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View Full Version : Motor Strength vs Port Area



shizzzon
04-25-2010, 11:30 PM
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....

4OZGLOVES
04-25-2010, 11:32 PM
truthfully I have no clue what I would pick, but I cant wait to see a video when it's all done.

power-fanatic07
04-25-2010, 11:41 PM
You said 30k on tap...10k for each sub... I would do 3 lvl 5 15's

slam
04-25-2010, 11:43 PM
what vehicle?

shizzzon
04-25-2010, 11:48 PM
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
04-25-2010, 11:49 PM
oh and it's a Scion tc :) the only walled tc around

Supergumby5000
04-25-2010, 11:51 PM
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
04-26-2010, 12:34 AM
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
04-26-2010, 12:49 AM
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
04-26-2010, 12:53 AM
with either of those 2 choices, the lowest port area per cube i would have is about 28sqin per cube.

cthedinger
04-26-2010, 01:08 AM
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
04-26-2010, 10:03 AM
why not 6 12's?

just curious

roarzorz
04-26-2010, 02:49 PM
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
04-26-2010, 05:57 PM
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
04-26-2010, 06:42 PM
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
04-26-2010, 06:43 PM
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
04-26-2010, 06:48 PM
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
04-26-2010, 06:54 PM
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
04-27-2010, 12:45 AM
What about 6 xl 10s? that way you could use all your amps and still have plenty room for port

shizzzon
04-27-2010, 07:02 AM
WAY too much power.

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

ContourSPL
04-27-2010, 09:37 AM
Hey Sean. This is Chris with the Jeep. What are you going to do about your sunroof? I think your car itself is going to be a huge limiting factor. Best of luck to you.

shizzzon
04-27-2010, 12:04 PM
no cuz my car hates glass-bracing plus i will experiment
with sealing sunroof from inside anyway

i can do 157s in the kick now i just gotta load elsewhere

T3mpest
04-30-2010, 02:22 AM
Since your burping I'd do the 12's. You get the most port area that way. Ultimately, the reason walls do so well at least partially and why cone area isn't as important is because when your playing near tuning a wall gives you alot of room for airspace which leads to a effecient alignment in terms of getting the cones to move. Also, you have a very large port area that ends up moving far more air than the woofers themselves near tuning. Bigger ports compress less so your getting a better chance at higher numbers. Also, I would assume 4 12's needs less airspace than 3 15's, so again all things equal your going to be more effecient this way, especially if your realy only concerned about a burp on one tone.

Annnarbor84
04-30-2010, 02:37 AM
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....

Whoever told you cone area is not needed, are off their ******* rockers...... That is complete bullshit, you need the get the most cone area and motor strength you can. A Team does great numbers and has a ton of experience with DC, I would take advise from someone who is actually loud, imo........

shizzzon
04-30-2010, 07:24 AM
The A team told me that so i guess i should listen and not listen to them at the same time...

I've witnessed low cone area do high numbers so i understand what the were suggesting me.

I've seen a 160 out of 2 18s and only 2 1500ds
and heard about 2 15s doin a 160 off of 4 4000ds.

basebalz13
04-30-2010, 10:57 AM
The A team told me that so i guess i should listen and not listen to them at the same time...

I've witnessed low cone area do high numbers so i understand what the were suggesting me.

I've seen a 160 out of 2 18s and only 2 1500ds
and heard about 2 15s doin a 160 off of 4 4000ds.


You should also know Bola Adenkule, He does a 160+ at the head rest with just 2 18's.


your limited to 340 amps of fusing, and working with a wall. I take it your going into Modified 4? Bola's class :).

Stalin-ohaulic
04-30-2010, 12:18 PM
i like the A-team recommendation too. I'm wondering though, how many cubes per sub are you factoring in and what impedence are you wiring to? Obviously I'm curious about your impedence rise. Also, I understand the premise of the question, but getting the port to act as a radiator is dependant on the motor strength so it's difficult to compare 1 vs the other when they are in a symbiotic relationship. I think a more appropriate question is "Power vs Enclosure Efficiency" and the answer is, which do you have more of, power or volume? Clearly you have more power than volume so build a small enclosure with as much port area as possible to minimize impedence rise while maximizing efficiency. Just my humble opinion.

shizzzon
04-30-2010, 01:02 PM
bola is in m5 this year.

from what ive played with, they want the
largest volume possible.
i figure 3-4 cubes per 12 and if thats too
much, i can always displace space.

slam
04-30-2010, 01:08 PM
More cone are will not necessarily get u louder. This is science and how u use space will determine what shows on the meter. first thing Id ask is what vehicle is this going in... this should tell u how many subs u need

shizzzon
04-30-2010, 03:43 PM
exactly slam, that's what i've been told too.

It's going in a scion tc.

I've played with a couple walls physically and some cad designs so i know what can fit in there on a flat baffle.

4 15s is impossible efficiently.
I'm currently running 3 15s but i can get more motor and port area with 5 12s.
I can also run just 2 18s but 4-5 12s seems to be the best bet, in my opinion.
I can still get just as much port with 2 18s as i can with 4-5 12s.

basebalz13
04-30-2010, 07:25 PM
bola is in m5 this year.

from what ive played with, they want the
largest volume possible.
i figure 3-4 cubes per 12 and if thats too
much, i can always displace space.


You sure?

shizzzon
04-30-2010, 07:39 PM
out of the 2 shows i've seen his stats so far, both have been in M5.

Maybe he's havin thoughts of switchin to M5.... He may accumulate points for both M4 and M5 this year.. who knows.

basebalz13
04-30-2010, 07:49 PM
He's only ran it once, that was because we all was in oklahoma running no fuses trying to get the loudest we could to win that 500 dollar cash price.

He should be in M4 for regular season.



Are you going to compete in Meca and go to finals? would like to see this.


two of the guys on my MECA team runs DC audio, nice subs. But he actually was having better results in a tiny box for his 15's something like 2.5 cubes per?

shizzzon
04-30-2010, 08:50 PM
huh... well i can always start big and displace later.