading DWEdit and actually taking a look see in the database - get it at SubGurus. Or maybe I'd check for you and let you know after my computer finishes its current defrag.

Yes, all Kilos have a:
MGK-400 Active Sonar
generic Active Intercept
MGK-400PBB
MRM-25EM ESM
Visual
MRK-50 radar
MGK-400 PNB

OK, if you wanna do the switch, here are some recommendations

Yes, I know the above site is in Japanese and it unfortunately went out of business, but it is the only one I have. Translating the important bit, the 636 is supposed to be twice as quiet as the 877EKM (which may be a export version but it is still a hell of a lot newer than the baseline Kilo). The sonar is 2.5 times as sensitive. there is already an unused Improved Kilo sonar which has no changes over the original, so change Nrd detection on that sensor from -13 now to -15, and make the new Kilos use it.
Kazuaki Shimazaki II is offline   Reply With Quote
Old 01-19-06, 08:19 PM   #12
LuftWolf
Ocean Warrior
 
Join Date: May 2005
Location: Free New York
Posts: 3,167
Downloads: 2
Uploads: 0
Default

I'm not so sure about detecting a kilo at 12nm. :hmm:

It must have had a diesel on or been cavitating, that's the only way I see that happening to be honest.

I was originally going to make separate sonars for the Kilo and Kilo Imp but then stopped because of a lack of a way to reasonably estimate the differences in the sonars, as well as the fact that while it is rumored they are upgraded, the MK-400 (I think) is listed for both in any source I came across.

I left them the same because it is reasonable to me that the standard Kilos' sonar would be upgraded to the 636 standard by nations fielding both Kilo Imp and 877's.
__________________
LW
LuftWolf is offline   Reply With Quote
Old 01-19-06, 09:05 PM   #13
Kazuaki Shimazaki II
Ace of the Deep
 
Join Date: Jan 2006
Posts: 1,140
Downloads: 5
Uploads: 0
Default

Quote:
Originally Posted by LuftWolf
I was originally going to make separate sonars for the Kilo and Kilo Imp but then stopped because of a lack of a way to reasonably estimate the differences in the sonars, as well as the fact that while it is rumored they are upgraded, the MK-400 (I think) is listed for both in any source I came across.
Early Soviet nukes used the MGK-200. By the time of the Victors they were to the -300, which they claim is superior to the BQQ-2. Then there is the MGK-400, which is used in the Kilos. Some sources claim the Victor-III used the MGK-400 as well, while others claim the MGK-500 series. I suppose they might have used the -400 for a few of the early ones until the -500s (Typhoons, Delta IVs, Sierra, Akula, Oscar) came in.

The fire control system in that one is apparently a MVU-110EM, which tracks 2 targets automatically, which is roughly what you see in the game Kilo.

The newer ones (EKM, 636) use the -400EM. It is the same size, but apparently includes better tranducers and all new computers and displays that among other things can track 12 targets automatically. The only info I have says it is about 2.5 times the sensitivity (see previous post). So it is not necessarily an easy upgrade for user nations - let alone Russia, who is lucky to keep its subs running.

BTW, if I do want to make a differentiation and assume the EM is 2.5 times more sensitive (there's no way to get it to track more targets short of massive code hacking) than the base version, am I correct to set the Nrd difference to "2".
Kazuaki Shimazaki II is offline   Reply With Quote
Old 01-19-06, 09:39 PM   #14
LuftWolf
Ocean Warrior
 
Join Date: May 2005
Location: Free New York
Posts: 3,167
Downloads: 2
Uploads: 0
Default

Quote:
It is the same size, but apparently includes better tranducers and all new computers and displays that among other things can track 12 targets automatically.
Then it sounds like the perfect thing to be fitted onto the 877's.

Seriously, the standard Kilo is already a pretty juicy target in LWAMI (behaving like a 25 year old sub which it is...), I don't really want to make it deaf as well.
__________________
LW
LuftWolf is offline   Reply With Quote
Old 01-20-06, 12:14 AM   #15
Kazuaki Shimazaki II
Ace of the Deep
 
Join Date: Jan 2006
Posts: 1,140
Downloads: 5
Uploads: 0
Default

Quote:
Originally Posted by LuftWolf
Seriously, the standard Kilo is already a pretty juicy target in LWAMI (behaving like a 25 year old sub which it is...), I don't really want to make it deaf as well.
That's why maybe we should improve the newer Kilo's sonar by 2 points rather than degrading the older Kilo's sonar by 2 points

In fact, I already improved the bow and tails of Gepard by 2 points on my own database (it now has the theoretical sensitivity of the 688I, still not as good as Seawolf's sonar of course, washout improved but still inferior to Yanks, and the waterfall is simply a better display than the SSAZ) - I'd have to remember to get a "stock" LWAMI copy before going multiplayer.
Kazuaki Shimazaki II is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 12:32 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright © 1995- 2024 Subsim®
"Subsim" is a registered trademark, all rights reserved.