LPCM - converting DTS-HD and loudness

  • 25 February 2021
  • 3 replies
  • 926 views

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Hi everyone, I have written about the work-arounds I have used to dealt with DTS (for the PlayBar at the time: 

and DTS-HD for the Arc: 

Since the Arc now supports multi-channel LPCM (only through eArc), I am thinking of converting all the DTS-HD tracks to LPCM. I would welcome any thoughts or knowledge on this topic from other users!!

The reason I want to do this is, as per my thread above, the best work-around I found was converting all DTS-HD tracks to Dolby Digital Plus (E-AC3) 970kbps, which was the highest quality of sound I could get the Arc to play in DD+.

For these conversions, I used Make MKV to digitise my discs and then use XMedia Recode to add a new default audio track for every DTS-HD sound track, which was DD+. I retained the DTS-HD track as second audio track so each movie had the original audio.

Anyway, I have tested this using LPCM as the primary track instead. In comparison to the DD+ tracks:

  • There appears to be no bitrate limitation -- so at least from a data point of view, the LPCM makes a lossless copy of the DTS-HD track
  • The tracks are about 30% larger in size compared to DTS-HD (which makes sense as they are not compressed in LPCM)
  • They play perfectly fine on the Arc
  • But LPCM is much much quieter. I can’t figure out if the “quality” is lower, I can say for sure the volume is some 30% lower. I don’t know what the reason is.

I noticed that many people have complained that LPCM is much quieter, so this may be a firmware/software issue with Sonos equipment… 

Despite the low volume, I think I will proceed in the hope that this issue will be sorted out later. I can’t imagine that DD+ would be better in terms of audio quality than LPCM. Thoughts welcome!!


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3 replies

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Hey @Evander, thanks for posting these guides!

 

It’s great to see Sonos users sharing their experiences and best practices with other tech!

 

I’ve personally been enjoying McLPCM content through a couple of different sources since the update and haven’t noticed a difference in volume compared to other formats, so I’m curious if that’s a source or content based issue.

 

Hopefully your links help someone out who needs it :) 

 
 
 
 
 
Userlevel 2
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Hi James, that’s helpful to know re your experience of volume. I am transcoding to LPCM from DTS-HD using XMedia Recode. Can I ask what programme you're using or how your converting to LPCM? Also, have you done this from DTS-HD? Thanks!

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I’ve only tried this once since it was a Blu-Ray that I really wanted to watch with the full audio experience intact. 

I used MakeMKV to rip the content from the disc and then convert the audio track from DTS-HD to LPCM-multi. Then I just transferred the .mkv to a portable SSD, connected to the TV and it worked! I didn’t notice any loss in volume or quality at all compared to the DTS-HD version.

 

As for non-converted content, the majority of my LPCM stuff comes from my Nintendo Switch, since that’s how they achieve surround sound in games