what is the frequency resonance of a xb(the frequency which you get the highest boost to the spl)

Most spl guru should know this

 

it's hard to give an exact number, every car is different and subject to change due to various conditions... temp humidity etc...

are you trying to build a PURE spl box?

 

The resonant frequency of 2 cars of the same kind aren't necessarily the same, and it changes with SPL levels. I mean, theres always going to be ranges for certain vehicles... like grand cherokee's peak from 44-47hz usually.

I have yet to find out for the xB, since I haven't installed anything in mine yet.

 

yes i planning if everything goes thru i plan on building a box for spl comps tuned to the frequency resonance

 

You might have to do a transfer function map yourself. I havent seen too many xB's with SPL systems.. You might want to contact Steve Cook at Audio X in Muscle Shoals Alabama, I heard he just stuck a system in an xB but not 100% sure if it is for SPL or just music.

Audio X number is:

256-383-6150
1905 Woodward Ave
Muscle Shoals, AL 35661

Hope that helps

 

Did some searching and never found the response to this....

anybody know what the peak frequency of the xB is? I am building a box to try out a couple ideas.... wanting to see if I can hit a 145 or better with a pair of 12's and 1200 watts.

 

as frequency increases, the wavelength decreases. sence sound travels at approximately 1130FT per second, the wavelength of a sound can be determined. with that said i will try to give a simple how too. first you wil need is a cd that can play test tones from around20Hz to 180Hz, a RTA (real time analyzer) or a SPL meter (little easyer to come by)radio shack used to sell one went to 130Db fo like 50 bucks but thats all u need all you want to see now is the sound increase
first measure the distance from the center of the woffer to the spot where the mic is put generly the windshield right it down as it will come in handy later.
as stated before speed of sound is app. 1130FT per second what we need is a wavelength that is as long as we measured early. how do we get that u ask, well bass notes are very long, 20HZ is 56.5 ft long. if we divide speed of sound by freq. we will get wave length

_______________SPEED OF SOUND
WAVELENGTH= ----------------------
___________________FREQ.

_______1130 Ft per second
56.5Ft = -----------------
____________20Hz
now with that info
time for trial an error build a ported box tunded to the the freq we found fits your car it may or may not be the best so turn on the old splmeter place it whe the jugeing mic will be turn on the test tone cd start with the freq. we came up with if you would like you can move the box around , change the port a little at a time, try changeing box volumes .25 cubic Ft at a time try diffrent freq around the one we came up with and go with the best result

 

55Hz for xA and xB, and 50Hz for tC.

 

how did u come up with thoes numbers? cuz no such number exist just moving a seat aroundmoving the box placement
sitting in or out of the car can chang thoes numbers alot

 

I am just looking for ballpark, I am rigging up a box just for fun to use for a month or so. But if I am going to build it I want it to be all it can be.


Basically in about a month I am getting a pair of 18's, they are gonna go in 5 cube sealed box, while I am waiting for them to be available I am going to stick a pair of 12's in the same box only create a 20" diameter baffle and mount a sub and 3 3" ports on each baffle. After port displacement I will be looking at roughly 4.5 cubes with 6 3" ports, should tune to about 42-47 hz depending on how much the bracing displaces in the box. That should give a frequency peak at around 55hz so it should work well.


If I was a serious competitor I would go through the long process you posted, but I am not even building a purpose built box, I am adapting a huge sealed box for 2 18' to be a big ported box for 2 12's while waiting on the 18's

 

rock on. 2 18"s, would like to hear that i dont care what kind if box u put them in if thay a quility speakers and properly amped thay should nock th $hit out of an xb

 

Mandos has all the graphs for each car... tC's average cabin gain is about 45Hz, I"m not sure about the xB... (yes, 45Hz is lower than usual for a small hatch, but it's true)....

 

is that with the windows up or down?

 

you'd have to ask him....

 

During the SPL contest at the show in Ames, IA 55Hz seemed to be the magic number for the xB's. I am thinking the tC's were 50Hz, but I'm not sure on that. Mandos would remember for sure, he was running the contest. These were the numbers with the windows up.

 

x a billion.

ALL the xBs peaked at 53~55Hz. But there were none with insane walls replacing the rear seats which might have changed it.

My tC peaks around 45Hz, but most of the rest I've seen were closer to 48~50, so I'd call the tC 45~50Hz.

Only one xA I've seen run and he was right around the 55Hz range.

 

i have to agree the xb FR is about 55hz i tried a box with 2 10'' subs and tried it in different positions and this was the best response 55hz i did a 149.8 on the audiocontrol meter with the mic on the dash at the windshield.... and thats with one mojo amp.