enclosure/sub woofer question

you always have the option to run one sub. or run smaller subs.

 

use separate chambers. you will lose some deeper end loudness. impossible to say how much, you could use a box program like Box Pro 6 to see how it will effect the output but i still think 2 will still be louder overall than just one in proper box. my 2 cents anyway

 

I would use separate chambers in your situation. an advantage is that if one sub goes out for whatever reason you would not risk damaging the other.As far as losing the lower end, you really dont need to worry much about that. you're cars cabin gain will compensate.
I've said before that i never use the factory box suggestions because they are normally
for a close to flat response, also i suggest tuning the box a little higher.

 

I would not use seperate chambers. One large chamber will perform much better than two smaller ones. Also if a woofer fails it will not harm the other woofer.

I agree.

 

tune low!! youl love it. atleast i do any way

 

OK this "tune it low" thing is getting old. NOT TRUE, tuning low to make it hit low is WRONG

Below is a plot of a Polk EX woofer in a 2.25 cu ft box.

The Green plot is the Polk tuned to 40Hz and the Red plot is tuned to 30Hz. Lets see whats going on



The 40Hz tuning gives us an f3 (how low it can go) 36.5Hz (we ignore anything below the -3dB point, its the beginning of rolloff)
The 30Hz tuning gives us an f3 (beginning of rolloff) 34.6 Hz

WOW, a 10Hz difference in tuning gave us a wooping 1.9 Hz lower. Big deal

Now lets look at relative gain. Which is louder?
The Green Plot (40Hz tuning) is above 0dB from around 40Hz to over 100Hz.
The Red Plot (30Hz tuning) drops below the 0dB line around 60Hz. The 40Hz tuning is a lot louder and at the lower frequencies. In fact, its louder from around 45Hz to over 100Hz.

Yes its true, the 30Hz tuning will play lower, 1.9Hz lower. And this is true of most woofers. Tuning lower (tuning too low) typically hurts performance. Wanna hit low, build your box bigger.

 

Tuning has a greater effect on gain (how loud it is) than it has on how low it goes. Now don't get carried away. For most sound systems we want to tune between 35 and 45Hz, and for me 40Hz is a starting point. Then I use software to fine tune.

TUNING is effected by both box size and Port Tuning, with box size having a greater effect one how low it hits. Then tuning effects how loud it gets.

Programs like WINISD can be a big help when building a box.

Also not all woofers perform exactly the same, so looking at how it performs using software will really help.

 

Lets look at how size effects tuning. Both boxes are tuned to 42Hz and I'm using the same woofer as with the previous plots

The Red Plot is a 1.5 cu ft box tuned to 42Hz

The Yellow Plot is a 3.0 cu ft box tuned to 42 Hz



Now lets compare the the two.

The smaller box has an f3 of 41.06Hz.
The larger box has an f3 of 36.16Hz. So now we are getting lower and we are much louder from 40 to 55Hz.

Now lets compare to my previous graph. Go back and look at the same woofer, in a 2.25 cu ft box, tuned to 40Hz. Its f3 was 36.5

In a 3.0 cu ft box, tuned to 42, its f3 is LOWER. So the box is .75cu ft bigger, tuned 2 Hz higher and its louder and lower.

Think about it

 

WINISD is a good program. I use it alot. BassBox is a mild pain to use, WINISD is easier and the results are quite good.

 

One large chamber will not preform better, that is a myth.As far
as the other woofer not being harmed is wrong, simply put,if 1 fails
you will have 1 sub running in a box 2x the size , the port tuning
becomes way off,the blown sub now acts as a passive radiator...ect. what
you (may) have is sub failure, due to mechanical and/or thermal runaway.
if you're lucky it will not happen before you turn the volume down
due to hearing how horrible it sounds.I am not saying you will blow the
other sub, but there is a chance.

Let me try to explain.if you run multiple woofers in the same encloser
at high power and one goes out there will be a shift in Performance,
however not to the extreme as i descibed.I based that on the fact you're
only using 2 subs in a fairly large box at high power.I try to keep my answers
simple so what i am saying is if you used say 6 subs in the same incloser
the effects would not be as severe as using 2(in the event of a sub failure)

Now... tuning low. Well tuning low means you sacrifice spl,now in a vehical
tuning very low is not necessary because of cabin gain(the resonance freq of
the car).you also have to consider the type of bass you want for the music
you listen to.

 

Yea, i agree and the vent length on both programs are wrong