Ports question.

[scooter99]

I'm wondering if you don't have enough room for suggested port area (w x h), if you would make up for that with length? I'm sure it's a stupid question and I'm sure I already know the answer, but I was wondering if there was more to it than that.

So for example, say I was trying to get 236.25 sq in of port area. That's 15" x 15.75" in case you're wondering. That's internal port area. SO external if I use one layer of port materials, then I'm looking at 16.5" x 17.25". Say I have the ability of having the 16.5" but not the 17.25" Say I can only go as wide as 12". That would leave me with a 15" x 10.5" internal port deminsion which would be 157.5 sq in. of port which is drastically less than my original target 236.25 sq.

What would the most efficient way to go about dealign with that?

Just trying to learn a little something with this. Thanks guys!

[will77530]

naw bro if you lengthen the port all your doing is lowering your tuning

[scooter99]

So then I just loose out on the port area then? I'm just limited by my space constraints?

What in effect does that do to the sound?

[scooter99]

Better yet, is there a site or link on here, that explains it all. Port area, ports area per sq ft, etc etc etc. I think it's about time I learn this shit!

[islandpride684]

here is a good start

[saabgotbass]

Some subs prefer more port than others. Also I believe that having too little port causes port noise. Iv always been told better to go a size down and have the proper box rather than going with something larger and not having the proper enclosure.

[Kyblack76]

Length the port, will lower tuning, not add area. Trim it to bring tune up....

Thats why the port area is in Square, ... not cubes..... make sense?

[scooter99]

Great video islandpride, thanks for posting that. I'll have to watch it about a dozen more times when I get home and can turn it up and pay better attention. Thank you for posting that though.

Yes Kyle, makes sense. These calculators confuse me sometimes. That video made sense watching it on my phone, but I want to really follow along on pen and paper at home and understand it better.

May end up letting the cat out of the bag tonight asking some of these questions.

Thanks guys.

[scooter99]

Ok another question. He goes into real good detail on how to determine your port area. That's fantastic. I get that now.

However, what about determining length based on hz tuning? So would I take the target tune frequency and divid the port area by that? Not sure if that's even correct, but I tried it and got something that makes sense. So that's why I'm asking the question.

Ok, let's just say it. So say I had a target of 364 in^2 of port area. The space I have to give me a double walled port, is an internal of 13.5. So I divided 364 by 13.5 and I got 26.93. So let's say an inner measurement of 13.5 x 27. That's an actual total of 364.5in^2. So if I have a target of about 42hz, do I divide 364.5 by 42 which would give me a length of 8.68". Is that correct or am I doning it wrong?

Final port would be 13.5 tall x 27 wide x 8.68 long for a tuning of 42hz (approx) @ about 14in^2 per ft.

[islandpride684]

http://www.diysubwoofers.org/misc/portcal.htm