Box Theory
I was under the imperession that a sealed box was capable of handling more power than a ported box.
First question:
I have built two boxes for my 12" X-Max subs. One ported and one sealed. The ported encluosure measures 3 cubic ft with 2 4"x8" ports tuned rather high (54 hertz I think).The sealed box measures 1.5 cubic ft. My question is, why does the sealed box bottom out before the ported box?
Second question:
When I originally built the sealed box I tested it in my wifes car (a wagon) and was very pleased with the performance other than a phasing issue. When I installed it my car(Lumina) I was very dissatisfied with the performance and hence the reason for building the second enclousure. Once again this box was tested in the house this time and I was pleased with the performance, until it was installed in my car. I have tried all firing angles, inside the cabin, in the trunk. Has anyone here ever experienced this before? I would really like to solve this as I have two more subs on the way.
Thank you for your time.
First question:
I have built two boxes for my 12" X-Max subs. One ported and one sealed. The ported encluosure measures 3 cubic ft with 2 4"x8" ports tuned rather high (54 hertz I think).The sealed box measures 1.5 cubic ft. My question is, why does the sealed box bottom out before the ported box?
Second question:
When I originally built the sealed box I tested it in my wifes car (a wagon) and was very pleased with the performance other than a phasing issue. When I installed it my car(Lumina) I was very dissatisfied with the performance and hence the reason for building the second enclousure. Once again this box was tested in the house this time and I was pleased with the performance, until it was installed in my car. I have tried all firing angles, inside the cabin, in the trunk. Has anyone here ever experienced this before? I would really like to solve this as I have two more subs on the way.
Thank you for your time.
2000 Watt CAFz'r
Joined: Jan 2001
Posts: 2,026
I had that problem with my old Pontiac Tempest. I tried three different box types (sealed, ported, and bandbass) and two woofers. All sounded crappy in the pontiac but great in my friend's Sundance hatchback. Maybe its a GM thing?
Guest
Posts: n/a
your box of 1.5 cubic ft sealed is very large for that woofer, the box has a very low qt, around .6, which is quite low and will limit power handling and allow the woofer to "bottom out".if the box parameter you gave for the vented box are accurate, the tuning freq. is more like 45 with an f3 of 37, with a horrible response plot. a hatchback or wagon as you stated will typically give you more output than if just sitting in a trunk. you can get some pretty wicked cancellation with woofer boxes in the trunk. the only real way to somewhat comtrol cancellation in trunks is to point the woofers forward or through the rear deck, and fully seal the cabin area from the trunk, the last point is VERY critical in attaining good sound, not to mention you will lose output in a trunk by the nature of the vehicle design, aka, trying to keep road noise from the trunk from getting into the cabin area, if you would like some help with the box design, pm me and i would gladly help you out as i have a ton of experience with the xmax woofers, btw what generation of 12" do you have 1,2nd or 3rd
The woofers are of the first generation, and the volumes mentioned are for two woofers, ie.the sealed box is .75 cubic ft per woofer and the ported box is 1.5 cubic ft per woofer and they are NOT shared chambers.
50 Watt CAFz'r
Joined: Feb 2004
Posts: 164
you cant go wrong with a sealed box as long as its the right one . try building a sealed box around 1.15 cu and then fill it with pillow down . that cheap stuff that you can buy at Wal-Mart. this will fool the sub into thinking that your box is larger that it acually is you'll get great response through out the whole sweep trust me it works.
1000 Watt CAFz'r
Joined: Aug 2001
Posts: 1,770
the only time a sealed box has more power handling than a ported is when you play it well below the tuned frequency
box size also plays into the power handling wether it sealed or ported
and if take around a tuned frequency a ported box per say has more power handling than a sealed
so you can spin it any way you want
it all how you design it and look at it
[ June 01, 2004, 05:06 PM: Message edited by: pinhead ]
box size also plays into the power handling wether it sealed or ported
and if take around a tuned frequency a ported box per say has more power handling than a sealed
so you can spin it any way you want
it all how you design it and look at it
[ June 01, 2004, 05:06 PM: Message edited by: pinhead ]
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