Tweaking my port. Will this work

[Jessica]

So my box is tuned to 35hz. I don't want to build a whole new box so I messed around in torres and if i decrease my port height to about 12.5 i can tune down to 30hz. I want to do this because it's super peaky right now. I'm hoping this will help with higher bass.

What i want to do is cut some 3/4" mdf into the same shape as my port and lay those in the top and bottom of the port for it's entire length to make it 12" tall.

The problem is it makes my port area/ft 10" So will this be a huge problem or should i start from scratch?

here is the box now

And this is what it will be after.

[bobobass]

personally, i always start from scratch if i want to change tuning, it just makes get better a building boxes, but you could do that. You will probably get some port noise though. no harm in trying anyway though.

[Pro7]

So you are trying to boost your upper bass by lowering tuning? I may be wrong but that seems counter productive ESPECIALLY when decreasing port area to 11" per

[bkolfo4]

So you are trying to boost your upper bass by lowering tuning? I may be wrong but that seems counter productive ESPECIALLY when decreasing port area to 11" per

The port tuning frequency does not affect the roll off of the upper frequencies. Not sure why everyone thinks that. But what a higher tuning frequency will do in most designs is cause a larger peak right above the tuning frequency. This large peak will be louder than the higher frequencies making them seem like they are missing (and it is even worse if this peak lines up with the car's resonant frequency), unless of course your sub has limited high frequency response by design. Lowering the tuning frequency will more than likely reduce the peak above the tuning frequency and give a flatter response.

Port area per foot means nothing. Need to know how much port area and what sub.

[Jessica]

I am trying to reduce my peaky-ness. I peak around 40-45hz bad. So if i lower tuning i should flatten it out some. But I think I will just invest in some mid-bass instead. I just went out and pointed my box forward in my hatch. It never worked with my sealed box but with this box is seems to help cut down on the peak, and it doesn't seem to hurt how loud it gets. At least to the ear.I don't know for sure but If i lose a couple deebeez to gain some quality then so be it.

[Jessica]

So you are trying to boost your upper bass by lowering tuning? I may be wrong but that seems counter productive ESPECIALLY when decreasing port area to 11" per

The port tuning frequency does not affect the roll off of the upper frequencies. Not sure why everyone thinks that. But what a higher tuning frequency will do in most designs is cause a larger peak right above the tuning frequency. This large peak will be louder than the higher frequencies making them seem like they are missing (and it is even worse if this peak lines up with the car's resonant frequency), unless of course your sub has limited high frequency response by design. Lowering the tuning frequency will more than likely reduce the peak above the tuning frequency and give a flatter response.

Port area per foot means nothing. Need to know how much port area and what sub.

Subs are in my sig, SA-12 and port area is in the boxes above in the pics.

The port width is right i think, because it's 3.75 at the exit and splits to two ports half that each.