diff --git a/Source/Core/Core/DSP/DSPAnalyzer.cpp b/Source/Core/Core/DSP/DSPAnalyzer.cpp
index abbdf88cc4..b2a2b2e21c 100644
--- a/Source/Core/Core/DSP/DSPAnalyzer.cpp
+++ b/Source/Core/Core/DSP/DSPAnalyzer.cpp
@@ -12,9 +12,7 @@
 #include "Core/DSP/DSPMemoryMap.h"
 #include "Core/DSP/DSPTables.h"
 
-namespace DSP
-{
-namespace Analyzer
+namespace DSP::Analyzer
 {
 namespace
 {
@@ -167,5 +165,4 @@ u8 GetCodeFlags(u16 address)
   return code_flags[address];
 }
 
-}  // namespace Analyzer
-}  // namespace DSP
+}  // namespace DSP::Analyzer
diff --git a/Source/Core/Core/DSP/DSPAnalyzer.h b/Source/Core/Core/DSP/DSPAnalyzer.h
index 5ed7e6cd8a..9d25c2167b 100644
--- a/Source/Core/Core/DSP/DSPAnalyzer.h
+++ b/Source/Core/Core/DSP/DSPAnalyzer.h
@@ -7,9 +7,7 @@
 #include "Common/CommonTypes.h"
 
 // Basic code analysis.
-namespace DSP
-{
-namespace Analyzer
+namespace DSP::Analyzer
 {
 // Useful things to detect:
 // * Loop endpoints - so that we can avoid checking for loops every cycle.
@@ -35,5 +33,4 @@ void Analyze();
 // Retrieves the flags set during analysis for code in memory.
 u8 GetCodeFlags(u16 address);
 
-}  // namespace Analyzer
-}  // namespace DSP
+}  // namespace DSP::Analyzer
diff --git a/Source/Core/Core/DSP/DSPHost.h b/Source/Core/Core/DSP/DSPHost.h
index 755493340f..b0a424806a 100644
--- a/Source/Core/Core/DSP/DSPHost.h
+++ b/Source/Core/Core/DSP/DSPHost.h
@@ -13,9 +13,7 @@
 // core isn't used, for example in an asm/disasm tool, then most of these
 // can be stubbed out.
 
-namespace DSP
-{
-namespace Host
+namespace DSP::Host
 {
 u8 ReadHostMemory(u32 addr);
 void WriteHostMemory(u8 value, u32 addr);
@@ -25,5 +23,4 @@ bool IsWiiHost();
 void InterruptRequest();
 void CodeLoaded(const u8* ptr, int size);
 void UpdateDebugger();
-}  // namespace Host
-}  // namespace DSP
+}  // namespace DSP::Host
diff --git a/Source/Core/Core/DSP/Interpreter/DSPIntArithmetic.cpp b/Source/Core/Core/DSP/Interpreter/DSPIntArithmetic.cpp
index 444b47467a..ca2a562eac 100644
--- a/Source/Core/Core/DSP/Interpreter/DSPIntArithmetic.cpp
+++ b/Source/Core/Core/DSP/Interpreter/DSPIntArithmetic.cpp
@@ -12,9 +12,7 @@
 
 // Arithmetic and accumulator control.
 
-namespace DSP
-{
-namespace Interpreter
+namespace DSP::Interpreter
 {
 // CLR $acR
 // 1000 r001 xxxx xxxx
@@ -1159,6 +1157,4 @@ void asrnr(const UDSPInstruction opc)
   dsp_set_long_acc(dreg, acc);
   Update_SR_Register64(dsp_get_long_acc(dreg));
 }
-
-}  // namespace Interpreter
-}  // namespace DSP
+}  // namespace DSP::Interpreter
diff --git a/Source/Core/Core/DSP/Interpreter/DSPIntBranch.cpp b/Source/Core/Core/DSP/Interpreter/DSPIntBranch.cpp
index a76f1a717e..ef487758a3 100644
--- a/Source/Core/Core/DSP/Interpreter/DSPIntBranch.cpp
+++ b/Source/Core/Core/DSP/Interpreter/DSPIntBranch.cpp
@@ -11,9 +11,7 @@
 #include "Core/DSP/Interpreter/DSPIntUtil.h"
 #include "Core/DSP/Interpreter/DSPInterpreter.h"
 
-namespace DSP
-{
-namespace Interpreter
+namespace DSP::Interpreter
 {
 // Generic call implementation
 // CALLcc addressA
@@ -263,6 +261,4 @@ void bloopi(const UDSPInstruction opc)
     dsp_skip_inst();
   }
 }
-
-}  // namespace Interpreter
-}  // namespace DSP
+}  // namespace DSP::Interpreter
diff --git a/Source/Core/Core/DSP/Interpreter/DSPIntCCUtil.cpp b/Source/Core/Core/DSP/Interpreter/DSPIntCCUtil.cpp
index 13c6892530..021a4a2fdf 100644
--- a/Source/Core/Core/DSP/Interpreter/DSPIntCCUtil.cpp
+++ b/Source/Core/Core/DSP/Interpreter/DSPIntCCUtil.cpp
@@ -9,9 +9,7 @@
 #include "Core/DSP/Interpreter/DSPIntCCUtil.h"
 #include "Core/DSP/DSPCore.h"
 
-namespace DSP
-{
-namespace Interpreter
+namespace DSP::Interpreter
 {
 void Update_SR_Register64(s64 _Value, bool carry, bool overflow)
 {
@@ -182,6 +180,4 @@ bool CheckCondition(u8 _Condition)
     return true;
   }
 }
-
-}  // namespace Interpreter
-}  // namespace DSP
+}  // namespace DSP::Interpreter
diff --git a/Source/Core/Core/DSP/Interpreter/DSPIntCCUtil.h b/Source/Core/Core/DSP/Interpreter/DSPIntCCUtil.h
index c50c2f15f0..12b8beda78 100644
--- a/Source/Core/Core/DSP/Interpreter/DSPIntCCUtil.h
+++ b/Source/Core/Core/DSP/Interpreter/DSPIntCCUtil.h
@@ -10,9 +10,7 @@
 
 #include "Common/CommonTypes.h"
 
-namespace DSP
-{
-namespace Interpreter
+namespace DSP::Interpreter
 {
 bool CheckCondition(u8 _Condition);
 
@@ -40,6 +38,4 @@ inline bool isOverS32(s64 acc)
 {
   return (acc != (s32)acc) ? true : false;
 }
-
-}  // namespace Interpreter
-}  // namespace DSP
+}  // namespace DSP::Interpreter
diff --git a/Source/Core/Core/DSP/Interpreter/DSPIntExtOps.cpp b/Source/Core/Core/DSP/Interpreter/DSPIntExtOps.cpp
index d1add0785a..e9b2e8c963 100644
--- a/Source/Core/Core/DSP/Interpreter/DSPIntExtOps.cpp
+++ b/Source/Core/Core/DSP/Interpreter/DSPIntExtOps.cpp
@@ -30,9 +30,7 @@ static void WriteToBackLog(int i, int idx, u16 value)
   writeBackLogIdx[i] = idx;
 }
 
-namespace Interpreter
-{
-namespace Ext
+namespace Interpreter::Ext
 {
 static bool IsSameMemArea(u16 a, u16 b)
 {
@@ -493,9 +491,7 @@ void ldaxnm(const UDSPInstruction opc)
 void nop(const UDSPInstruction opc)
 {
 }
-
-}  // namespace Ext
-}  // namespace Interpreter
+}  // namespace Interpreter::Ext
 
 // The ext ops are calculated in parallel with the actual op. That means that
 // both the main op and the ext op see the same register state as input. The
diff --git a/Source/Core/Core/DSP/Interpreter/DSPIntExtOps.h b/Source/Core/Core/DSP/Interpreter/DSPIntExtOps.h
index dfc99e0bea..ec1e23ac9e 100644
--- a/Source/Core/Core/DSP/Interpreter/DSPIntExtOps.h
+++ b/Source/Core/Core/DSP/Interpreter/DSPIntExtOps.h
@@ -11,11 +11,7 @@
 // Many opcode have the lower 0xFF (some only 0x7f) free - there, an opcode extension
 // can be stored.
 
-namespace DSP
-{
-namespace Interpreter
-{
-namespace Ext
+namespace DSP::Interpreter::Ext
 {
 void l(UDSPInstruction opc);
 void ln(UDSPInstruction opc);
@@ -42,7 +38,4 @@ void dr(UDSPInstruction opc);
 void ir(UDSPInstruction opc);
 void nr(UDSPInstruction opc);
 void nop(UDSPInstruction opc);
-
-}  // namespace Ext
-}  // namespace Interpreter
-}  // namespace DSP
+}  // namespace DSP::Interpreter::Ext
diff --git a/Source/Core/Core/DSP/Interpreter/DSPIntLoadStore.cpp b/Source/Core/Core/DSP/Interpreter/DSPIntLoadStore.cpp
index 25add808b7..a3488da8ae 100644
--- a/Source/Core/Core/DSP/Interpreter/DSPIntLoadStore.cpp
+++ b/Source/Core/Core/DSP/Interpreter/DSPIntLoadStore.cpp
@@ -8,9 +8,7 @@
 #include "Core/DSP/Interpreter/DSPIntUtil.h"
 #include "Core/DSP/Interpreter/DSPInterpreter.h"
 
-namespace DSP
-{
-namespace Interpreter
+namespace DSP::Interpreter
 {
 // SRS @M, $(0x18+S)
 // 0010 1sss mmmm mmmm
@@ -261,6 +259,4 @@ void ilrrn(const UDSPInstruction opc)
   dsp_conditional_extend_accum(dreg);
   g_dsp.r.ar[reg] = dsp_increase_addr_reg(reg, (s16)g_dsp.r.ix[reg]);
 }
-
-}  // namespace Interpreter
-}  // namespace DSP
+}  // namespace DSP::Interpreter
diff --git a/Source/Core/Core/DSP/Interpreter/DSPIntMisc.cpp b/Source/Core/Core/DSP/Interpreter/DSPIntMisc.cpp
index 3eb9c19987..bf30aa2312 100644
--- a/Source/Core/Core/DSP/Interpreter/DSPIntMisc.cpp
+++ b/Source/Core/Core/DSP/Interpreter/DSPIntMisc.cpp
@@ -10,9 +10,7 @@
 #include "Core/DSP/Interpreter/DSPIntUtil.h"
 #include "Core/DSP/Interpreter/DSPInterpreter.h"
 
-namespace DSP
-{
-namespace Interpreter
+namespace DSP::Interpreter
 {
 // MRR $D, $S
 // 0001 11dd ddds ssss
@@ -159,6 +157,4 @@ void srbith(const UDSPInstruction opc)
     break;
   }
 }
-
-}  // namespace Interpreter
-}  // namespace DSP
+}  // namespace DSP::Interpreter
diff --git a/Source/Core/Core/DSP/Interpreter/DSPIntMultiplier.cpp b/Source/Core/Core/DSP/Interpreter/DSPIntMultiplier.cpp
index 1d3e0bc4f1..e30b5fefa0 100644
--- a/Source/Core/Core/DSP/Interpreter/DSPIntMultiplier.cpp
+++ b/Source/Core/Core/DSP/Interpreter/DSPIntMultiplier.cpp
@@ -11,9 +11,7 @@
 #include "Core/DSP/Interpreter/DSPIntUtil.h"
 #include "Core/DSP/Interpreter/DSPInterpreter.h"
 
-namespace DSP
-{
-namespace Interpreter
+namespace DSP::Interpreter
 {
 namespace
 {
@@ -594,6 +592,4 @@ void msub(const UDSPInstruction opc)
 
   dsp_set_long_prod(prod);
 }
-
-}  // namespace Interpreter
-}  // namespace DSP
+}  // namespace DSP::Interpreter
diff --git a/Source/Core/Core/DSP/Interpreter/DSPIntUtil.h b/Source/Core/Core/DSP/Interpreter/DSPIntUtil.h
index 3791001309..8903e830d0 100644
--- a/Source/Core/Core/DSP/Interpreter/DSPIntUtil.h
+++ b/Source/Core/Core/DSP/Interpreter/DSPIntUtil.h
@@ -11,9 +11,7 @@
 #include "Core/DSP/DSPCore.h"
 #include "Core/DSP/DSPStacks.h"
 
-namespace DSP
-{
-namespace Interpreter
+namespace DSP::Interpreter
 {
 // ---------------------------------------------------------------------------------------
 // --- SR
@@ -379,5 +377,4 @@ inline s16 dsp_get_ax_h(int _reg)
   return (s16)g_dsp.r.ax[_reg].h;
 }
 
-}  // namespace Interpreter
-}  // namespace DSP
+}  // namespace DSP::Interpreter
diff --git a/Source/Core/Core/DSP/Interpreter/DSPInterpreter.cpp b/Source/Core/Core/DSP/Interpreter/DSPInterpreter.cpp
index 7b71260034..e9231ca09b 100644
--- a/Source/Core/Core/DSP/Interpreter/DSPInterpreter.cpp
+++ b/Source/Core/Core/DSP/Interpreter/DSPInterpreter.cpp
@@ -14,9 +14,7 @@
 #include "Core/DSP/DSPTables.h"
 #include "Core/DSP/Interpreter/DSPIntTables.h"
 
-namespace DSP
-{
-namespace Interpreter
+namespace DSP::Interpreter
 {
 namespace
 {
@@ -237,6 +235,4 @@ void nop(const UDSPInstruction opc)
 
   ERROR_LOG(DSPLLE, "LLE: Unrecognized opcode 0x%04x", opc);
 }
-
-}  // namespace Interpreter
-}  // namespace DSP
+}  // namespace DSP::Interpreter
diff --git a/Source/Core/Core/DSP/Interpreter/DSPInterpreter.h b/Source/Core/Core/DSP/Interpreter/DSPInterpreter.h
index b42fce5127..7d94804604 100644
--- a/Source/Core/Core/DSP/Interpreter/DSPInterpreter.h
+++ b/Source/Core/Core/DSP/Interpreter/DSPInterpreter.h
@@ -6,9 +6,7 @@
 
 #include "Core/DSP/DSPCommon.h"
 
-namespace DSP
-{
-namespace Interpreter
+namespace DSP::Interpreter
 {
 void Step();
 
@@ -146,5 +144,4 @@ void xorc(UDSPInstruction opc);
 void xori(UDSPInstruction opc);
 void xorr(UDSPInstruction opc);
 
-}  // namespace Interpreter
-}  // namespace DSP
+}  // namespace DSP::Interpreter
diff --git a/Source/Core/Core/HLE/HLE_VarArgs.h b/Source/Core/Core/HLE/HLE_VarArgs.h
index 45eee262ff..3a4ecbf8fe 100644
--- a/Source/Core/Core/HLE/HLE_VarArgs.h
+++ b/Source/Core/Core/HLE/HLE_VarArgs.h
@@ -12,9 +12,7 @@
 
 #include <type_traits>
 
-namespace HLE
-{
-namespace SystemVABI
+namespace HLE::SystemVABI
 {
 // SFINAE
 template <typename T>
@@ -172,5 +170,4 @@ private:
   double GetFPR(u32 fpr) const override;
 };
 
-}  // namespace SystemVABI
-}  // namespace HLE
+}  // namespace HLE::SystemVABI
diff --git a/Source/Core/Core/HW/DSPHLE/DSPHLE.cpp b/Source/Core/Core/HW/DSPHLE/DSPHLE.cpp
index 6784477ed7..1dc8df59de 100644
--- a/Source/Core/Core/HW/DSPHLE/DSPHLE.cpp
+++ b/Source/Core/Core/HW/DSPHLE/DSPHLE.cpp
@@ -11,9 +11,7 @@
 #include "Core/HW/DSPHLE/UCodes/UCodes.h"
 #include "Core/HW/SystemTimers.h"
 
-namespace DSP
-{
-namespace HLE
+namespace DSP::HLE
 {
 DSPHLE::DSPHLE() = default;
 
@@ -216,5 +214,4 @@ u16 DSPHLE::DSP_ReadControlRegister()
 void DSPHLE::PauseAndLock(bool do_lock, bool unpause_on_unlock)
 {
 }
-}  // namespace HLE
-}  // namespace DSP
+}  // namespace DSP::HLE
diff --git a/Source/Core/Core/HW/DSPHLE/DSPHLE.h b/Source/Core/Core/HW/DSPHLE/DSPHLE.h
index 4a948ece25..84eb4f217e 100644
--- a/Source/Core/Core/HW/DSPHLE/DSPHLE.h
+++ b/Source/Core/Core/HW/DSPHLE/DSPHLE.h
@@ -13,9 +13,7 @@
 
 class PointerWrap;
 
-namespace DSP
-{
-namespace HLE
+namespace DSP::HLE
 {
 class UCodeInterface;
 
@@ -73,5 +71,4 @@ private:
   bool m_halt;
   bool m_assert_interrupt;
 };
-}  // namespace HLE
-}  // namespace DSP
+}  // namespace DSP::HLE
diff --git a/Source/Core/Core/HW/DSPHLE/MailHandler.cpp b/Source/Core/Core/HW/DSPHLE/MailHandler.cpp
index 6d8de40b54..0f0a013ab2 100644
--- a/Source/Core/Core/HW/DSPHLE/MailHandler.cpp
+++ b/Source/Core/Core/HW/DSPHLE/MailHandler.cpp
@@ -12,9 +12,7 @@
 #include "Common/MsgHandler.h"
 #include "Core/HW/DSP.h"
 
-namespace DSP
-{
-namespace HLE
+namespace DSP::HLE
 {
 CMailHandler::CMailHandler()
 {
@@ -135,5 +133,4 @@ void CMailHandler::DoState(PointerWrap& p)
     }
   }
 }
-}  // namespace HLE
-}  // namespace DSP
+}  // namespace DSP::HLE
diff --git a/Source/Core/Core/HW/DSPHLE/MailHandler.h b/Source/Core/Core/HW/DSPHLE/MailHandler.h
index a3503cefb7..7f451009b7 100644
--- a/Source/Core/Core/HW/DSPHLE/MailHandler.h
+++ b/Source/Core/Core/HW/DSPHLE/MailHandler.h
@@ -11,9 +11,7 @@
 
 class PointerWrap;
 
-namespace DSP
-{
-namespace HLE
+namespace DSP::HLE
 {
 class CMailHandler
 {
@@ -35,5 +33,4 @@ private:
   // mail handler
   std::queue<std::pair<u32, bool>> m_Mails;
 };
-}  // namespace HLE
-}  // namespace DSP
+}  // namespace DSP::HLE
diff --git a/Source/Core/Core/HW/DSPHLE/UCodes/AX.cpp b/Source/Core/Core/HW/DSPHLE/UCodes/AX.cpp
index 7f38ee7cb8..481805b879 100644
--- a/Source/Core/Core/HW/DSPHLE/UCodes/AX.cpp
+++ b/Source/Core/Core/HW/DSPHLE/UCodes/AX.cpp
@@ -22,9 +22,7 @@
 #define AX_GC
 #include "Core/HW/DSPHLE/UCodes/AXVoice.h"
 
-namespace DSP
-{
-namespace HLE
+namespace DSP::HLE
 {
 AXUCode::AXUCode(DSPHLE* dsphle, u32 crc) : UCodeInterface(dsphle, crc), m_cmdlist_size(0)
 {
@@ -727,5 +725,4 @@ void AXUCode::DoState(PointerWrap& p)
   DoStateShared(p);
   DoAXState(p);
 }
-}  // namespace HLE
-}  // namespace DSP
+}  // namespace DSP::HLE
diff --git a/Source/Core/Core/HW/DSPHLE/UCodes/AX.h b/Source/Core/Core/HW/DSPHLE/UCodes/AX.h
index ea1256221d..2803162834 100644
--- a/Source/Core/Core/HW/DSPHLE/UCodes/AX.h
+++ b/Source/Core/Core/HW/DSPHLE/UCodes/AX.h
@@ -15,9 +15,7 @@
 #include "Common/CommonTypes.h"
 #include "Core/HW/DSPHLE/UCodes/UCodes.h"
 
-namespace DSP
-{
-namespace HLE
+namespace DSP::HLE
 {
 class DSPHLE;
 
@@ -155,5 +153,4 @@ private:
     CMD_SEND_AUX_AND_MIX = 0x13,
   };
 };
-}  // namespace HLE
-}  // namespace DSP
+}  // namespace DSP::HLE
diff --git a/Source/Core/Core/HW/DSPHLE/UCodes/AXStructs.h b/Source/Core/Core/HW/DSPHLE/UCodes/AXStructs.h
index 098e05073f..6f0f718ae2 100644
--- a/Source/Core/Core/HW/DSPHLE/UCodes/AXStructs.h
+++ b/Source/Core/Core/HW/DSPHLE/UCodes/AXStructs.h
@@ -6,9 +6,7 @@
 
 #include "Common/CommonTypes.h"
 
-namespace DSP
-{
-namespace HLE
+namespace DSP::HLE
 {
 struct PBMixer
 {
@@ -337,5 +335,4 @@ enum
   FILTER_LOWPASS = 1,
   FILTER_BIQUAD = 2,
 };
-}  // namespace HLE
-}  // namespace DSP
+}  // namespace DSP::HLE
diff --git a/Source/Core/Core/HW/DSPHLE/UCodes/AXVoice.h b/Source/Core/Core/HW/DSPHLE/UCodes/AXVoice.h
index 96ab3a504f..8ed68c875e 100644
--- a/Source/Core/Core/HW/DSPHLE/UCodes/AXVoice.h
+++ b/Source/Core/Core/HW/DSPHLE/UCodes/AXVoice.h
@@ -23,9 +23,7 @@
 #include "Core/HW/DSPHLE/UCodes/AXStructs.h"
 #include "Core/HW/Memmap.h"
 
-namespace DSP
-{
-namespace HLE
+namespace DSP::HLE
 {
 #ifdef AX_GC
 #define PB_TYPE AXPB
@@ -566,5 +564,4 @@ void ProcessVoice(PB_TYPE& pb, const AXBuffers& buffers, u16 count, AXMixControl
 }
 
 }  // namespace
-}  // namespace HLE
-}  // namespace DSP
+}  // namespace DSP::HLE
diff --git a/Source/Core/Core/HW/DSPHLE/UCodes/AXWii.cpp b/Source/Core/Core/HW/DSPHLE/UCodes/AXWii.cpp
index c64ddfd48d..8e94982875 100644
--- a/Source/Core/Core/HW/DSPHLE/UCodes/AXWii.cpp
+++ b/Source/Core/Core/HW/DSPHLE/UCodes/AXWii.cpp
@@ -19,9 +19,7 @@
 #include "Core/HW/DSPHLE/UCodes/AXVoice.h"
 #include "Core/HW/DSPHLE/UCodes/UCodes.h"
 
-namespace DSP
-{
-namespace HLE
+namespace DSP::HLE
 {
 AXWiiUCode::AXWiiUCode(DSPHLE* dsphle, u32 crc) : AXUCode(dsphle, crc), m_last_main_volume(0x8000)
 {
@@ -669,5 +667,4 @@ void AXWiiUCode::DoState(PointerWrap& p)
   p.Do(m_last_main_volume);
   p.Do(m_last_aux_volumes);
 }
-}  // namespace HLE
-}  // namespace DSP
+}  // namespace DSP::HLE
diff --git a/Source/Core/Core/HW/DSPHLE/UCodes/AXWii.h b/Source/Core/Core/HW/DSPHLE/UCodes/AXWii.h
index 5dddb2795b..f933a96ee1 100644
--- a/Source/Core/Core/HW/DSPHLE/UCodes/AXWii.h
+++ b/Source/Core/Core/HW/DSPHLE/UCodes/AXWii.h
@@ -7,9 +7,7 @@
 #include "Common/CommonTypes.h"
 #include "Core/HW/DSPHLE/UCodes/AX.h"
 
-namespace DSP
-{
-namespace HLE
+namespace DSP::HLE
 {
 struct AXPBWii;
 class DSPHLE;
@@ -115,5 +113,4 @@ private:
     CMD_END_OLD = 0x0F
   };
 };
-}  // namespace HLE
-}  // namespace DSP
+}  // namespace DSP::HLE
diff --git a/Source/Core/Core/HW/DSPHLE/UCodes/CARD.cpp b/Source/Core/Core/HW/DSPHLE/UCodes/CARD.cpp
index 3533cb6a89..5d6c682e95 100644
--- a/Source/Core/Core/HW/DSPHLE/UCodes/CARD.cpp
+++ b/Source/Core/Core/HW/DSPHLE/UCodes/CARD.cpp
@@ -10,9 +10,7 @@
 #include "Core/HW/DSPHLE/DSPHLE.h"
 #include "Core/HW/DSPHLE/UCodes/UCodes.h"
 
-namespace DSP
-{
-namespace HLE
+namespace DSP::HLE
 {
 CARDUCode::CARDUCode(DSPHLE* dsphle, u32 crc) : UCodeInterface(dsphle, crc)
 {
@@ -52,5 +50,4 @@ void CARDUCode::HandleMail(u32 mail)
   m_mail_handler.PushMail(DSP_DONE);
   m_dsphle->SetUCode(UCODE_ROM);
 }
-}  // namespace HLE
-}  // namespace DSP
+}  // namespace DSP::HLE
diff --git a/Source/Core/Core/HW/DSPHLE/UCodes/CARD.h b/Source/Core/Core/HW/DSPHLE/UCodes/CARD.h
index 65f0613a5f..b2488f7920 100644
--- a/Source/Core/Core/HW/DSPHLE/UCodes/CARD.h
+++ b/Source/Core/Core/HW/DSPHLE/UCodes/CARD.h
@@ -7,9 +7,7 @@
 #include "Common/CommonTypes.h"
 #include "Core/HW/DSPHLE/UCodes/UCodes.h"
 
-namespace DSP
-{
-namespace HLE
+namespace DSP::HLE
 {
 class DSPHLE;
 
@@ -23,5 +21,4 @@ public:
   void HandleMail(u32 mail) override;
   void Update() override;
 };
-}  // namespace HLE
-}  // namespace DSP
+}  // namespace DSP::HLE
diff --git a/Source/Core/Core/HW/DSPHLE/UCodes/GBA.cpp b/Source/Core/Core/HW/DSPHLE/UCodes/GBA.cpp
index 72a3f86b3c..08e2c21319 100644
--- a/Source/Core/Core/HW/DSPHLE/UCodes/GBA.cpp
+++ b/Source/Core/Core/HW/DSPHLE/UCodes/GBA.cpp
@@ -12,9 +12,7 @@
 #include "Core/HW/DSPHLE/MailHandler.h"
 #include "Core/HW/DSPHLE/UCodes/UCodes.h"
 
-namespace DSP
-{
-namespace HLE
+namespace DSP::HLE
 {
 void ProcessGBACrypto(u32 address)
 {
@@ -137,5 +135,4 @@ void GBAUCode::HandleMail(u32 mail)
     WARN_LOG(DSPHLE, "GBAUCode - unknown command: %08x", mail);
   }
 }
-}  // namespace HLE
-}  // namespace DSP
+}  // namespace DSP::HLE
diff --git a/Source/Core/Core/HW/DSPHLE/UCodes/GBA.h b/Source/Core/Core/HW/DSPHLE/UCodes/GBA.h
index d6aa4d90bd..bbca6ce379 100644
--- a/Source/Core/Core/HW/DSPHLE/UCodes/GBA.h
+++ b/Source/Core/Core/HW/DSPHLE/UCodes/GBA.h
@@ -7,9 +7,7 @@
 #include "Common/CommonTypes.h"
 #include "Core/HW/DSPHLE/UCodes/UCodes.h"
 
-namespace DSP
-{
-namespace HLE
+namespace DSP::HLE
 {
 class DSPHLE;
 
@@ -27,5 +25,4 @@ struct GBAUCode : public UCodeInterface
   void HandleMail(u32 mail) override;
   void Update() override;
 };
-}  // namespace HLE
-}  // namespace DSP
+}  // namespace DSP::HLE
diff --git a/Source/Core/Core/HW/DSPHLE/UCodes/INIT.cpp b/Source/Core/Core/HW/DSPHLE/UCodes/INIT.cpp
index b359e98ccf..2a531e5cbb 100644
--- a/Source/Core/Core/HW/DSPHLE/UCodes/INIT.cpp
+++ b/Source/Core/Core/HW/DSPHLE/UCodes/INIT.cpp
@@ -10,9 +10,7 @@
 #include "Core/HW/DSPHLE/MailHandler.h"
 #include "Core/HW/DSPHLE/UCodes/UCodes.h"
 
-namespace DSP
-{
-namespace HLE
+namespace DSP::HLE
 {
 INITUCode::INITUCode(DSPHLE* dsphle, u32 crc) : UCodeInterface(dsphle, crc)
 {
@@ -39,5 +37,4 @@ void INITUCode::Update()
 void INITUCode::HandleMail(u32 mail)
 {
 }
-}  // namespace HLE
-}  // namespace DSP
+}  // namespace DSP::HLE
diff --git a/Source/Core/Core/HW/DSPHLE/UCodes/INIT.h b/Source/Core/Core/HW/DSPHLE/UCodes/INIT.h
index 82943cd0ba..73f2dd5860 100644
--- a/Source/Core/Core/HW/DSPHLE/UCodes/INIT.h
+++ b/Source/Core/Core/HW/DSPHLE/UCodes/INIT.h
@@ -7,9 +7,7 @@
 #include "Common/CommonTypes.h"
 #include "Core/HW/DSPHLE/UCodes/UCodes.h"
 
-namespace DSP
-{
-namespace HLE
+namespace DSP::HLE
 {
 class DSPHLE;
 
@@ -24,5 +22,4 @@ public:
   void Update() override;
   void Init();
 };
-}  // namespace HLE
-}  // namespace DSP
+}  // namespace DSP::HLE
diff --git a/Source/Core/Core/HW/DSPHLE/UCodes/ROM.cpp b/Source/Core/Core/HW/DSPHLE/UCodes/ROM.cpp
index b896dd5e5c..77a902a4ca 100644
--- a/Source/Core/Core/HW/DSPHLE/UCodes/ROM.cpp
+++ b/Source/Core/Core/HW/DSPHLE/UCodes/ROM.cpp
@@ -20,9 +20,7 @@
 #include "Core/HW/DSPHLE/MailHandler.h"
 #include "Core/HW/DSPHLE/UCodes/UCodes.h"
 
-namespace DSP
-{
-namespace HLE
+namespace DSP::HLE
 {
 ROMUCode::ROMUCode(DSPHLE* dsphle, u32 crc)
     : UCodeInterface(dsphle, crc), m_current_ucode(), m_boot_task_num_steps(0), m_next_parameter(0)
@@ -130,5 +128,4 @@ void ROMUCode::DoState(PointerWrap& p)
 
   DoStateShared(p);
 }
-}  // namespace HLE
-}  // namespace DSP
+}  // namespace DSP::HLE
diff --git a/Source/Core/Core/HW/DSPHLE/UCodes/ROM.h b/Source/Core/Core/HW/DSPHLE/UCodes/ROM.h
index d79eaccd5b..086160391c 100644
--- a/Source/Core/Core/HW/DSPHLE/UCodes/ROM.h
+++ b/Source/Core/Core/HW/DSPHLE/UCodes/ROM.h
@@ -7,9 +7,7 @@
 #include "Common/CommonTypes.h"
 #include "Core/HW/DSPHLE/UCodes/UCodes.h"
 
-namespace DSP
-{
-namespace HLE
+namespace DSP::HLE
 {
 class DSPHLE;
 
@@ -41,5 +39,4 @@ private:
 
   void BootUCode();
 };
-}  // namespace HLE
-}  // namespace DSP
+}  // namespace DSP::HLE
diff --git a/Source/Core/Core/HW/DSPHLE/UCodes/UCodes.cpp b/Source/Core/Core/HW/DSPHLE/UCodes/UCodes.cpp
index 6fd250e47d..edc3a7a876 100644
--- a/Source/Core/Core/HW/DSPHLE/UCodes/UCodes.cpp
+++ b/Source/Core/Core/HW/DSPHLE/UCodes/UCodes.cpp
@@ -29,9 +29,7 @@
 #include "Core/HW/DSPHLE/UCodes/Zelda.h"
 #include "Core/HW/Memmap.h"
 
-namespace DSP
-{
-namespace HLE
+namespace DSP::HLE
 {
 constexpr bool ExramRead(u32 address)
 {
@@ -306,5 +304,4 @@ std::unique_ptr<UCodeInterface> UCodeFactory(u32 crc, DSPHLE* dsphle, bool wii)
 
   return nullptr;
 }
-}  // namespace HLE
-}  // namespace DSP
+}  // namespace DSP::HLE
diff --git a/Source/Core/Core/HW/DSPHLE/UCodes/UCodes.h b/Source/Core/Core/HW/DSPHLE/UCodes/UCodes.h
index 88594296dd..dcfe1b6ffd 100644
--- a/Source/Core/Core/HW/DSPHLE/UCodes/UCodes.h
+++ b/Source/Core/Core/HW/DSPHLE/UCodes/UCodes.h
@@ -11,9 +11,7 @@
 
 class PointerWrap;
 
-namespace DSP
-{
-namespace HLE
+namespace DSP::HLE
 {
 class CMailHandler;
 class DSPHLE;
@@ -106,5 +104,4 @@ private:
 };
 
 std::unique_ptr<UCodeInterface> UCodeFactory(u32 crc, DSPHLE* dsphle, bool wii);
-}  // namespace HLE
-}  // namespace DSP
+}  // namespace DSP::HLE
diff --git a/Source/Core/Core/HW/DSPHLE/UCodes/Zelda.cpp b/Source/Core/Core/HW/DSPHLE/UCodes/Zelda.cpp
index 329b270ad9..7657f4e861 100644
--- a/Source/Core/Core/HW/DSPHLE/UCodes/Zelda.cpp
+++ b/Source/Core/Core/HW/DSPHLE/UCodes/Zelda.cpp
@@ -18,9 +18,7 @@
 #include "Core/HW/DSPHLE/UCodes/GBA.h"
 #include "Core/HW/DSPHLE/UCodes/UCodes.h"
 
-namespace DSP
-{
-namespace HLE
+namespace DSP::HLE
 {
 // Uncomment this to have a strict version of the HLE implementation, which
 // PanicAlerts on recoverable unknown behaviors instead of silently ignoring
@@ -1854,5 +1852,4 @@ void ZeldaAudioRenderer::DoState(PointerWrap& p)
   p.Do(m_buf_front_left_reverb_last8);
   p.Do(m_buf_front_right_reverb_last8);
 }
-}  // namespace HLE
-}  // namespace DSP
+}  // namespace DSP::HLE
diff --git a/Source/Core/Core/HW/DSPHLE/UCodes/Zelda.h b/Source/Core/Core/HW/DSPHLE/UCodes/Zelda.h
index 32ab7f804d..761943be00 100644
--- a/Source/Core/Core/HW/DSPHLE/UCodes/Zelda.h
+++ b/Source/Core/Core/HW/DSPHLE/UCodes/Zelda.h
@@ -10,9 +10,7 @@
 #include "Common/CommonTypes.h"
 #include "Core/HW/DSPHLE/UCodes/UCodes.h"
 
-namespace DSP
-{
-namespace HLE
+namespace DSP::HLE
 {
 class DSPHLE;
 
@@ -286,5 +284,4 @@ private:
   // Main object handling audio rendering logic and state.
   ZeldaAudioRenderer m_renderer;
 };
-}  // namespace HLE
-}  // namespace DSP
+}  // namespace DSP::HLE
diff --git a/Source/Core/Core/HW/DSPLLE/DSPDebugInterface.cpp b/Source/Core/Core/HW/DSPLLE/DSPDebugInterface.cpp
index 49ca4e819a..a8a16554ed 100644
--- a/Source/Core/Core/HW/DSPLLE/DSPDebugInterface.cpp
+++ b/Source/Core/Core/HW/DSPLLE/DSPDebugInterface.cpp
@@ -13,9 +13,7 @@
 #include "Core/DSP/DSPMemoryMap.h"
 #include "Core/HW/DSPLLE/DSPSymbols.h"
 
-namespace DSP
-{
-namespace LLE
+namespace DSP::LLE
 {
 void DSPPatches::Patch(std::size_t index)
 {
@@ -312,5 +310,4 @@ void DSPDebugInterface::Clear()
   ClearPatches();
   ClearWatches();
 }
-}  // namespace LLE
-}  // namespace DSP
+}  // namespace DSP::LLE
diff --git a/Source/Core/Core/HW/DSPLLE/DSPDebugInterface.h b/Source/Core/Core/HW/DSPLLE/DSPDebugInterface.h
index 0510f7f9ea..e2d1a5242b 100644
--- a/Source/Core/Core/HW/DSPLLE/DSPDebugInterface.h
+++ b/Source/Core/Core/HW/DSPLLE/DSPDebugInterface.h
@@ -10,9 +10,7 @@
 #include "Common/CommonTypes.h"
 #include "Common/DebugInterface.h"
 
-namespace DSP
-{
-namespace LLE
+namespace DSP::LLE
 {
 class DSPPatches : public Common::Debug::MemoryPatches
 {
@@ -79,5 +77,4 @@ private:
   Common::Debug::Watches m_watches;
   DSPPatches m_patches;
 };
-}  // namespace LLE
-}  // namespace DSP
+}  // namespace DSP::LLE
diff --git a/Source/Core/Core/HW/DSPLLE/DSPHost.cpp b/Source/Core/Core/HW/DSPLLE/DSPHost.cpp
index 204e36dbec..b8f42f7e41 100644
--- a/Source/Core/Core/HW/DSPLLE/DSPHost.cpp
+++ b/Source/Core/Core/HW/DSPLLE/DSPHost.cpp
@@ -24,9 +24,7 @@
 // core isn't used, for example in an asm/disasm tool, then most of these
 // can be stubbed out.
 
-namespace DSP
-{
-namespace Host
+namespace DSP::Host
 {
 u8 ReadHostMemory(u32 addr)
 {
@@ -84,5 +82,4 @@ void UpdateDebugger()
 {
   Host_RefreshDSPDebuggerWindow();
 }
-}  // namespace Host
-}  // namespace DSP
+}  // namespace DSP::Host
diff --git a/Source/Core/Core/HW/DSPLLE/DSPLLE.cpp b/Source/Core/Core/HW/DSPLLE/DSPLLE.cpp
index 2ea1f01628..6f27f485fc 100644
--- a/Source/Core/Core/HW/DSPLLE/DSPLLE.cpp
+++ b/Source/Core/Core/HW/DSPLLE/DSPLLE.cpp
@@ -30,9 +30,7 @@
 #include "Core/HW/Memmap.h"
 #include "Core/Host.h"
 
-namespace DSP
-{
-namespace LLE
+namespace DSP::LLE
 {
 static Common::Event s_dsp_event;
 static Common::Event s_ppc_event;
@@ -340,5 +338,4 @@ void DSPLLE::PauseAndLock(bool do_lock, bool unpause_on_unlock)
   else
     m_dsp_thread_mutex.unlock();
 }
-}  // namespace LLE
-}  // namespace DSP
+}  // namespace DSP::LLE
diff --git a/Source/Core/Core/HW/DSPLLE/DSPLLE.h b/Source/Core/Core/HW/DSPLLE/DSPLLE.h
index f6797fa1ca..2e05ee3f6a 100644
--- a/Source/Core/Core/HW/DSPLLE/DSPLLE.h
+++ b/Source/Core/Core/HW/DSPLLE/DSPLLE.h
@@ -14,9 +14,7 @@
 
 class PointerWrap;
 
-namespace DSP
-{
-namespace LLE
+namespace DSP::LLE
 {
 class DSPLLE : public DSPEmulator
 {
@@ -49,5 +47,4 @@ private:
   Common::Flag m_is_running;
   std::atomic<u32> m_cycle_count{};
 };
-}  // namespace LLE
-}  // namespace DSP
+}  // namespace DSP::LLE
diff --git a/Source/Core/Core/HW/DSPLLE/DSPSymbols.cpp b/Source/Core/Core/HW/DSPLLE/DSPSymbols.cpp
index 04e3bd5dcf..fe0bcf3b92 100644
--- a/Source/Core/Core/HW/DSPLLE/DSPSymbols.cpp
+++ b/Source/Core/Core/HW/DSPLLE/DSPSymbols.cpp
@@ -14,9 +14,7 @@
 #include "Core/DSP/DSPCore.h"
 #include "Core/DSP/DSPDisassembler.h"
 
-namespace DSP
-{
-namespace Symbols
+namespace DSP::Symbols
 {
 DSPSymbolDB g_dsp_symbol_db;
 
@@ -106,6 +104,4 @@ void Clear()
   lines.clear();
   line_counter = 0;
 }
-
-}  // namespace Symbols
-}  // namespace DSP
+}  // namespace DSP::Symbols
diff --git a/Source/Core/Core/HW/DSPLLE/DSPSymbols.h b/Source/Core/Core/HW/DSPLLE/DSPSymbols.h
index 2b9184291c..df08124e4b 100644
--- a/Source/Core/Core/HW/DSPLLE/DSPSymbols.h
+++ b/Source/Core/Core/HW/DSPLLE/DSPSymbols.h
@@ -9,9 +9,7 @@
 #include "Common/CommonTypes.h"
 #include "Common/SymbolDB.h"
 
-namespace DSP
-{
-namespace Symbols
+namespace DSP::Symbols
 {
 class DSPSymbolDB : public Common::SymbolDB
 {
@@ -31,6 +29,4 @@ int Addr2Line(u16 address);
 int Line2Addr(int line);  // -1 for not found
 
 const char* GetLineText(int line);
-
-}  // namespace Symbols
-}  // namespace DSP
+}  // namespace DSP::Symbols
diff --git a/Source/Core/Core/HW/DVD/DVDThread.h b/Source/Core/Core/HW/DVD/DVDThread.h
index 4bb1b6263e..548d4b7b33 100644
--- a/Source/Core/Core/HW/DVD/DVDThread.h
+++ b/Source/Core/Core/HW/DVD/DVDThread.h
@@ -15,23 +15,23 @@ namespace DiscIO
 {
 struct Partition;
 }
+
 namespace DVDInterface
 {
 enum class ReplyType : u32;
 }
+
 namespace DiscIO
 {
 enum class Platform;
 class Volume;
 }  // namespace DiscIO
-namespace IOS
-{
-namespace ES
+
+namespace IOS::ES
 {
 class TMDReader;
 class TicketReader;
-}  // namespace ES
-}  // namespace IOS
+}  // namespace IOS::ES
 
 namespace DVDThread
 {
diff --git a/Source/Core/Core/HW/WiiSave.h b/Source/Core/Core/HW/WiiSave.h
index 4b00c183ae..cde5d938b2 100644
--- a/Source/Core/Core/HW/WiiSave.h
+++ b/Source/Core/Core/HW/WiiSave.h
@@ -11,17 +11,14 @@
 
 #include "Common/CommonTypes.h"
 
-namespace IOS
-{
-namespace HLE
+namespace IOS::HLE
 {
 namespace FS
 {
 class FileSystem;
 }
 class IOSC;
-}  // namespace HLE
-}  // namespace IOS
+}  // namespace IOS::HLE
 
 namespace WiiSave
 {
diff --git a/Source/Core/Core/IOS/FS/FileSystemProxy.cpp b/Source/Core/Core/IOS/FS/FileSystemProxy.cpp
index e0b7398977..d844963ea2 100644
--- a/Source/Core/Core/IOS/FS/FileSystemProxy.cpp
+++ b/Source/Core/Core/IOS/FS/FileSystemProxy.cpp
@@ -15,11 +15,7 @@
 #include "Core/HW/SystemTimers.h"
 #include "Core/IOS/FS/FileSystem.h"
 
-namespace IOS
-{
-namespace HLE
-{
-namespace Device
+namespace IOS::HLE::Device
 {
 using namespace IOS::HLE::FS;
 
@@ -587,6 +583,4 @@ IPCCommandResult FS::Shutdown(const Handle& handle, const IOCtlRequest& request)
   INFO_LOG(IOS_FS, "Shutdown");
   return GetFSReply(IPC_SUCCESS);
 }
-}  // namespace Device
-}  // namespace HLE
-}  // namespace IOS
+}  // namespace IOS::HLE::Device
diff --git a/Source/Core/Core/IOS/FS/FileSystemProxy.h b/Source/Core/Core/IOS/FS/FileSystemProxy.h
index 22683e191e..1bf273ff6e 100644
--- a/Source/Core/Core/IOS/FS/FileSystemProxy.h
+++ b/Source/Core/Core/IOS/FS/FileSystemProxy.h
@@ -15,11 +15,7 @@
 
 class PointerWrap;
 
-namespace IOS
-{
-namespace HLE
-{
-namespace Device
+namespace IOS::HLE::Device
 {
 constexpr IOS::HLE::FS::Fd INVALID_FD = 0xffffffff;
 
@@ -90,6 +86,4 @@ private:
   u16 m_cache_chain_index = 0;
   bool m_dirty_cache = false;
 };
-}  // namespace Device
-}  // namespace HLE
-}  // namespace IOS
+}  // namespace IOS::HLE::Device
diff --git a/Source/Core/Core/IOS/IOS.cpp b/Source/Core/Core/IOS/IOS.cpp
index 3099fa2421..6a45ae4e57 100644
--- a/Source/Core/Core/IOS/IOS.cpp
+++ b/Source/Core/Core/IOS/IOS.cpp
@@ -57,9 +57,7 @@
 #include "Core/PowerPC/PowerPC.h"
 #include "Core/WiiRoot.h"
 
-namespace IOS
-{
-namespace HLE
+namespace IOS::HLE
 {
 static std::unique_ptr<EmulationKernel> s_ios;
 
@@ -801,5 +799,4 @@ EmulationKernel* GetIOS()
 {
   return s_ios.get();
 }
-}  // namespace HLE
-}  // namespace IOS
+}  // namespace IOS::HLE
diff --git a/Source/Core/Core/IOS/IOS.h b/Source/Core/Core/IOS/IOS.h
index 4f283f4c9b..419e0ab542 100644
--- a/Source/Core/Core/IOS/IOS.h
+++ b/Source/Core/Core/IOS/IOS.h
@@ -19,9 +19,7 @@
 
 class PointerWrap;
 
-namespace IOS
-{
-namespace HLE
+namespace IOS::HLE
 {
 namespace FS
 {
@@ -146,5 +144,4 @@ void Init();
 void Shutdown();
 EmulationKernel* GetIOS();
 
-}  // namespace HLE
-}  // namespace IOS
+}  // namespace IOS::HLE
diff --git a/Source/Core/Core/WiiUtils.h b/Source/Core/Core/WiiUtils.h
index f922983209..3004897bb6 100644
--- a/Source/Core/Core/WiiUtils.h
+++ b/Source/Core/Core/WiiUtils.h
@@ -17,13 +17,11 @@ namespace DiscIO
 {
 class WiiWAD;
 }
-namespace IOS
-{
-namespace HLE
+
+namespace IOS::HLE
 {
 class Kernel;
 }
-}  // namespace IOS
 
 namespace WiiUtils
 {