# Problem playing EAC3 and TrueHD audio on a Mac connected to an Arcam amp **URL:** \ **Category:** Factual Questions\ **Created:** [March 11, 2022, 7:16am UTC](https://boards.straightdope.com/t/problem-playing-eac3-and-truehd-audio-on-a-mac-connected-to-an-arcam-amp/960879 "2022-03-11T07:16:55Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![MozeJose](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mozejose/32/13445_2.png) [@MozeJose](https://boards.straightdope.com/u/MozeJose)\ **Post date:** [March 11, 2022, 7:16am UTC](https://boards.straightdope.com/t/problem-playing-eac3-and-truehd-audio-on-a-mac-connected-to-an-arcam-amp/960879/1 "2022-03-11T07:16:55Z")
I know this is a very specific topic for this message board, but I’ve already asked it on the Apple, Arcam, and Plex forums without any replies. I have an M1 Mac mini running Monterey (12.2.1) and am using Plex Media Player (4.75.0) to play video files that are being served from a Synology DiskStation DS918+ (DSM 7.0.1-42218 Update 3) running Plex media Server (1.25.6.5577-7000). The computer is connected via an HDMI cable to the AV port on a Arcam AVR10. When I play a video with an EAC3 5.1 or TrueHD 5.1 or 7.1 soundtrack, it’s output in stereo and the volume is very low. Is there a fix for this issue? I do not experience the issue with other Dolby Atmos, DTS, or other Dolby digital soundtracks. ---
**Author:** ![wolfpup](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolfpup/32/10618_2.png) [@wolfpup](https://boards.straightdope.com/u/wolfpup)\ **Post date:** [March 11, 2022, 7:34am UTC](https://boards.straightdope.com/t/problem-playing-eac3-and-truehd-audio-on-a-mac-connected-to-an-arcam-amp/960879/2 "2022-03-11T07:34:58Z")
Maybe what you should do instead of trying to troubleshoot the specific complicated details is just convert the audio using FFMPEG to a format that works for you – for example, EAC3 to AC3. This is a free open-source command line utility available for both Windows and Mac. The command line syntax may seem daunting but it’s well documented and once you get it right, it works very well. A starter here: > **[A quick guide to using FFmpeg to convert media files](https://opensource.com/article/17/6/ffmpeg-convert-media-file-formats)** > > There are many open source tools out there for editing, tweaking, and converting multimedia into exactly what you need. ---
**Author:** ![MozeJose](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mozejose/32/13445_2.png) [@MozeJose](https://boards.straightdope.com/u/MozeJose)\ **Post date:** [March 11, 2022, 8:34am UTC](https://boards.straightdope.com/t/problem-playing-eac3-and-truehd-audio-on-a-mac-connected-to-an-arcam-amp/960879/3 "2022-03-11T08:34:44Z")
Does FFMPEG automatically remux the file? ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [March 11, 2022, 9:37am UTC](https://boards.straightdope.com/t/problem-playing-eac3-and-truehd-audio-on-a-mac-connected-to-an-arcam-amp/960879/4 "2022-03-11T09:37:04Z")
Does it also happen with VLC? ffmpeg can remux the file (not “automatically” AFAIK) but first use ffprobe to compare the channel layout of a problematic and a non-problematic file ---
**Author:** ![Charlie\_Tan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/charlie_tan/32/12582_2.png) [@Charlie\_Tan](https://boards.straightdope.com/u/Charlie_Tan)\ **Post date:** [March 11, 2022, 9:53am UTC](https://boards.straightdope.com/t/problem-playing-eac3-and-truehd-audio-on-a-mac-connected-to-an-arcam-amp/960879/5 "2022-03-11T09:53:00Z")
> [@MozeJose](#): > > an HDMI cable Stupid question: The arcam has 7 HDMI ports input. Would that play a part? ---
**Author:** ![MozeJose](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mozejose/32/13445_2.png) [@MozeJose](https://boards.straightdope.com/u/MozeJose)\ **Post date:** [March 11, 2022, 10:31am UTC](https://boards.straightdope.com/t/problem-playing-eac3-and-truehd-audio-on-a-mac-connected-to-an-arcam-amp/960879/6 "2022-03-11T10:31:34Z")
> [@DPRK](#): > > Does it also happen with VLC? Yes, but the volume is “normal”. ---
**Author:** ![MozeJose](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mozejose/32/13445_2.png) [@MozeJose](https://boards.straightdope.com/u/MozeJose)\ **Post date:** [March 11, 2022, 10:32am UTC](https://boards.straightdope.com/t/problem-playing-eac3-and-truehd-audio-on-a-mac-connected-to-an-arcam-amp/960879/7 "2022-03-11T10:32:51Z")
> [@Charlie\_Tan](#): > > > [@MozeJose](#): > > > > an HDMI cable > > Stupid question: The arcam has 7 HDMI ports input. Would that play a part? The issue is the same regardless of which HDMI port is used. ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [March 11, 2022, 10:56am UTC](https://boards.straightdope.com/t/problem-playing-eac3-and-truehd-audio-on-a-mac-connected-to-an-arcam-amp/960879/8 "2022-03-11T10:56:51Z")
`mplayer` is also worth a try since it gives verbose output and will complain about any problems with the channel layout (e.g trying to play 5.1 surround sound on 2 channels without mixing) btw `ffprobe`ing a file gives information about the streams like `Audio: eac3, 48000 Hz, 5.1(side), fltp, 640 kb/s (default)` ---
**Author:** ![wolfpup](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolfpup/32/10618_2.png) [@wolfpup](https://boards.straightdope.com/u/wolfpup)\ **Post date:** [March 11, 2022, 10:45pm UTC](https://boards.straightdope.com/t/problem-playing-eac3-and-truehd-audio-on-a-mac-connected-to-an-arcam-amp/960879/9 "2022-03-11T22:45:39Z")
> [@MozeJose](#): > > Does FFMPEG automatically remux the file? Yes, that’s pretty much integral to how it works. It takes either the video stream and/or the audio stream, converts one or both to a different codec or else copies it unchanged, and re-muxes into a specified output file. Once you figure out the switches and arguments you need, it’s a simple one-step operation that is invoked by a single command line and can be put into a command file. For example, this command will copy the video codec from infile.mp4 as is, while converting whatever multichannel audio codec there is to AAC at 192Kbps and downmix to two channels, and remux to outfile.mp4: `ffmpeg -i infile.mp4 -vcodec copy -acodec aac -ab 192k -ac 2 outfile.mp4`