Dear fellow enthusiasts,
so I finally joined this forum to participate in this thread.
Short background story before hand: I am located in Germany (so no native English speaker

) and have received my first NAD M33 in November 2020, after having to wait for quite some time. I was very happy with the unit besides that it made some high frequency noise out of the unit when you came closer to it (not noticeable when I was sitting at my listening position). But in April of this year around the time the 6th April update of BluOs was released, it suddenly displayed a message on the screen that something is wrong with "serial communication" and it stalled. So I started an BluOs update routine and it always quit with "Error 11". NAD couldn't connect to the unit, so I it was decided that I receive a new unit in exchange. I had to wait for 6 weeks, in which I couldn't listen to music or watch a movie with my projector.
Now that I have the new unit I am very happy to also discover that it doesn't make the high frequency noise. So maybe the first unit had a defect from the start.
So I discovered this thread because I was curious what others had to say on the M33 and to make use of its full potential. My setup is the NAD M33 with the MDC HDM-2 module + Lindemann B 605 speakers + SVS SB-16 Ultra subwoofer as a 2.1 system. This I also use for "home cinema" with a projector. I also use Dirac Live full version.
I was very curious at to why I have not been completely satisfied after having measured and applied the NAD filter with Dirac Live. So I have tested what has been stated before, to switch between "Select Attached Speakers - 1 Subwoofer" and "Select Attached Speakers - No Subwoofer" option when Dirac Live filter is active and "Tone Controls - OFF". And wow, what a difference. The track "Lost Without you" by "Freya Ridings" mentioned earlier in this thread is painful to listen to because of the distortion when the subwoofer is selected ON (1 or 2). It immediately changes back to perfect when subwoofer is selected OFF. So this has something to do with how the M33 works internally, right? This is definitely not acceptable in my point of view. Even if it only occurs on some tracks that have been recorded "problematic".
Also I can not believe this only affects some M33 units as it is more of a software not hardware problem, isn't it? I rather believe that not every speaker is capable of showing it. The Lindemann B 605 have the Scan Speak Revelator series mid and tweeter, and it shows it absolutely clearly.
As somebody mentiones they have been in contact with NAD about this and they already are working on it I suppose it is not of much help if I contact them, too. But somebody mentioned that this could also be a problem which can't be solved? In this case I need some input because I could still return the unit during the next week.
What do you think?
Best regards,
Stefan