is it possible to make a box too big? i want to get 2 15s. and i have an extended cab f-150. i want the box to come up level with the windows. then all the way across and have a sub on each side. but if the box goes all the way to the floor is a big box gunna have too much air?

 

yes a box can be to big just as yes you can make one to small. look at the recommended air space for the subs. then do some basic geometry to find the volume of the box and see how close it comes out.
But 15s usually need a lot of air space, but it all depends on what space the individual subs require

-james

 

also depends on what kind of speakers your getting.... certains speakers work better with little to no space and very tight and some need a schoolbus of air

 

he sounds like he really wants to blow u away with dat idea

 

To: big box
Re: airspace

 

well i was thinking 2 alpine type r 15s and make a sealed box.

 

Can a sealed box be too big? Not technically, but it really depends on your goals. A bigger box is generally more efficient (less air 'spring' to push against) and will play lower. The tradeoff is flatter response (which can be less efficient at certain frequencies) and lower mechanical power handling. This power rating is called excursion limited power handling, and basically is the point at which the speaker can't move any further, and therefore, won't get any louder. So, if this number is lower, you can use less power (re: more efficient) to get full excursion, so its not really a tradeoff.

Once you get over 3 times the woofers Vas, you are technically infinte baffle (no box), and the box no longer has any effect on the woofer. I have built systems like this, and actually like the way they sound.

So to answer your specific question on Type R's. Alpine's site says 1.3 to 2.5 cu ft sealed each. Vas is 3.5 cu. ft. So, unless your box ends up more than about 18 cu ft (3xvasx2 woofers) it won't be infinite baffle, which isn't a bad thing anyway. You could always build a 5 cu ft box (alpine spec) and then use trim plates to fill in the space, if you want to be more precise.

Toby

 

what about 3 rockford p2s or p3s. i want to fill the whole back of the cab. i have alot of space

 

Why not 2 size/power hungry subs?

 

2 FI BTL's would satisfy you..