New sub box...where'd my range go?

**Sven the Sexman** · 09-01-2012

I just built an new box for my subs. I have 2 JL 12w6v2's in a sealed box built to JL's specs...well at least I tried. I have perfect bass drum reproduction, but I put on "How Low" by Ludacris and found I lost a lot of depth in the music; I can't hit those low notes. Is this something I'll have to deal with since I'm now sealed rather than ported? Also, I have a single chamber...I did not split the box. Could that have something to do with it? This is my first ever home built sub box. Is it possible I miscalculated and need to polyfill the box? Otherwise, it sounds great...especially given the materials I had to work with, but I just feel like it is lacking. Any thoughts? Thanks in advance.

**wa04compg** · 09-01-2012

It is prob because its a single chamber...I have had both ported sealed vented and the vented box hit the hardest

**develand** · 09-01-2012

A sealed box generally gives a cripser more controlled sound, but also can take more power to reach the same thing a ported can. Ported are generally deeper and louder but dont have the crispness or sound quality.

**Sven the Sexman** · 09-01-2012

So, the depth I used to have might not be attainable with my current setup?

**develand** · 09-01-2012

Potentially... what are your amp specs?

12w6's are pretty good subs, so you should be able to hit pretty low.

**Sven the Sexman** · 09-01-2012

JL 1000/1v2

1000w "RMS" all the time

**develand** · 09-01-2012

You shouldnt really have a huge problem.. but I have always had sealed. I have heard that ported delivers a lot deeper.

**Sven the Sexman** · 09-01-2012

My old box was definitely deeper and louder. It was also taking up a good majority of my trunk space. LOL

**Beelzeboul** · 09-01-2012

when you did the specs for the box did you take into account sub displacement?

ie box calls for 4.00cubic feet with a .17 sub displacement making total box size 4.17
I wouldn't suggest going much above what they suggest for the sub.

1.25/1.6 is where that sub starts to shine.

also those subs run best at around 400-600 watts

ported will also give more spl

**Sven the Sexman** · 09-01-2012

I believe JL's dimensions took into account the sub displacement. I on the other hand, modified those numbers for my own personal needs. I'm looking up a sub box volume calculator now.

EDIT: I looked up a box volume calculator and the box should have an internal volume around 2.75 cu ft with the sub displacement calculated in. JL specs 1.25 cu ft for each sub. So I'm basically a little big except I have some braces in there which could probably account for a few tenths of a cubic foot.

**Sven the Sexman** · 09-02-2012

Ok, I got it figured out. It was an overlooked amp setting. I had to adjust the "Q" on the amp because I went from a dual chamber ported box to a large single chamber sealed enclosure.

This thread can be closed now, and thanks to everyone who tried to help me out.

**matt5112** · 09-02-2012

Why isn't the EQ off?

Set gain properly, bass boost off, infrasonic to the point where your sub will reach Xmax at your maximum nominal power.

Derp.

How big was the old box?

This is what your new box looks like before cabin gain:

Heres probably what your old one looked like based on the JL rec specs:

Apply some filters to emulate a 50 Hz LPF and cabin gain, ignore the low SPL on these graphs, this particular program wasn't designed to do this.

Vented box will make more "boom boom" above 25 Hz, but the sealed does better below that. Even more so if you factor in the vented box unloads around there and would require a SSF/HPF to prevent you from hitting Xmech.

Vented clearly producing more sound in the "useable" region.