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Discussion Starter #1
Okay I know this topic has been covered before. I know this because I used the wonderful search feature along with Google. Problem is, I tried sorting through all the theories and nonsense for solutions to no avail. So the question is, how the hell do I fix this? Perhaps I need to find a way to vent the cabin to the outside?
 

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My guess is there is no way to overcome that. If the waves bounce around in the cabin, they will eventually begin to cancel each other out.
 

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Discussion Starter #4
Winter... About that. See, that's the problem, because around here, during the winter it snows and ****. And honestly, I like to listen to my music loud, but I don't necessarily want to piss off the people around me. If I can get my subs to play as loud and clean as they do with the windows open, I'd be a very happy man. I just haven't found anyone offering a realistic solution online.
 

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Discussion Starter #7
I tried putting them out of phase and that didn't really do anything but make them sound more hollow or nasal, I don't know how to describe it.

Not sure about downfiring them. I'm actually ready to try firing them through the ski pass and sealing them off from the trunk. But I have a feeling I'd lose a lot of output in doing that.
 

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that is the ***** of cabin gain. in a car a sub is gonna essentially be tuned by the car. if you calculate the volume of air in the car, you can calculate what the tuning freq of the car is. by opening the windows you have taken that away and made the internal volume of the car infinite. there is NOTHING you can do about this unless you find a way to change the laws of physics.
 

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I'd try every aiming and positioning you could, but likely will still change with window some. Could try changing the box tune.
 

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I have an Accord like the one in your sig but I've never noticed the subs sounding "better" with the windows open. I did however, notice that they seemed to get a bit louder when I opened the windows if that's what you mean. My subs were firing towards the trunk and I took the factory 6x9's out and replaced the grilles.
 

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Discussion Starter #12 (Edited)
what subs you using, in what box?

Aiming your subwoofer box

id also try xing your sub very low, like 35hz, and try very high 120hz

just see what it sounds like?

worst case, hang your subs from your rear shelf.

Currently they are 12" Pioneer Champion series, each in their own air space at 1.5 cu ft net, each with their own port, and tuned to 35Hz. I plan on replacing them eventually but I need either rob a bank or wait until my wallet learns to make dollar bills magically appear :p

They are rear firing, though I haven't removed the rear deck speakers yet to see if that helps. Folding the seat does very little as the enclosure pretty much takes up that entire space.

As far as the laws of physics are concerned, I've tried defying them, bending them, and otherwise ignoring them, and have only netted the result of broken expensive things. You know, bones, valves, ring lands, stuff like that.
 

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I'd try porting them a little lower tune and see what they do, maybe try 30-32Hz.
 

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there is NOTHING you can do about this unless you find a way to change the laws of physics.
I like what you're saying here. Lets explore this option further.
 

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I guess you could try putting vents in all the car doors or something like that, but not knowing what it would do. My IB subs don't seem to care except under 30Hz or so and not much difference at that. I can bump the EQ one notch at 20Hz and take care of it but since output there is sufficient I don't bother.

Can you temp add to the port length on your box just to try it?
 

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Discussion Starter #16
Hadn't thought about dropping the port tune. Though, they're tuned to 35Hz, not sure if going lower would actually do anything different but if I needed I suppose I could add a bit of length.

I did try a little experiment today. My trunk is sealed about as well as it can be. I don't use the rear speakers so I went ahead and removed them to allow the trunk to vent into the cabin a bit better. As it turned out, things improved greatly. The gain is still there when I roll the windows down but the change is less drastic.
 

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My sub actually sounds better with the windows up. Where are you cutting the sub?
 

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I had a couple cars I took the panel out of the seatback. The sub seems to go through the seat cushion but not the other stuff, providing it is removable. Used a little black/gray carpet to cover it up.
 

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Ok, this is a common problem in small cars with ported enclosures. You're going to hate my solution - but it is the solution. That driver is way, way, WAY wrong for a vented enclosure that small. If you must have it that small, plug the damn port. It's basically peaking up 4dB at 55Hz. It probably sounds very boomy and ill-defined with the windows up.

One fix (but wholly impractical as you'll see) is to build the enclosure bigger, but keep the tuning the same at 35Hz. Even better, plug the damn port so your roll-off is 6dB/octave below tuning rather than 12-20dB/octave. The recommended size for a vented enclosure is actually 6 cubic feet tuned to 21Hz!! But since the Fs of the driver is 35Hz, you'll end up with wooly, uncontrolled output with weak power handling.

So go sealed. In your current 1.5 cubes, you get a -3dB point of 38Hz and a mild passband bump of 0.5dB.

The problem is that the interior of a small car resonates at "a" particular frequency (say 80Hz) and opening a window drops the 'tuning frequency' by a significant portion. So if you can't drive around with the windows down, you need to change the characteristics of the "rear" enclosure which is your current subwoofer system.

Cheap(er) subwoofers are cheap because they have a small motor structure (under than plastic shell on the magnet). Newer drivers combine the small motor with a heavy cone and long Xmax. This is a classic sealed-box driver.

Get making sawdust or buy some socks and stuff your ports.
 
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