Monophonic HD file won't play with convolution activated [Ticket Open]

Got today from Devialet a free sample of an Ella Fitzgerald album / Live at the Concertgebouw.
The file was recognised by Roon, but no sound coming out when played.
The file utilmately played well - and the song is fantastic - only if I deactivate the set of convolution filters I use for room/speakers correction.
I certainly would like to be able to play mono tracks with the correction enabled!
Is it a bug ? the intended behaviour ?
Thanks for answering !

Convolution may require a software patch or a separate configuration file to handle true single channel mono tracks. For reference, mono CDs never are single channel mono, rather, dual channel mono. The same holds for many other media, too.


Thanks. The expected behaviour for me would be:

  • Roon converts “true mono” tracks into stereo tracks of identical channels
  • audio stream is processed as any other in the DSP

I do not see a reason to create separate convolution files.

That may be possible, dependent upon at what point in the signal chain Roon applies channel mapping.


Let’s tag @support to comment.

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I just purchased an album Live at the Concertgebouw 1961 by Ella Fitzgerald

I have made 8 convolution files from 44.1 to 384 in Stereo WAV

Works normal on all my files, except for this album, because this album is mono.

Album format AIFF 176.4kHz 24bit MONO

I have to turn off Convolution in order to play this album.

Any ideas why?


In case it is useful for debugging the issue, here is a link to the first seconds of the file

Hi @alec_eiffel and @Anthony_Chan ---- Thank you for the reports and the feedback both are appreciated!

Alec, I have downloaded the sample but I am certain our techs will need a complete file. Would it be possible for you both to send us one of these monophonic files each, for testing?


Hi Eric:

I am not sure how I can share the actual music file with you due to copyright issue.
Is that possible if Roon can purchase this music at:
It is a great album IMO. :sweat_smile:

Basically, if convolution is on, Roon does not convert mono channel music to 2.0 channel. If Convolution is off, you can see the signal path indicates Mono to 2.0.
In software point of view, I am not sure how easy it is since I am not a programmer, but I suggest just add “Mono to 2.0” to the beginning of the path, before convolution filter being applied that should solve the issue


Some Roon users in this thread and others need to stop being anal retentive about sending copyrighted music files to tech support for research purposes. That is not against the law. It is called fair use.



I’ve sent the problematic file to support so that they can investigate.
FYI I tried Jriver with the same convolution filters and .cfg and it played. I hope Roon can provide a fix, should be simple IMHO.

Hi @alec_eiffel ----- Thank you for the follow up! Confirming that I have seen your PM and have since downloaded the supplied media. Very appreciated :thumbsup: :clap:

Moving forward, I am going to be passing my report over to our techs for evaluation and testing. Once my report has been updated and passed back, I will be sure to update this thread with the team’s thoughts/findings. Your patience is appreciated!


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Thanks for the insight, @Anthony_Chan! If you are able to get the media over to us, we will gladly take a look.


Hi @alec_eiffel ----- Thank you again for the feedback and the sample! I touched base with our techs this morning, who are performing the tests with your media, and they have asked if you could please also provide us with the convolution filters you are using as well. This will ensure that the our test conditions, “line up”, with your use of Roon. Let me know!


Here are my filters

No other DSP except Headroom management at -9dB.
Output is Devialet Roon Air (but didn’t work on other outputs).

Awesome, thanks @alec_eiffel! Very appreciated!


Any fix? I miss Ella :slight_smile:

Hi @alec_eiffel ---- Thank you for the patience and my apologies for the wait.

I wanted to touch base with you as your ticket has made it’s way “out of” our QA lab and is currently with our developers, who will be continuing testing moving forward. Once I have some more feedback in regard to their progress, I will be sure reach out immediately.


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Oops sorry I intended to tag Eric not Mike

I apologize for being paranoid about sending music files, thanks for your information.