Some sealed boxes do infact respond better with an open port, however no guarantee that one would. Could the resonance be caused by something not tight, such as a crossover or wires striking the inside of the box?.<br><br> You say it is sealed but can you open it?<br><br> Stuffing it with fiberglass insulation also can make a difference. I have worked with both open and sealed boxes and there are so many variables it is hard to say what could be causing yours to do what it is. Might just come down to the material the box is made from, resonating at a particular frequency.<br><br> Not much help I know but maybe I gave you a different direction to look anyway.

 

I own a car audio shop and would need some more info before making any suggestions. You could make you box better or worse with a port, but you can try this. We tune custom boxes this way. If you want to port it get a piece if PVC pipe. About 12&quot; long and about 3-4&quot; in diameter then move the pipe in and out of the box so the lengh in the boc changes this will tune it to the best sound then cut it off at the best sounding length. Leather also makes a huge difference in how a sub will perofrm. I currently run 2 12's under the rear bench in a custom box with no port I prefer the sound of a non ported box.

 

Something ain't right. I have a 10 inch DVC bandpass on the back seat powered by both channels from a 300 watt Crossfire. No resonance at all. It has a three inch port in the back and is about 8 to 10 inches away from the right rear door. Very clear and lots of base. The air coming out of the port will just about blow your glasses off when it is cranking. <br><br>Is it a noise from something in the truck or the speaker?<br><br>Jamie hit it right, need more info.

 

[move] It's probably just the LOOSE NUT behind the wheel..!!! [/move]

 

your crossover is set wayyy to high IMO, try for 60-80hz .........<br><br>chances are the woofer is resonating at higher frequencies (something a bandpass box wouldn't have trouble with since the box filters out the higher frequencies)<br><br>try turning down the crossover point first........<br><br>there's a lot more to tuning a box then just cutting a hole, port volume tunes the box to certain frequencies ........<br><br>give me the woofer model number, and your box volume and I'll see what I can find for you

 

I just read your last post again, did you ay you can feel air coming from around the speaker when you play it, <br><br>if so this is your problem leaky boxes will resonate like crazy.........seal it up, it has to be leak free ...........

 

dodgeram hit it right. The speaker needs to be sealed and you need to make sure you have enough volume in the box for the size speaker you have. There are places on line you can go to check that and I think that is what dodgeram has in mind if I read right.

 

If the speaker is buzzing and the buz goes away when u place ur hand/finger on the speaker surface or butel edge(preventing movement) the speaker may be blown. The magnet may not be big enough, the dampening factory of ur amp may be to small allowing the speaker to move to much. By completely sealing the case and the speaker in u will help the speaker to move less this may help ur problem. <br><br>Dan<br>some speaker info. Speaker are designed for a specific purpose besides being made to deliver certain frequecies they are design for specific size and type of enclosures. Power capacity and SPL are important when chosing a speaker. A key point to remember is it take twice the power to deliver 3 more DB at a specific SPL(sound pressure level)<br><br>Hope this helps

 

Several things:<br><br>1) If you are feeling air come out of the box this is a bad thing. Sealed boxed are supposed to be SEALED. You can take the sub out and put down some weather stripping around the edge of the hole, most of the time that will stop a lead around the sub itself. If it is you box leaking you can use silicone sealant or liquid nails on the inside of the box to fill in the leak.(note: if using silicone let it cure over night or it can damage any rubber on the sub.<br><br>2)Going from sealed to ported USUALLY is a bad thing using the same box. Subs need a certain amount of internal air space to funtion properly in a sealed box and normally a different internal volume (larger volume) for ported boxes. Ported boxes are almost always louder than a sealed box but you sacrifice Sound Quality. Though with some of the newer subs out you can achieve great SQ while still reaching high SPL (hard hittin' smack ya in the head bass)<br><br>3)Several things can cause a buzz. If it's more of a whine sound and it changes when you give the truck a little throttle then that is whats called alternator whine. 9 out of 10 times that is caused by a bad ground. RCA's can also cause a buzz or a whine if they are ran on or near power wire. But to start with make sure you have a good BARE METAL ground and go from there. <br><br>Hopefully that will get you started. I use to do this part time in college and still do installs for friends aswell as myself. If you have any questions let me know