Sub pointing

[zerocover]

I have a fosgate sub in a 2 cu ft. ported box.
Now I know alot of people say it doesnt matter which way the sub is pointing but this thing is ported.

Whats the general consencous around here as to which way to point it? We were playing with a friend of mines ported pc sub and were amazed as to how much better it sounds when the port faces you instead of the speaker faceing you.

I also stuffed the box with pollyfill it gave the sound a much nicer rounded off tone to it. Opposed to haveing everyone complain of headaces in the car. I was thinking about pulling it out so the port can do its job better. Opinions

[MD323]

I have a fosgate sub in a 2 cu ft. ported box.
Now I know alot of people say it doesnt matter which way the sub is pointing but this thing is ported.

Whats the general consencous around here as to which way to point it? We were playing with a friend of mines ported pc sub and were amazed as to how much better it sounds when the port faces you instead of the speaker faceing you.

I also stuffed the box with pollyfill it gave the sound a much nicer rounded off tone to it. Opposed to haveing everyone complain of headaces in the car. I was thinking about pulling it out so the port can do its job better. Opinions

if your mounting it in your trunk, point it towards the rear of the car(the sub itself) this will give you the best restults and avoid what is called cancelation,MTX's web site is very informative along with car audio mag, ( subscribed to by me 3 years running)

[blue LEDz]

with most sub systems in cars, if you pointed it towards the front of the car you would lose about 3 dB due to reflected sound wave cancellations. here's a good write up about it:

http://www.installer.com/tech/aiming.html

course a lot of it has to do with the frequency played, which is even more of a concern when dealing with ported enclosures. around the tuning freq, nearly all the sound comes from the port, not the sub. in general it's best to have the sub and the port facing the same direction, however, i've seen and also build some that sound great with the port 90 degrees off from the sub. but in pretty much every system except extreme vehicles, point the sub(s) and port(s) to the rear or 90 degrees off that. subs facing up and ports facing back works quite well.

as for the stuffing, that's one thing that is hit or miss. sometimes it works well, sometimes it doesn't. it doesn't hurt to try, just make sure you keep it away from the port. i usually just staple some polyfil to the walls. i've seen people use chicken wire to hold it down. other people use regular home insulation stapled to the walls. i don't recomend fiberglass insulation because the particles could possibly get in the subs motor and cause damage.

[zerocover]

The box is really too dam huge I find I get the best sound iff the sub is pointed back and the port is to the side.

All the other times everything sounds way too boomy, and gives me headaces. I think its tuned too high, even though it should be at some 34hz. Perhaps taking out some polyfill would help.

[blue LEDz]

what are the internal dimensions of the enclosure? what is the port size and length?

[zerocover]

2"x15.5" front with a dept of 14 at the bottom and 9 at the top. Err this is outside so just subtract the 3/4" mdf.

The port is around a foot im not to sure on that. I remember tunning it to 33-34 hz though. 4" port.

[blue LEDz]

i'm guessing that was supposed to be 20"x15.5"? if so, you've got about 1.6 cu ft before subtracting sub and port displacement.

[zerocover]

My bad 28" x 15.5" in front. The bitch is just too wide.

Eventually I hope to just pull out the small top part of the rear seat and plop a 15" in there. Possibly with some kind of plastic covering so people can sit there in a pinch. No more boomy ported boxes for me even though mine seems to hit lower then any other set up ive heard. People around here blow, I need someone to teach me the path.

[DeanSweetP5]

corner loading is your friend... point them towards the back of the car.

-Dean

[zerocover]

I have the port to the passangers side and the sub pointing back now. NIce sound but its alot quieter then ever. At least its not boomy anymore.

[blue LEDz]

so you are working with more like 2.47 cu ft before sub and port displacement? got the specs on the port yet?

[zerocover]

13" is the port length
0.042cuft is the speaker displacement

[blue LEDz]

13" is the port length
0.042cuft is the speaker displacement

well you should be peaking at about 34 hz. are you using any bass boost?

[zerocover]

Nothing at all, the origional idea was to have the sub hit nice and low so the speakers didn't have to. The sub was designed so I could save the speakers the need to be pushed too low, Ive shreaded my fair share.

All the bass boost stuff is turned off. Its strange becuase some songs seem to hit really hard like they rattle you down to your bones but others it wouldn't matter iff I had no sub at all.
Where should I have the sub highpassed to? its at 90hz now. I was thinking of droping that though, even lower.

[blue LEDz]

you should have a subsonic/infrasonic filter on the sub around 20-22 hz and a low pass somewhere between 50-80 hz. everything else should be high passed between 60-100 hz. start with the sub low passed at 50 hz and everything else high passed at 100 hz, then slowly increase the low pass on the sub until it blends well with the other speakers.