Optimal box placement, 2014 fusion, LF sound wave travel

[planet audio 10+ year member]

I have 2014 ford fusion titanium with sony sound system. I installed 2 rockford P3 12" in sealed box built to rockford recommended specs. I'm using the pacs ampro4 for my preouts. The car was shaking but the sound wasn't very loud. I finally figured out that the rear seats and deck are super insulated for trunk noise. I removed the sound insulation from the rear deck and the difference is light and day.

So now I'm wondering about box placement and how low frequency sound waves travel. When the waves travel from the sub, back of the box, to the rear of the trunk, when they come to the seats and deck, are the seats eating up any of the sound, or will the sound that hits the seats then travel up to the open deck? If I position the box with subs facing towards the deck, will the sound go from the sub, back of the box, then right into the cabin through the deck? If so will that create a louder sound? Please reference my crude drawing lol.

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[shredder2]

The car was shaking but the sound wasn't very loud.

I think building a more efficient, low tuned enclosure would get you way better gains over ANY sealed box placement. I'd go ported with those P3's myself.

But as far as your question goes I'd leave them rear firing with that sealed box and vent the trunk into the cabin somehow (remove any rear deck speakers?), but playing with placement ought to be easy so try finding what works best. Just don't expect any dramatic gains by doing so.

So many things I can ask, like did you check phase? What amp are you using? Any electrical done yet? I'm assuming you wired to get the most out of whatever amp you currently have?

Those P3-12's will perform way better in a 3.5-4ft3 ported box than 2ft3 sealed especially on lower power.

 

[planet audio 10+ year member]

So I currently have the deck sound insulation and the 6x9s removed, and the result is immediate. And I can actually tell the gain is set waaay too high, even though the clipping indicator doesn't come in, prolly bc I was trying to compensate for the poor audio. I have them Wired into 2ohms with a JL JD1000/1 amp (1000w rms). Rockfords website recommends a sealed enclosure at 1.02 ft3. Custom sounds built me a 1.04 ft3 sealed box bc he said it would hit a little lower. There is no polyfill in the box.

With the deck insulation removed the subs sound way better, so now I can adjust the amp properly. As it stands, at 1/3 volume the subs hit hella low, are loud and rumble. At 3/4 volume, the subs aren't proportionately loud, but the car shakes more.

I was just curious if the less distance the sound waves traveled until they reached the front seats, would the sound be louder, and how substantial the difference would be.

 

[AnthonyO 10+ year member]

Try the box in different positions. For audio competition I have seen high SPL scores with the subs firing forward but slid all the way back to the trunk. I have also seen high spl scores with the enclosure firing backwards pushed all the way back firing into a corner. So just play around with it and see what works

 

[planet audio 10+ year member]

Yea I plan on it, Im just glad I figured out what was killing the performance I was hella baffled. And I was more or less curious how low frequency sound waves traveled and reacted to the environment.

 

[planet audio 10+ year member]

So do you mind building me a box plans for the ported enclosure you are taking about? Does it matter if the ports are round or slotted? I'd prefer slotted if there is no difference.

 

[Firewalker]

Contact @Buck he can design you a box for a small fee, setup for your subwoofer, music tastes and the vehicle you have. You will need to provide him with pictures of the area and measurements. But trust me when I say this it is worth every penny you pay him it comes with a full sheet of everything you need to build a box but the material and tools.

 

[shredder2]

So do you mind building me a box plans for the ported enclosure you are taking about? Does it matter if the ports are round or slotted? I'd prefer slotted if there is no difference.

Too much missing info to really do it right but sure. I have this design for a trunk/hatch from awhile back designed for a cab 1600.1 amp.
Its pretty basic but it does great and the efficiency should do wonders output-wise. It should emphasize those lows better than a sealed box for sure and should gain across the entire bandwidth while sounding better.
You can't ask for a design without listing H x W x D usually but this might fit...

 

[planet audio 10+ year member]

Ill give that a shot. Size isn't an issue, it's a fusion I'm 6'4" and can fit comfortably in my trunk. It's like 45w x 17h x 50l. I paid custom sounds $250 for the sealed box they built. Ive never had subs that used a box so small.

 

[shredder2]

Here's a simple ported design. I think you'll see real gains over your small sealed with this one.

Good luck!

 

[planet audio 10+ year member]

Thanks! I just attempted my first box for my home stereo using 1/4 plywood I had laying around and it came out great. (Aside from obvious box flex) I didn't want to use good material and mess it up on first attempt. I will give this box a shot.