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For a bass driver, the Monacor SP-382PA is an excellent 15 inch driver - decent QTS & low Fs. It's what I use in my OBs.

Simon Hickie wrote: ↑Thu Oct 17, 2019 2:39 pm For a bass driver, the Monacor SP-382PA is an excellent 15 inch driver - decent QTS & low Fs. It's what I use in my OBs.

The Eminence Beta 15" is good for OB use.

Thanks. Do you know of any 12" ? - i can't get 15" between the floor joists.

karatestu wrote: ↑Thu Oct 17, 2019 2:54 pm Thanks. Do you know of any 12" ? - i can't get 15" between the floor joists.

When I was working on my OB design, I had to weigh up 1 x 15 inch vs 2 x 12 inch per side. In the end, I found a real paucity of highish QTS 12 inch drivers. The pro driver market seems one to look at. I'll see what I can remember.

This one, although Fs is a little high https://www.monacor.co.uk/categories/12-3/vnr/103310/

Or https://www.monacor.co.uk/categories/12-3/vnr/103950/

Paul messanger built some drivers in to his wall according to the doc. He didn't discover nirvana

I am not sure what i would find.

The bass sound that can be produced from a box less speaker would be a start.
And increased amounts of low bass
No baffle step loss
No big speaker cabinets would be nice

To me the idea of having all the drivers in the floor and tweeter sunk into the plastered brick walls really appeals. I can just see my kids pouring juice through the grilles though

Mid range is said to sound flat and uninteresting when done in infinite baffle. Who knows ?

Simon Hickie wrote: ↑Thu Oct 17, 2019 10:37 am Soundstage implications are interesting. I have to say that my DIY OB speakers provide an extraordinarily big 3D soundstage that's high wide and deep - distinctly better than my semi-omnis. However, they need room to breathe with a meter or more behind them. Therefore, this would mean more rather than less speaker in the room.

My DIY sealed boxes (the ones with the 18 inch drivers) need about that distance behind them too. Maybe it’s partly to do with driver size as well as with the open baffle...?
I mean, how much bass energy can my sealed boxes’ 18mm of braced MDF absorb and internally reflect anyway...? (Similarly for wooden floorboards or plasterboard walls and ceilings.)
Maybe a lot of sealed / IB speakers are effectively semi-OB below a certain frequency! :-D

Thanks for the driver recommendations.

The 12 inchers do have a higher Fs than i would like. The 15" looks perfect but not sure i could shoe horn it in. Might need to get the chain saw out