# Plex Optimized Versions Passthrough Audio

**URL:** <https://forums.plex.tv/t/plex-optimized-versions-passthrough-audio/711676>\
**Category:** Plex Media Server\
**Tags:** media-optimizer\
**Created:** [April 24, 2021, 10:40pm UTC](https://forums.plex.tv/t/plex-optimized-versions-passthrough-audio/711676 "2021-04-24T22:40:10Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![TaSTEFuL](https://avatars.discourse-cdn.com/v4/letter/t/f4b2a3/32.png) [@TaSTEFuL](https://forums.plex.tv/u/TaSTEFuL)\
**Post date:** [April 24, 2021, 10:40pm UTC](https://forums.plex.tv/t/plex-optimized-versions-passthrough-audio/711676/1 "2021-04-24T22:40:10Z")

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So when you optimised a file with Plex it not only transcodes the video, it also transcodes the audio to AAC. The issue is that it transcodes down lossless 7.1 audio to lossy 5.1 (Or if a mobile profile is selected 2.0).

I want to optimise my 4K HDR H265 content to 1080p SDR H264 15 Mbps for remote playback as my server cannot transcode that on the fly (but it can easily transcode the 15Mbps to whatever is required).

My question is:

Is there anyway of modifying the Plex Optimised Versions profiles to pass through the audio like in Handbrake?

I would prefer to use Plex over Handbrake as the optimised versions are seamlessly incorporated and can be easily managed within Plex.

Handbrake HDR to SDR is also a lot more tedious and complicated than just using Plex.

I tried using the original quality option within Plex but this till transcoded the audio.

Server Version#: Version 4.56.4

> **[r/PleX - Plex Optimized Versions Passthrough Audio](https://www.reddit.com/r/PleX/comments/mxu8yg/plex_optimized_versions_passthrough_audio/)**
>
> 3 votes and 3 comments so far on Reddit

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**Author:** ![OttoKerner](https://sea1.discourse-cdn.com/plex/user_avatar/forums.plex.tv/ottokerner/32/10079_2.png) [@OttoKerner](https://forums.plex.tv/u/OttoKerner)\
**Post date:** [April 25, 2021, 12:40pm UTC](https://forums.plex.tv/t/plex-optimized-versions-passthrough-audio/711676/2 "2021-04-25T12:40:44Z")

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> [@TaSTEFuL](#):
>
> I want to optimise my 4K HDR H265 content to 1080p SDR H264 15 Mbps

It doesn’t make much sense to leave the original 7.1 audio in lossless quality. Because this will take up to ~6 mbps of bandwidth of your 15 mbps.

If you want to proceeed with this idea nonetheless, you will have to create your optimized versions yourself.  
Maybe you can use Plex’s optimized version, throw it into [MKVtoolnixGUI](https://mkvtoolnix.download/ "MKVtoolnixGUI"), then add the full-quality file as well and disable the appropriate audio and video tracks so you’ll end up with the transcoded video, but the original sound.  
Then replace the optimized file on your server with the output of MKVtoolnix.

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**Author:** ![TaSTEFuL](https://avatars.discourse-cdn.com/v4/letter/t/f4b2a3/32.png) [@TaSTEFuL](https://forums.plex.tv/u/TaSTEFuL)\
**Post date:** [April 25, 2021, 12:46pm UTC](https://forums.plex.tv/t/plex-optimized-versions-passthrough-audio/711676/3 "2021-04-25T12:46:26Z")

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Thank you for the reply I will try that!

The 15 mbps is more for storage space and so that the server doesn’t need to do the 4K HDR H265 to 1080p SDR H264 conversion on the fly.

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**Author:** ![OttoKerner](https://sea1.discourse-cdn.com/plex/user_avatar/forums.plex.tv/ottokerner/32/10079_2.png) [@OttoKerner](https://forums.plex.tv/u/OttoKerner)\
**Post date:** [April 25, 2021, 12:51pm UTC](https://forums.plex.tv/t/plex-optimized-versions-passthrough-audio/711676/4 "2021-04-25T12:51:52Z")

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In this case I advise you to set  
Settings - Server - Transcoder - ‘Show Advanced’ - “Background transcoding x264 preset”  
to “Slow”, or “Slower”, or maybe even “Very Slow”, to maximise the quality of your optimized versions.

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**Author:** ![system](https://global.discourse-cdn.com/plex/original/3X/2/a/2acb9765406f63293d357b4ec509ec39aa28f2ad.png) [@system](https://forums.plex.tv/u/system)\
**Post date:** [July 24, 2021, 12:52pm UTC](https://forums.plex.tv/t/plex-optimized-versions-passthrough-audio/711676/5 "2021-07-24T12:52:28Z")

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Closed on July 24, 2021, 12:52pm UTC

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