Questioni have 2 audiobauhn 12i am building my own box but would like to know the recommended air space for the individual speaker.aw1120t.what kind of box and airspace would sound the best. its going in a 2001 pontiacgrandam gt. thank you for your time and i am waiting for your responce.thanks again
Answer
hi,
If you go here:
http://www.audiobahninc.com/frame2004.html
and click on teck support, there are guides for you to use.
Are you after accuracy? or spl?
Given your choice of speakers I presume it is spl.
Even if you are after accuarcy, working around the cars' resonances area major issue. So I will add these comments:
As to SPL the best thing to do (if possible) is tune the box to the car itself.
Now, I do not know whether you want sealed/ported or bandpass but generally:
1 and 2 kind of go hand in hand, btw.
1)
Determine the average resonant frequency of the interior.
This can be done two ways.
A. Hire a shop that is familiar with, and has a sweep signal generator and have them sweeep the interior while monitoring it with a RealTime Spectrum Analizer [also called an RTA].
B. Using a measuring tape, measure out the car interior, front to back. Start at the back (where your speakers or ports will be) and measure to the 'dash'.
*With todays longer dashes and low windshield angles, you have to make a guess as to where the 'front' of reflected sound really is.
Since we know the speed of sound, and math, this is a plausible way to get a rally good 'ballpark' on the resonance of the interior. Experience really helps here, but trial and error yeilds experience.
In otherwords, use the RTA method if money is not an issue. :P
2)
You'll need to determine where the main speaker baffle (or external ports) will be. You may want them facing backwards closer to the rear of the car or facing forward ect. It is unlikely that facing them up will do much bettter in a car, but knowing that 'no mobile audio idea is wrong until tried and proven so', I will not say they wouldn't work.
Just so you know....'what sounds best' is a very vague thing to say without knowing exactly what your expectations of it are.
This is one of those times when seeing it (and speaking with you) in real life is paramount. I think that link will provide you with everything else you could need.
Good luck and thanks for the question.
Sincerely,
Jerry Mael
