Type 4 Passive Sonar

No.149 四式水中聴音機
Sonar.png Small Sonar
Effects: Armor+1 ASW+12 Accuracy+1
Scrap value: Steel 1 Bauxite 3 (Unbuildable)

Equipment Card Type 4 Passive Sonar.png

Equipment Character Type 4 Passive Sonar.png

Equipment Item Type 4 Passive Sonar.png

Equipment Full Type 4 Passive Sonar.png

Refittable Class
Coastal Defense Ship Destroyer
Light Cruiser Torpedo Cruiser
Heavy Cruiser Training Cruiser
Aviation Cruiser Fast Battleship
Battleship Aviation Battleship
Light Carrier Standard Aircraft Carrier
Armored Carrier Seaplane Tender
Submarine Aircraft Carrying Submarine
Submarine Tender Fleet Oiler
Repair Ship Amphibious Assault Ship

Introduction

小型艦艇にも装備可能な、新型パッシブソナー兵装です。
九三式水中聴音機に比べて、その対潜発見能力は格段に向上しました。
数は少ないですが、大戦末期に建造された後期型の駆逐艦などの対潜兵装として装備されました。

This SONAR can be equipped on smaller ships, and is a new type of armament: the "passive SONAR."
Compared to the type 93 SONARs, this has increased ASW.
There are few of these because it was made in the later part of the war, and were equipped by some of the newer destroyers.

Mechanics

  Sonars are the main equipment used for ASW, being required to trigger most OASW, and greatly enhancing ASW Damage Synergy. Their main stat is "ASW"  .

ASW Damage Synergy
 Small Small Sonars
 
Type 93 Passive Sonar
 
Type 4 Passive Sonar
 
Type 3 Active Sonar
 
Type 3 Active Sonar Kai
 
Type124 ASDIC
 
Type144/147 ASDIC
 
HF/DF + Type144/147 ASDIC
 Large Large Sonars
 
Type 0 Passive Sonar
 DCP Depth Charge Projectors (DCP)
 
Type 94 Depth Charge Projector
 
Type 3 Depth Charge Projector
 
Type 3 Depth Charge Projector (Concentrated Deployment)
 
Prototype 15cm 9-tube ASW Rocket Launcher
 
RUR-4A Weapon Alpha Kai
AP
 
Mk.32 ASW Torpedo (Mk.2 Thrower)
AP
 DCR Depth Charge (Racks) (DCR)
 
Type 95 Depth Charge
AP
 
Type 2 Depth Charge
AP
 
Lightweight ASW Torpedo (Initial Test Model)
AP
 
Hedgehog (Initial Model)
AP
 
Type 2 Depth Charge Kai Ni
AP
 Other ASW Mortars
 
Type 2 12cm Mortar Kai
 
Type 2 12cm Mortar Kai (Concentrated Deployment)
ASW Damage Modifiers: [math]\displaystyle{ \text{Mod}_\text{synergy} = {Mod}_\text{1} \times {Mod}_\text{2} }[/math]
[math]\displaystyle{ {Mod}_\text{1} }[/math]   +  
(Any Sonar + Any Depth Charge)
1.15
[math]\displaystyle{ {Mod}_\text{2} }[/math]  DCP +  DCR and NO  Small 1.1
 Small +  DCP +  DCR 1.25
Examples
[math]\displaystyle{ \text{Mod}_\text{synergy} }[/math]  Small +  DCP +  DCR 1.4375[math]\displaystyle{ 1.15 \times 1.25 }[/math]
 Large +  DCP +  DCR 1.265[math]\displaystyle{ 1.15 \times 1.1 }[/math]
Armor Penetration
Indepentant of synergies, some equipment provides additional armor penetration to ASW attacks.

The flat armor penetration value is calculated as follows:

[math]\displaystyle{ \text{Pen} = \sum\limits_{\text{Equipment}} \Big( \sqrt{\text{ASW}_\text{Equipment} - 2} + \text{Mod}_\text{ship} \Big) }[/math]
With
  • [math]\displaystyle{ \text{ASW}_\text{Equipment} }[/math] the base ASW   stat of the applicable equipment,
  • [math]\displaystyle{ \text{Mod}_\text{ship} }[/math] being 1 for DE, 0 otherwise,
Note
  • Armor penetration from equipment stacks,
  • The final armor of the targetted submarine cannot go below 1.

Notes

How To Obtain

Upgradeable from: Type 93 Passive Sonar 

From quest: B74

From limited-time quest: SB05

Ranking reward for:

  • Aug 2015: 1-5 (x2), 6-20 (x2), 21-100 (x2), 101-500
  • Apr 2016: 1-5, 6-20, 21-100, 101-500
  • Dec 2016: 1-5, 6-20, 21-100, 101-500

Event reward for:

Uses

Used to improve: Type 4 Passive Sonar 

Updates History

  • 2015-09-22: Implemented as ranking reward
  • 2015-09-25: Became improvable
  • 2017-09-29: Stats increased:  +0 →  +1
  • 2020-01-14: Visible bonuses added
  • 2021-03-01: Visible bonuses added for Katori-class 
     

Fit Bonuses

Ship Extra Requirement                 Note
Yuubari Kai Ni D  +3 +5 Non-stackable
Noshiro Kai Ni  +2 +4 Non-stackable
Isuzu Kai Ni 
Naka Kai Ni 
Yura Kai Ni 
Yuubari Kai Ni/Toku 
 

Yukikaze Kai Ni 
+1 +3 Non-stackable
Akizuki-class 
 
 
 
+1 +2 Non-stackable
Katori-class 
 
+2 +3 One-time between Type 93 Passive Sonar , Type 3 Active Sonar , Type 4 Passive Sonar  and Type 3 Active Sonar Kai 

Improvement

  Type 4 Passive Sonar

Improvement Not
Upgradable
★ Improvement
Level
0~5 6~9


  Consumed 5/7 6/10
  Consumed 3/5 4/6
Equipment
Consumed
 x2  
Items
Consumed
-
Resources  10  0  50  60
Ship Helper Conversion
 
Yuubari Kai Ni/Toku/D
-
Mon Tue Wed Thu Fri Sat Sun
 
Isuzu Kai Ni
Mon Tue Wed Thu Fri Sat Sun
 
Katori Kai
Mon Tue Wed Thu Fri Sat Sun
 
Akizuki/Kai
Mon Tue Wed Thu Fri Sat Sun
 
Teruzuki/Kai
Mon Tue Wed Thu Fri Sat Sun
Improvement   effects
  1★ 2★ 3★ 4★ 5★ 6★ 7★ 8★ 9★ Max★
  0.75 1.06 1.29 1.50 1.67 1.83 1.98 2.12 2.25 2.37
  0.67 0.94 1.15 1.33 1.49 1.63 1.76 1.89 2.00 2.11
  ASW 1.30 1.83 2.25 2.60 2.90 3.18 3.43 3.67 3.90 4.11
  Torpedo 1.50 2.12 2.59 3.00 3.35 3.67 3.96 4.24 4.50 4.74

See Also