Subwoofer Placement

[EightySix Four]

In my truck, if I was to place a both of my twelves in the far back corner of the cab facing upward, would that cause the sound to sound like it's far off or make it noticeable from which direction it is?

I always thought it didn't matter where sub's went because the bass vibrates everything so it's more or less non directional...

 

[Heisenberg]

You mean facing up as opposed to facing forward? You won't be able to tell any difference.

 

[EightySix Four]

no, the location, they're in the far right hand corner of the cab, not centered or anything. They won't sound "far away" or anything like that correct?

 

[Heisenberg]

Ah. No, it's not going to sound weird or anything. Lower frequencies are pretty nondirectional compared to higher ones.

Edit: It may mess up the stereo imaging some though, depending if you've got them wired in stereo or not.

 

[EightySix Four]

Thanks, that's what I thought. How much better for me would it be if I had them facing downwards v.s. upwards?

 

[pinion9]

You won't be able to tell the difference. However, there will be some performance difference if you are looking for pure SPL.

Also, you may also get a standing wave. Depends on frequency of sub, contour of roof, etc. If you aren't building a performance SPL vehicle, just looking for some kickass bass, do it the easiest way for you.

 

[pinion9]

Originally posted by: Heisenberg
Ah. No, it's not going to sound weird or anything. Lower frequencies are pretty nondirectional compared to higher ones.

Edit: It may mess up the stereo imaging some though, depending if you've got them wired in stereo or not.

Bass doesn't image because the wavelengths are long. Generally speaking, if the wavelength is shorter than the distance between your ears, imaging occurs. Otherwise there is no imaging.

 

[pinion9]

Originally posted by: crazySOB297
Thanks, that's what I thought. How much better for me would it be if I had them facing downwards v.s. upwards?

Is this enclosed or ported?

 

[EightySix Four]

Alright, I have 2 infinity kappa perfect 12DVQ's, and I'm just looking for the best sound I can possibly get out of my performance restricting vehicle.

Enclosed, not enough air space for ports.

 

[Heisenberg]

Originally posted by: pinion9
Bass doesn't image because the wavelengths are long. Generally speaking, if the wavelength is shorter than the distance between your ears, imaging occurs. Otherwise there is no imaging.

Huh, didn't know that rule of thumb for imaging. In that case yeah, you'd have to be way above a couple hundred Hertz for it to happen.

 

[mrchan]

Play around with it and see if you notice a difference.

 

[pinion9]

Originally posted by: crazySOB297
Alright, I have 2 infinity kappa perfect 12DVQ's, and I'm just looking for the best sound I can possibly get out of my performance restricting vehicle.

Enclosed, not enough air space for ports.

In my opinion you should face your subs forwarded to get the best SPL. I've had a lot of setups and you should imagine how that moving air will reflect. They are sound waves. Facing forward has always given me the best sound and pressure.

 

[Howard]

Originally posted by: Heisenberg

Originally posted by: pinion9
Bass doesn't image because the wavelengths are long. Generally speaking, if the wavelength is shorter than the distance between your ears, imaging occurs. Otherwise there is no imaging.

Huh, didn't know that rule of thumb for imaging. In that case yeah, you'd have to be way above a couple hundred Hertz for it to happen.

Localization is generally agreed to occur above 80-100Hz.

 

[Howard]

Originally posted by: pinion9

Originally posted by: crazySOB297
Alright, I have 2 infinity kappa perfect 12DVQ's, and I'm just looking for the best sound I can possibly get out of my performance restricting vehicle.

Enclosed, not enough air space for ports.

In my opinion you should face your subs forwarded to get the best SPL. I've had a lot of setups and you should imagine how that moving air will reflect. They are sound waves. Facing forward has always given me the best sound and pressure.

Considering that bass wavelengths are acoustically large compared to the size of most enclosures, the sub acts as a point source. No matter how you rotate it, the radiation should be the same.

 

[EightySix Four]

So facing up/down/whatever, is fine?

 

[Howard]

Originally posted by: crazySOB297
So facing up down, whatever, is fine?

I would orient the box so that it's facing toward the horizontal (i.e. not up or down). This prevents sagging - a permanent diaphragm offset (relative to center).

 

[BrokenVisage]

Car stereo installation and placement/imaging is KEY, so yes it matters.

 

[EightySix Four]

The door speakers already have awesome placement and great imaging, but I thought we decided here in the thread that subs don't matter in placement a huge deal.

 

[IHateMyJob2004]

1) Higher bass frequencis do image. That's why there are mid-bass speakers for up front if you really want imaging. The OP probably doesn't care about imaging though.

2) Has anyone asked if this is A small truck, full size, standard cab, king cab or extended cab? How the hell can you Pieces Of Stuff give advice and act like know it alls if you don't even ask this?

IMHO: Go sealed for the smallest enclosure and aim them forward or upwards. Can't give good advice with the answer to (2).

Oh, and if you are running a 500+ watt sub amp, you might want ot look into atleast a 0.5 Farad Cap. You should probably do this regardless.

EDIT: Watching hockey. Hope others help you out.

 

[EightySix Four]

2001 F150 Lariat Crew Cab... Removing rear "small" seat. (60/40 bench, removing 40) and putting sub box there. Trying to figure out how exactly I wish to accomplish this. And the sub amp is 1500+ watts. (2 farad cap)

 

[Howard]

Originally posted by: crazySOB297
2001 F150 Lariat Crew Cab... Removing rear "small" seat. (60/40 bench, removing 40) and putting sub box there. Trying to figure out how exactly I wish to accomplish this. And the sub amp is 1500+ watts. (2 farad cap)

You already bought the amp?

 

[EightySix Four]

I have the amps and the subs...

It's an Infinity Reference 1211a

Kappa Perfect 6.5 inchers in all the doors, driven at ~110 watts each
2x Kappa Perfect 12DVQ Subs with an Infinity Reference 1211a amp (1516 watts dynamic) (854 watt RMS)

Planning on a sealed enclusre due to lack of airspace in the cab.

 

[Howard]

Originally posted by: crazySOB297
Planning on a sealed enclusre due to lack of airspace in the cab.

Air space? You mean cabin volume? Or do you mean the enclosure must be small?

 

[EightySix Four]

I mean there's not enough air there for the subs to eh "breathe..." There's just not enough air in that area for it to move. I guess you could say cabin volume.

 

[Rubycon]

You know with all the crazy things people do with their cars (like put a window a/c unit in the side with a 120v generator on the trunk!) I'm surprised that no one has reinforced their roof, cut a hole and mounted a large woofer with the magnet sticking up like a big bubble gum machine. Put lights on it and people would think you're a roller. :laugh:

On the highway with all that air the voice coil would not have a problem over heating.