diff --git a/ArcFormats/ArcFormats.csproj b/ArcFormats/ArcFormats.csproj
index 827a9a1f..aa007d41 100644
--- a/ArcFormats/ArcFormats.csproj
+++ b/ArcFormats/ArcFormats.csproj
@@ -78,6 +78,7 @@
     <Compile Include="elf\ImageG24.cs" />
     <Compile Include="elf\ImageGP8.cs" />
     <Compile Include="ExHibit\ImageGYU.cs" />
+    <Compile Include="Ffa\AudioWA2.cs" />
     <Compile Include="Gpk2\ArcGPK2.cs" />
     <Compile Include="Gpk2\ImageGFB.cs" />
     <Compile Include="MersenneTwister.cs" />
diff --git a/ArcFormats/Ffa/AudioWA2.cs b/ArcFormats/Ffa/AudioWA2.cs
new file mode 100644
index 00000000..9a5e2eb2
--- /dev/null
+++ b/ArcFormats/Ffa/AudioWA2.cs
@@ -0,0 +1,157 @@
+//! \file       AudioWA2.cs
+//! \date       Wed Nov 11 21:14:30 2015
+//! \brief      FFA System compressed PCM format.
+//
+// Copyright (C) 2015 by morkt
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to
+// deal in the Software without restriction, including without limitation the
+// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+// sell copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+// IN THE SOFTWARE.
+//
+
+using System.ComponentModel.Composition;
+using System.IO;
+using GameRes.Utility;
+
+namespace GameRes.Formats.Ffa
+{
+    [Export(typeof(AudioFormat))]
+    public class Wa2Audio : AudioFormat
+    {
+        public override string         Tag { get { return "WA2"; } }
+        public override string Description { get { return "FFA System PCM audio format"; } }
+        public override uint     Signature { get { return 0x4D435041; } } // 'APCM'
+
+        public override SoundInput TryOpen (Stream file)
+        {
+            return new Wa2Input (file);
+        }
+    }
+
+    public class Wa2Input : SoundInput
+    {
+        public override string SourceFormat { get { return "raw"; } }
+
+        public override int SourceBitrate
+        {
+            get { return (int)Format.AverageBytesPerSecond * 8; }
+        }
+
+        public Wa2Input (Stream file) : base (null)
+        {
+            var header = new byte[0x2C];
+            if (header.Length != file.Read (header, 0, header.Length))
+                throw new EndOfStreamException();
+            if (!Binary.AsciiEqual (header, 8, "WAVEfmt "))
+                throw new InvalidFormatException();
+
+            var format = new WaveFormat();
+            format.FormatTag                = LittleEndian.ToUInt16 (header, 0x14);
+            format.Channels                 = LittleEndian.ToUInt16 (header, 0x16);
+            format.SamplesPerSecond         = LittleEndian.ToUInt32 (header, 0x18);
+            format.AverageBytesPerSecond    = LittleEndian.ToUInt32 (header, 0x1C);
+            format.BlockAlign               = LittleEndian.ToUInt16 (header, 0x20);
+            format.BitsPerSample            = LittleEndian.ToUInt16 (header, 0x22);
+            format.ExtraSize                = 0;
+            this.Format = format;
+
+            uint pcm_size = LittleEndian.ToUInt32 (header, 0x28);
+            var pcm = new byte[pcm_size];
+            Decode (file, pcm);
+            Source = new MemoryStream (pcm);
+            this.PcmSize = pcm_size;
+            file.Dispose();
+        }
+
+        void Decode (Stream input, byte[] output)
+        {
+            int sample = 0;
+            bool nibble_read = false;
+            short v7 = 0x7F;
+            int input_byte = 0;
+            int dst = 0;
+            while (dst < output.Length)
+            {
+                byte nibble;
+                if (!nibble_read)
+                {
+                    input_byte = input.ReadByte();
+                    if (-1 == input_byte)
+                        break;
+                    nibble = (byte)(input_byte >> 4);
+                }
+                else
+                {
+                    nibble = (byte)(input_byte & 0xF);
+                }
+                nibble_read = !nibble_read;
+                int v11 = (ushort)v7;
+                int diff = (short)(v11 * (byte)(2 * (nibble & 7) + 1) >> 3);
+                if (0 != (nibble & 8))
+                {
+                    sample -= diff;
+                    if (sample < -32768)
+                        sample = -32768;
+                }
+                else
+                {
+                    sample += diff;
+                    if (sample > 0x7FFF)
+                        sample = 0x7FFF;
+                }
+                ushort v13 = (ushort)(v11 * Wa1Reader.SampleTable[nibble] >> 6);
+                if (v13 > 0x7F)
+                {
+                    v7 = 0x6000;
+                    if (v13 < 0x6001)
+                        v7 = (short)v13;
+                }
+                else
+                {
+                    v7 = 0x7F;
+                }
+                LittleEndian.Pack ((ushort)sample, output, dst);
+                dst += 2;
+            }
+        }
+
+        #region IO.Stream methods
+        public override long Position
+        {
+            get { return Source.Position; }
+            set { Source.Position = value; }
+        }
+
+        public override bool CanSeek { get { return Source.CanSeek; } }
+
+        public override long Seek (long offset, SeekOrigin origin)
+        {
+            return Source.Seek (offset, origin);
+        }
+
+        public override int Read (byte[] buffer, int offset, int count)
+        {
+            return Source.Read (buffer, offset, count);
+        }
+
+        public override int ReadByte ()
+        {
+            return Source.ReadByte();
+        }
+        #endregion
+    }
+}
diff --git a/supported.html b/supported.html
index 8550a8cc..9b6c7a6e 100644
--- a/supported.html
+++ b/supported.html
@@ -202,7 +202,7 @@ Nikutai Ten'i<br/>
 </td></tr>
 <tr class="odd"><td>*.grd</td><td><tt>CMP_</tt></td><td>No</td></tr>
 <tr class="odd"><td>*.igf</td><td><tt>ZEUS</tt></td><td>No</td></tr>
-<tr><td>*.dat<br/>*.arc</td><td>-<br/><tt>M2TYPE</tt></td><td>No</td><td rowspan="3">FFA System/G-SYS</td><td rowspan="3">
+<tr><td>*.dat<br/>*.arc</td><td>-<br/><tt>M2TYPE</tt></td><td>No</td><td rowspan="4">FFA System/G-SYS</td><td rowspan="4">
 Dokusen Kango<br/>
 Hensai Keikaku<br/>
 Inran OL Sawatari Tokiko<br/>
@@ -214,6 +214,7 @@ Ryoujoku Costume Play<br/>
 </td></tr>
 <tr><td>*.pt1</td><td>-</td><td>No</td></tr>
 <tr><td>*.wa1</td><td>-</td><td>No</td></tr>
+<tr><td>*.wa2</td><td><tt>APCM</tt></td><td>No</td></tr>
 <tr class="odd"><td>*.pak</td><td><tt>DataPack5</tt><br/><tt>GsPack4</tt></td><td>No</td><td rowspan="2">Autobahn<br/>Root<br/>Clover</td><td rowspan="2">
 Aiyoku no Apron<br/>
 Para-Sol<br/>