4th order for 15'' sp4 d1

[lonelyprince24 0]

I just purchased a 15" sp4 d1 with all the bells and whistles. Now i have read that it is best in a 4th order enclosure. In the Fi specs it states its 3-5 cubes in 4th order enclosure. Now my question is then since im a newbie at 4th order. Is this correct: ported side 5 cubes so sealed side has to be half that so 2.5/2.71(counting woofer displacement) or should the motor be in the ported side? and what do i have to tune the ported side to? what is the best tuning for this sub? This is going in a 2012 chrysler 300. I will be running a kicker zx2500.1 at 2 ohms (that should be enough power right?) . My buddy said 65 herts so is that correct? I listen to alot of dubstep and rap kind of music. i had figured 2.18 and 4.36 for cubes? is that too small? will closer to 5 be better?  Also had a question about round ports, is it better to have less larger ports or more smaller ports or is that all depending on dimensions? Sorry if i sound like a fool. Any help would be greatly appreciated. Also does anyone know how long after you order does it usually take to get your sub? Thanks ahead of time!!

[dbsupra 69]

Wow.

I'm not sure where you got the idea it is best in a 4th order bandpass. 4th order is just a ported enclosure which is the specs you quoted. A 4th order bandpass is something different which has a rear sealed and ported front chamber.

If you build it to the specs you quoted with the ported/sealed and randomly tune it to 65hz like your buddy says expect it to sound like crap. Save your time and just poke a couple holes in the shipping box to run some speaker wire and drop it in the trunk. Would probably sound better.

[nadcicle 77]

Can't really give a definitive answer on the 4th, but I've heard a 2:1 ratio at between 42-48hz is what alot of people tune them at. (No experience with one myself). However, I can say that I've heard that the build time on the SP4's dwindle around a month. (From a reliable source) Sorry I couldn't be of more help :\

[frogcase2002 393]

I think you should probably talk to someone that does box designs and have them help you with your enclosure.

[///M5 2,833]

Now i have read that it is best in a 4th order enclosure. In the Fi specs it states its 3-5 cubes in 4th order enclosure.

Indeed. 4th order ported NOT bandpass. You do not want a 4th order bandpass.

Can't really give a definitive answer on the 4th, but I've heard a 2:1 ratio at between 42-48hz is what alot of people tune them at. (No experience with one myself).

Absolutely wrong. 2:1 ratio won't do anything good for you. If ANYONE ever recommends the same ratiometric design for any driver they are showing their ignorance and all information they've relayed should be ignored. Wherever you picked that up from stop reading as it is confusing you.

[nadcicle 77]

Now i have read that it is best in a 4th order enclosure. In the Fi specs it states its 3-5 cubes in 4th order enclosure.

Indeed. 4th order ported NOT bandpass. You do not want a 4th order bandpass.

>Can't really give a definitive answer on the 4th, but I've heard a 2:1 ratio at between 42-48hz is what alot of people tune them at. (No experience with one myself).

Absolutely wrong. 2:1 ratio won't do anything good for you. If ANYONE ever recommends the same ratiometric design for any driver they are showing their ignorance and all information they've relayed should be ignored. Wherever you picked that up from stop reading as it is confusing you.

 

 

Well, could you please elaborate and explain instead of debunking and showing my ignorance. 

 

Help is just that. Not a free chance of disproving anyones methods. I sure appreciate help when it's given.

[///M5 2,833]

Now i have read that it is best in a 4th order enclosure. In the Fi specs it states its 3-5 cubes in 4th order enclosure.

Indeed. 4th order ported NOT bandpass. You do not want a 4th order bandpass.

>Can't really give a definitive answer on the 4th, but I've heard a 2:1 ratio at between 42-48hz is what alot of people tune them at. (No experience with one myself).

Absolutely wrong. 2:1 ratio won't do anything good for you. If ANYONE ever recommends the same ratiometric design for any driver they are showing their ignorance and all information they've relayed should be ignored. Wherever you picked that up from stop reading as it is confusing you.

 

Well, could you please elaborate and explain instead of debunking and showing my ignorance. 

 

Help is just that. Not a free chance of disproving anyones methods. I sure appreciate help when it's given.

Explain? It is rudimentary Physics. Do you design a sealed box with a random size, do you a ported box without knowing what driver you are using? 4th order BP are the same. They need to be designed around goals and the driver. Not sure what else you need??

[S.DeYoung 967]

http://www.diysubwoofers.org/bnd/4thord1.htm

[ricksi30 923]

 

 

Now i have read that it is best in a 4th order enclosure. In the Fi specs it states its 3-5 cubes in 4th order enclosure.

Indeed. 4th order ported NOT bandpass. You do not want a 4th order bandpass.

>Can't really give a definitive answer on the 4th, but I've heard a 2:1 ratio at between 42-48hz is what alot of people tune them at. (No experience with one my

self).

Absolutely wrong. 2:1 ratio won't do anything good for you. If ANYONE ever recommends the same ratiometric design for any driver they are showing their ignorance and all information they've relayed should be ignored. Wherever you picked that up from stop reading as it is confusing you.

 

 

Well, could you please elaborate and explain instead of debunking and showing my ignorance. 

 

Help is just that. Not a free chance of disproving anyones methods. I sure appreciate help when it's given.

Explain? It is rudimentary Physics. Do you design a sealed box with a random size, do you a ported box without knowing what driver you are using? 4th order BP are the same. They need to be designed around goals and the driver. Not sure what else you need??

 

Exactly, it is like saying all ported enclosures should have the same amount of port area. Or all sealed enclosures should be 1 cu ft. The same thing goes with the port area per cubic foot crap, there isn't a rule of thumb, it is driver and application dependent.

[nadcicle 77]

 

 

Now i have read that it is best in a 4th order enclosure. In the Fi specs it states its 3-5 cubes in 4th order enclosure.

Indeed. 4th order ported NOT bandpass. You do not want a 4th order bandpass.

>Can't really give a definitive answer on the 4th, but I've heard a 2:1 ratio at between 42-48hz is what alot of people tune them at. (No experience with one my

self).ockquote>Absolutely wrong. 2:1 ratio won't do anything good for you. If ANYONE ever recommends the same ratiometric design for any driver they are showing their ignorance and all information they've relayed should be ignored. Wherever you picked that up from stop reading as it is confusing you.

 

 

Well, could you please elaborate and explain instead of debunking and showing my ignorance. 

 

Help is just that. Not a free chance of disproving anyones methods. I sure appreciate help when it's given.

Explain? It is rudimentary Physics. Do you design a sealed box with a random size, do you a ported box without knowing what driver you are using? 4th order BP are the same. They need to be designed around goals and the driver. Not sure what else you need??

 

 

Perhaps I should have elaborated. I am only asking because you know what sub the guy has and what he has tried working with. Given that you know the sub and we both know we can find the specs of the subs on their website. Why not help with design as it has already been established that you show you know what you are talking about? I can understand that I might not have put enough thought in to my post and may have reading comprehension issues, but the one thing I am not confused about is that you seem to have a good understanding that could be utilized in answering the question with more informative explanations. 

 

I give a lot of quick statement answers with disclaimers and never claimed to know exactly what I was talking about and wait for others to chime in. Not to be called out and say that everything I read is ignorant or the way I read it seems confusing to me, but I like learning and enjoy reading informative reasoning. As your signature states. Don't read this the wrong way, because the way you come off is exactly what you seem to want to reflect and I am taking everything you say as a learning experience and value the help myself not only because the OP is asking, but because I have a FI SP4 18" sitting in my garage that I am trying to figure out what I want to do with. 

Edited March 20, 2013 by nadcicle

[///M5 2,833]

Sorry, thought that was more clear. Build a ported box based on the recommendations on Fi's website.

What you can read into this is that you should NOT build a 4th order band pass for it.

[nadcicle 77]

Sorry, thought that was more clear. Build a ported box based on the recommendations on Fi's website.

What you can read into this is that you should NOT build a 4th order band pass for it.

 

I am trying to grasp the concept of what you are saying, but you are making it difficult to do so. Are you saying that given the recommendations on Fi's website that it just won't work in a 4th or do you have personal experience in building a 4th for this sub? What I've read in to is that you are going by numbers and I will take it that way and go ahead and go with the recommended ported enclosure. I do appreciate the fact that you've pointed it out that one shouldn't do a 4th, but I like reasoning behind things so my ignorant self can comprehend it. Instead, I am forced to do a ton reading between the lines and I for one like to weed out all the bullshit and not theorize to much. So with all that said I will go ahead with a ported install because of its "proven" advantage. Thanks!

[///M5 2,833]

4th order bandpass enclosures are in 95+% of the cases a net negative and not a good thing. No reason to design one as the standard ported enclosure will be a much better choice.

[Quentin Jarrell 671]

4th order has nothing to do with the type of box. 4th order is the roll off of the box just like a 4th order butterworth filter.

Any type of box, sealed, ported, sealed bandpass, ported bandpass, Infinant Baffle, ect, ect, ect. Is possible to achieve "4th order" if designed to do so

[lonelyprince24 0]

4th order has nothing to do with the type of box. 4th order is the roll off of the box just like a 4th order butterworth filter.

Any type of box, sealed, ported, sealed bandpass, ported bandpass, Infinant Baffle, ect, ect, ect. Is possible to achieve "4th order" if designed to do so

Ok maybe i didnt write this up correctly--- according to what i was told and what i have read that the specs say 3-5 cubes for 4th order reflex enclosure. Now if that is the case then if my ported part is 5 cubes, then my sealed will be 2.5 cubes? or is that totally incorrect? and i read posted on ssa somewhere that Fi said that Sp4 works best in a 4th order enclosure. Sorry Im not trying to get anyone into any arguments, just what i read. If you have personal experience with the SP4 then any sort of positive input would be helpful. Thank You

 

So what ive asked about is a bandpass box?

so then i guess i dont understand the difference between a regular ported enclosure and a 4th order enclosure. I thought all 4th orders were bandpass. So whats the difference? and how can i get the most out of my sub?

Thanks again

Edited March 22, 2013 by lonelyprince24

[Quentin Jarrell 671]

No what Fi is recommending is a reflex enclosure. What you are asking about is a single reflex bandpass enclosure.

[95Honda 486]

Again, the "order" refers to the roll-off, not the actual physical configuration of the enclosure.

 

4th order refers to the alignment attenuating roughly 24 decibels per each octave on the bottom end (and the top on a band-pass).

 

You need to fully understand this before you press ahead designing anything for yourself.

[lonelyprince24 0]

Again, the "order" refers to the roll-off, not the actual physical configuration of the enclosure.

 

4th order refers to the alignment attenuating roughly 24 decibels per each octave on the bottom end (and the top on a band-pass).

 

You need to fully understand this before you press ahead designing anything for yourself.

okie dokie!!!! Wheres a good place to learn this? Cuz usually i just use this site http://dbdynamixaudio.com/category/calculators/

 

So are fourth orders generally for suvs and hatch backs?

So what would be my best application since its in a trunk? Was Gonna try a labyrinth style.

Edited March 22, 2013 by lonelyprince24

[///M5 2,833]

Again, the "order" refers to the roll-off, not the actual physical configuration of the enclosure.

 

4th order refers to the alignment attenuating roughly 24 decibels per each octave on the bottom end (and the top on a band-pass).

 

You need to fully understand this before you press ahead designing anything for yourself.

okie dokie!!!! Wheres a good place to learn this? Cuz usually i just use this site http://dbdynamixaudio.com/category/calculators/

 

So are fourth orders generally for suvs and hatch backs?

So what would be my best application since its in a trunk? Was Gonna try a labyrinth style.

Stop picking a "style" and a "different" box.

As stated above 4th order has NOTHING to do with the box alignment.

Some facts:

1) When porting, 99% of the installs in a vehicle a standard ported box is best. This is a 4th order.

2) A 4th order bandpass in general is a shitty alignment. It has a purpose, but that purpose is ignored in 99% of the BP boxes that are put into cars.

3) Labyrinth, clamshell and other stupid terminology is meaningless and again not useful in implementing in your box design. To have a quality ported box you need to focus really on two major things. Port & Box Volume. Port of course includes an area and a length.

4) You will confuse yourself and end up with worse results if you stray from Fi's recommendations. Don't.

[lonelyprince24 0]

ok will do. i am working on a ported one now and will post my results that i came up with if you will look at them that would be great. thanks again