Subs

[snyper1982]

like the poster above me said... it depends on how you design the box. to make a truly effective ported box, the box would be HUGE... this is not really possible in many cars trunks.

1.5cu/ft compared to the 1.25 cu/ft of the sealed. 3 cu/in. Doesnt seem all that much bigger to me. You CAN get good good sound from a ported box, with the right design, most people just dont know HOW to design a box properly. Ported boxes are just better than the sealed IMO. There are downsides like everything though, harder to build, a little bigger etc.

 

[remmargorp]

I'm not arguing for the sake of proving a point. I am adding on (so that others that read this can know).

It also depends on the driver going into the box that determines how long it will/can go in a given application.

Take a speaker with a low Qts (general rule of thumb is 0.4 or less) and it will perform better in a ported box. Now take a speaker with a middle range Qts (0.4 to 0.7) and it will perform better in a sealed (which includes going lower than in a ported more efficiently).


Also, WinISD is only good for a computer representation of how a box/subwoofer will perform (however not in car, it would be impossible for any program to tell you how it would perform in any given car). Until you use a spectrum analyzer along with an RTA in car and find out how low that speaker is going in your ported box (and how flat the response is), I would not simply state ported is better (or will get lower) (however you did say it was your opinion, which you have the right to state).

I happen to own quite a few testing instruments that I get to use for car audio and like I said in my previous post, for the majority of in-car applications, sealed will allow the driver to extend lower than in a ported enclosure (it will also do it more efficiently).

 

[remmargorp]

1.5cu/ft compared to the 1.25 cu/ft of the sealed. 3 cu/in. Doesnt seem all that much bigger to me.

Not sure how you came to a 3 cubic in difference.

1728 cubic inches to a cubic foot

1.5 cu/ft = 2592 cu/in
1.25 cu/ft = 2160 cu/in

the difference is 432 cubic inches. Still however, not big (when it comes to trunk space), I just wanted to ensure that the numbers were correct (for anyone reading the post to gather information).

 

[snyper1982]

Not sure how you came to a 3 cubic in difference.

1728 cubic inches to a cubic foot

1.5 cu/ft = 2592 cu/in
1.25 cu/ft = 2160 cu/in

the difference is 432 cubic inches. Still however, not big (when it comes to trunk space), I just wanted to ensure that the numbers were correct (for anyone reading the post to gather information).

Haha, yeah. Don't know what the hell was going through my mind at that moment. I am speaking from personal experience when I say that the subs sound better in a ported box, maybe it is the fact I use higher quality subs(w7's) I don't know.

Also you don't HAVE to have an RTA to determine which one will go lower. All you need is an SPL meter and a test cd with 30hz, 45hz, and say 60hz. I know it won't be as accurate, but it should suffice for what we are needing it for here. An RTA is invaluable for setting up your system though. Just out of curiosity, what RTA are you using? I was looking at getting the TruAudio software. Hear anything about it before?
PS
I am not arguing either, and I am glad we can keep this disagreement civil, and help others out while we are at it.

 

[Trucloner11]

You just need to make sure however big they are that you have an amp to push um...remember sometimes not enough watts is much worse than to many.

 

[snyper1982]

You just need to make sure however big they are that you have an amp to push um...remember sometimes not enough watts is much worse than to many.

Please explain that statement.... I hope you are meaning sound wise, and not saying that having to little power will damage components.

 

[neilb]

<<<agrees with ^^^

I don't understand where the idea that having lower power is bad for components came from, but it is doing the rounds. People seem to forget that turning the volume down reduces the immediate output of the amp.

As for a ported box gong lower than sealed, those must have been real bad sealed boxes you used.
From what I emember (and generalisation) a ported box is (almost) a sealed box at frequencies above the tuned frequency of the port as those frequencies can't get out. Below the frequency of the port the sub is almost unloaded and can lose control at high outputs (but gives you your 3dB) and the slope really drops off, the sealed box retains control and has a more gradual reductin in SPL below the speakers rf (res freq).

The effect of the small space in a car appears to increases the output at low frequencies which helps the sealed box some more.

Personally, I prefer sealed. I apologise for any glaring inaccuracies in this post (it's been a long time since I really kne this stuff) and am willing to be put right.

 

[snyper1982]

I did say that it has been my experience that it was that way. I posted a graph(albeit a simulation) showing it. The frequency in which they match up is well below 30hz, and the they are both droped off so far that in practical use, you will most likely never here those frequencies anyways. Like I stated before, maybe it is due to the speakers I have used, I cannot be certain.

BTW both boxes are built to Manu. Specs, so I am also assuming they know what they are talking about. I am in the process of getting an RTA, so I will be sure to test this out in a real world application.

No worries, all your info seems spot on. As with anything, take it with a grain of salt, and try it out yourself. Sound is so subjective there is no right or wrong answer.