Subwoofer between speakers?

Subwoofer placement is a complicated issue. I never advise using one sub. Two subs would ideally be placed in the corners with digital correction of the group delay. Without digital correction the subs are better off between the speakers against the wall with all speakers and subwoofers on the same radius from the listening position. This assumes that all the drivers are in phase with each other which may or may not be true. What you have within reason between the speakers does not affect the imaging at all. Some people are fooled by their visual perceptions. Just don't part a bus between your speakers.

On the subject of the op

Obviously every room presents it’s own opportunities and limitations. This is just what i found in mine as we installed four subwoofers.

In a nutshell, what mijostyn said. My take: dont overcomplicate, you have already done the hard work in locating your speakers. Your subwoofers, always in multiples of two, simply go alongside, with at least a large hand span between sub and main speakers, and basically on the same radius as your main speakers, just ever so slightly behind so they are a tiny bit further from your ear than the main speakers. You can adjust this by ear.

Locating Inside or outside your main speakers may be decided by domestic considerations. But i tried both, and massively preferred having the subs outside of the speakers. When they were between the speakers, it sounded as though i was listening to the main speakers through the subwoofers- that I’d created a river of sound from the subs that hit me first and to some extent blotted the sound of my main speakers.

So my advice, go with a minimum of two subs, alongside, outside and slightly behind your mains. Use main speakers with strong low end and then roll your subs in below 40hz. Ideally feed them direct from your pre amp.

Then remove everything that rattles from your listening room, and use blu-tac to damp vibrating wall art😊

My apologies for ’drivel’.

Missed the edit window to soften it to ’nonsense’

I may be a little tooo passionate about sub bass

I may be a little tooo passionate about sub bass

Impossible!

"An articulate, extended and veracious low end adds realism out of all proportion to the numbers." - moi

And if only people would roll at least the ½ octave above the main’s corner frequency, there would be a lot less boomy bloat 🙄

Sub placement is site-specific, the site being your room. 
 

My sub is behind my chair, in the back of the room.