Quick ? about Port tuning.

[Biker 10+ year member]

I just built a 2.5 CU FT ported box tuned at 32 Hz for 2 ten's.

If I make the port smaller would that acomplish the tunning frequency lower or higher?

Thanks Biker

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[traksta15 10+ year member]

do you mean make the port length shorter or the port opening smaller?

 

[slayorktc 10+ year member]

not 100% sure.. been awhile but i belive if you make the port longer it will lower the freq and if you make the port smaller it will also lower the tune.. correct me if im wrong... :/

 

[Trixter 10+ year member]

if your talking about length and keeping the area the same then....

shorter port length = higher tuning freq.

longer port length = lower tuning freq.

if your talking about the area and keeping the length the same then...

smaller port arera = lower tuning freq.

larger port area = higher tuning freq.

 

[Biker 10+ year member]

So technically speaking, the length and size of the port do the same thing? In other words, you could make the port size smaller and shorter to acomplish the same tuning. Or if you make it longer then it needs to be larger to get the same tuning.

So is it as simple as - The less area for air to escape inside the lower the tuning frequency all the way to sealed?

 

[Trixter 10+ year member]

something like that....but when you port it, if the port area isn't big enough you can get port noise....if it's too big, the sub can reach over excursion.

 

[Biker 10+ year member]

Can someone explain something to me. As I understand it if a ported box is tuned to say 32 Hz. then the sub performs the best at 32 Hz, Yet the lower frequencys can cause your sub to over travel at less than max wattage.

If that statement is true then since my LPF sends everything below 60 Hz how to I keep from damaging my subs if the song hits beats way below 32 Hz.

Is this a valid question or am I missing something.

Thanks Biker

 

[jake760 10+ year member]

not 100% sure.. been awhile but i belive if you make the port longer it will lower the freq and if you make the port smaller it will also lower the tune.. correct me if im wrong... :/

Right there. for your other question, turn on the subsonic filter on the amp. Also, you can play a little ways under tuning safely.

 

[Beginer 10+ year member]

Can someone explain something to me. As I understand it if a ported box is tuned to say 32 Hz. then the sub performs the best at 32 Hz, Yet the lower frequencys can cause your sub to over travel at less than max wattage.
Thanks Biker

If you tune box to 32Hz, sub won't be loudest at 32Hz. It will be loudest about 5-10Hz higher than tuning freq. Depending on box size, ports, car, subs, etc.

 

[Trixter 10+ year member]

you can use the sub sonic filter (if your amp has one) to filter out the low freqs.

it is not true that anything below 32hz will blow your sub just because that's what your box is tuned to 32hz. there is slope on the low end, just as there is a slope on the high end. i have never used a SSF on any enclosure i have ever built. if you want to get technical about it, you'd have to see the freq. slope for that sub and box in compairsion to the subs x-max to find the freq. where it will cross over at to cause the damage. most of the time you will be fine with a low tuned box (28-34hz) i f you were tuned to 65hz or something then i would say to use it.