Reply to thread

Message

<blockquote data-quote="Blu84Rex" data-source="post: 2619144" data-attributes="member: 573118">I am trying to figure out the math and I am getting stuck on the port length &amp;amp; tunning on a box for 2 12&quot; type r&#039;s.Outside measurements are 40&quot; wide, 15&quot; High, 15&quot; deep.Which brings the gross volume to 4.06ft^3 and after driver displacement 3.91ft^3.The local stereo guy says that the port measurements should be13.5&quot; high2.75&quot; wide15&quot; deepThat would tune to 38hzI would like to tune somewhere closer to 33hz.&nbsp; What would the length of the port have to be for that?I also have a couple of math questions.&nbsp; How do I find out the displacement of the port and how do I measure the port?&nbsp; do I start from the outter face of the box and&nbsp; stop 2.75&quot; from the back and start from the side and go over the remaining distance.</blockquote>

[QUOTE="Blu84Rex, post: 2619144, member: 573118"] I am trying to figure out the math and I am getting stuck on the port length & tunning on a box for 2 12" type r's. Outside measurements are 40" wide, 15" High, 15" deep. Which brings the gross volume to 4.06ft^3 and after driver displacement 3.91ft^3. The local stereo guy says that the port measurements should be 13.5" high 2.75" wide 15" deep That would tune to 38hz I would like to tune somewhere closer to 33hz. What would the length of the port have to be for that? I also have a couple of math questions. How do I find out the displacement of the port and how do I measure the port? do I start from the outter face of the box and stop 2.75" from the back and start from the side and go over the remaining distance. [/QUOTE]

Verification