Box/Tuning for Orion HCCA 15"

[GatiBeats]

I drive a 06 Pontiac Grand Prix which has a small (and awkward) trunk opening. Because of this, my box must be within 36w x 15d x approx. 17h. It also must me 1" mdf all around and 2 in the front. I went to a local audio shop and they told me a build for my Orion HCCA 15 would be nearly impossible and cost over $700 in labor alone. The back of the box needs to be at least an inch away from the rear of the sub since it is pole vented, and the magnet requires a support to hold it up, rather than putting all of the stress on what is mounted. I was shooting for around 3.5-4ft^3 at 33-35hz. Any ideas on box and port dimensions?

[Joe X]

Ok so this could be done:

Enclosure Specifications:

Fb = 35 Hz
Vb = 3.5 ft^3

External Height = 17.25 in
External Width = 36 in
External Depth = 15.25 in

Cut Sheet List:

* All Dimensions in Inches.
* Wood Thickness is 3/4 for all Parts.

External Enclosure Parts:

2 x Front & Back (3 parts) = 36 x 17 1/4

Left & Right Sides = 13 x 15 3/4

Top & Bottom = 36 x 13

Port Quantity and Dimensions:

Number of Ports = 1
Pipe Port Diameter = 6
Pipe Port Length = 13 3/8

Threaded metallic bracing 1/2" as shown, the aero port needs about 6" clearance in front of it for proper operation, if that is not possible a bent aero port should be used firing forward.

[GatiBeats]

Ok so this could be done:

Enclosure Specifications:

Fb = 35 Hz

Vb = 3.5 ft^3

External Height = 17.25 in

External Width = 36 in

External Depth = 15.25 in

Cut Sheet List:

* All Dimensions in Inches.

* Wood Thickness is 3/4 for all Parts.

External Enclosure Parts:

2 x Front & Back (3 parts) = 36 x 17 1/4

Left & Right Sides = 13 x 15 3/4

Top & Bottom = 36 x 13

Port Quantity and Dimensions:

Number of Ports = 1

Pipe Port Diameter = 6

Pipe Port Length = 13 3/8

Threaded metallic bracing 1/2" as shown, the aero port needs about 6" clearance in front of it for proper operation, if that is not possible a bent aero port should be used firing forward.

Is there a way I could use 2 4" ports rather than one 6"? and if so, how long would they have to be? Would a flared port be better?

[Joe X]

It's a bit less port area and you are somewhat low right now but if you want to do that then two ports 12 3/4" long will tune you the same, and yes you should use PSP flared ports. You will need 4" of free airspace in front of the ports for proper operation.

EDTI: The flares of PSP ports are really big in diameter so one port would likely need to be low and it may get a clearance issue.

[GatiBeats]

I was looking at using one of these port kits:

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=268-352

It says the outside flare diameter is 7 1/4" so if I put them 1/2" apart and 3/8" from the top an bottom, theoretically it should work out.

[Joe X]

Right, there is enough space to install them but you should make sure that there is 4" clearance in front of each of the two ports.

[GatiBeats]

Assuming I used the 6" port, would it change the tuning if I made the port external?

[Joe X]

Yes, you can run it partially external or entirely external, as your net volume grows the tuning would drop some but just adjusting the length of the port can tune it back to 35Hz.

[GatiBeats]

So if the net volume grew I would need to make the port a little shorter?

[Joe X]

That's right, if you tell me how you plan to set it up I can tell you the new length.