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View Full Version : What will happen if I stick a subwoofer in a\ smaller box then reccomended?



hitman34608
06-24-2010, 08:03 PM
Well Foolishly years ago I bought to big of a subwoofer 18 inch RE SX I no please spare me I learned my lesson. What I was wondering is subwoofer requires a 8 cubic feet box and I really don't have the money or resources to build that big of a box what would happen if I stuck it in a box smaller then 8 cubic inches? Only reason why I would even think about doing this is cause I cant sell it! I have tried and all I got was some really low offers .

goingdef
06-24-2010, 08:11 PM
woulnd't get quite as loud but would take a little more power

hitman34608
06-24-2010, 08:17 PM
Alright thats not as bad as I thought. If you don't mind me asking whats is smallest box I could get away with? Like 3 or 4 cubic feet box or ?

ciaonzo
06-24-2010, 08:18 PM
Copy pasta because I don't feel like typing to paraphrase.




I prefer larger as opposed to smaller when it comes to sealed box volume. You do not increase power handling by putting a woofer in a smaller box. All you do is roll it off at a higher frequency. To produce a certain output level at a certain frequency, you must move a certain amount of air. There is no magic in a smaller box that enables it to have more low frequency output without bottoming the cone. If you move your woofer to a smaller box and find it no longer bottoms out on you then this is because it also does not play as low as it did in the larger box and because it's less efficient, not because you have increased it’s power handling. ( A larger box has a more gradual roll off on the low end) Yes, you can now play a particular track louder than before without bottoming so perhaps you have increased, “apparent power handling” but the real fact of the matter is that your smaller box is acting as a high pass filter not to mention that it has reduced efficiency. What’s worse is that you have also increased the total Q or “Qtc” of the system. It’s a much better thing to leave a woofer in a larger box and address the bottoming issue with more appropriate methods. The larger box will have better efficiency, and better damping. When you increase the restoring force by making the box smaller you just make the amplifiers job of controlling the cone motion all that much harder. The same is true for drivers with a very small Vas. While the Thiele Small parameters suggest proper damping and performance in a small box, the real performance is not the same. These compact systems don’t take up much space but they have a lot of difficulty resolving detail in bass. It’s what I call the, “one note fits all” sound. Seems like no matter what note is played, you get a lot of content of that one note that the tight restoring force likes to play.

papito
06-24-2010, 08:19 PM
hey i know you from gpn

hitman34608
06-24-2010, 08:24 PM
Yea long time ago who are you ?

goingdef
06-24-2010, 08:27 PM
Alright thats not as bad as I thought. If you don't mind me asking whats is smallest box I could get away with? Like 3 or 4 cubic feet box or ?

I can't help on that one never owned an 18" but for a 15" I used 4.5 never tried for less then that but I'm sure someone can answer that for you there's lots of people playing with 18"s right now it seems like.

hitman34608
06-24-2010, 08:31 PM
I can't help on that one never owned an 18" but for a 15" I used 4.5 never tried for less then that but I'm sure someone can answer that for you there's lots of people playing with 18"s right now it seems like.

Alright Thanks for help and any one with experience with 18 inch subwoofers can help me with my question will be very helpful. Also thanks for that article if Im understanding it right I going to make the sub work harder in smaller box and have more chance of it bottoming out is that right?

JL Audio
06-24-2010, 08:32 PM
i've used a single mt 18 in 6.8 cubes ( after displacement ) and it was just fine.

I forget how many cubes each of meades subs see but I know it's less than that.

Bumpin' Goalie
06-24-2010, 08:39 PM
Size of enclosure will affect response curve, power handling, efficiency.

ciaonzo
06-24-2010, 08:44 PM
Alright Thanks for help and any one with experience with 18 inch subwoofers can help me with my question will be very helpful. Also thanks for that article if Im understanding it right I going to make the sub work harder in smaller box and have more chance of it bottoming out is that right?Close, but not quite. It will bottom easier in a larger enclosure but I think you've got the general idea. Smaller box will be less efficient and have a much higher Qtc. Neither is ideal.

And what goalie said.

hitman34608
06-24-2010, 11:55 PM
i've used a single mt 18 in 6.8 cubes ( after displacement ) and it was just fine.

I forget how many cubes each of meades subs see but I know it's less than that.

O really ? Man this is some great news I had this subwoofer sitting in my room for like 2 years thinking I could not put it in a smaller box .