OK, well there are two potential issues that immediately come to mind.
With a large open plan living space, any soundbar is going to struggle moving enough air to have any kind of impact.
And the other issue is placing the soundbar inside a media cabinet. If the cabinet is totally enclosed (rather than having open sides), then you’re effectively putting a box inside another box and hoping it’ll sound good. Imagine someone actually speaking from inside a cabinet. Well, it‘ll sound like that.
Much may depend on the height of the soundbar once it’s in the intended location: if the media unit is reasonably high, so the soundbar is nearer your ear height than knee height, then you may just get away with it, as long as your main seating position is pretty much straight on, perpendicular to the soundbar, and not too far away from it.
Worse case scenario: the media cabinet is low AND enclosed, then putting a soundbar there, even a good one, may actually sound worse than your TV. I’m sorry if this isn’t a very palatable response, but I’m just telling you how it is. You did ask!
£500 is still a fair wad of cash to spend if the positioning makes it sound like £150 soundbar in a better location.
However if the media unit and TV are fairly low slung, I’d actually consider mounting the soundbar above your TV, so you give the soundbar half a chance of projecting itself into the room.
Take a look at the sort of positioning that DALI have done for their own photos on the Katch One. That’s the sort of thing to aim for ideally…
DALI Katch One photos in situ
But before parting with any cash, I’d recommend visiting your local dealer and listening to a few: just make sure they set it up in a similar way to how you intended to set it up at home, because that massively influences the results. And definitely get them to play some 2-channel music on it. Take your phone and stream some music you’re familiar with.
As you intend to use it for music duties too, then I can only re-state my previous recommendations, but with even more emphasis.
I’m a music fan as much as, if not more than movies, so that tends to influence my suggestions. Although two boxes will always be better than one for making music, the DALI Katch One will at least manage to be properly musical. DALI’s experience with manufacturing their own drivers, for more traditional hifi speakers, means that musical performance is a key design aim for their engineers. Not something that is genuinely considered with many soundbars to be honest.
But the little Ruarks are properly musical too. I think you would be genuinely surprised at what these little things can do. Ruark have a long history of making mid to very high end hifi speakers. (I own two pairs of their superb speakers). Sadly they stopped making them in 2006 to concentrate on products like their current range of all-in-one DAB radios, products like the MR1 and others. You can visit their website to see the sort of things they do now. But they’ve always retained their musical nous. They’re very well judged products. You could even add a subwoofer later for some low end grunt. (Look at maybe a REL T-zero or BK Gemini…
BK Electronics link
BK sell direct, so sound for pound, are exceptional value.
Hope all the above gives you a starting point anyway. Please don’t take my comments the wrong way. I am genuinely trying to help. I just don’t like the idea of people wasting their money on products that may be disappointing, especially when there are better alternatives out there for the same money.
Frankly I think many manufacturers of soundbars are rather cynically cashing in on people’s desire for invisible hifi, by churning out products that are at times, expensive AND pretty poor. And the hifi/AV media don’t help either by slapping 5* reviews on these same products. What they fail to mention is that their 5* review is FOR A SOUNDBAR. In many cases, if they were judged against very different, but similarly priced products, then they wouldn’t score any where near as highly.
Anyway, I hope you find something in the end that fits the bill.