Poor quality downmixed audio

I have noticed recently that the the audio quality of infuse appears to be significantly worse when decoding and down-mixing multichannel sources (Dolby/DTS or LPCM) vs other apps/sources.

I use a 2.1 setup, with the ATV decoding everything in 2.0 24/16bit 48KHz LPCM. Following the 7.3.4 Infuse release, the LFE track is also now mixed into the 2.0 stereo down-mix from multichannel tracks instead of being discarded.

It is hard to describe exactly the issue I am hearing and I have no way to do a direct digital recording to compare, but there appears to be some severe clipping and distortion in the LFE, along with a generally narrower sound stage and more “compressed” sound with reduced dynamic range.

An obvious example of the issues described is with the Dolby Amaze demo (available here) using either the standard DD or True-HD Atmos version. At around 00:36 there is a bass rumble, which when played in Infuse sounds terrible with significant clipping and distortion. Also around 00:20 there is a sound that pans left and right, which in Infuse sounds very narrow.

If the same file is played in MrMC (which can also mix the LFE on down mix) the audio quality is noticeably more dynamic, with no clipping in the bass and the full dynamic range maintained. Given this is an app on the same ATV with the same settings then the problem is with how Infuse is handling the decoding and down-mix. Even using VLC (which drops the LFE) the quality is much better and more dynamic than Infuse.

I have no way to tell if similar issues occur when the ATV is outputting 5.1 or 7.1 LPCM and a down mix is not involved, but presumably as the LFE is not being mixed my assumption is that it do not.

There is no reason why MrMC should sound significantly better than Infuse, they are decoding and outputting the same signal on the same hardware. It would also be nice if Infuse provided the option to adjust the LFE mix volume, as well as disable it entirely in the same way as MrMC.

Infuse: 7.3.10 (tvOS)
tvOS: 15.5

Relevant AppleTV settings:
Audio Format: Stereo (makes no difference set to stereo or auto as the display EDID is forcing 2.0 PCM)
Reduce Loud sounds: Off
Audio mode: Auto

Bump as this audio issue is still a problem on 7.4

Bump, issue remains as of 7.4.2 tvOS

I had the same sound quality issue as yours.

However, I found this problem while using the Airpods Max to watch a video on my iPhone.

This video is the Dolby Amaze demo you mentioned. And, right around 00:36 you mentioned there is a bass rumble, which when played in Infuse sounds terrible.

Also, this is an audio quality issue that only appeared after my iPhone was upgraded to iOS 15.7. Before this, my iPhone was iOS 15.4.1, and I watched the Dolby Amaze demo countless times under this version, but it never had bad bass.

Have you solved this problem now?
best wishes

Infuse: 7.4.5 (iOS)
iOS: 15.7 (iPhone 13 Pro Max)

No nothing has changed, the audio issue persists in the current release.

No response, no investigation, just ignored. Even raised directly as a support ticket got nowhere.

Surprised more people dont notice, but if you care about audio quality then take your money elsewhere.

I no longer use infuse as my primary device as a result.

Hi, I have same problem with downmix to stereo. I also try another app (vlc, plex) and there is it much better. So this must be a Infuse app problem. Any reaction from developer?

See above, situation has not changed and no reaction from the Devs.

There have been a number of posts regarding poor audio quality in Infuse vs other software that are not just related to downmixing.

I am not aware that any are being investigated and have given up chasing as it is clear it is never going to be fixed.