From c3ff505b73187e5d9c8fa548ad7a3abb244c3fe3 Mon Sep 17 00:00:00 2001
From: Ken Cooke <ken@highfidelity.io>
Date: Thu, 24 Aug 2017 10:06:41 -0700
Subject: [PATCH 1/3] More aggressive noise gate threshold

---
 libraries/audio/src/AudioGate.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libraries/audio/src/AudioGate.cpp b/libraries/audio/src/AudioGate.cpp
index 0afeee19be..cb339d5e32 100644
--- a/libraries/audio/src/AudioGate.cpp
+++ b/libraries/audio/src/AudioGate.cpp
@@ -147,7 +147,7 @@ GateImpl::GateImpl(int sampleRate) {
     _sampleRate = sampleRate;
 
     // defaults
-    setThreshold(-36.0);
+    setThreshold(-30.0);
     setHold(20.0);
     setHysteresis(6.0);
     setRelease(1000.0);

From 4a253023eec88246755fd5611ec414b65cc0079f Mon Sep 17 00:00:00 2001
From: Ken Cooke <ken@highfidelity.io>
Date: Thu, 24 Aug 2017 10:15:54 -0700
Subject: [PATCH 2/3] float constants

---
 libraries/audio/src/AudioGate.cpp    | 8 ++++----
 libraries/audio/src/AudioLimiter.cpp | 4 ++--
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/libraries/audio/src/AudioGate.cpp b/libraries/audio/src/AudioGate.cpp
index cb339d5e32..0c4fe8b64c 100644
--- a/libraries/audio/src/AudioGate.cpp
+++ b/libraries/audio/src/AudioGate.cpp
@@ -147,10 +147,10 @@ GateImpl::GateImpl(int sampleRate) {
     _sampleRate = sampleRate;
 
     // defaults
-    setThreshold(-30.0);
-    setHold(20.0);
-    setHysteresis(6.0);
-    setRelease(1000.0);
+    setThreshold(-30.0f);
+    setHold(20.0f);
+    setHysteresis(6.0f);
+    setRelease(1000.0f);
 }
 
 //
diff --git a/libraries/audio/src/AudioLimiter.cpp b/libraries/audio/src/AudioLimiter.cpp
index 4ddff1f5a5..e20a070bd6 100644
--- a/libraries/audio/src/AudioLimiter.cpp
+++ b/libraries/audio/src/AudioLimiter.cpp
@@ -52,8 +52,8 @@ LimiterImpl::LimiterImpl(int sampleRate) {
     _sampleRate = sampleRate;
 
     // defaults
-    setThreshold(0.0);
-    setRelease(250.0);
+    setThreshold(0.0f);
+    setRelease(250.0f);
 }
 
 //

From 684b7fee5a73fffc5d8b0dc880233285fc863044 Mon Sep 17 00:00:00 2001
From: Ken Cooke <ken@highfidelity.io>
Date: Thu, 24 Aug 2017 11:20:22 -0700
Subject: [PATCH 3/3] DC filter cutoff at 0.5Hz

---
 libraries/audio/src/AudioGate.cpp | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/libraries/audio/src/AudioGate.cpp b/libraries/audio/src/AudioGate.cpp
index 0c4fe8b64c..a4d731a447 100644
--- a/libraries/audio/src/AudioGate.cpp
+++ b/libraries/audio/src/AudioGate.cpp
@@ -25,10 +25,10 @@ static inline int32_t saturateQ30(int32_t x) {
 }
 
 //
-// First-order DC-blocking filter, with zero at 1.0 and pole at 0.99994
+// First-order DC-blocking filter, with zero at 1.0 and pole at 0.9999
 //
-// -3dB @ 0.5 Hz (48KHz)
-// -3dB @ 0.2 Hz (24KHz)
+// -3dB @ 1.0 Hz (48KHz)
+// -3dB @ 0.5 Hz (24KHz)
 //
 // input in Q15, output in Q30
 //
@@ -41,7 +41,7 @@ public:
 
         x <<= 15;               // scale to Q30
         x -= _dcOffset;         // remove DC
-        _dcOffset += x >> 14;   // pole = (1.0 - 2^-14) = 0.99994
+        _dcOffset += x >> 13;   // pole = (1.0 - 2^-13) = 0.9999
     }
 };