Who has a 18" BTL?

[xluben 10+ year member]

What's the advantage of more port area? or dissadvantage if you have too much?

bigger port = less restricted airflow

 

[SHiZNiLTi 10+ year member]

bigger port = less restricted airflow

so less restricted airflow = a slight change in tuning / port noise / or ? Can I get some more info on this please?

Thanks and sorry for hella questions.

 

[xluben 10+ year member]

http://www.carstereo.com/help/Articles.cfm?id=21

bigger port = longer length (to achieve the same tuning)

if your port is way too small it will have so much turbulence you will hear port noise.

 

[sku 10+ year member]

http://www.carstereo.com/help/Articles.cfm?id=21
bigger port = longer length (to achieve the same tuning)

if your port is way too small it will have so much turbulence you will hear port noise.

Besides port noise is port compression...i.e. you at trying to move to much air in too small of an opening...

At this point the box behaves like a leaky sealed box....really bad news...excursion will shoot through the roof with no corresponding increase in output levels...bad news...

Too much port area focuses your frequency gain in a very narrow band...good for SPL...not so musical though....

Bigger box = good for hitting the lows but mid level frequency response may suffer (depending on where you tune to)...Bigger box = more efficient = less watts need to move the sub...this is basically that Iron law thing...forgot the name of it...

Some common things to keep in mind...

 

[SHiZNiLTi 10+ year member]

Besides port noise is port compression...i.e. you at trying to move to much air in too small of an opening...
At this point the box behaves like a leaky sealed box....really bad news...excursion will shoot through the roof with no corresponding increase in output levels...bad news...

Too much port area focuses your frequency gain in a very narrow band...good for SPL...not so musical though....

Bigger box = good for hitting the lows but mid level frequency response may suffer (depending on where you tune to)...Bigger box = more efficient = less watts need to move the sub...this is basically that Iron law thing...forgot the name of it...

Some common things to keep in mind...

Great info that answered all questions I had.