DSD conversion with KEF LS50W

Core Machine (Operating system/System info/Roon build number)

Core on a ASUSTOR NAS AS6102T

Processor : Intel® Celeron™ CPU @ 1.60GHz

RAM : 2.00 GB

“Disks” : 2 HDD western digital RED series , no RAID

“System ADM version” : 3.4.3.RAE2

“Firmware” : 2.23
“ROON for NAS version” : 1.7 (build 511) stable

Network Details (Including networking gear model/manufacturer and if on WiFi/Ethernet)

Mesh network of ASUS routers :
1 main router : RT AX88U
2 mesh routers : AX92U

All routers connected on Ethernet

Audio Devices (Specify what device you’re using and its connection type - USB/HDMI/etc.)

1 KEF LS50 Wireless connected via Ethernet cable to a router

Description Of Issue

When i’m playing a DSF DSD64 2 channels 1bit file, i get clips and stops régulary.
The conversion options are:

  • No MQA support
  • Sampling rate MAX (PCM): 192 KHZ
  • PCM 24
  • MQA “core” YES

My KEF are supposed to be able to decode those sample rates.
When i change sample rate from 192 to 96, everything works flawlessly.

The sample rate used to downsample from the DSD to PCM is a bit strange :
DSD64 -> 352,8 KHZ PCM
352,8 -> 176,4 KHZ
64 bit float -> 24 bit

I’m wondering if the 176,4 KHZ part is part of the problem…
Maybe not…

I tried to check the load of my NAS But nothing was over 50% of use (ram, cpu, network load)

Considering t’s working fine with 96KHZ sample rate, it’s not a “real” issue except that it would be great to be able to use the max DSP capabilities of my DAC/SPEAKERS.

The same apply with multiple DSD’s : 64/128/256 ones…
FLAC MQA 44,1 KHZ 24 bits 2ch 387 works ok
FLAC 192/24 is ok
WAVE 192/24 is ok

Plus i expérience loss of core when using ROON on an android phone.
Reading other posts, it looks like the connexion to roon core doesn’t like mesh systems.
I’m not on a ORBI, but there is something to investigate there.

What’s your processing speed in the signal path? Post a screenshot of it.

Between 14x and 6x

I’m not sure whether your case is a related issue, just FYI:

Flac 192/24 and wave 192/24 are playing well.
I think you were right to point the conversion rate because issues seems to happens more often when i’m playing DSD 128 or 256.
The strange part is that at no point, my NAS seems to be overloaded. Neither CPU, nor Ram…
That’s someting i can live with, and if i have some time, i’ll try to setup another core on a more powerfull computer

Hi @Thomas_PRIVAT,

So that you are aware, this Core does not meet our Roon Minimum Requirements.

If you try to up-sample 44.1 content to 176kHz, does that also cause issues?

If you use the USB input, do you have similar issues?

Sorry for the delayed answer… I took time to install roon core on another server (win10 serveur) and the conversion is made in 12x , twice as fast as my Nas and i have no issue anymore.
So the x6 in the roon remote screen seems not to be enough to convert DSD64 to PCM @192mhz.

What’s strange is that my CPU occupation on WIn10 is quite heavy ( Desktop core I7 4770K ) while CPU charge on my NAS showed very little use of it.

Anyway, looks like i have to invest in a new nas…

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