box tuning?

hey you guys im making a box for 4 12's ported. They are memphis power reference subs and the spec sheet recommends 40 hertz.  I listen to deep rap and i want it to hit low and deep. Is 40 to high or should i go to like 35 or something. thanks

I doubt many will agree with me, but as a former user of ported boxes, I think that you get much better performance from sealed boxes. Ported boxes give you a much louder sound at certain frequencies, but it is only truly good at those certain frequencies. In fact, some rap songs don't even sound good with ported boxes. I think mine was tuned to around 35 hertz. If there were hard beats around that frequency, they were loud and clear, but ask for a noise anywhere outside that frequency range, and the sound is muted and in some cases in audible. Sealed boxes give you great sound quality and bass response over a larger frequency range. Plus they're a heck of a lot easier to make...haha~wayland

my specs that came with the box said do it at 40 do u think doin it at 35 would be ok? adn would it be that much deeper?

Using 4 subs, you have space considerations.  If you look at the recommended ported box specs for that type of sub you'll see that 43 Hz is the tuning for the smaller (1.5 ft) size box and 38 Hz  for the bigger 2 ft size.  Now, with all those subs and their displacements, port displacements and bracing that will be involved...you got yourself a BIG box either way you look at it.  But if you intend to go with 4, you have to give up the space.  Use one of the two recommendations in that chart.Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

I dont know what kind of vehicle this is in but my sub box was just a hair under 9 cubic feet total for my 4 12's and I had to make two of those, one for my swift and one for my S-10 so it might not be about lack of room, just about lack of comprimise. As far as porting frequency, I tend to port my boxes real low, like my last one ended up being around 27-28 hz. Not the best for SPL comps but sounded way better to me and I needed my vehicles to be able to be both, comp and daily driverdouble-secret reverse-osmosis speaker-cone-induced high-level interference distortion, Its a killer

ok thanks stevdart. i do have enough room so im going to go with the bigger 2.0 foot cubic box. but now each box is gonna have a seperate slot vent port so should i build each chamber to the opt one sub box. or can i use the opt 2 box? and also how come its 2.0 cubit ft for the one but for the 2 sub specs it says to make it 3.5ft i dotn get it?

What Ravendarat is saying is good advice.  Manufacturers give a workup for what they believe the majority of that particular models' buyers might want.  This sub has an Fs of 32 or 33, so tuning low (down to 25) can be done.  However, the bass in most hip-hop/ rap is higher than that, and much closer to the 40 Hz area.  Use the calculator to figure tuning for a lower port tuning for possibly better all-round listening, but use the 40 Hz range for most response with what you are referring to as "deep rap".Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

what does the calculator help me with?i think im gonna use winisd because the ports are gonna have to be L ports and the box is gonan have to custom fit my dakota extended cab. Should i still port it at 38 hertz? and how much difference would 2 herts be like would it be noticeable?

yes! your best bet is using winISD, it will show you different frequency response for different box sizes and frequency cutoff points. look for the flattest curve on the graph, that way you get the most out of your subs.