My car is a Scion xB and I have two 12w7's that i would like to build a box kind of resembling a wall
the subs and ports will each be behind the rear seat headrests facing the front of the cabin.
My question is will it still sound good with them firing basically toward the windshield as opposed to rear firing letting the waves bounce off the hatch and then toward the front?
Measure. Form idea of vehicle acoustics. Test. Interpret results. Edit your idea of vehicle acoustics. Test again.....etc
The (12v) scientific method will (usually) not let you down
or.
Gimme some pics and measurements of the vehicle cabin. Ideas on what performance you want. And a rough idea of how you want to build the box. I'll crunch some #'s and see what I can come up with. I won't say I will nail the design first try, but damit....I'll give 'er hell
In many cases (not all) in a vehicle, when you fire sub/port back w/ a given 'on paper' tuning....the actual 'in cabin' tuning will be quite a bit lower. And the reverse can be true.
For instance, flipping a box around to fire into the cabin and dropping the rear seats in a fold-down-seat trunk car can very commonly result in a loss of low freq. output, but gain in SPL at higher freq.
In these cases, firing port/sub forward can be helped by tuning lower than you would usually think. And by opening the trunk, you can help to release standing waves. IIRC, we gain about 0.4dB in NickV's Alero w/ his 2 DD2510's and pop 151's @ 57hz when we crack the trunk just a hair...but that is in a semi-spl setup (daily/low tuning w/ his box is different)
So i think im gonna do just a normal box , subs and port facing up.
My box will be 38x22x15 total internal volume minus port will be 5 cubic feet and will have a single port has an opening of 13.5" x 3" and length of 17.5" to tune it to 30hz
While there is no barrier between the subs will it still act as each sub having around 2.5 cubic feet and does it have enough port area?
The subs will get a true 1000 rms each (2000 RMS) total
i dont know about the box but do you have the electrical to actually run 2000 rms such as big 3, HO alt, performance battery(s) if not you will come no where close to that because most stock alts put out around 90 amps which wont power that
2000 rms / 14.4 volts (at best) = ~139 amps. Also have to consider your car is going to need atleast 30% of whatever your stock alt puts out. Of course max current draw is only at full output which you probably won't see all the time, so actual amperage draw should be less than 139 amps. Also have to factor in amplifier efficiency which will increase how much current is being pulled off the car. If your 2k rms is 80% efficient, thats 2500 rms your electrical is seeing.