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View Full Version : Does Port length matter past Tuning Frequency and Port Area?

MerkConvoy501
04-19-2014, 12:38 PM
So building me a box for four 12's. My port area is around 15 per cubic ft. Tuning frequency is right were i want it, but the port length seemed short for me.

It is a [email protected] for four 12's

117 port area
31 port length

bbeljefe
04-19-2014, 12:56 PM
Port length is what determines your tuning frequency so, it is critical relative to tuning. Another thing that's critical is net volume. You mentioned your box is 7.6ftⁿ but you did not mention whether that's gross or net volume. Ports, braces and subs displace a certain amount of internal volume and that has to be taken into consideration when calculating port length.

If what you posted is net volume, then your tuning is not 32, it's 28. If it's gross volume, then your tuning is higher. And most likely, a good deal higher than 32Hz, depending on the construction of the port.

MerkConvoy501
04-19-2014, 01:01 PM
thanks for the reply i am using re box calculator like i always have. Im pretty sure they take into account displacement

MerkConvoy501
04-19-2014, 01:03 PM
37x19.5x28=20,202/1728=11.6 External so my 7.6 is internal after displacement

MerkConvoy501
04-19-2014, 02:11 PM
What is the best way to post a screenshot to the website>?

mikesmith0890
04-19-2014, 02:13 PM
Re box calc is a joke.

Torres Box Tuning Calculator - Software Informer. It allows you to calculate the box and port dimensions for your audio speaker. (http://torres-box-tuning-calculator.software.informer.com/)

torres in my experience if you're using a calc is much better.

MerkConvoy501
04-19-2014, 02:30 PM
Hopefully this link works