flapping noise in subs

[Tonglebeak]

Just wondering, if the sub is making a flapping noise while it's hitting hard...is that normal, or is that a sign that the sub is being pushed too far? Or is there something loose in the setup or something?

If it's being pushed too far, how could a 350w rms amp overpower a 400w rms with no noticeable clipping?

Thanks.

[jeffman2121]

while the resistance on the the sub might not be set right with the amp, say you have a 2 ohm sub and you have your amp wired at one ohm, that would be bad, that or if its more of a popping sound that does means its being pushed to hard, so you could fine tune the adjustments on your deck or you could fine tune and or unbridge your amp if it is bridged or put it in a sealed box

[PaulD]

I'll give it a good guess .............. the reason is because you are using a ported box with no subsonic filter. Below the port tuning freq, the sub is virtually unloaded (just like holding the raw driver up in the air with no box) and so it doesn't take much power to bottom the sub out.

[Tonglebeak]

I'm sorry for not mentioning this. It's a sealed box. I have the subsonic filter set to 20hz, and the lowpass set to 250hz, so it plays within that range.

You're saying though that if I raise the subsonic filter up, to say 25 or 30hz, it'll stop doing that?

[BlasZ24]

You have the low pass set too high. It could be part of your problem. Lower the low pass filter to below ~60Hz and see if it clears up your problem.

[bjboertje]

having the lowpass too high would not cause the sub to bottom out. just cause localization issues. you should set the low pass around 80hz.

[PlayStation3]

ok this is now getting weird today when i went out my type r is bottoming out i spent the last 2 hours trying to get it to stop and no luck. btw i have a active xover it's my hu

nm last night i remebered that i helped a freind install his system and i was showing him how to set his gains with a dmm and we used mine as an example and i forgot to set it back.

[PaulD]

it's quite possible tongle is just overdriving his subs

[PlayStation3]

yea causing sqaure waves to get pushed out instead if sine waves

[Tonglebeak]

I increased the subsonic filter to 40hz, and decreased the low pass to 90hz. No more flapping.

[bjboertje]

try 30hz for the subsonic, 40 is pretty high.