Subwoofer plopping on DD Plus content

Good morning my fellow Naimees :slight_smile:

I guess I am something of a relic because I still use my Naim AV2 based setup for watching series and movies, but I figured some of you might also still enjoy the sound a Naim home theatre setup brings to the table.

I am on my second AV2 and am using it with my Sony KD75XF9005. I noticed that on Netflix and Prime content I get a thumping sound from my subwoofer. Not always but on a fairly regular bases when the sub is actually playing. It’s a hollow thump. Similar to when a speaker reaches its limits. But the nSub for sure is far from doing so. Especially at low volumes. To be sure, I also tried a different MJ Acoustics sub I still have in the attic. Both show the same behaviour.

I tested with KODI and normal DTS and DD content and it seems to be linked to DD Plus. So the system seems to work per se, but as soon as the source is DD Plus, the subwoofer gets messed up. Don’t get me wrong, it still plays the LFE. But almost everytime the LFE gets a signal, it also makes a slight plopping/thumping noise.

Since Prime and Netflix only have DD Plus now and the TV does not support conversion to normal DD, I was wondering if anybody else had noticed this?

I even tried an old FireTV gen 1, which only supports 1080p but can be set to output DD. When I connect that to the AV2 via optical cable, it works as it should. So the problem seems to be the DD Plus from my Sony via optical to the AV2.
The sub works perfectly if I disable DD Plus and output stereo (using DSP Neo:Music and BassMix).

So, can anybody help me out? Has someone else experienced this or is there something I could try? I reset the AV2 numerous times. And could not find any other settings to adjust. The nVi I used to own had a menu wherr you could switch between 44kHz and 48kHz and stuff like that. But I don’t think the AV2 does, does it?

Anyway, hi everyone :slight_smile: