A few questions on building the best box for my ride

[ATLien]

I have an '02 Durango R/T with two 12" RF HX2s.

I'm planning on building a ported box with one slot directed between the back seats. (it will be right where my amp is mounted)

(1) Would you recommend the subs to be mounted facing up or back?

(2) My subs are lazy. How do I make em bump those real short beats more clearly?

[cthedinger]

do subs up port back

and get a better amp i am sure they will move a lot more that way

[ATLien]

do subs up port back

I'd like to know a little more as to why you would recommend the port facing back. Would that increase SPL or SQ? I just like to have a better understanding of why and how things work exactly.

and get a better amp i am sure they will move a lot more that way

I know Boss is a shitty brand but it's pumping 2000W max and I can't even turn the gain very high before the subs want to give out. (I wonder if this has something to do with my prefab Kicker box)

Edited November 28, 2009 by ATLien

[ATLien]

No really, why exactly should the port be facing back? What difference would it make? I know their are some smart smart people on this forum. It's time to come out of the woodwork and get technical.

Edited November 28, 2009 by ATLien

[ATLien]

Ya gotta post to keep em posting

:hairtrick:

Just thinking to myself here. It could also have something to do with my amp settings...

Gain is right at about a quarter up.

Bass boost is all the way up.

Input Db level or whatever is turned all the way up.

Daaamn where do ya learn all this shit?

[HHR Ed]

In a SUV and certain hatchbacks, Subs up and ports firing back can increase SPL and give better SQ.

This is due to a few reasons.

The subs are able to use back pressure off of the ceiling to better control cone movement. And the port firing back actually lets the air just outside the port gradually match the impedance of the air in front of the enclosure.

Also, if your bass boost is turned up, that will add distortion and could limit the quality and SPL of your setup.

The max output of the amp is an unrealistic number.

It is better to have higher rms power for a clean signal.

[ATLien]

Alright, I'll going to go with a ported box, subs facing up with port facing back.

I have another question.

Crutchfield says,

Recommended Ported Box Volume: The ported box volume range recommended by Rockford Fosgate is 1.75 cu/ft to 4.0 cu/ft. Within this range, the ideal size recommended by Rockford Fosgate is 2.0 cu/ft, so this is the enclosure recommended by Crutchfield. One 4" diameter x 10-3/4" long port, tuned at 35Hz, should be used with a 2.0 cu/ft enclosure.

I'm going to be using two 12" subs so obviously I need to double up on ct/ft for the box size but how does this affect the tuning of the port? Do I need to increase the size since more subs are used? I'm a little lost right here. How do I tune the box to 35hz when more subs are used?

Also, how do I measure displacement?

Edited November 29, 2009 by ATLien

[arnold1992]

Find a box calculator to help you out a little bit and tuning of the port is the opening of the port (surface area) and length of wood connecting to the opening (port length)...usually the longer the port length the lower the tuning in accordance to the box size and port area...turn you bass boost off btw and careful with your gain,.

[Marlo Stanfield]

First of all what hx2s do u have, power or punch?? Next how much power do u plan on running if you're planning to replace the amp?? If not what model is that amp, so we can check the actual RMS ratings(which will still be wayy overrated).

[ATLien]

First of all what hx2s do u have, power or punch?? Next how much power do u plan on running if you're planning to replace the amp?? If not what model is that amp, so we can check the actual RMS ratings(which will still be wayy overrated).

I have the punch series.

Here are the specs for the subs. I'll be using two of these.

# dual 4-ohm voice coils

# CONsealer gasket hides mounting screws and prevents air leaks around the frame

# frequency response 26-200 Hz

# power range 150-500 watts RMS (250 watts per voice coil)

# peak power 1,000 watts

# sensitivity 88 dB SPL

# top mount depth 5-13/16"

# sealed box volume 0.8-4.0 cubic feet

# ported box volume 1.75-4.0 cubic feet

Here are the specs for the amp.

# Max power 2-ohm 1000W x 2, RMS power 4-ohm 300W x 2

# Max bridged power 4-ohm x 2000W x 1, signal-to-noise ratio > 102dB, THD 0.01%

# Features remote subwoofer level control, tri-mode operation and bridgeable

# 11 7/8" W x 2 5/8" H x 16 13"/16" L

Right now I have the subs wired up at 4 ohms bridged according to Rockford's diagram.

You think I should drop down to 2 ohms or leave it at 4?

Edited November 29, 2009 by ATLien