How to properly concaternate two audio files together?

Question

I ripped two Blu-rays and I'm trying to combine the audio from both into one file. I've decoded it from DTS-HD MA to Wave64, and I used avisynth to remove the black screen audio (4 seconds) from the first file.

Now I'm trying to concatenate the two into one file. The format doesn't matter at this point, FLAC Wave64, whatever.

I tried both of these commands:

"C:\Users\Marcus\Desktop\ffmpeg\ffmpeg.exe" -f concat -i "C:\Users\Marcus\Desktop\catlist.txt" -c copy "E:\Media\Movies\The Lord of the Rings\The Two Towers\Audio\TheTwoTowers.flac"

Here's the second command:

"C:\Users\Marcus\Desktop\ffmpeg\ffmpeg.exe" -i "concat:E:\Media\Movies\The Lord of the Rings\The Two Towers\Audio\Part1.w64|E:\Media\Movies\The Lord of the Rings\The Two Towers\Audio\Part2.w64" -c copy "E:\Media\Movies\The Lord of the Rings\The Two Towers\AudioTheTwoTowers.w64"

They're both 6.1 channels, with a bit depth of 24 bit, and 48,000 kHz sample rate.

concat.txt merely has the part 1 on line 1, and part 2 on line 2, the second command does the same: It only copies the first part to the output file.

What am I supposed to do? I've been struggling with this since yesterday, I've also tried Eac3to but it doesn't support joining containerless audio.

I would give you a log from FFmpeg, but Command Prompt won't let me copy its text (I've tried the right click > select all > Ctrl+C method, and the appending >XXX.log method to no avail).

I just went to MMG from mkvtoolnix, and tried adding the *.w64 files, to mux into an MKV, and the *.w64 file is recognized as an "MPEG-4 part 10 ES stream. While the *.wav and *.flac are recognized just fine, the *.w64 files play fine in foobar and VLC though. Not sure if the w64 is being read incorrectly, or if it has the wrong FourCC info or what.

Eac3to can't join Matroska files, so now I'm trying to mux the w64 files into m2ts files to join them withh eac3to.

Eac3to can't join audio, even when in a supported container, neither can TsMuxer, it fails with error code -2

    ffmpeg version N-52233-gee94362 Copyright (c) 2000-2013 the FFmpeg developers
    built on Apr 18 2013 02:58:04 with gcc 4.8.0 (GCC)
    configuration: --disable-static --enable-shared --enable-gpl --enable-version3 --disable-w32threads --enable-avisynth --    enable-bzlib --enable-fontconfig -- enable-frei0r --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-   libcaca --enable-libfreetype --enable-libgsm --enable-libilbc --    enable-libmp3lame --enable-libopencore-amrnb --enable-  libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-  libschroedinger --enable-libsoxr -- enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-  libvorbis   --enable-libvpx --enable-libx264 --enable-libxavs --enable-libxvid --enable-zlib
    libavutil      52. 26.100 / 52. 26.100
    libavcodec     55.  2.100 / 55.  2.100
    libavformat    55.  2.100 / 55.  2.100
    libavdevice    55.  0.100 / 55.  0.100
    libavfilter     3. 56.103 /  3. 56.103
    libswscale      2.  2.100 /  2.  2.100
    libswresample   0. 17.102 /  0. 17.102
    libpostproc    52.  3.100 / 52.  3.100
    [w64 @ 0000000001fd3200] Estimating duration from bitrate, this may be inaccurate
    Input #0, w64, from 'concat:E:\Media\Movies\The Lord of the Rings\The Two Towers\Audio\Part1.w64|E:\Media\Movies\The    Lord of the Rings\The Two   Towers\Audio\Part2.w64':
    Duration: 03:55:24.51, bitrate: 8063 kb/s
    Stream #0:0: Audio: pcm_s24le ([1][0][0][0] / 0x0001), 48000 Hz, 6.1, s32, 8064 kb/s
    File 'E:\Media\Movies\The Lord of the Rings\The Two Towers\AudioTheTwoTowers.w64' already exists. Overwrite ? [y/N]     Output #0, w64, to 'E:\Media\Movies \The Lord of the Rings\The Two Towers\AudioTheTwoTowers.w64':
      Metadata:
        encoder         : Lavf55.2.100
        Stream #0:0: Audio: pcm_s24le ([1][0][0][0] / 0x0001), 48000 Hz, 6.1, 8064 kb/s
    Stream mapping:
      Stream #0:0 -> #0:0 (copy)
    Press [q] to stop, [?] for help
    size=   53171kB time=00:00:54.01 bitrate=8064.0kbits/s    
size=  112661kB time=00:01:54.44 bitrate=8064.0kbits/s    
size=   161813kB 
    time=01:46:20.76 bitrate=8064.0kbits/s    
size= 6281254kB time=01:46:20.95 bitrate=8064.0kbits/s    
size= 6294322kB     time=01:46:34.23 bitrate=8064.0kbits/s    

    video:0kB audio:6294322kB subtitle:0 global headers:0kB muxing overhead 0.000002%