Help Designing Box.. Building My First Ported

[JoeSmith502]

I have two 2005 RE XXX 12"s that I want to put in my 91 DeVille. The max dimensions I have to work with are 36" Width x 14" Height x 26-29" Deep. I found a box when searching through the forums I was going to try but it is to wide. I like the design and maybe someone could help me come up with one that would fit my dimensions. There is a picture of it below. The specs on that box were:

40Wx13Hx29D
5.3-5.4@28Hz after port displacement, before sub displacement
Port Width-3"
Port Area-70
I didn't take into account any sort of bracing other than the double baffle.
Port width is 3"
First port length is 24.5"
Second port length is 7.25"

If you think a box like this would **** and could suggest a better one I would appreciate it. I like the way it has the ports on the ends. Also never having a ported box before what does the "tuning" part mean? Is that the frequency its loudest at? Also, in the pic it doesn't show the chambers seperated. Are they supposed to be seperate or one big chamber? The amp I will be using is a DD Z1A.

Thanks for the help and I will donate some $ to the person who designs the box that I decide to use.

[psych0ticnemes1]

That design looks pretty good if you can fit it in your vehicle. Subs are allowed to share a chamber, which is the case here. 28htz is a little low unless you want a strictly sound quality setup. Simply put, tuning is what gives the sub its loudest range of play. The tuning frequency isn't always the loudest frequency that your subs will produce. It is complex. The tuning is more related to the frequency range you want your sub to produce. Higher tuned setups (38-40htz) tend to get louder but can lack on the lower end of the spectrum. I hope this answers some of your questions.

[JoeSmith502]

That design looks pretty good if you can fit it in your vehicle. Subs are allowed to share a chamber, which is the case here. 28htz is a little low unless you want a strictly sound quality setup. Simply put, tuning is what gives the sub its loudest range of play. The tuning frequency isn't always the loudest frequency that your subs will produce. It is complex. The tuning is more related to the frequency range you want your sub to produce. Higher tuned setups (38-40htz) tend to get louder but can lack on the lower end of the spectrum. I hope this answers some of your questions.

Thanks for your reply.. so how would a ported box tuned to 28hz compare to a sealed box in SPL and SQ values? Is a ported box always louder but has lower SQ? I like my bass to be well rounded.. meaning I like all the frequencies to play at about the same level. So if I wanted a good SQ that could play the lower frequencies what kind of box would you suggest? Sealed? Ported? Also, with the two subs sharing the same chamber at 5.0 cubes, wouldn't that be way above the recommended air space for each sub? If I wanted to, could I make seperate chambers for each sub? Thanks for your help.. it is greatly appreciated! Joe

[vitveet]

Hello! Well, to start off, this is strictly my opinion but I don't like the port width on that enclosure....! Port area def. isn't enough and the enclosure is only 3" wide and 13" high?!?!?!? Actually, if you want to get technical, 11.5" high?!?!?!?! I'd think about ditching that design for these subs....again, totally my OPINION! Just don't think that design will do justice for those subs!
Ported will almost always be louder! Of course if all depends on the design and build quality of the enclosure (most important thing). If you want a nice mixture of SQ/SQL and SPL, I'd suggest around a 34 hz tuning for these subs! That'll impress you and everyone that sits in the car both on the LOWS and sheer SPL! With that amp, if I had to do a basic "guestimate", you'd probably be around a 144 to 145 on the termlab (add on about 2 dbs for the AC mic).
Hope that reply helped!
Email me for more info on a design and build! Thanks!

V.

[BuckyBoy]

Hello! Well, to start off, this is strictly my opinion but I don't like the port width on that enclosure....! Port area def. isn't enough and the enclosure is only 3" wide and 13" high?!?!?!? Actually, if you want to get technical, 11.5" high?!?!?!?! I'd think about ditching that design for these subs....again, totally my OPINION! Just don't think that design will do justice for those subs!
Ported will almost always be louder! Of course if all depends on the design and build quality of the enclosure (most important thing). If you want a nice mixture of SQ/SQL and SPL, I'd suggest around a 34 hz tuning for these subs! That'll impress you and everyone that sits in the car both on the LOWS and sheer SPL! With that amp, if I had to do a basic "guestimate", you'd probably be around a 144 to 145 on the termlab (add on about 2 dbs for the AC mic).
Hope that reply helped!
Email me for more info on a design and build! Thanks!

V.

Basic rule of thumb is between 12-16 square inches of port per cubic foot of airspace. So, for a 5.4ft^3 enclosure somewhere between 64-86. That enclosure has 69.

[BrianChia]

Optimal port area is dependent on many factors, namely the size and quantity of subs and the amount of excursion with the power supplied. A larger enclosure does require greater port area, but this is because the larger enclosure allows greater excursion from the driver. The XXX is a fairly high excursion driver and if it is going to see a lot of power I'd definitely give it more port than 69 sq. in.