Port Size and Length

[PokeFan 10+ year member]

Can someone help me out with this? I need to know what the ports should be for this box.

This is what I've come up with I think it's right.

Wedge box

2 8" L7's

42x16

top depth=3.5 bottom=9

Tuned to 30hz

Box should be 1.53^3 @30hz

I don't know what other info you need if any let me know.

Click to read more...

 

[Jeremy M 10+ year member]

.....well i dont' think this is accurate but i'm showing the port to be 1" wide and about 24.5" long........4.5 deep, and 20" long.....being that the port will be L shaped

 

[NissanKicker 10+ year member]

.....well i dont' think this is accurate but i'm showing the port to be 1" wide and about 24.5" long........4.5 deep, and 20" long.....being that the port will be L shaped

You're correct...

.... Crazy box... but you're correct.

 

[PokeFan 10+ year member]

lol, So Nissan. Are you saying this is a bad design or just weird?

Jeremy thanks, but you kinda lost me here. So if the ports are to be 24.5" long my only option would be the front face of the box facing the rear right? So the opening would be 1" tall and 24.5 long across the bottom?

The 4.5 deep and 20 long is where you lost me though. Is that 4.5 back and then 20 up? If that's the case would the back being at a slant affect that port size?

 

[PokeFan 10+ year member]

Sorry simple math could've figured that I guess. The total port should be 24.5" with a 1" opening right? So do the opening dimensions matter as long as it's 1" opening?

 

[NissanKicker 10+ year member]

Well... It's a truck box.

Question:

... Why are you wanting it tuned to 30?

I'd do 40hz at the lowest.

The total port length is 24.5 ( 4.5" back & 20" to the right - port opening will be on the left front side ).

... for this is work... It has to be a 1" opening.

 

[Jeremy M 10+ year member]

yah it's a 1" wide opening, then it goes back 4.5 inches, then makes a 90 degree turn and goes for 20"

that will give u ur tuning.....

 

[Jeremy M 10+ year member]

that's with port forward BTW.

 

[PokeFan 10+ year member]

Yes, it's essentially a truck box. I'm trying to get away with taking up as little room as possible in my rear cargo area. With those top and bottom dimensions it will sit flush with the top of my seats and basically just go straight down.

I don't know anything about the tuning. I found a calculator online that you put in all the sub info and it kicked out the tuning specs. I'm up for suggestions and if I need to look at this again I'm all for it. Any help at this point is appreciated.

 

[Jeremy M 10+ year member]

i think and this is my opinion, that 30hz on those 8's is really low but i could be wrong. Unless u have good mid's to pick up some of the bass.

 

[PokeFan 10+ year member]

Mids are decent but I wouldn't count on them picking up enough of the bass to make me happy.

 

[NissanKicker 10+ year member]

Soo.. I'd do more like 40hz - 50hz tuning range

Probox ported truck enclosures are 50hz... And they are IMPRESSIVE! so, 50hz MAX - 40hz MIN

 

[PokeFan 10+ year member]

Well, I played around a bit and came up with a 40hz before I saw your post. Should I shoot for 50 instead? 45?

Here's what I've got but the only issue is this box will be facing the other direction. How would I go about making the port against the slant? Subs will be mounted to the flat face and the angle will be against the seat. Does this create other problems?

 

[dman4486 5,000+ posts]

tuning will depend on what you want to achieve from the sub stage....30 for 8's is low, but not unheard of! if you want outstanding range and sq, then 30hz with the correct 8 can sound very good.

I have 2 10s tune at 24hz and they sound amazing on the lows with extremely flat response which was my target.

 

[NissanKicker 10+ year member]

You might be better off using a Sqaure port...

... 40hz is good... 45hz is good... 50hz is good.

( just depends on what you're shooting for:

40hz * universal * ( good lows, GREAT MIDS, good highs )

45hz ( Decend amount of lows, GREATER MIDS, Great highs )

50hz ( Limited Lows, GREATER MIDS, Greater highs )

- 30hz ( GREAT lows, good mids, limited highs )