which would be better? (boxes)

[oraxid24124]

alright my ? is which is louder.....i am fairly new to car audio being i just got a car last year.......a sealed box or a ported?

[sr20de4evr]

ported

[bumpinstang77]

in order.... IB, sealed, ported, T-line, 4th order b-pass, 6th-order bpass. Take into consideration that each enclosure degrades in sound quality in that order with the exception of a transmission line, which is better then regualr ported in SQ.... but very difficult to correctly build.

[Mannyb18b]

what about snail shell

[oraxid24124]

yea i was thinkin ported but some friends said sealed

[bumpinstang77]

sealed sucks IMO ....snail shells are transmission lines.

[Mannyb18b]

Ya thats what i was thinkin too, jus didnt know thats what they were called. To me, sealed is just a way of hookin up a sub quickly n simply. Many people will argue that sealed is pure sound quality, but i think a properly built ported enclosure can sound just as good, SS specially.

[sr20de4evr]

Originally Posted by Mannyb18b

Many people will argue that sealed is pure sound quality, but i think a properly built ported enclosure can sound just as good

as far as transient response goes, sure, but as for upper bass, low bass, and flat frequency response in a car, not a chance in hell

[dean,can]

sealed boxes:deep and accurate . sealed boxes tend to need a lot of power.it all depends on how the woofer matches the box.deep bass extensions and excellent power handing (ported boxes) deep and lively ported boxes use amplifier power more efficiently.you get more output than you would from a comparable sealed box at anu given amplifier wattage

[dean,can]

bandpass boxes are rap monsters.(bandpass boxes are very efficient.)boxes are usually very loud and often very boomy,are designed for maximum thump .

[bumpinstang77]

Ported tuned low can sound just as good as sealed AS LONG AS you have VERY strong midbasses to keep up starting around 60hz

[CBFryman]

Originally Posted by dean,can

sealed boxes:deep and accurate . sealed boxes tend to need a lot of power.it all depends on how the woofer matches the box.deep bass extensions and excellent power handing (ported boxes) deep and lively ported boxes use amplifier power more efficiently.you get more output than you would from a comparable sealed box at anu given amplifier wattage

Incorrect.
A properly built ported box is just as accurate as a sealed box. T/S parameters ultamitle determine what enclosure will be optimal but generally for car stereo Bass Reflux is the best (ported)

As far as loudness goes order is as follows.
IB, Sealed, Ported, 4th Order Bandpass, TL, Horn, 6th Order Bandpass.

IB: Great SQ. Because you do not utilize sound waves coming fro mthe rear of the cone you automoaticly loose 3dB.

Sealed: Personally i dont like how they sound. they have a flatter responce but it is also not as loud and the -3dB drop off often comes long before you even get near dabbleing in Infrabass frequincies. Of coruse you wont be listening to Music with 15Hz tones so unless you are a home theatre buff these work fine. They are the simplest to construct and calculate for unless your are looking for the best responce curve or a peak at a certian Fs.

Ported: aka 4th order bas reflux. The first to utilize the energy from the rear of the cone. High tuning allows for high SPL but doesnt do much for low extension because the responce drops off like a cliff around 1/2 octave below tuning. SQ is equal to that of a sealed enclosure if properly constructed and calulated, i also prefer the sound of ported.

4th Order bandpass: Though it doesnt utilize the waves from the rear of the cone the port works with great efficency in its frequincy band. SQ is saccrifecd because the narrow frequincy band makes bass with any ammount of frequincy range sound "Boomy" if improperly integraded into the stereo. If properly integraded into the stereo it can actually sound very good.

Transmission Line: These are really amazing enclosures. Tey are basically one big port from the back of the woofer on. They work with great efficnecy. This is because there is perfect delay time between front cone excursion and rear cone waves reaching open space. Spectacualr SQ (that of IB) if properly constructed. The whole idea is to make the line 1/2 or 1/4 the wavelength of the desired tune frequincy with the exact "port" area of the cone. These will give a 6dB gain at and around tuning frequincy and 3-6dB everywhere else.drivers with low overall Q work wonders in these.

Horn: Great SQ, Awsome bass, amazing enclsoures. downfall? they are extremely large. cone mouth must have a diameter of 1/2 Fs for optimal eficency. What does that mean? you want to tune to 20Hz... the wave length of 20Hz is 56.35ft. that is a mouth diameter of just over 28ft. Not propable for home use. It cane be cut down to 1/4 for 1/2 the efficiency (still very efficent) but that is still a very large mouth. Ever been to a rock concert? noticed thoes giant boxes on or next to the stage? figure out they are what are pumping out that massive ammount of bass? thoes are bass horns. it is possible ot make a very efficent horn for home use but it isnt propable for car stereo use. (as a matter of fact i know a guy who got 116dB in room from 23w and a JL w0 10)

6th Order. Extremely efficent, horribly peaky responce curve. often 2 different tunnings are used to help flatten it out. Adire Tempst 6th order calulated by Win ISD.... you figure it out. 1st one is with tuning at 20Hz and 100Hz and hte second one at 40 and the other at 41. im getting some SPL ideas.





Edit: sorry, i put an SPL chart on the 1st one.

[CBFryman]

After messing adound in WinISD i was able to get a peak gian of [email protected] by making the Front chamber 101l and hte rear 100l and the front Fs 45Hz and the rear 47Hz....now these figures arent real world but according to this i should be making 121.4dB from 1w with a tempest..... of course WinISD also says a tempest will get louder than a Brahma untill you give the brahama nearly 75% more power. ie the tempest has 400w and the brahma has 700w. in a ported enclosure the brahma would have maxed out its suspension by then..... hmmmmm....

[sr20de4evr]

Ported tuned low can sound just as good as sealed AS LONG AS you have VERY strong midbasses to keep up starting around 60hz
sure, if by very strong midbass you mean they can out perform the sub by 10-15dB from 50hz+. This is physically impossible unless you have
1) ported door pods
2) multiple midbasses
3) some INSANE midbass drivers like the xxx, extremis, or anything very good that's 8" or larger (dls iridium 8.x, dynaudio system 360, PG titanium 951, those are all that I know of, and even those probably wouldn't be able to do it)

A properly built ported box is just as accurate as a sealed box.
accurate how?
if you mean being "quick" then yes, if you mean accurate as in playing what was intended as accurately as possible, definitely not

but generally for car stereo Bass Reflux is the best
absolutely not
ported is best for home where the flat anechoic response resembles the actual in-room response very closely. You stick a ported box in a car and the cabin gain will screw it up royally. With some SEVERE EQing you can tame the response so it's relatively flat, but this will take a lot of processing power. Meanwhile, all you have to do is drop a decent sub in a decent sealed box and you have a near perfect in-car response right away. When I put my brahma in the car I measured the response, and apart from a small 2dB drop at 31hz, it's bone flat from the high teens to the 50hz lowpass. If you can take ANY sub in ANY ported box and pull a response like that, I will paypal you $10 right now (just because I'm determined doesn't mean I'm not poor )

[sr20de4evr]

Originally Posted by CBFryman

the tempest has 400w and the brahma has 700w. in a ported enclosure the brahma would have maxed out its suspension by then..... hmmmmm....

the brahma would be bottoming out with 700rms ported?
I hope you mean the tempest, because ported the brahma would be able to take the full 1500 or more as long as you're talking about above tuning. Even sealed the brahma can handle more than 700rms before bottoming unless it's in a HUGE enclosure, and ported drastically reduces the excursion, especially around tuning.