Sealed box sounding bad. need some help.

[hdorre]

Would adding poly make it sub think its even in a LARGER box? I think hes losing some mechanical also. Why i bring that up.

resonance lowers, which is a characteristic of increasing box size. However, mechanical cone control doesnt seem to be affected at ALL.. not with my 15s on 3500 per when i messed with polyfill in my 4th... and not with the 12 18s build either.

He messaged me as well lol

[Kyblack76]

Would adding poly make it sub think its even in a LARGER box? I think hes losing some mechanical also. Why i bring that up.

resonance lowers, which is a characteristic of increasing box size. However, mechanical cone control doesnt seem to be affected at ALL.. not with my 15s on 3500 per when i messed with polyfill in my 4th... and not with the 12 18s build either.

He messaged me as well lol

take your freaky ass toes da fuck outta here .........

west side

hope your all doing well kid

[Amart88]

^^

LOL

Thanks all. I am going to head out and grab some polyfill and try that option before i mess with shrinking or anything.

[ShadeTreeMechanic]

Sealed boxes need lots of power as in it will be power hungry. When I ran 4 15s sealed at .5 ohm it would drop the voltage easier than the 2 15s ported at .5 ohm that I switched to.

[Triticum Agricolam]

QTS directly implies how good a driver is at being a transducer, turning power into linear movement. It's also VERY possible for two drivers in a sealed common chamber to be running out of phase, which is why i asked. I'm not talking about 180deg out of phase, i'm talking about a progressively going out of phase throughout the frequency and power range due to the standing and rearward waves hitting each other, essentially changing the suspension compliance of the driver. Every driver gets progressively out of phase throughout the frequency range unless you apply some form of correction filter device for it.

I don't see how polyfill is going the change the fact that it sounds muddy and out of phase since since the drivers are in their own chambers, all it's going to change is the speed of the rearward waves... but it's a cheap solution and everyone has some laying around, so no harm in trying it out.

Op, to me it sounds like you have one of the drivers wired backwards. I've corrected the same thing a dozen times and it sounds exactly like what you described. Let's hope that's it, because a 15 minute fix is obviously optimal.

Just how high of a QTC do you think this system has?

Yes, phase changes with frequency, but two identical subs in equal size enclosures are not going to have much phase change relative to each other. How far out of phase from each other do you think the are getting?

To the OP - could we get a picture of this box? Is it symmetrical, or are each side shaped significantly differently?

[Amart88]

QTS directly implies how good a driver is at being a transducer, turning power into linear movement. It's also VERY possible for two drivers in a sealed common chamber to be running out of phase, which is why i asked. I'm not talking about 180deg out of phase, i'm talking about a progressively going out of phase throughout the frequency and power range due to the standing and rearward waves hitting each other, essentially changing the suspension compliance of the driver. Every driver gets progressively out of phase throughout the frequency range unless you apply some form of correction filter device for it.

I don't see how polyfill is going the change the fact that it sounds muddy and out of phase since since the drivers are in their own chambers, all it's going to change is the speed of the rearward waves... but it's a cheap solution and everyone has some laying around, so no harm in trying it out.

Op, to me it sounds like you have one of the drivers wired backwards. I've corrected the same thing a dozen times and it sounds exactly like what you described. Let's hope that's it, because a 15 minute fix is obviously optimal.

Just how high of a QTC do you think this system has?

Yes, phase changes with frequency, but two identical subs in equal size enclosures are not going to have much phase change relative to each other. How far out of phase from each other do you think the are getting?

To the OP - could we get a picture of this box? Is it symmetrical, or are each side shaped significantly differently?

It is for the most part symmetrical except for one notch. I moved the divider over = amount of airspace to compensate. Also on the finished box, there are some protrusions on the top of each side for the magnets. they are of = size also. From what i have researched, my QTC is 0.448 right now. if i shrink it will go up and if i enlarge it will go down. i think.

EDIT: also, to put it to rest, im going to pop test both woofers and trace back to amp to make 110% sure "again" that they are wired correct.

[Amart88]

UPDATE: Upon further inspection, i have found a small leak on one side. also need to seal the gaskets. Will address the leak first. Has the florescent light on in the garage. the buzzing hid the air when i pushed on the dust caps.

[Amart88]

Ok, another Update!

Sealed all the gaskets and pinhole leak. along with the whole inside. Pop tested and traced all wires back. everything is in order. I added polyfill this morning. Plays a bit louder lower. But still after 1/3 volume on the pac it sounds distorted. especially on the lower frequencies. I love the sound, just with i could play louder cleanly. I have heard from a few guys on here, that they could be losing cone control on the low end. so I am going to try shrinking the box volume to raise the qtc. See if that helps. if that don't work, im lost.

[reedal]

since you're down firing and the distance between the cone and floor is not very much, could there be a back-pressure returning and causing a force against the direction the cone is traveling?

[Amart88]

since you're down firing and the distance between the cone and floor is not very much, could there be a back-pressure returning and causing a force against the direction the cone is traveling?

Maybe, but i have been testing with he box sat upright for convenience. with the seat up and woofers facing rear. it sounded the same when face down though.