problems with box/wall build....

[aaron7114 10+ year member]

I got my box built yesterday and installed it today and put the wall up. Its in a 4 door honda accord.

The box is 42" wide, 14" deep, and 32" tall.

The port which is on the front of the box goes from the top to bottom and is 5 inches wide. Then the port length is 9" straight back. No Turns. The port is in the middle of the front between the two 15" L5s.

The box is supposed to be tuned to about 45 hz. I tuned it that high for comps. However it seems quite a bit higher than that. Like I already had planned I made a port plug that made the port width 3" to cut the tuning down to around 36 hz i believe. It sounded better. However it only really hits one note good. The first bass note on throw it up is the only note that really has any output, even at that its still not really all that loud, definately not louder than it was in the trunk. It pushes some major air though, blows stuff around. All the other bass notes have hardly any output at all.

I sealed off all the air leaks, and checked my wiring several times. They are hooked up to a kicker kx2500. I haven't changed anything other than the box and of course where the box is.

I really dont know whats wrong but I would really like to get it fixed as quickly, and easily as possible. The wall is about 5 inches behind the front seats. Its really not anywhere near as loud as it was with them in the trunk, and of course like I said it really only hits one note. So I figure its gotta be somethin with my port, but i dunno. Thats the only thing I can think of.

Anyone know what the problem might be?

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[bigbangtheory 5,000+ posts]

Would imagine something is probably wrong with the box build.

Still wondering why you wall off two L5's, but its your shit.

Like you said, you checked leaks, checked wiring, checked everything, so maybe its something in the build. Have any pics of it?

 

[aaron7114 10+ year member]

I really dont think its the build. I built it exactly to the specs that I got from the internet. Also it has to be a much better build that my box in my trunk because I had to build it directly in the trunk.

 

[aaron7114 10+ year member]

Alright I know I **** at sketchup really bad but at least you can get an idea of what the box looks like.

This is of course without my port plug. The port plug makes the port width 3 inches instead of 5.

The box is 42" wide, 14" deep, and 32" tall.

9" Port Length

 

[aaron7114 10+ year member]

could someone please calculate the tuning on that box to make sure it is right?

Also do you think if I make a turn in my port on each side to make the port length longer it would help?

Would this box be better?



All the dimensions are the same except the port length is longer.

 

[aaron7114 10+ year member]

I came up with a couple more designs. I dont know if they would be any better or not. But here they are.

Original Design:



2nd Design:



3rd Design:



All of those are with the port width 5" for comps. Then I of course will have a port plug to make the width 3" or 3 1/2" wide for daily driving.

 

[tommyk90 5,000+ posts]

With those dimensions and the 5" wide port, i'm getting a tuning of 60 hz.

With the 3" wide port, that drops the tuning to 47 hz. Which would explain why it only plays the first note of throw it up.

 

[aaron7114 10+ year member]

With those dimensions and the 5" wide port, i'm getting a tuning of 60 hz.
With the 3" wide port, that drops the tuning to 47 hz. Which would explain why it only plays the first note of throw it up.

Wow! That is definately whats wrong with it I would say.

What would be the easiest way to lower the tuning? I can't really take the box out so I would have have to just make adjustments on the size of the port.

 

[tommyk90 5,000+ posts]

Wow! That is definately whats wrong with it I would say.
What would be the easiest way to lower the tuning? I can't really take the box out so I would have have to just make adjustments on the size of the port.

In order to drop the tuning enough with the 5" wide port to tune it to 45 hz, you would eat up a LOT of the box airspace.

The only thing I could recommend that would drop the tuning without making the box too small would be to use the 3" port plug and lengthen it.

Another option would be to cover up the slot port with a panel of aeroports. That way you can adjust the tuning and port area to get the desired results.

 

[mazdakid 5,000+ posts]

with the port that short its kinda hard to lower the tuning without making it really small

 

[aaron7114 10+ year member]

Alright what if I make the port length longer then make the width smaller

 

[aaron7114 10+ year member]

I dont have to have the port width 5". I just made it that big to get the tuning how I wanted it on the RE enclosure calculator.

So could someone tell me how wide and how long my port needs to be? I would like it to be tuned to around 45 hz for comps and around 36-37 for daily.

 

[aaron7114 10+ year member]

I'm just gonna add 7 inches on each side of the port. 7 inch turn that is. Where it is a "L" shape on each side. Then I'm gonna make the port 1 1/2" for daily.

 

[aaron7114 10+ year member]

Alright well I put 7 inches on each side of the port. Then I made a port plug which cut the port width down 1 1/2" and I made the port 1 1/2" shorter, height wise.

Here is what it looks like now without the port plug



Then of course like I said with the port plug it cuts the port width down to 1 1/2" and I also made the port height 1 1/2" shorter.

It sounds better than it did....but it still seems like its tuned high and its still not really loud.

 

[aaron7114 10+ year member]

bump