well, i finally got my box metered today, and what do i find out? that screwed up the tuning on my new box i was in such a hurry to get to the comp before they stopped, so i didn't check where my car was peaking at before the show, so i just burped it at 46 hz, where it was designed to be the best and only got a 142.1 i lost over 5 dB with the new box so i get back from the show, to figure out what went wrong, and i've figured it's a combination of 2 or possibly 3 things. first being that i checked it, and it peaks at 49-50 hz, not 45-46 hz. next is the fact that the box is so friggin huge it probably doesn't allow enough air flow around it into the cabin of the car and lastly, it's possible that 2 cubes per side was too large of an air space for one 10. all 3 are design flaws on my part, and i'm so ****ing pissed at myself right now. so i've come to the conclusion that i'm going to build a box into the car. it'll take up the entire width and height of the front of the trunk. it'll be a ported box, facing forward. i'm designing it so that i can remove the entire front baffle, so i can change it out to a single 12, or a dual 10" setup easily. the back is going to a bitch to do, cause i've got an idea of how i can build it, and still be able to change the volume of the box. it's going to have sort of a step down effect. i figure it'll have 3 or 4 sets of "steps" so i'll have 3 or 4 different possibilities for volume. i don't know really how to explain it, but maybe you all can get an understanding of what i'm thinking of doing. the front board will have an area 1.5 times the size of the cone of the sub for the port. once i get my SPL meter, i'll be starting with the largest sized port possible, then working down. and i'll be experimenting with lengths and all that too. i figure i'll go through 20 different port areas, and god know's how many lengths. so it'll be probably at least 30 hours of testing i was talking with a guy at the show, his screen name is ALL4SPL on the audio forums he's on, and that's his liscense plate too he said he spent 5 hours testing to get the highest SPL in his CRX by just adjusting the seats, sitting in it or standing outside it, adjusting the sun visors, opening the glove box, and everything else he could. and he said it gained him .2 dB's by finding out the best combination his car has a sun roof, and he's even gone so far as to figure that he looses .2-.3 dB's if you put pressure further than 12" towards the center of the sun roof. mind you, he did a 156.2 with two 12's he had RE HC's, but changed them out for 2 L7's, and gained 1.5 dB's. course he did go from round to square subs that increase the surface area of the cone
ok, i'm done venting. it just goes to show that SPL is a very pickey science
ok, i'm done venting. it just goes to show that SPL is a very pickey science
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