I need help building a port for a woofer box!

[HassanZia]

Hey!
I have a 8" 50W woofer with 8ohm impedance n i've build a box with 17.6" height, 13.5" width and 13" base. I used chipboard of 2cm thickness. I wanna know the port size. Currently I've made a port of 1" height and 1.2" gap from the back. It's not L port just one piece of 10.7" x 11.7". I'm not satisfied with it coz it doesn't sounds good n no air comes out either but when i remove the tweeter, that hole of 2.5" diameter act as a good port but i dnt want round port i want square port as i build.
If sm1 can help me with this plz pvt me or reply here coz im new to this site n dnt know around.
Plz I really need help!

Peace!

 

[weltersys]

This site would help to find out what your box is tuned to:
Speaker Enclosure Volume Calculator

In general, tuning the box (Fb) below the driver's Fs won't give much output.
I don't understand your port description, but it sounds like it may just be tuned too low for the speaker.

Without speaker parameters, hard to give any more useful advice.

 

[GM]

The numbers do not quite work out, but it appears the cab is tuned to around 43 Hz, so I'm guessing that either there is a leak to keep the vent from working and/or the driver has a much higher Fs.

GM

 

[HassanZia]

Hmmm

Thanks u both it was actually a quite help
As im new to this stuff. I just made that square port without any research so when I used the tweeter hole as a port it went like it was ment to be. I dnt like round ports but I guess I have no solution left....
The website u gave me said port length = 6.064 n dia = 2.216

 

[mdocod]

More than likely when you use the tweeter hole as a port, you are getting a very hefty spike in the upper bass range. Some would call that a one-note-wonder sort of build. Typical of many car sub designs.

I come up with ~45hz tuning... Whether or not your driver will work with that box size and tuning frequency well is entirely unknown without more details about the driver.

Do you know what driver this is? T/S parameters?

 

[ODougbo]

If you can find out more info on the driver that would be the best, if not take some pics.

A 8" car woofer can work in a really small box.

I'm a fan of 8" woofers, car and HT. I was on a roll for a while, cranked out a bunch of them. The tall black one has been sitting around for a while now, never used.

 

[HassanZia]

OK

Here is the picture but all I know is its 8" 50W and 8ohm...

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

 

[ODougbo]

My two cents:

If you want to get the most out that woofer, make a adapter and mount it to the car's speaker deck, e.g. one of the 6" x 9" hole(s). The trunk will be cabinet.

 

[GM]

With no specs, a large sealed cab as suggested is your best option, though you can try and get the specs or at least some box design suggestions from the manufacturer: info@styline.org

GM

 

[HassanZia]

I've mailed em @GM but they haven't replied dnt know y.....

 

[mdocod]

I'm going to guess it's one of those units with so little dampening that having the characteristics won't do you any good. Except to find out that you'd be better off mounting it on the side of a barn.

 

[head_unit]

I've mailed em @GM but they haven't replied dnt know y.....

Hi Hassan, they probably don't know and/or don't care. As a speaker engineer, I can look at that thing and tell you it is very inexpensive and therefore almost certainly has a high Q. That doesn't necessarily mean it will sound bad, but such speakers usually want a big cabinet as noted before.

1.5 cubic feet is not tiny for an 8" so it is surprising to me you get no vent output. But it is hard to do more without impedance data. Do you have any electronic equipment that might be usable to make an impedance curve?

Pictures of your box might help us.

 

[HassanZia]

Hi Hassan, they probably don't know and/or don't care. As a speaker engineer, I can look at that thing and tell you it is very inexpensive and therefore almost certainly has a high Q. That doesn't necessarily mean it will sound bad, but such speakers usually want a big cabinet as noted before.

1.5 cubic feet is not tiny for an 8" so it is surprising to me you get no vent output. But it is hard to do more without impedance data. Do you have any electronic equipment that might be usable to make an impedance curve?

Pictures of your box might help us.

Yeah they ain't so hi-fi and are old ma frnd gave it to me n I thought it might make a good speaker for my room. And here are the pix of the box. The pvc pipe is temporary i just inserted it to check if the hole for the tweeter makes a good port.....
I'll put rexine or sm other cloth. The box really looks horrible....

An externally hosted image should be here but it was not working when we last tested it.