Motor Strength vs Port Area

[shizzzon 10+ year member]

I know cone area really doesnt mean much for walls. I've only had 2 walls and am about to tear it down and build another to try and break 160db.. hopefully.

I have over 30kw on tap to be able to use so power isn't a problem.

I'm looking at sub choice. I am part of Team DC Audio and have gotten some ideas from other competitors but they don't know the port area i can work with with different sub choices.

Since i have no longterm knowledge of walls, i ask those that do and see what others think.

Out of 16-18cuft NET possibly-

2 18" Lvl5s @26kw = 450sqin of port (146lb of motor)

3 15" Lvl4XLs @19.5kw= 500sqin of port (150lb of motor) - recommended by Rusty @DC

4 12" Lvl4XLs @26kw = 650sqin of port (200lb of motor) - recommended by the A-Team

5 12" Lvl4XLs @32.5kw = 500sqin of port (250lb of motor)

Before anyone say it, rusty said anything less than 10kw per sub, i need to run Lvl4XLs in the lanes. If i try to run 3 Lvl5 15s... it's too much power on tap (39kw) and i'll blow fusing since i'm in a fused class.. So i have those options above.

Many competitors have told me cone area is not needed when using a wall. I have seen this in person proven plenty of times!

What i have noticed for walls is i need LARGE internal volume and LARGE port.. tuned correctly of course.

But what i've experienced too is it helps to have plenty of motor and plenty of coil to dissipate heat loss. ( i also do 30sec averages too.)

Rusty told me 3 15" XLs would be better than 2 18" Lvl5s because they are actually more efficient and have more coils to dissipate heat.

However... the A-Team thinks i should go with more motor and suggests i go with 4 12XLs since it gives more motor and more port area... but the least efficient...

I know efficiency comes from cone area which i shouldnt be lookin at so basically... i'm lookin for reassurance, hehe, that 4 or 5 12" XLs is the way to go....

Click to read more...

 

[4OZGLOVES 10+ year member]

truthfully I have no clue what I would pick, but I cant wait to see a video when it's all done.

 

[power-fanatic07 5,000+ posts]

You said 30k on tap...10k for each sub... I would do 3 lvl 5 15's

 

[slam 5,000+ posts]

what vehicle?

 

[shizzzon 10+ year member]

i should be more specific about the power i'm putting next to the options.

I have 6 AQ3500ds (older version not the 4300ws)

They'll all be at 18.5v

for 3 lvl5s - each amp would be wired @0.7 ohms

I've tested 4 AQ3500ds @0.4 ohms vs 6 @0.7 ohms and the 4 pulled 230A more and gained me 0.2 db.

So i do not want to wire them at 0.7 per amp because i'm afraid it won't be as good as the other options.

I have about 2.3x rise clip-free and 3.1x severely clipped.

That would be 13kw per 15 (rated power not actual)... with 500sqin of port.

You think that's a wise choice?

 

[shizzzon 10+ year member]

oh and it's a Scion tc //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif the only walled tc around

 

[Supergumby5000 5,000+ posts]

with that much power on tap, i would go with the A-team on this one. I would be more concerned with cooling rather than mathematically-determined efficiency numbers, considering heat dissipation will be a large factor in the true efficiency of the install.

 

[shizzzon 10+ year member]

ok.. and port area?

they recommended 4 12s but never commented on 5 12 idea.

I'd lose 150sqin of port by goin to another 12 but i'd gain motor, more power, higher efficiency.... just less port area.

I've ran over 13,000w before on 4 15s with less than 140sqin of port total and still got over a 153 with it with a single layered wall.

 

[cthedinger 10+ year member]

Personally i would do either 4 or 5 xl 12s jut make sure you have 18-20 sq in of port per cube and i think you would be golden.

 

[shizzzon 10+ year member]

with either of those 2 choices, the lowest port area per cube i would have is about 28sqin per cube.

 

[cthedinger 10+ year member]

which is good as long as your not below 18 preferably 20 i think you will be putting out great numbers. the is a guy down the road from me who hits a 159.4 with 4 18in xls on 4 aq3500s each wired to .5 ohms at 14 volts he old has 15 sq in of port. granted he has an explorer and you have a sedan but i think you should be able to hit a 160 with enough port and motor i would say do 5 xl 12s and put an aq on each sub wired down to at least .7 ohms if not .5 ohms.

 

[iamamp3pimp 5,000+ posts]

why not 6 12's?

just curious

 

[roarzorz 10+ year member]

For loud musical setups I prefer multiple subs. Spread the power out and the subs will be much happier long term. First thing I'd do is figure out what sub arrangement will allow for the most to be used. Then pick your sub based on how much power each will see.

 

[shizzzon 10+ year member]

I could almost care less about being loud on music.

ANY loud burp wall with as much power as i have can get plenty loud for every day driving at a reasonable volume level.

I choose not to go with 6 12s because the major loss of usable port area.

With 4 12s, i can use 650sqin

with 5 12s, it drops to 500sqin.

6 12s, it's gonna be under 400sqin.

 

[skmfkr 5,000+ posts]

why not 4 15s? what class are you trying to do? looks like your in kentucky and you mentioned fuses so im guessing some class in meca

 

[shizzzon 10+ year member]

with 4 15s, which i've done before, i could use 140sqin of port.. terrible wall... that was my first one. Luckily i still did over a 153 with it though.

My car is small, very small.

So small.. i can only stack 2 12s on top of each other. Anything bigger than a 12, the subs have to be staggered.

 

[skmfkr 5,000+ posts]

oh ok i see what your saying. yeh i think im with robin with the 6 12s idea but i think me and him are thinking more of a middleweight bass boxing build than a burp car.

 

[shizzzon 10+ year member]

oh ok now we are on the same page.

I'm not looking for sustained pressure levels, just burps.

I do park n boom which is like bassboxing except they meter you outside the car for 30second average.

Of course, that needs to be sustained but because it's based on a fuse limit, i will never heat the coils up in time so that's not as important to me.

I dont need that part of competition to get me to finals. Just burping.

 

[cthedinger 10+ year member]

What about 6 xl 10s? that way you could use all your amps and still have plenty room for port

 

[shizzzon 10+ year member]

WAY too much power.

I want to run 4 @0.4 ohm and i'm limited by 340A of fusing in this class.