Box Tuning

[6.5LDiesel 10+ year member]

I am wondering what the tuning of my box is, I put it in box pro box and thinking I screwed it up because its way off where its suppose to be...

The dimensions are 22.25' wide 15.5" tall and 16.25 deep. The port is 1.75 wide and 20.625" long. This box was suppose to be for a 12w7

parameters:

Fs = 27.2 Hz

Qms = 7.807

Vas = 2.331 cu.ft

Xmax = 1.142 in

Sd = 84.01 sq.in

Qes = 0.514

Re = 2.47 ohms

Z = 3 ohms

Pe = 750 watts

If you could help me out here it would be greatly appreciated! Part of the learning process!

Click to read more...

 

[marcotheclepto 10+ year member]

im getting 2 cu ft at ~36.5 Hz port length measured from the center?

 

[bubbagumper6 5,000+ posts]

Port a round port or are you missing a dimension?

 

[marcotheclepto 10+ year member]

Port a round port or are you missing a dimension?

i assumed it was a slot port with height of 14 (when they just list width they usually mean the height is the other dim)

 

[6.5LDiesel 10+ year member]

Its an L port, correction, it was 21.375, and that is including the front baffle

that is both L pieces added together

Length one was 13.75 (with the 1.5" baffle) and length 2 is 7.625

 

[marcotheclepto 10+ year member]

coming up with something closer to 1.75 @ ~38-7 now. assuming the baffle is on the widthxheigh side

 

[SicAudio 5,000+ posts]

you cannot get an accurate slot port tune with BBP it miscalculates it.

just call Harristech if no one believes it...

use this for figuring your ports...

Port Length Calculator

do not forget to account for port displacement tho...

 

[6.5LDiesel 10+ year member]

you cannot get an accurate slot port tune with BBP it miscalculates it.
just call Harristech if no one believes it...

use this for figuring your ports...

Port Length Calculator

do not forget to account for port displacement tho...

I was using BBP to see what tuning I had, not to tune it since I had already built the box

I came up with 37.85hz with the link you sent me accounting the sub and port displacement.

 

[SicAudio 5,000+ posts]

BPP won't do it for a slot port at all

I came up with 38.1 accounting for JL's posted sub displacement and port..

anything within 1-2 Hz of desired tuning is just fine too... I am not a fan of tuning below 35-36 for the W7 subs either. they have a decent FS already so 35-38 gives em that nice peak around 50-55 Hz where most music has alot of bass anyway //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

and you can trust Marco, I have yet to see him be wrong //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[6.5LDiesel 10+ year member]

BPP won't do it for a slot port at all
I came up with 38.1 accounting for JL's posted sub displacement and port..

anything within 1-2 Hz of desired tuning is just fine too... I am not a fan of tuning below 35-36 for the W7 subs either. they have a decent FS already so 35-38 gives em that nice peak around 50-55 Hz where most music has alot of bass anyway //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

and you can trust Marco, I have yet to see him be wrong //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

I was shooting for 32 but managed to screw it up..The subs sound like crap in this box is why I was wondering the tuning..

 

[SicAudio 5,000+ posts]

you said subs? as in more than 1 in that 1 box? or single boxes?

if you have more than 1 sub in that box that is Problem #1 if not something else is amiss here...

we just did a design for 6 of them on 6 1000/1V2 amps in a cherokee with very similar airspace and tuning and they flex the glass...

 

[6.5LDiesel 10+ year member]

Yes subs, but that was a box for one of them, same box but that was one side, and both have their own chamber and port. Dimensions I have were the outside of the middle brace to the one side, depth and height, figured it would make it easier. These 2 subs, on the right freq flexed the windshield and A columns a good bit, not to mention the back wall of the cab moves a good inch.

This would be nice for SPL, since having the box rear firing in a ext cab truck, and looking for SQ this box is awful. Sealed was orgasmic, but didnt give the output I needed...Only thing this box can do for me is get loud, and sound like crap on anything else then rap...

The dimensions of the whole box are 44 1/8 wide, 17 deep (with 1.5" double baffle) 15 1/4 high. That is the same port height and length (14 high and 21.375 long) There are 2 ports