Focal sub installed

Bwcad1 · Post by **Bwcad1** » Tue Apr 29, 2008 9:03 am

Deffinatly not enough port your basically using a sealed box. you have like 10sqin of port area that's bad news. welcome to the joys of box design. remember just because your tuning works out doesnt mean its right. you need to make your port bigger and increase the length of your port to get a proper design and you will get proper output.

tomcat · Post by **tomcat** » Fri May 02, 2008 3:12 am

How much port area do I need then? If not WinISD then how do I caculate it?

tomcat · Post by **tomcat** » Thu May 08, 2008 4:09 am

I'm still not sure that if its tuned to low or that the port is bis enough. I used WinISD to calculate it.

But now that I have had time to tune it in it sounds great, and its really loud. I may have been a little impatient in my initial reaction. I just needed some time to get used to the SQ of this sub. Now I realize that my old sub didn't sound as great as I thought it did.

If I can get it better with a bigger port I'm all ears. Just tell me how big and/or how to calculate it better.

Bwcad1 · Post by **Bwcad1** » Thu May 08, 2008 4:15 am

let me put it this way

THE PORT IS WAY WAY WAY WAY WAY WAY WAY TO SMALL

winisd doesnt take into account port volume or velocity. and your tuning is not that low.

id reccomend making your port 4 times bigger than that. if i were you i would just order a 4 inch precision port from http://www.thrilleraudio.com/detail.aspx?ID=43 take about an inch off the overall length and install it.

what is the fs of that sub?

tomcat · Post by **tomcat** » Thu May 08, 2008 4:38 am

Fs is 25.25

So just add the 4" port to whats already there? I can make the slot bigger, its 1" x 14.5" x 17.25" right now. Adding the round port would be easier though.

Bwcad1 · Post by **Bwcad1** » Thu May 08, 2008 4:50 am

you should probably just build a new box. besides practice is good for you

tomcat · Post by **tomcat** » Thu May 08, 2008 5:00 am

Airspace and port size recomendations? I'll fire up the saw and charge the batteries for my drill.

I also have to build two boxs for some cadence TXW10-4s'.

Bwcad1 · Post by **Bwcad1** » Thu May 08, 2008 5:20 am

same as before and use the round port. or make it 40sqin

solacedagony · Post by **solacedagony** » Thu May 08, 2008 6:28 am

Not thread jacking here, just wondering on port volume. Port volume will have an effect on frequencies outputted through the port.

But is this one of those things where there is diminishing returns? Continue making the port bigger and you hit a max output through the port? Or does output continue to increase as you increase port volume?

/jack

tomcat · Post by **tomcat** » Thu May 08, 2008 7:17 am

I may be over thinking this but a 4" round port has an area of 12.5664 sq. inches. A slot port with 40 sq. inches is 3 times bigger. So how the air travels though a round port compared to a slot makes that much differance? How big would a square port have to be, some were in the middle?