New box, over double the port area, sounds the same :/

[Triticum Agricolam]

I want to ask this first, it still is, the larger the more port area, the more output you will have and in turn have less bandwidth. As well you can do the inverse with less port area? Because if so it is the perfect bandwidth currently, don't want to make it any less.

Well when I was asking about that, I meant in the aspect. A new box will be built, not modifying the current to change it. To what you said, I think the only thing that could help this, is to make the box bigger, because as the first sentence asked, if that is true. I do not want to have any less of a bandwidth to it.

So port area, under normal conditions, should have no effect on bandwidth. This is a car audio urban legend I wish would go away. If your port area is sufficient, making it larger won't change a thing. The only time where port area will effect bandwidth would be if you had a box that had peaky output, if you purposefully undersized the port it would reduce output around tuning (due to port compression) and make the box less peaky, resulting in larger bandwidth. This would be a terrible solution to the problem of a peaky box though, since it would only work when at max output where port velocity is highest and it would be shooting yourself in the foot in terms of max output. It would be like purposefully undersizing the exhaust system on your car because you keep breaking the tires loose in first gear.

What effects bandwidth is box size and tuning. If you make the box bigger you will increase output around tuning and decrease bandwidth. Bandwidth is a relative measurement, its how loud the box gets at one frequency relative to how loud it gets everywhere else. When it comes to usable bandwidth, just how big of a variation in output someone is willing to tolerate is up to each person to decide. For the sake of the discussion lets say you want to keep everything within plus or minus 3 db, so that gives a 6 db window of usable bandwidth. If your box peaks around tuning your usable bandwidth is going to be the point above and below tuning where output is 6 db down from that peak. If you make the box bigger its going to increase output around tuning, but won't increase output much anywhere else, since your peak went up, the frequency above and below tuning where output is 6 db down from that peak is going to get closer together, thus your effective bandwidth is less. The opposite happens if you make the box smaller, everything is a trade off.

[RooTxBeeR]

I want to ask this first, it still is, the larger the more port area, the more output you will have and in turn have less bandwidth. As well you can do the inverse with less port area? Because if so it is the perfect bandwidth currently, don't want to make it any less.

Well when I was asking about that, I meant in the aspect. A new box will be built, not modifying the current to change it. To what you said, I think the only thing that could help this, is to make the box bigger, because as the first sentence asked, if that is true. I do not want to have any less of a bandwidth to it.

So port area, under normal conditions, should have no effect on bandwidth. This is a car audio urban legend I wish would go away. If your port area is sufficient, making it larger won't change a thing. The only time where port area will effect bandwidth would be if you had a box that had peaky output, if you purposefully undersized the port it would reduce output around tuning (due to port compression) and make the box less peaky, resulting in larger bandwidth. This would be a terrible solution to the problem of a peaky box though, since it would only work when at max output where port velocity is highest and it would be shooting yourself in the foot in terms of max output. It would be like purposefully undersizing the exhaust system on your car because you keep breaking the tires loose in first gear.

What effects bandwidth is box size and tuning. If you make the box bigger you will increase output around tuning and decrease bandwidth. Bandwidth is a relative measurement, its how loud the box gets at one frequency relative to how loud it gets everywhere else. When it comes to usable bandwidth, just how big of a variation in output someone is willing to tolerate is up to each person to decide. For the sake of the discussion lets say you want to keep everything within plus or minus 3 db, so that gives a 6 db window of usable bandwidth. If your box peaks around tuning your usable bandwidth is going to be the point above and below tuning where output is 6 db down from that peak. If you make the box bigger its going to increase output around tuning, but won't increase output much anywhere else, since your peak went up, the frequency above and below tuning where output is 6 db down from that peak is going to get closer together, thus your effective bandwidth is less. The opposite happens if you make the box smaller, everything is a trade off.

What fucking books do you suggest damnit?! That is so completely nuts than what I have been thinking.

[Triticum Agricolam]

What fucking books do you suggest damnit?! That is so completely nuts than what I have been thinking.

Lol, yeah. As far as book go, this one is what a lot of folks say to get, though I haven't read it myself: https://www.parts-express.com/speaker-building-201-book--500-044

[Joe X]

This one is pretty nice, not too much math:

http://www.amazon.com/Loudspeaker-Design-Cookbook-Vance-Dickason/dp/1882580109

It even includes some infos on car audio applications towards the end.

[ckeeler11]

So would you say if I would want to attempt to make it as loud as possible, what aspect of the box should I go with first? I would think try to shrink the box a little bit and increase the port area. Am I right there?

Its hard to give you a straight answer because it depends on what the limiting factor of the system is now, and everything is a trade off.

So when it comes to port area there really are only two kinds of ports, those that detrimentally restrict airflow, and those that don't. Obviously you want your port to be in the second category. Once it's big enough to not restrict airflow, making it any bigger won't have any effect other than to take up more space. So the trick is making sure you have enough port area to not restrict airflow, but not make it so big it wastes box space. If your port is bigger than it needs to be, shrinking it down so you could gain more box volume could be beneficial, but only if you gain box volume by doing so. If your port is too small, port compression can REALLY kill output, so making the port bigger at the expense of box volume would probably gain you some output, sounds like you have plenty of port area though.

As far as box size goes, the bigger you make the box, the more efficient it will be around the tuning frequency and the more output you will get. The trade off here is as you make the box bigger your cone excursion goes up, so you have to be careful with that. Also group delay goes up and the frequency response becomes more peaky, both of which negatively affect sound quality, which may or may not be important to you. As far as box size, output, and cone excursion go, let say you have two boxes, one is 3 cubes and the other is 5 cubes, both are tuned to 35 hz. With the 3 cube box you can hypothetically put 2K watts to it before you run out of excursion, the 5 cube box you can only put 1700 watts before excursion gets too high. The 5 cube box will get louder around tuning on 1700 watts than the 3 cube box will on 2k (at least in theory). Also the 5 cube box will be easier on your amp since it will have slightly higher impedance. However the 3 cube box will sound better and as you get away from the tuning frequency they are both going to have about the same output.

My recommendation would be if you haven't adjusted his gain overlap from 0 to -5 or so, you should do that first. -5 should still be a pretty safe level and will result is almost 4 times as much power going to the sub than a 0 setting would. Things like making the box volume bigger will increase output, but its not going to be by much. You would never hear the difference between a 4 cube and a 4.5 cube box for example.

Very informative post thank you.

[RooTxBeeR]

Thanks for the replies, triticum, I'm going to pick your brain and and just copy paste your responses to a word document lol