So let me get this straight

[Tek]

ok so I hear that you can blow a sub by playing it below its tuning frequency. But say if a box is tuned at 34 HZ, will you blow it by playing it at like, 33 or 32 HZ? How far below the tuning frequency do you have to be before you need to watch out?

[C-Fizzy]

I think it's around 4 hertz below your tuning frequency.

[superdave07]

Are you talking about the tuning of your sub or the box?

[BeachJoshua]

So these vids where people purposely blow subs, why dont they put them in a box and play low tones?

[HHR Ed]

tuning frequency is very general of a term. It could mean the peak or the F3.

Either way, it is on a slope of output. So there is no exact point. It would depend on how much power and how much unloading is occurring.

What happens under a the F3 point of en enclosure is that the port and enclosure no longer hold air as a spiring supporting the cone of the woofer. They start to act more like free air.

Some woofers can handle this extra, unsupported excursion and some cannot. Depends on the woofer and the power level.

[fritosaregood]

tuning frequency is very general of a term. It could mean the peak or the F3.

Either way, it is on a slope of output. So there is no exact point. It would depend on how much power and how much unloading is occurring.

What happens under a the F3 point of en enclosure is that the port and enclosure no longer hold air as a spiring supporting the cone of the woofer. They start to act more like free air.

Some woofers can handle this extra, unsupported excursion and some cannot. Depends on the woofer and the power level.

agreed, this is a big factor.

the smaller your port area, the sub should be able to go farther below tuning before unloading on itself. you usually wont hear much when you go too far below the tune anyway.

and ppl dont do that to blow subs because its usually only mechanical failure that happens and things rip apart, unless the coil jumps the gap and hits the top plate on the way back in. not any pretty smoke doing it like that.

[IH8PunkRok]

the equation i use to find F3 is as follows

F3 = (Vas / Vb)^1/2 (Fs)

Vas being a T/S parameter of the sub

Vb being the enclosure volume (not sure if it is before or after displacement. i use after)

and Fs is the resonant frequency (also listed in T/S parameters)

this will give you a general idea of where not to play

Edited May 26, 2010 by IH8PunkRok

[DirtyD78]

wow i just learned sumthin new ty guys

[cheese20323]

me too. But I sort of got it when i was setting my LPF and Subsonic....

[Tek]

Are you talking about the tuning of your sub or the box?

the box.

but if I tune a box to 34 HZ, that's low enough to the point that I shouldn't have too many problems?