Passive sub low bass cut off required?

Passive sub low bass cut off required?

Anyone know of a simple bass filter for a passive sub? Or a simple cheap sollution before the power amp?

I would like to be able to cut the low bass around 19Hz or 25Hz in a passive 100 liter sub, to protect the cone from over excursion and was wondering if anyone knew of a simple circuit or such I could build or buy?

I am also wondering if I should fit a passive low pass filter crossover? Though it will be utilised with sub out from an AV amp?

Really I want to roll of the low bass from around 25Hz or 19Hz and don't need anythng above 120Hz I guess? It's a simpe 100 litre ported enclosure with a 15" driver which will be port tuned to either 19Hz or 25Hz.

Cheers

 

simplest thing would be a capacitor of around 1000uf and an inductor of 10 mh in series with the driver,assuming its an 8 ohm driver.