CleanSierra

I guess I'll add the same comment to this one as I did the previous two: WAIT TO BUY A SUB OR SUBS UNTIL YOU HAVE A CAR THAT'S YOURS IN THE DRIVEWAY.

Id choose the two 6" port option for(usually) ease of tuning and not needing such a damn long port. I actually just looked it up. For the 9" port, in 5 cubes net, tuned to 32 Hz, you'd need it to be just at 27" That's actually pretty comparable to the length on the two 6" options. If the 9"er is easier for this specific build, let er rip man. Should be really cool looking and since its metal, paint is easy

Those metal ports are insane. That one was 19" port for the bandpass box is NUTS. I think if you're going to go those metal ports, go for twin 5" ports or twin 6" ports. If 5 cubes net and tuning at 32 Hz, only 17" length needed. If the 6" option, they'll need to be quite a bit longer at 25" in length. Two 5" aeros should be enough, twin 6" ports would be where I would go with it.

They call them Psychoports? What.The.Fuck. I'm going to Google RIGHT now!

Where are you getting a metal "psychoport"? I had to repeat your typo because it sounds gangster as Hell. I agree, the 9" is fine if you can get it to a reasonable length for a desirable tuning.

What about 2 6" ports?

They definitely need a larger than average port to operate properly. I'm not sure where you hard that they like small port area from. I won't argue the pretty area per foot thing I'm this thread. Jow many aeros and what size diameter port are you planning on?

I'll get you the port area when I'm in front of my PC again. I could figure it out by plugging numbers in right now, but would rather not do the math. it's saved on my PC so that's where I'd rather get the info. I'm guessing around 32-34" just looking at it though. Its a 3.75" wide port by 14.5" in height

Just over 3 cubes after displacements, tuned at ~33 Hz. Port area is 54" and there is a double baffle.

HERE:

I would hope to Christ a Level 6 had beefy enough spiders to handle 1K in ANY size box. Shit, free air I'd think even.... Edit- Will - No disrespect sir, I know you know that product line

One DC XL on a 5K? When do you plan on adding the other one, or two?

If you guys think the port area for a regular ported box is crazy high, try clicking the "is this enclosure a bandpass" button. Minds will be lost, click at your own risk

I wonder if that is why companies like DD and SQ recommend port on the higher side? Stiffer suspensions and high Xmax. Btw, I'm glad N8 and others are chiming in. I know he's been around a lot and has(and knows people) seen a lot for good real world experience.

40 MM of Xmax is seriously hefty.And like N8 and myself said, you can surely get away with less in a vehicle cabin. Every vehicle is different and how much less depends on more factors than one. And it's not super expensive to test. Build two or three boxes, that's just a couple sheets of wood for a couple of 12s.

I gotcha, thank you for the info I was definitely curious. So number chasing guys. They would have benefited from hugely peaked box at tuning I would think too I would think. But like you said, it would come at a cost.

N8, this is from pure curiosity on my part but I have a question. Is it with the higher powered systems where you've seen the too much port result in decreased output? Like 20K plus sub stage? Because I know that Real96SS got a little bump in output when he took a little port area out. But we are talking a lot 3 9Ks and 6 Team Fi subs in a 16V setup.

The calculator was shown to me by Bkolfo, whom I trust and is a knowledgeable guy. Its all based on stuff found I'm the Loudspeaker Cookbook. Small's formulas and such He runs quite a bit of port as well I believe and has had good results. Isn't he also an AA dealer?

But what determines TOO much port area? A TL, ears? I agree that less port area can be used since sound waves can't even fully generate in the vehicle cabin. Avoiding peaky response and mouse are the two biggest things. When you REALLY look at the purpose of the vented enclosure in general, the idea is not to BE flat responding if we want to get technical. Its to have a bump in output around tuning frequency and then to rollloff above and below tuning.

Also if you click the FORMULA, it will redirect you to the page where the hard formula is to actually do the calculation by hand. I've done it and it checks out.

There's your formula: http://www.carstereo.com/help/Articles.cfm?id=31 You can get away with less in a vehicle cabin but I try not to cut from the suggested minimum number TOO much. The 15" per foot is a rule of thumb for MOST drivers. However, port area isn't driven by how much airspace you have. A given sub, just for generic example an 18" sub, will need the same amount of of port if it's in a 5 cube as it would if it's in a 6 cube box. Desired tuning, Xmax, and cone area is what should be being used to determine port area.

I knew you weren't starting a war We are all good bro. I was just stating my approach to enclosure design in regards to port area. I think Xmax is an important factor in port area design. The part where it gets tricky is I'm not sure how accurate some of the company's Xmax figures are. Not DC specifically, but some I've seen that make me wonder.

I've built several using the port area formula that I suggest and I have yet to make a peaky enclosure. I realize CJ has specific knowledge of real world experience with the subs in question. I've heard the Level 4s on a DC 3.5K I'm the same vehicle with two very different enclosures. They were in a forum member's vehicle with equipment that Cody sold him. The first enclosure had like 36" of port and got loud at tuning but fell on its face above and below tuning. The second enclosure has around 80-90" of port and it's way more musical and not nearly as peaky. The rolloff is much less noticeable and it's got more range for sure. The system sounds better with the larger port area. Granted, the first enclosure was UNDER what Cody suggests, so maybe it's not a fair comparison. I have yet to have port noise in an installation and I have yet to make box that doesn't have good musical range. I know Brian, Bkolfo, HATES the port area per foot recommendations because a sub needs X amount of port regardless of what airspace it's in. Xmax, tuning and cone area are supposed to drive the port area for a drive to operate efficiently, according to Small and all collected in the Loudspeaker Cookbook by Vance Dickason. I know there is a difference between theory and application though and I've built enclosures with less that the "mimimum" recommended. I've still tried to stay close since I believe in the formula.

I recommend port just the same as Krakin. There are a few port calculators that really make it easy and they also offer the formula from Small as well. I use the same program that Krakin uses and it's also the one that Bkolfo uses. All from the Loudspeaker Cookbook. Two Level 4 12" subs are right at 85" using the same formula.And Krakin's suggestion was slightly under what the calculator suggests. It's actually 62.31"

That's 3X rated power, travel at your own risk. I know I personally wouldn't but that's me. Just set the gain to proper voltage to get RMS or slightly above after checking with DD1 or Oscope to find clip point.