4-doors are longer than their 2-door counterparts and I read somewhere that if the quarter wave has more length to develop it results in a higher SPL. Maybe the extra length changes the angle of the wave making it seem louder (hits the roof and goes down to your ears instead of hits the roof and then hits the back of the front seat).

 

Ones a 1997 Oldsmobile LSS (4 door)

The other is a 2001 Oldsmobile Alero (2 door)

Both are relitively the same legth, size, and trunk space.
Both have no speakers in the the rear deck, and seats where up.
Both cars are running 700rms

Mine sounds much louder (to the ear) than the 2 door does.

 

Heres my opinion, noobish as it may be.
It depends. LOL
I would say vehicles with more interior space have more potential because of more air inside to move, IF you have enough of a system to move it all.
Its like putting a 12" sub into 2 different enclosures, first a 1c-ft box then a 3c-ft box. The larger box will probably be louder.
What do you guys think, cause thats just a guess.

 

I thought if was less air to move the louder (walls). If you have a system that could move "all of it" than it'd be a hair trick cuz it's just shoving it out the window. Even if you could do that, if there were less air to move, it'd still be shoving it out the window only faster.

Which car has deadening? Which has a sunroof?

 

both have sunroofs, both have deadened trunks

 

That is it, it depends.

Always remember that the cabin effect will give you from 0 to 10dB (or even more), so the car is entirely responsible for those 10dB (the rest is the equipment, of course). That means that is quite easy to change the loudness by changing cars, even if they look the same.

 

If the interior is nearly the same size than it doesn't count. I think one's down on power.

 

I get some really good results bringing up the REALLY low stuff in
vehicles with a longer interior...vs a shorter interior

more room for the wave length to form

 

A friend and i went to an event a while back. His car sounded MUCH louder than mine to the ear. I mean seriously it sounded like 2 of my systems put together.
On the meter mine ended up being like 1.5db louder, even though mine sounded very weak compared to his. This was according to several people's opinions, and both cars were metered more than once with the same result.
Weird eh?
Although i guess it doesnt completely apply here because they were both 4 door cars.
I say meter them both and see if it is actually making much difference or if it just SEEMS like it is.

 

imho..it's the cabin, not the doors..