Choking a port?

[Mexar 10+ year member]

I want to build a sub up / port back box for my hatchback... but how far away from the actual back of the car should I leave the port... as in, if I built the box with only 1" of space between the port and the hatch, will it muffle the effectiveness of porting?

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[ThatChevyGuy 5,000+ posts]

5-6 inches at least.

 

[Pioneer~Saturn 5,000+ posts]

Yea, i would give it some room...5 inches would be about the closest i would want

 

[mazdakid 5,000+ posts]

if the size is going to be a problem then why not just turn it to the side in the back corner?

 

[Mexar 10+ year member]

Because in order to get 4~ cubes for my dual 12's... I need to take up 99% of the hatch area (Trying to stay below the window line, for view issues)

 

[WOT]

I did alot of research into this when i built my current 17 cube box, and yeah the rule I came across and was told about many times was that the port if firing to the rear or was against a wall, had to be ATLEAST the width of the port away from the hatch

My port was 5.75" wide, so I made it like 6" away from my hatch

Alot of room to give up, but it aparenelty makes a good difference

 

[Immacomputer 10+ year member]

Eh, you can get it closer to the back if you need to and not have any real noticeable effects. You may gain some too actually by adding a little more loading to the system. The "rule" of 1 port width from the back is like all other rules, vague and not 100% correct. Half the port's width would still be acceptable but tuning will usually be a little lowered due to the extra loading and increased effective port length.

For those of you who really think you need to have the box a port's width away from the back should try getting it as close as it safe for the subs (if they're on the same plane) and they should listen for differences and then pull it far away from the back. I bet they would find increased output around tuning with it closer to the back. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif