actually i would say to be more precise build a box with a flat curve even if it needs to be ported using a box building program like i have and run your test tones one by one and find the loudest frequency ....but the sealed box is the next best thing but even the size of that can make a difference in accuracy
ok I get what your saying but where can I find more info on how to tune a port? and when you find out what your port is tuned to do you want to set your low pass at that or alittle higher or lower so you can gain 3 db?
Dont just measure you loudest frequency inside your car. You will need to find your resonance freq...not the frequency your bow peaks at in your car. Do something more like this:
Put your sub in a sealed box and put it in your car. Burp at every frequency between 30-80hz and record your SPL at every frequency. Then take your box out of the car and put in on the ground. Place the mic ~3ft away from the speaker and go through the burps again. Record you SPL at every frequency. Then find the difference in SPL at each frequency. What ever frequency you find your highest "cabin gain" at is the frequency you want to try and build a box to peak at (this will roughly be your resonance freq.).
doing this will usually get you within +/- 1hz of youre resonance frequency.
ok marshall but seriously bud my ported idea is better because the curve is already flat across the board from 30 to 80 and your idea would not be it would drop off on the lower frequencies ....with my way you can plot the optimum box size for your sub and then port to the resonant frequency which is much more precise and profitable db wise
different box sizes can produce different amounts of db gain esp with ported boxes the port tune is not the be all end all...as far as sealed boxes you can actually go to big but you gain some low end and loose top end
i agree with you on the program comment but assuming they are accurate id go my way....the best way i think to do it is my adjustable box size idea with adjustable sealed and ported options takes away alot of the guess work ...just run your test tones meter it and graph it....doing this in car of course
the epic150 is a peice of crap...readings jump all over the place w/ that mic.
As for just measuring inside the car...If the box has a peak and at certain freq, that may show up as your "resonance freq" if you measure inside the car alone. If you measure out side of the car and compare your findings, the measurment outside acts as your "control" in this little expirement. ya get what i'm sayin?
yeah i got ya this freq....plus so many inside vs outside equals gain so your right but then what i would do is map out the optimum box size for that frequency .....the only other thing is suspesion and power limits thats where the adjustable box volume idea of mine would come in handy
im glad you told me about that epic 150 but how does it jump all around i mean it should be consistent...you sure its not due to coils heated up or voltage ratings droping or raising....you no what i mean?