I just finished my ported box, and it its pretty loud, but i noticed that on some long bass notes, the bass starts to flutter, like it can't hold the note (eg. louder softer louder softer throughout the note). If you look at the sub you can see it change in excursion? It's hard to explain what i mean. Could this be associated with group delay, or maybe voltage drops? My box is 1.65 cubes for the sub with a port tuned to 35hz. The sub is a mtx mzs1004. Thanks for any replies.

 

sounds like the vent isn't big enough which has been discussed recently.... (I would describe that sound as a flutter)..... if its a slot you are fubar... if its a tube make it longer/wider.... or use an areo port... (as dukk would obviously suggest)

Either that or it sounds like you could be unloading the sub because you are playing it below tuning....

 

i don't think its port noise as it is a 3"x4" port, 15" long and tuned to 35hz. The noise isn't the port (no chugging or puffing), its the actual sub? it doesn't sound like the sub is unloading, but it might be (theres no slapping of any kind)?

 

sounds like a sub

 

The subs ok, not the best but i got it brand new for $55. The best way to explain it is like this:
when i'm playing a long note it should sound like WAAAAAAAAAAAAAAAAAAAH
but it sounds like WAAWAAWAAWAAWAAWAAH.
(sorry for the crackpot description )

thanks for the replies though.

 

Cheap sub = cheap sound, in car audio you get what you pay for.

 

your sub is loosing control... either because of the box or the amps weak damping factor is unable to control the sub... or both

 

Sounds to me that ur sub is trying to play below the port tuning frequency, in which the sub is basically seeing "free air" and is out of control. If your amp has a subsonic filter on it, turn it on and your problem may be solved

 

Turn out it was a combination of the song and shitty mp3 compression. Thanks for all the replies. As for the sub losing control, its funny, I used the MTX specs, but decided that MTX is completely useless as they tuned their box to 45hz. I tuned mine to 34, and i don't listen to music that goes below that.