weak input signal to amplify

[pra3718]

My first DIY chip amp is 5.1 channel. I have got a DVD Player having 6 channel oputput. My home-made Amp 44Watt per channel sounds good. But the Same Amp for Sub-woofer sounds very very weak. I think, My DVD Player's sub output is weak. What should I do to improve the Subwoofer Signal to amplify.

Regards.

 

[Puffin]

I assume that the sub output from the DVD player is not active and it seems as though you will need active equalisation.

 

[pra3718]

Thank you,
i.e. Adding buffer basic circuit (NE5532), my problem would be solved? OR Active Filter would be solved this.
Please help me in detail
Regards