Enclosure question for Massive Hippo 84 in 1.1 cuft @ 35hz

[erdna14]

Long time lurker, first time poster so bear with me.

Vehicle : 2006 Ford Focus ZX4 ST

Location in the vehicle: Driver side trunk facing passenger side (Factory enclosure location)

Space available (Length x Width x Height): 8x20x20

Subwoofer make and model: Massive Hippo 84

Subwoofer Size: 8"

Number of Subwoofers: 1

Type of Port (Kerfed, Slot, Aero, etc.): slot

What type of music do you like?: dubstep & rap mostly

Is your goal SPL or Everyday Music?: everyday music

Tuning Freq (Hz): 35hz

Volume : 1.13 cuft after displacements

Questions:

I've run I to an issue with my design. I'm really trying to stick within the dimensions listed as I'm trying to maximize trunk space. Having just got rid of a massive 4.75 cuft enclosure, I'm really liking having trunk space and don't want to lose it.

My issue is with the port that I have designed. The easiest way to build the enclosure puts the sub and port on different planes (sub towards passenger side, port towards rear or front of vehicle). I know that's not ideal, but how detrimental would it be SQ wise? And is there a better way to port the enclosure without having to change the design completely?

Box specs:

Front/back - 20" x 18.5"

Top/bottom - 20" x 8"

Side 1 - 18.5" x 6.5"

Side 2 - 16.875" x 6.5"

Port - 6.5" x 15.4"

Port Ratio - 4:1

Vol before displacements - 1.29

Vol after displacements - 1.13

Here's what I'm working with at the moment:





Resonant frequency of the car is right around 55hz, FWIW.

Click to read more...

 

[erdna14]

Nothing?

 

[bigmizzle99]

Its such a small box, why not just build it and test? You're not gonna chase numbers with that so just build it and listen to it and then you judge whether it sounds good to you or not. If you dont like it, then change the design.

 

[bbeljefe]

You shouldn't have any problem with the vent facing forward in the trunk but I'm curious about the vent you describe. Is it a slot or a round vent? Either way, it's a lot of vent area for a single 8, unless I'm reading things completely wrong. Also, unless that sub is a very low EPB sub, the box is on the large side of what it would like.... if the area you gave is net.

 

[erdna14]

You shouldn't have any problem with the vent facing forward in the trunk but I'm curious about the vent you describe. Is it a slot or a round vent? Either way, it's a lot of vent area for a single 8, unless I'm reading things completely wrong. Also, unless that sub is a very low EPB sub, the box is on the large side of what it would like.... if the area you gave is net.

The EBP is 76. I am basing this off the manufacturer recommended ported enclosure. Its a slot port. The port I derived from online calculators and didn't do the actual math of figuring out the area. And I adjusted the dimensions to use the box as part of the port.

Here is the spec sheet:

 

[bbeljefe]

The EBP is 76. I am basing this off the manufacturer recommended ported enclosure. Its a slot port. The port I derived from online calculators and didn't do the actual math of figuring out the area. And I adjusted the dimensions to use the box as part of the port.
Here is the spec sheet:

Okay, but is your vent a slot or round vent? Or is the 6.5" number you mentioned the vent area?

 

[erdna14]

Slot port. The dimensions of the port are 1.625x6.5x15.4 incorporating the box wall as part of the port. Based on my calculations that puts the area at 100.1 sq in and the volume at .09 cu ft.

 

[erdna14]

I went ahead and made the box. I think it came out great. It sounds exactly like I wanted it to. Here are some pics from test fitting it to find mounting points: