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View Full Version : Please Explaine Standing wave to me



Wragold
03-27-2013, 05:54 PM
So I got a new car, a Scion Tc, now Im planing out a box to put my system in (I think its in my Sig). Ive measured from the backglass of the hatch to the front windshield. 9.5' or 113". Now should I trying to match my box tuning to work with the vehicle or go from the recommended speaker specifications? (http://www.jbl.com/resources/brands/jbl/products/productrelateddocuments/en-us/boxesandparameters/p1224rev3_27_06.pdf)

I don't know if I'm doing my math wrong, but when I match the port tuning to the car I end up with a port of like 60hz. 1130/60=18.83/2=9.4 Or am I just doing it all wrong?

wickedwitt
03-27-2013, 06:06 PM
http://thumbs.dreamstime.com/thumblarge_444/125533860073yxuy.jpg

I kid, I kid. Are your goals SPL or music? If music you do not want to tune up there. Remember that something as small as distance/orientation in regard to your back wall are going to completely change 1/4 wave mechanics and net you gains/losses in output and range.

You are better off to build the box with 1)The drivers and power you have on tap and 2) Your goals 3) Orientation/Fit constraints in mind. Then work on placement.

Wragold
03-27-2013, 06:28 PM
lol i get it standing wave.

This is my daily driver, so yes its going to be playing music. What happens at 1/4 wave? I was solving for 1/2 wave.
http://i50.tinypic.com/zkpt89.jpg
you can see that Im working with limited room. I think the Vas for the sub was calling for 1.93x2 so total 3.86' cubed. I think I have some plans on paper that would get me close to 3.8'. Im going to have to glass the inside to mold over some bumps on the floor. Now I was down to the port. In the sub specs it shows the box being tuned to 33hz. So are you saying just build my box with the tuning I want and hope there's not cancellation?

wickedwitt
03-27-2013, 06:36 PM
lol i get it standing wave.

This is my daily driver, so yes its going to be playing music. What happens at 1/4 wave? I was solving for 1/2 wave.
http://i50.tinypic.com/zkpt89.jpg
you can see that Im working with limited room. I think the Vas for the sub was calling for 1.93x2 so total 3.86' cubed. I think I have some plans on paper that would get me close to 3.8'. Im going to have to glass the inside to mold over some bumps on the floor. Now I was down to the port. In the sub specs it shows the box being tuned to 33hz. So are you saying just build my box with the tuning I want and hope there's not cancellation?

You have a hatch, there shouldn't be cancellation. Don't port back and end up less than the port width from the back hatch. I don't recall whether port up or port back is better in a hatch, someone else can chime in on that. You should have no cancellation issues however. Also, 33hz would be wonderful for a music vehicle.

Wragold
03-27-2013, 06:44 PM
You have a hatch, there shouldn't be cancellation. Don't port back and end up less than the port width from the back hatch. I don't recall whether port up or port back is better in a hatch, someone else can chime in on that. You should have no cancellation issues however. Also, 33hz would be wonderful for a music vehicle.

I was going port up in between the subs. That way the bass is pumping into the cabin area. If this ends up working then the factory carpet pull over will still be able to hide the subs.

garretttt4
03-27-2013, 06:50 PM
You spelled explain wrong.

esmokah
03-27-2013, 08:19 PM
I have tried sub/port up and sub/port back in my hatch and sub/port back is louder. I do like to look of sub up, but I will switch back. I want to try two tens up and port back.

tc300
03-27-2013, 09:07 PM
I would do a downfiring and port back set up.......

macsdad
03-27-2013, 09:20 PM
I have a hatch back and sub up port works very well, just my .02.