The one thing that really matters is the one thing you don't mention: crossover frequency. It should be below 100Hz, and 80Hz is even better.
This is because bass this low in frequency, you cannot localize it. If a sub is putting out any energy above about 100Hz you will localize it and that is why your bass seems to be coming from one spot.
Below 80 you can't tell where the sub is, you can only tell there's more bass. Where the bass is coming from, your main speakers provide those location cues. Also since you can't localize there is no L and no R.
Look at my system. https://systems.audiogon.com/systems/8367 There's five subs. They're spaced asymmetrically around the room. There's one up front that's left of center, and I never have any idea its putting out any bass at all. Never can tell any of them is putting out anything. At all. Only hear plenty of good clean clear articulate dynamic and extremely deep bass. In spite of all the different drivers and cabinets and locations the bass is beautifully integrated seamlessly into one enveloping sound stage.
So your solution is:
Move the center sub to near one corner. Set it to 80. Adjust the level. Buy as many more subs as you can, put them near to - but not all the same distance from - the other corners. Adjust them all. Enjoy better bass than you ever heard before.
Its kind of a new thing. Been around 20 years but news travels slow. Do a search- Swarm subwoofer system, Distributed Bass Array. You will see.
This is because bass this low in frequency, you cannot localize it. If a sub is putting out any energy above about 100Hz you will localize it and that is why your bass seems to be coming from one spot.
Below 80 you can't tell where the sub is, you can only tell there's more bass. Where the bass is coming from, your main speakers provide those location cues. Also since you can't localize there is no L and no R.
Look at my system. https://systems.audiogon.com/systems/8367 There's five subs. They're spaced asymmetrically around the room. There's one up front that's left of center, and I never have any idea its putting out any bass at all. Never can tell any of them is putting out anything. At all. Only hear plenty of good clean clear articulate dynamic and extremely deep bass. In spite of all the different drivers and cabinets and locations the bass is beautifully integrated seamlessly into one enveloping sound stage.
So your solution is:
Move the center sub to near one corner. Set it to 80. Adjust the level. Buy as many more subs as you can, put them near to - but not all the same distance from - the other corners. Adjust them all. Enjoy better bass than you ever heard before.
Its kind of a new thing. Been around 20 years but news travels slow. Do a search- Swarm subwoofer system, Distributed Bass Array. You will see.