Trio subwoofer...

[Brian Steele]

Have a look at this design - simple 3x12" subwoofer capable (on paper) of just over 126dB @ 700W in its passband from a box that's just around 7.5 cu.ft. or so. Total driver cost is around $285 (less if you build two or more subs).

What do you think? Feasible, or there are cheaper and easier ways of getting to the same output levels with the same F3 point?

 

[xrk971]

A sketch of the design would be helpful - is it simply a large vented box with 3 drivers?

 

[Brian Steele]

A sketch of the design would be helpful - is it simply a large vented box with 3 drivers?

That's correct. No fancy design here.

 

[GM]

Well, just looking at Small's vented box efficiency chart, a ~7.5 ft^3/40 Hz F3 is maxed out at 5%, so short of finding cheaper drivers, probably not without designing to a narrower BW with fewer drivers.

GM

 

[Brian Steele]

Well, just looking at Small's vented box efficiency chart, a ~7.5 ft^3/40 Hz F3 is maxed out at 5%, so short of finding cheaper drivers, probably not without designing to a narrower BW with fewer drivers.

GM

Good stuff. I thought it looked pretty good on paper. 126dB of linear output, F3 of 40 Hz and a box that's around 7.5 cu.ft. in size, for $285 in drivers.

 

[xrk971]

What is group delay on this design compared a TH with similar output?

 

[Brian Steele]

What is group delay on this design compared a TH with similar output?

It hits about 12 ms @ 40 Hz, which isn't too bad at all. See first image


Concerning a comparison to a TH, that would depend on the design of the TH. I think it should compare very well though. Second image shows the predicted group delay for my POC #3 TH, which has a similar cutoff point.

 

[GM]

Good stuff.

Yeah, my dual HE 15"~20 ft^3/16 Hz ML-horn barely makes 1%. I'd need about 40 ft^3 to hit 5%. Too big even for me unless built-in.

GM