WOW, I haven't posted in the general discussion for a while. Mostly Donut Shop.

I currently have two 12 Inch subs in my Ford Explorer. I don't really want to go with a bigger amp and or more powerful subs. What I am wondering is what kind of change I will notice if I simply got a sub box for three subs and added a third sub?

I wouldn't be running anymore power to them, but I'd obviously be having more cone area. Would this just give me deeper sounding bass, or would it indeed sound louder because of the extra cone area? This has never been explained to me so I was always curious.

I would think I would notice some kind of a difference. Maybe just air movement throughout my vehicle?

What amp and sub combo are you using?

Rockford 800watt aII and two 12 Inch Kicker Comp VR's 4OHM DVC

Athough the 800a2 is only rated for 4ohm bridged the A-series were great amps and you will have no problem running a third D4 sub in series on it.
It is likely giving the subs ~900rms as it is so adding a third will give you a bit more power and enough to still drive them very well given the correct enclosure.
As long as you have enough airspace to make a box big enough for three VR12's then you will see a decent increase in output over what you have now.

I would suspect not much of a difference unless you increased power output as well.

^^^ Well, you'd think with more cone area moving you'd notice some sound difference. :confused:

1.76 db increase from difference in cone area...

You can probably squeeze a couple hundred extra watts out of the amp, and will also have less power compression... (You could risk blowing outputs ???)

If you are going to do it, why not just sell the 12 and get 3 15s.. :D ?

[ December 07, 2004, 08:50 PM: Message edited by: Haunz ]

see basic car audio electronics' website for a table that you can plug your specs into to give you an estimate of spl. Scroll down on the right side to number 31(speakers)to get to the section that has this table. I believe that by adding just one more driver and leaving all else the same, you will only gain about 1.5- 2.0 dB in spl.http://www.bcae1.com/

^^^ Getting some 15's isn't a bad idea. I've never had 15's though. I've heard they tend to sound a little sloppy???

you can make it much louder by simply building a new box and keeping the same number of subs. What kind of box do you have now? THe loudest street A vehicle in the world used 2 10" kicker L7s in an explorer...true they had a whole lotta power but still. I don't know what type of box you have but I bet you could easily gain more by changing the box to something more suited for the truck than by adding an extra speaker

It's only 1.25CI per chamber. That was the largest box I could just go pick up somewhere without having a place build me a larger box for millions of dollars.

I just wanted to get the subs in there for now so I grabbed that box. It was only 80 bucks so I figured if I ever wanted to go bigger I could, no big deal. I'd build my own box, but that is something that I don't think I'd be very good at. Or I really wouldn't know how to go about it.

well building your own is the best way to go assuming you have a home depot nearby and a drill and glue and screws...just get some help planning it out and get home depot to cut the peices you need. you can probobly gain a good 6db (four times as loud) just by making a well designed ported box (I assume yours right now is sealed) which alot of people on this website could help with and it would only cost around $40 in materials and an afternoon worth of time

^ It generally takes 10db to sound 2x as loud ;)

(6db is 2x the accoustical energy and it takes either 4x the power or cone area or 2x of both)

thats an old misconception, i have a 15 in a ported box and if you heard it sloppy isn't a word that would come to your mind.

"shocking Canada" I believe you need 20dB more to be 4x as loud. As "Haunz" has pointed out there is a doubling of percieved loudness every 10 dB. Therefore, 2 doublings(20dB) will give you 4x the loudness.

You heard wrong. People like to say stupid things based on assumptions. The logic is "If the cone's bigger, it must move slower, right?" This logic fails to take into account things like the motor, suspension, and all the other parts that make a speaker work. There's more to accuracy than just the size of the cone. But believe what you will ;)

Some of the tightest subs I've heard, and will soon own, were 15's in a TINY box considering what subs they are.

With enough power and in a small box 15's can be VERY tight and controlled. I think Sean knows what I'm talking about when I say even in a mid to large size ported box, a 15 can be very tight and responsive.

Still one of the better sounding 15's I've heard Sean, I shoulda bought it off you.

No matter how many times you tell a person the enclosure will determine the "boomy/sloppy" response and not the woofer size they just don't listen. [img]graemlins/dunno.gif[/img]

Brandon, what are you doing in Cobourg (no "H" ;) )?

So, if I were to get 15's. What size box would I want to use to get really deep yet not sloppy bass?

LOL, trying to get away from the hell I call Oshawa.

I moved out here about a month ago or so now, might be coming back westward soon though, not quite to Oshawa though, maybe Port Hope, possibly Newtonville.

Hey, Steve told me he was building your car a while back, how's that coming along? Finished yet?

Steve's doing some of the trunk work as I still don't have a wood shop to play around in. I miss the old days when I had everything at my disposal.
It's coming along slowly.

Mreastside, the box size/port area will depend on the 15" you choose.

Uhh... actually the loudest Street A. vehicle in the world is a Fiat Panda using 2 DD 99's and an EXT-3000 [img]graemlins/thumb.gif[/img]