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View Full Version : Are 4th orders worth it?



Braindead
09-15-2013, 01:00 PM
Are they louder than regular ported boxes, and do they take up alot more space?

Beatin'
09-15-2013, 01:27 PM
Box volume will determine how loud or how much space.

Ported will give you louder low end. 4th orders are typically designed to give you louder upper end bass with decent low end extension compared to a sealed box. If you design a 4th to play low and loud like a ported box then it won't play upper bass notes at all. It would be like a ported box that can't play high.

In the end, it depends on what subs you have and what are their TS parameters.

mat3833
09-15-2013, 02:20 PM
Box volume will determine how loud or how much space.

Ported will give you louder low end. 4th orders are typically designed to give you louder upper end bass with decent low end extension compared to a sealed box. If you design a 4th to play low and loud like a ported box then it won't play upper bass notes at all. It would be like a ported box that can't play high.

In the end, it depends on what subs you have and what are their TS parameters.

thats not really true at all. 6th orders are the ones that play a certain range and not anything else. 4th orders tend to be built to peak at a certain frequency and maintain that peak over a range. since they have a sealed section response rolls off at ~6db/octave VS 12db/octave of ported. you can build a 4th order to sound awesome on music and play low, the only way a ported box will "give you louder low end" is if you built the ported box to give you a peak really low. the nature of a ported box lends itself to a peak just before roll-off. 4th orders are great, but take alot of work and most of the time arent worth it. they also take up alot more space than a standard sealed or ported.

Matt

shauncox26
09-15-2013, 02:56 PM
Example i have 2 obsidian audio 12s i had them in a ported box somewhere around 4.5ft^3 tuned to 30hz and tthe lows were amazing but i lacked upper bass power, but everything below 35 tell my subsonic kicked in was beast. Now they were on a rf t.1500bdcp at 1 ohm roughly 1700. Now i have one in a 2:1 4th tuned to 40Hz. I have tremendous highs and a fairly flat response down to 30Hz and a slow roll off into the twentys. With the 4th i have around the same output as the two in the ported on a 1/4 the power. I used a 40Hz 0db test tone and clamped a mild 456watts rms rising from 1.9 to 4.9 ohm. It is all in preference but im hooked on the flat response of a good 4th. They can be efficient beasts, but they are hard to build, and tune. Though if done right u won't believe the difference.

Beatin'
09-15-2013, 03:35 PM
thats not really true at all. 6th orders are the ones that play a certain range and not anything else

you obviously don't know what a 6th order is.

mlstrass
09-16-2013, 01:15 AM
So much misinformation in this thread LOL

4th orders can murder down low, last one I built does around a 158 @ 30Hz. My 6th order is loud and pretty flat from 30-55Hz and plays up to 80Hz with ease...

myjaja
09-16-2013, 01:19 AM
and it starts.... :popcorn:

T3mpest
09-16-2013, 11:54 PM
A key thing to remember when deciding what type of bandpass box to use is subs that tend to work better in sealed alignments work better in 4th orders and port friendly boxes do better in 6th. It's a simple and easy thing to remember and will make sure you not wasting your time when designing. All these designs are trading bandwidth for effeciency so asking if something is louder than something else, especially without even saying what driver or what frequency you want to be loud is a simplistic question honestly being laughable.

Most car audio subs with a 4th order tend to peak very hard down low. You'll see alot of these designs with peaks at 20-30hz. This isn't because of the box inherently so much as the drivers they tend to use. A good 4th order can have a response of around 1.5 octaves, maybe 2 octaves worth in a car, but it won't be as loud if you do that. General rule of thumb for any bandpass is 1.5 octaves of response.

Last thing to keep in mind is I hear on here a lot, "xth order bandpasses only play a limited range, that's why I like ported".. First thing to point out, how many of you guys CAN or even DO run your subs much over 60hz. 60-30hz is only 1 octave, bandpasses can do that, no sweat. Second, how many of with your ported box tuned to 30ish hz have anything ballparking a flat response. Generally your flat from maybe 30-50, which again is smaller than an octave. The lack of bandpass response doesn't give you any hope of fighting cabin gain to achieve a flat response, a well designed bandpass with the right drivers can sometimes do that.

For example a 6th order has 2 resonant points, with a dip somewhere between them. If you careful, you can put the dip where you cabin gain helps the subs the most, and put the upper and lower dips where you need extra bass to flatten things out. Very few vehicles will be flat between 60-80 as compared to 30-50 and a bandpass can help with that, particularly a 6th order.