
Sonos
Beam (Gen 2)
Compact value, but virtual Atmos and app issues.

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I think the LG S90TR is looking like the best mid-range pick this year, 7.1.3 Atmos, great dialogue clarity, and solid bass for the price. The Samsung HW-Q800D is another strong option if you want something punchy and immersive. If you’re short on space, the Sonos Beam Gen 2 is still a really solid compact choice.
I got the S90TR on FB marketplace for 350. Still over your budget but maybe look there for a good deal.
It is worth it, even tho the upfiring speakers wont be ideal, everything else will be an upgrade, better drivers, better subwoofer etc.
I bought a basically brand new LG s90tr for $450 on Facebook marketplace. It pairs really well with my LG C5. I would be shocked if it didn't drastically heighten your audio experience in that room. Marketplace, eBay and Best buy all have some around your price point if you're willing to buy used.
The S90TR is actually what made me give LG a chance because in the in-store demo for that thing was a BEAST! Unfortunately that is not an option for me in my living conditions plus it was $800 (on-sale) so I had to look elsewhere. I bought the SC9S thinking I might get the same bam but no cigar plus, like I said to someone else, you can’t get rear speakers for it, it’s discontinued, and the app support isn’t very good. That’s putting my subjective standards aside on its sound performance. I was contemplating the Sonos and I heard the same thing about the Sennheiser AMEBO being the cats pajamas but my wallet doesn’t agree plus for that price point I would rather get a full system later in life. So I landed on Klipsch after reviewing and looking at recommendations and I’m very happy. I’m not shoehorned into a specific manufacturer market and I can upgrade it in the future (if stuff doesn’t get discontinued). I am jealous of your S90TR setup though lol
In a similar boat... the reddit community seems very downbeat on LG Soundbars so considering selling my new S90TR despite good RTings review

Sonos
Beam (Gen 2)
Compact value, but virtual Atmos and app issues.

Sonos
Arc Ultra
Immersive Atmos and bass, but pricey and poor for music.

Samsung
Q990F (HW-Q990F/ZA)
Value for movies/Atmos, but music and bass are mixed.

Samsung
Q990F
Value for movies and easy setup, but music falls flat.

Samsung
HW-Q990D
Powerful, immersive value, but poor music and buggy software.

Ranked #1
Sonos - Beam (Gen 2)

Ranked #1
Sonos - Beam (Gen 2)

Ranked #1
Sonos - Arc Ultra

Ranked #1
Sonos - Playbar

Ranked #1
Sonos - Arc Ultra