# Sealed box too big??



## the_dealer (Apr 18, 2013)

Hey guys, I sold my old kicker l3 10" to my buddy. We built a 1.7 cuft sealed box before displacement of the sub. He's running 400 watts to it. Vehicle is a regular cab Silverado. with the windows up the thing slams. Plays lows like a boss. It really surprised me for a sealed box. The problem is when the windows are rolled down it distorts and barely has any output. Just cracking the window you can immediately tell a difference, and with them all the way down it sounds like ****. He has to turn his sub level down so far you can barely hear the damn thing. Did we make the box too big? Kicker calls for .8 cuft compact, 3 cuft sq. I was under the assumption that it could be anywhere in between. it also doesn't really play the punch notes in rock or country, but plays the lows good(with windows up). We sat my box in his seat just to rule out cabin gain and mine stayed got louder with the windows down. Hell this sub had more output in the 1cuft ported box that I had it in. What could be going on here? 

We were originally planning on a 4" port for it, but he wanted to try it sealed(that's the reason for the box being so big). His a/c doesn't work so windows down is a must. What do yall think? I'm still a newbie when it comes to box building


----------



## AdamClark (Sep 8, 2013)

sounds like the box tuning is way off.. when the windows are down the resonant freq. of the vehicle changes.. .8 to 3 cube is a huge variance in size... it seems like 1.7 before displacement would work very well.. does the sound change when the vehicle is sitting still just by rolling down the window? or does it only change when the trucks in motion?


----------



## qwertydude (Dec 22, 2008)

If you run bigger sealed boxes power handling, especially for the lows, can be significantly reduced.

As far as playing punchy notes they don't tend to play punchy because of lower motor strength combined with a heavy cone assembly.

One thing that may be happening it is distorting but you don't hear it because of cabin gain. Opening the windows may be reducing the cabin gain so you really hear just how the subwoofers are straining. And simply putting a subwoofer in the front seat doesn't simulate what's happening with the standing waves which could be building up. Truck cabins are incredibly tricky to get to sound right and simple changes in subwoofer or head position or even opening the windows can affect the sound. But if you're hearing distortion when the window's opened, I can guarantee you it's there when it's closed and you likely aren't hearing it. Best way to hear if there's distortion, take the subwoofer out of the car completely and run it. If you hear distortion you're overdriving it.

Funny thing about running small boxes is you get ringing which is why it's likely the smaller box sounded better. The ringing is hiding the distortion from running the subwoofer past it's linear xmax.

I say this because the L3's are pretty poor performing subwoofers. The L5's only have 12.9 mm Xmax, they don't even list the Xmax for the L3's, likely cause it's embarassingly low maybe 8mm if you're lucky. So by running larger than recommended sealed boxes but maintaining the same maximum power you're forcing the subs into overexcursion and simply don't hear it with the windows up.

One thing though about Kickers, they always require some ridiculously gigantic boxes to run ported. They'll have tremendous one note boomy output though so that's what makes them popular with the Best Buy crowd.

But running sealed they simply don't have the Xmax to have decent SQ and output.

The above problems just tend to make the Kicker square subs not very popular on an SQ oriented site like this.


----------



## the_dealer (Apr 18, 2013)

The distortion is there stopped or moving with the windows down. We put it in the 1cuft ported truck box that I had and it didn't happen. Rolling the windows down actually made it louder and sound better. When re ran the wire outside the truck with everything the same, the ported box didn't distort like the sealed. Actually it didn't take hardly any volume to make the sealed distort. He has his gain down and his remote boost almost all the way down. With the ported box outside the truck, he was able to turn the volume up about 3/4 of the way before distortion. Sealed box not even half way up.


----------



## BuickGN (May 29, 2009)

qwertydude said:


> If you run bigger sealed boxes power handling, especially for the lows, can be significantly reduced.
> 
> As far as playing punchy notes they don't tend to play punchy because of lower motor strength combined with a heavy cone assembly.
> 
> ...


I agree. Just a quick note, the lower power handling on the low end is because efficiency is increased. Maybe running a subsonic filter would clarify the problem. Does this amp have a subsonic filter?


----------



## qwertydude (Dec 22, 2008)

> The distortion is there stopped or moving with the windows down. We put it in the 1cuft ported truck box that I had and it didn't happen. Rolling the windows down actually made it louder and sound better. When re ran the wire outside the truck with everything the same, the ported box didn't distort like the sealed. Actually it didn't take hardly any volume to make the sealed distort. He has his gain down and his remote boost almost all the way down. With the ported box outside the truck, he was able to turn the volume up about 3/4 of the way before distortion. Sealed box not even half way up.


Those above listed symptoms are exactly the signs of an overdriven sealed subwoofer.

The reason the ported sounded cleaner is the increased damping the ported box adds prevents overexcursion. Thus the subwoofer stays within its linear range and most of the output comes from the port.

So you can pretty much surmise that the L3 even though you can run it sealed, just doesn't do to well sealed because of limited Xmax.


----------



## the_dealer (Apr 18, 2013)

Hmm, so I guess we are going to try ported with it like we planed. Should be right there between the reccomended 1.25-1.75 cuft. I had this sub in the kicker ported truck box. A little over 1 cu ft with unknown tuning. Now I had this running off 350 clean watts in a soft top jeep. Even without the top it had more output then his sealed does.(with everything turned down where its not distorting

Edit: I was thinking it was because the box is too big. With the windows up is creates pressure pushing the sub?? It seems backwards, usually in trucks you hear the distortion with the windows up, but not with them down. We also blocked off the port in the prefab box to make it sealed, and still had the same results. The 1cuft of the prefab box doesn't include port displacement or sub displacement, so I'm guessing its right around .85 sealed off. No sound difference after sealing the prefab besides it didn't hit the lows good. It gave it more punch. I'm thinking as already stated, its just not good In a bigger sealed box. my buddy listens to alot of gangsta rap and alot of lil John esb. He likes the way it sounds with the windows up lol.


----------



## the_dealer (Apr 18, 2013)

And yes, his amp has a subsonic filter, but it might be a boost? Are they the same thing? I want to say it's 10hz-40. He has it set on 10hz. He also has the low pass filter on 400hz, but the lpf on his hu @80hz.


----------



## sqshoestring (Jun 19, 2007)

Try it at 30hz should handle more power that way. Experiment, it will take away the lowest bass but let you lean on it harder. There is not that much sound under 30hz anyway a lot of boxes are tuned to play above that. He might like it higher or lower, but lower it will puke on you faster when you dial it up. Note this does not change the tuning of your box it just cuts out the lowest frequency that takes the most power and makes the most xmax in the sub.

Some SQ people here like me prefer not to run a SS to get those low frequency though I have run 10-15hz SS, but its all personal taste as well as dealing with the equipment you have on hand. Once I put a pair of 15s in IB getting lots of 30hz became much easier. It you don't have the equipment you have to take what you can get.

If you do a ported you will want to set the SS at your tuning or just under. Ported it will unload under tuning and the sub will start to move a lot. If you don't know play a sine sweep on it loud enough to make the sub move at low tones, as it drops it will move a lot at real low bass. Turn the SS up until it does not change much as low bass comes in.


----------



## BuickGN (May 29, 2009)

the_dealer said:


> And yes, his amp has a subsonic filter, but it might be a boost? Are they the same thing? I want to say it's 10hz-40. He has it set on 10hz. He also has the low pass filter on 400hz, but the lpf on his hu @80hz.


That's probably a subsonic. If its being boosted at 10hz, you found your problem. Once you confirm if its a subsonic filter or not, try setting it to 30 or 40hz (40 would be better) and see if the problem goes away or gets better. It should say subsonic or highpass on it. Porting is probably the answer but setting the subsonic is free and it will help understand what's wrong with the setup.


----------



## the_dealer (Apr 18, 2013)

Aight, we will try that tomorrow. We were going to port it anyways with 4" PVC and the port entry roundover'd with a router. He just wanted to try it sealed because he thought it would have better sq, but still hit the lows in the bigger box. That's why we did it at 1.7 cuft, because it was going to be ported. But his thing was if he could get it to sound right sealed we'd leave it. I'm starting to think the square subs don't like large sealed boxes. With the bass down so it's distortion free, you can't even tell there's a sub in there. I can't imagine how ****ty it would sound in kickers reccomended "sq" box of 3cuft.


----------



## BuickGN (May 29, 2009)

It's not the large box.


----------



## the_dealer (Apr 18, 2013)

well we dicked around with the subsonic filter(which was in fact a filter), its set about 35hz. The low end isn't as hard. It didn't effect anything. Guess we are going to port it as planned. With it turned down so it doesn't distort with the windows down, you can barely tell there's even a sub in it. Hell it was louder in my jeep with no top and the prefab box sealed off. We also tried my amp in there. 

NOw i wish i sold the kicker to someone i didn't know. Thank god I'm running sundown in my **** and don't have to worry


----------



## minbari (Mar 3, 2011)

qwertydude said:


> If you run bigger sealed boxes power handling, especially for the lows, can be significantly reduced.
> 
> As far as playing punchy notes they don't tend to play punchy because of lower motor strength combined with a heavy cone assembly.
> 
> ...



this! ^^^

sealed and low xmax do not mix well. with a sealed box the only way you get more output is with more cone movement. when you have low xmax, you will not get alot of output.

one of the best sounding subs I ever had was made by kicker. the old Blues BL10. it had xmax of 7mm and a pair of them on 180watts total would do 132db in a 5cuft ported box. in a sealed box, they bottomed out like crazy.


----------



## the_dealer (Apr 18, 2013)

Does anyone know the displacement of the l3 10"? We are about to cut the port to length and we want to make sure it's tuned between 33-35hz


----------

