would innuos mk3 streamer benefit from network filter

I'd look at the DAC.  DACs can be harsh. All a digital streamer can do is send more bits to the DAC.  I also don't think wires are generally harsh.  If I wire sounds harsh, it is carrying the harshness from a component.

Jerry

Not familiar with a mark3, but have a Pulse which sounded very good out of the box connected to my DAC with an Audioquest Carbon usb and using the supplied mains lead. After a week or two of adjusting to the superb sq I switched the mains lead to an Audioquest NRG z3 mains cable and the sq deteriorated. Quickly switched back to the supplied lead (uk) and sq restored. A mystery as I use  Z3s for my DAC, SACD and Luxman amp with good results. 

You can tweak the Settings for better sound :-

Go to Settings

-> Audio -> Select low latency

-> Advanced Settings

-> Compact music library database

-> Clear queue cache

Yes, the filters, cables, etc offered by Network Acoustics do a great job on the ethernet side of things. What usb cable and dac are you using. Also, ensure that your settings in Roon bypass the dsp, etc.

Thanks for the responses.

I bought the unit used so break in shouldn't be an issue.  But I will give it time,  maybe it wasn't used much.  The Lumin u2 mini improved greatly with time.

I am using it with a Schiit Yggdrasil.

No power conditioner.  Decent cables but not real high end.  But the Lumin and the Aurender both sound great with this setup.  I was thinking maybe the Lumin and the Aurender somehow did a better job filtering the ethernet,  in which case a filter would help?

I am sure I could get better cables, switches, routers etc.  but since the Lumin and Aurender both sound great I really don't want to go down that road.  

These are all being used with a Raven Audio Blackhawk which has never been a bottleneck with anything I have used so far.

Thanks for the tips on tweaking the sound. Tried low latency, didn't seem to make much of a difference , I will also try the other tweaks,

Maybe it is just a bad system match or just my particular hearing proclivities.

Thanks ro all who replied.