# Does high fs mean poor lower output?



## trabadoor22

I'm considering trying out another sub and was looking at the Fi Q12 and the Ascendant Audio Havoc 12". I'm just concerned that both have higher fs specs and I am wondering if that translates into less output in the lower frequencies. Both would fit my enclosure requirements, kind of important since it's custom fiberglass, and they seem to get good marks here.


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## curtis96olds

it doesnt always turn out like that, infact the FI Q is a low end monster (im assuming the AA havoc is to since FI and AA are sister companies but dont quote me on the AA one) but you wouldnt be disappointed in the low end output on the FI Q i can tell you that much.


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## stills

my jbl 1000gti's have an fs @ 65hz


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## SomeGuy748

A high fs does not mean decreased low end output. It's not quite that simple. The fs should be used to help determine enclosure type and size.

Found this definition on another website. Seems to explain it pretty well.

fs is the resonant frequency of a speaker in free air (not in an enclosure). At resonance, the speaker's impedance increases dramatically. The speaker's impedance may go from 4 ohms to more than 20 ohms at resonance.


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## fish

I believe the sub's resonant frequency changes once in an enclosure & also varies from the type of enclosure. It's then called Fb or F3, I can't remember for sure though.


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## sq_assasin

fish said:


> I believe the sub's resonant frequency changes once in an enclosure & also varies from the type of enclosure. It's then called Fb or F3, I can't remember for sure though.


It does change. The enclosure has it's own rolloff point. That is why the two should be considered together.


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## bassfreak85

FS is simply your resonant frequency.. its doesn't limiter lowend output per say but low end extension.. IE you can have a woofer with a FS of 30 drop down to 26hz with no problem but not have a ton of output and you can have a woofer with the same fs drop to about 30 and have sicking output..
one parameter will never tell you the story when the story is so complex that its takes books to explain....


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## trabadoor22

Thank you everyone for the responses. I guess I will have to check out one of those two subs then.


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## eCrack

fish said:


> I believe the sub's resonant frequency changes once in an enclosure & also varies from the type of enclosure. It's then called Fb or F3, I can't remember for sure though.


Lots of misinformation in this thread. fb = tuning frequency of the enclosure. f3 is the frequency at which the enclosure loses 3db of output under its output at tuning. Resonant frequency is the frequency at which the vehicle gets the loudest. When you align fs, fb, and resonant freq you'll get some nice results.


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## fish

eCrack.net said:


> Lots of misinformation in this thread. fb = tuning frequency of the enclosure. f3 is the frequency at which the enclosure loses 3db of output under its output at tuning. Resonant frequency is the frequency at which the vehicle gets the loudest. When you align fs, fb, and resonant freq you'll get some nice results.


Thanks for clearing that up, too many "f"s to keep up with.:blush:


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## subwoofery

trabadoor22 said:


> I'm considering trying out another sub and was looking at the Fi Q12 and the Ascendant Audio Havoc 12". I'm just concerned that both have higher fs specs and I am wondering if that translates into less output in the lower frequencies. Both would fit my enclosure requirements, kind of important since it's custom fiberglass, and they seem to get good marks here.


FYI, there's an old review on SSA stating that the Havoc is the Q on steroids  

Kelvin


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