Cable upgrade

For bryston gear, I always liked Brystons cables the best. There are cables out there that have much fancey jackets, but Ive found the Brystons have the qualities I'm looking for in a cable, and there very affordable compared to many that I felt performed less.

Ive been in hi end audio, and studio recording for many years now. Its Bryston all around for me personally.

I think for me I'm looking for a more open sound when watching movies.
When I have action and dialogue in a movie sometimes I find it hard to hear what the actors are saying.
I'm not sure if it's just my room or cables that I'm using for the 3 fronts?
I use Audioquest Cv4.2.
The room is 5 meters x 4 meters have a large rug in the middle of it.
Big wooden coffee table in the middle.
Timber blinds on one side of the room and half opened on the other side which gose into the dinning room.
Also have a large L shaped couch.
What do you think my dialogue issue is?

Keep spending 250-2000 $ on cables and interconnects. I did but sold them all. ANTICABLE results, not hype.

Your dialog issue is either your center speaker or your preamp

Center speaker is only 2 months old and has been rated to be quite a good center speaker.
I am using the Bryston bbs2 for my contour 5.4 fronts and am using the Arcam avr 600 to drive my rears and center.
I'm not to sure where I'm going wrong?
If it's the Arcams preamplifier section then what would you recommend?
I have tried different cables such as Tara labs vector 2 and chord signature and did hear a difference but these were only minor differences.