Have you heard that system you posted?

They are horrid! and yeah 4 subwoofers all different sizes, brands, some designed for a car on 12v.... Can't imagine it sounding very nice at all.

One good subwoofer. Two if it is a large room, not a large bedroom but an actual large room like 10x10m.

I personally wouldn't bother with 7 way either unless you quadrupled the budget. Surround sound doesn't mean sound coming at you from all directions at once. It means sound feeling like it is coming from where it is supposed to. Hearing that guy creeping behind your left ear. Hearing the car behind you getting closer, feeling the helicopter do circles around you.

I have my current 3 speaker set up staging about 10x better than most budget 'surround sound'. Unless you have a decent sized room where you can afford to have speakers 2m behind your seating position, there isn't much if any benefit in a 7.1 over a 5.1.

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