4 15s in blazer

my buddy and i are attempting to put four ma audio 151xq subs in the back of his xtreme blazer wat would be best for the vehicle a sealed or ported box???

Assuming with that many your wanting SPL, then ported, if you got the room to give up(your back seats). I would probably start out with 12cu.ft. net and 120sq.in of port area. Tuned to around 35-38Hz.

have about tne cu/ft or air space in the back.. i told my buddy we need to port it(its his ride) but he insists on a seal;ed box...how much is it going to suffer if we seal it. and if sealed should each sub have its own chamber?

well 12 net would actually be close to 14 gross internal with driver displacements and port displacement figured into it. Sealed is looking like the better option. Since you have the room you do. I would run separate sealed chambers.

if we did use that port how wud we determine how deep to make the port...

the port calc on this site would be a good place, but at 12 cu.ft. net and 120sq.in port area. The port will be at Fb= 35Hz 13" long. So that adds .9cu.ft to your volume. so you need 12.9cu.ft and still need to add driver displacement to this and any additional bracing. If all you have is 10 cubic foot gross. I would be looking at sealed. I could figure you a ported box but it would really be a waist i think. Sealed would be happy in that Vb.

if you are going for SPL i would recommend not going with MA audio.  i have friends that have bought ma because they thought they were getting a good deal and put power on them and poof...  smoke.   its just a hatred of ma i guess but if you are serious about getting into spl you might want to reconsider using ma

pcummings32 wrote: if you are going for SPL i would recommend not going with MA audio.  i have friends that have bought ma because they thought they were getting a good deal and put power on them and poof...  smoke.   its just a hatred of ma i guess but if you are serious about getting into spl you might want to reconsider using ma

We have a truck here locally running 10, 10s MA's sealed, running off 4000rms. He does 154db all day on music. I agree they are not the best sub out there, but the enclosure plays a huge part in how loud something will go.

thanks a lot for the help guys i guess sealed is the way we  will go..ill keep u posted