Just wondering, I'm now at the point to tweak my system, and I have a sealed 13" Focal KX33 sub driving with JL 500/1 amp. The sub can only go down to around 30Hz, should I turn on the infrasonic filter and leave it at 30Hz? I was told in a sealed box, the filter is not necessary.

Your opinion is greatly appreciated.

 

I would use it.

 

i would also use it, and i do use mine. it saves power cuz the amp wont try to output 5 - 30hz at the same volume. if u set it above 30 you'll hear a difference in the music. but i'd just put it at 30 anyways. in this case "30" on the dial is actually 30....so set it there :P

 

Thank you, I thought the dial might not be accurate so I set mine to 22Hz right now instead of 30Hz The sub according to the specs, can only go down to 30Hz. I'll change it later on, thank you.

 

^ The spec actually says "No response below 30hz"?

 

The transfer function of the cars cabin will easily allow for useable response to 20HZ. There is a lot of wasted energy that is consumed trying to reproduce those frequencies. Usually, there is a slope related to the filter however (18db/oct, 24db/oct, etc). This is why you likely see the response that DUKK has given. If it truly has no response at all below 30hz, I would put that amp on a meter and look at the response while adjusting the filter. Never know, it maybe worthwhile....Good luck!

 

if ur sub can handle alot of excursion then dont worry about it but if it cant then use it.