PDA

View Full Version : Too little port area?



divebombvt
03-23-2012, 12:34 AM
I am putting a kicker L5 15" in a 6.59 cu ft box(6.4 after displacements) I am using one 6 inch adjustable aeroport tune to 27.5hz-35hz. The port is completely external and of course flared to cut down on port noise. I know that I am no where near the 12-14" per cube rule, im only pulling about 4.42 per cube right now. To keep the port external each port needs to be no longer than 12". Should I get some 10" pvc and flare it myself, or get another 6" aeroport or two and just leave some of the port in the box, how much does internal versus external port effect outcome. I'm just a daily driver, no spl, a little flex would be cool :)

Falcons
03-23-2012, 12:35 AM
thats a wide range of tuning you got there lol

divebombvt
03-23-2012, 12:43 AM
Ha, I just cut 3 insert pieces to add together and tune. I can do 27.5 30 32 and 35 roughly. I could get down to 26.65 if I add everything, but I am thinking that might be a little low lol

thats a wide range of tuning you got there lol

wickedwitt
03-23-2012, 12:45 AM
You need more port than that. Try finding another couple 6"s or do like you said and build one.

divebombvt
03-23-2012, 12:48 AM
In order to do either I would have to put some of the port in the box, how much will this effect the amount of air it pushes. This setup I am describing is just so its not sealed while I figure out a tuning I like. Still under construction so throw ideas my way

Moble Enclosurs
03-23-2012, 03:04 AM
There are too many figures to do before you will know what exactly will happen when you partially load the port(s) into the box, but I will say that if you are looking for a more daily driver setup, you have two things you can automatically improve on before even a design can be figured. You are looking at the design in a different way than it should be viewed right now.
1. Since you mentioned no spl, you may find you will have much more options by utilizing a slot ported design idea, due to the fact that the port characteristics and placement can be manipulated much more versatile than a round port for many reasons. So, I would look into those characteristics as well for proper loading into the port.
2. Even with a slot port idea for options of maintaining a daily driver response curve, you will find it tougher to obtain it with the l5 than many other subs out there that will give you better broadband output than the l5 for the cost. I mentioned recently in another post about sq and kicker drivers being argumental with each other in most cases. This can be mainly due to limited space, but still, better options are available.

That said, if you still decide to go round ported with an l5, the port being inside the enclosure will have an effect on the output you will get. This is from the airflow characteristics giving constraints when inner loading is present, so having it external is a great idea. But if you have no choice but to put in partially into the enclosure, try to keep it as close to the wall as possible on any perpendicular sides of the box. This will help in efficiency of the design for possible increased output compared to a center loaded round port.
And finally, I do agree with more port area. And dual 6" Aeros are a great idea for this project given the subs size and power and acoustical characteristics.

pr-festiva
03-23-2012, 07:42 AM
what type of car is this going in?

divebombvt
03-23-2012, 11:34 AM
99 Subaru legacy sedan haha, I had to put the box together in pieces inside of the trunk to get 6 cubes to fit in my trunk :)

what type of car is this going in?

pr-festiva
03-23-2012, 12:13 PM
a 10'' flare is going to be 14'' or more in diameter at the mouth so you might not have room.

divebombvt
03-23-2012, 11:06 PM
Box is 15.5" tall and has a 42" wide face, so it will but thanks for the concern, cause everything is cramped in there.

a 10'' flare is going to be 14'' or more in diameter at the mouth so you might not have room.

pr-festiva
03-23-2012, 11:36 PM
if the 10'' is going to be external try 12'' long the psp calc.says it will be 42.5Hz but the calc is wrong tuning will be 7-8Hz lower