BillFitzmaurice.info

So I regularly go out doing playback gigs as a duo in very small clubs and pubs here in the UK where a couple of small active 8" speakers are all that's required both size and SPL wise, and I was considering trying to build a higher quality system to replace the above including a small sub to achieve a nice rounded low end.

So I was thinking that a Tuba 18 or Tall Autotuba but which and why? I probably only need it to play down to about 45/50Hz and the T18 looks promising for that. Any response curves or predicted response curves for a T18 not placed in a corner?

There are no charts for T18 other than with corner placement as that's the preferred placement, with wall placement an option only if that's the only option. Because 75% of the system power demands are in the sub passband an 8" loaded sub won't keep up with a pair of 8" loaded mains, or SLA Pro, which is what you should be looking at for mains.

Yes I respect that, what would you expect the response of the T18 at 50Hz or thereabouts to drop to when wall loaded?

6dB less than in a corner. Away from a wall 12dB less. Then there's the matter of a driver able to handle the job. They're out there, but they're not cheap.