412 CVX

See how much power you can throw to it before it blows

The red line represents a 6th order for 2 8's. the rear chamber is tuned to 25hz, the front 60hz (2:1 ratio) The blue line represents a 4th order for 2 8's. ported chamber tuned to 50hz (2:1 ratio) the green line represents a ported box for 2 8's tuned to 36hz the pink line represents a sealed box for 2 8's this graph is showing the loudness (SPL) of the same 8 inch subwoofers over different frequencies in 4 different types of boxes this is a very generalized reference i made so you can see the basic differences between the types of boxes. as you can see both the 4th and 6th order both get louder than the ported and sealed boxes, but their frequency response (bandwidth/passband) is much narrower and peakier. they both roll off sharply after their peak frequency. So what does this mean? ported and sealed boxes can be more musical, and play a wide range of frequencies (somewhat) consistently. Whereas 4th and 6th order bandpass boxes peak at a higher DB level, but can be peaky and fairly inconsistent. Keep in mind that everything changes once you put it inside a car, theory and reality are very different. there are plenty of exceptions in every situation, and for that reason the numbers in this graph are irrelevant.

if only...

on a weekday?? haha trooper

don't do the baffle like that...

welcome! thanks for hopping on the bandwagon!

add an inch to your port height. in order to have 3 common port walls take box height -1.5 (if using .75 mdf)

12-16 is the norm for daily boxes because that's what people have found to work the best. trust me, you're not the first to try adding more port area. This rule of thumb isn't something somebody just randomly decided was best and we all jumped on the bandwagon; it's something (somewhat) universally agreed upon. and yes, port length is still measured by the yellow line

i think it's time to go back to the drawing board. unless you like throwing $30 away. I have a feeling this won't sound very good. you can build a much smaller box that will more than likely be more efficient. keep the volume at around 2 cubes, keep port area between 14-16 per cube keep the port length under 40 unless you listen to nothing but chopped and screwed music tune higher. somewhere between 33-36 should be good you don't HAVE to do 3 common port walls if it doesn't work well in your dims. shoot for a 1:6 ratio of port width to height.

FYI-- too much port area. that's probably why you needed such a long port. if your port is more than 40 inches long, that's probably a good sign you need to go back and redesign. keep it between ~12-16 inches per cube for a slot port. to answer your question, physical port length does not apply in this situation with the way you did your port. it only applies if all the physical pieces of your port are touching eachother. or in other words, you keep 3 common port walls the entire length of the port. the yellow line represents the total port length. i.e. the number you typed into the box which is 50 in this case.

get 2 more sa 15's. and i don't think you tuned your port right if it's only 4 inches long

No. that's a horrible ground.

what are the maximum dimensions your box could be?

How the hell do you have over 20 cubic feet in your trunk?

JL is overpriced, i wouldn't buy new JL subs. what's your budget for new subs?

Can't argue with someone who has experience.

Joe, your port is still right up against the back hatch, BAD idea. mine is slightly smaller, which should help since you're overpowering the subs a considerable amount.

forgot you messaged me. this is what i had in mind. it's 9.5 cubes tuned to 35. yes the ports are facing up, but you will still get plenty loud.

if there is open space behind the box, then it might work. but if the port is just gonna be set against a wall, then no, it won't work very well.

mind expanding on this a little more? the only thing i've sold recently is my box designs. not a physical product. i would just return the money, but he could have actually be paying me for something, in which case i don't want to give away money i've earned. lol if it turns out it was just an accident, then i'll gladly return the funds. i'd just like to know

I just emailed him. and i'll put his name in the title. hopefully he gets back to me soon.

I suppose i could just e-mail him... didn't think of that

there's at least 4 people with that name living in the state it was listed from. i'll keep trying though

A little honesty goes a long ways is there any chance a mod could see if he's even a member here?

got it figured out, thanks all.