Ported box setup.

[callandor2k]

Ok I am going to ask yet another debate question.

I know that the slot ported boxes are better in their own way than tube ported boxes and vice versa. I've been reading through some of the sub owners manuals and some give specs for sealed, round ported and slot ported boxes. Sealed being the smallest, round ported being the middle sized and slot ported being the largest of the three boxes.


Now call me a worry wart or what ever. But I don't like running an amp that has a higher rms wattage rating than the sub it is pushing. If anything I would under power by a little than take a chance on overpowering it by a little. Since I have a 1000w rms amp I am thinking of running 2 x 500 - 600w rms subs in a modified round ported box. By modified I mean round port converted into a square port. The reason for this is space. If I were to go with a slot ported I would take up about half of my trunk space and be using 1 sub. If I go with a square ported box I can get 2 subs in same space and be utilizing the amps full power (theoretically speaking).


So here is my rough design. Tell me what you think.



I know that this isn't the way some of you would do it. But this is just an Idea. Since I have time to explore options till I can afford to buy the subs and wiring.

[Bwcad1]

Using less the what the amp produces is a hell of a lot easier on equipment. when your running your amp at maximum potential everyday your stressing the components. i know you said you wanted your equipment to last for a long time so that's not such a good idea for you.

That box design while work definitely has severe limitations. You don't have enough port area and you will have insane amounts of port noise.

If your running a single amp your better off without the divider and moving the subs to the outside and port to the middle.

Round ports and square ported boxes take up ruffly the same amount of space when properly designed.

That box is still better suited for a single sub but i can tell you want 2. That's completely OK you just wont have an optimized box for the sub.

Also your cutout diameter for a 12 should be like 10.75-11 not 11.97

[JeremyC]

I want to add something to your theory about over and under powering.

There really isn't such a thing as underpowering a sub. All your doing is limiting its max output.

Its just like turning the volume down, or limiting how loud you can turn it.

Say your running a 2K watt rms amp on a 1000 watt RMS sub. As long as your gains are set properly, and you never turn your deck up till your input stage of your amp is maxed your sub will never see 2K watts.

Say you do turn the deck up till the input stage of your amp is maxed. All you have to do is turn the deck down the equivlent of 3db and your back down to 1K watts rms.

Cut the deck by 3 more db, and now your at 500 watts rms.

See what I'm gettign at here.

Most of us match the RMS output of our amp to the rms rating of the sub. That way we can get every last drop of output when we want it, and still know were not going to run into thermal issues.

There is nothing wrong with running an amp with a higher rms than the speaker its conected to. In some situations the added dynamic headroom can be a plus, especially in your higher end SQ cars.

And the extra headroom can keep the amps from running as hot when you do decide to crank it up a little. BUT..... You have to know your system, and how its set up. So unless your willing to pay someone with the right tools, and a lot of experiance, or you really know what your doing. I wouldn't sugest it.

[Ryan from Ohio]

Pretty much what Bill said.

If you dont have the room to run the ported properly then go for the sealed.

Ported boxes not done properly are no good.

What subs are you going to run? That will play an effect on what box size and how much port area you truly need.

[MobileAudio219]

Pretty much what Bill said.
If you dont have the room to run the ported properly then go for the sealed.
Ported boxes not done properly are no good.
What subs are you going to run? That will play an effect on what box size and how much port area you truly need.

Yep.

Also certain subs don't favor ported boxes, and certain subs don't favor sealed boxes.

[callandor2k]

Pretty much what Bill said.
If you dont have the room to run the ported properly then go for the sealed.
Ported boxes not done properly are no good.
What subs are you going to run? That will play an effect on what box size and how much port area you truly need.

I decided on one of these 3 subs.

MB Quart RWE-304

Hifonics Brutus BRZ12D4

Hifonics Atlas ATL12D4

Dual sealed chamber cause I don't have the trunk space for a good ported box. But will most likely be one of the Hifonics. Not sure if I really like the looks of the Atlas series. It's different. But it looks like the cone part is plastic, though I am sure it's not.

[callandor2k]

I want to add something to your theory about over and under powering.
There really isn't such a thing as underpowering a sub. All your doing is limiting its max output.
Its just like turning the volume down, or limiting how loud you can turn it.
Say your running a 2K watt rms amp on a 1000 watt RMS sub. As long as your gains are set properly, and you never turn your deck up till your input stage of your amp is maxed your sub will never see 2K watts.
Say you do turn the deck up till the input stage of your amp is maxed. All you have to do is turn the deck down the equivlent of 3db and your back down to 1K watts rms.
Cut the deck by 3 more db, and now your at 500 watts rms.
See what I'm gettign at here.
Most of us match the RMS output of our amp to the rms rating of the sub. That way we can get every last drop of output when we want it, and still know were not going to run into thermal issues.
There is nothing wrong with running an amp with a higher rms than the speaker its conected to. In some situations the added dynamic headroom can be a plus, especially in your higher end SQ cars.
And the extra headroom can keep the amps from running as hot when you do decide to crank it up a little. BUT..... You have to know your system, and how its set up. So unless your willing to pay someone with the right tools, and a lot of experiance, or you really know what your doing. I wouldn't sugest it.

What I meant by underpowering the subs is where I am not running full sub rated rms to it from the amp. I know it's not really underpowering it. But that is what I call it.

I guess I should of said. I would rather run a little under the rated RMS of the subs than run too much.

[Bwcad1]

What I meant by underpowering the subs is where I am not running full sub rated rms to it from the amp. I know it's not really underpowering it. But that is what I call it.
I guess I should of said. I would rather run a little under the rated RMS of the subs than run too much.

Just bear in mind going that direction puts is more stressful on your equipment.

The atlas cone is plastic. there are tons of subs that use plastic cones now. Some of mine do.

[callandor2k]

I won't be running full RMS of the AMP anyway. But if I want to do it every now and then, it's there to use if I want it.

If setting gains at 3/4 radio volume and sqrt(wattage x Ohm load)= Voltage is accurate. I rarely go over 1/2 volume most of the time anyway. And if I do, it's not for very long.

[Ryan from Ohio]

You will be fine.