Hey guys,

I've built boxes before with factory volumes etc in mind but this is my first venture into building a box for SPL.

Im running 1000wrms through my Kicker S12L7 and don't have a clue about tuning. I've been searching these forums for step by step help to tuning a box.

What Hz do i tune my box to & how?

Can people give me some advice?

tune it to 40hz for starters and see how it goes, and just keep cutting the port a couple of inches shorter until your scores level out.

Yeah, 40hz is a good starting point, download the box design program from the downloads section on this site, or find a different program like blau box or something similar. That will tell you what size the port needs to be for the tuning frequency.

what internal box volume? and what car (ie what is your cars "resonant frequency") I may be able to give you a closer idea of where to tune to...

[ November 25, 2002, 18:56: Message edited by: Bassaholic ]

I've got a series 2 vt commodore and i really don't know what the resonant frequency is (or how to find out! )

The box is 90Litres without a port yet as im only in the first stages of building it.

Oh yeah, is this a 2002 (silver cone) model or 2001 model? and is it a dual 2 or dual 4 ohm? (I should have asked this before..)

[ November 25, 2002, 21:00: Message edited by: Bassaholic ]

It's the 2002 model (silver cone) and its 2Ω impedance

for quick port length calculations you can use winisd pro http://www.linearteam.dk

but keep in mind, that if you use a slot port (a rectangle port that uses a box wall as a port wall, the port will need to be half the width shorter than the required length - the width actually being the shorter one of the length and width)

assuming 90L internal before displacements, I'd start with a 3" x 10" slot port by 14.25" long (76mm x 254mm x 362mm) (also assuming the port will be constructed out of 3/4" - 18mm wood)

that will result in about 78L net volume tuned to 38hz

To find the exact length, I'd start with that and chop off 1" (about 2.5cm) at a time. On a real SPL meter, try playing 60-40hz (1hz at a time) tones at close to full volume until you find your peak SPL (at whatever frequency - record your results on paper or something) starting to lower.. then rebuilt the port to the loudest length and your done

[ November 25, 2002, 21:23: Message edited by: Bassaholic ]

i think those big sedans hit pretty low... so maybe start at about 35hz....

[ November 25, 2002, 22:00: Message edited by: rippedskin ]