peaking 2nd order filter in speaker filter

[Ryjuuuhn]

Hi all,

I wanted to design a subwoofer in addition to my bleutooth speaker, this had to be a portable subwoofer of approximately 4liters in size.
After some testing with a thousands of speaker drivers I found out that a new version of Winisd was available.
In this version i messed around with some speaker filters until I found the option of a peaking 2nd order filter.
I am quite familiar with calculating filters and simulating them in Matlab.
But I could not find any information regarding the use in speaker filters, to use them to create a peak.
Because this filter allowed me to push a speaker downto 40 Hz(-3dB point) in a closed enclosure with 3 liters of volume.
I wanted to make this filter before the amplifier, which I already designed in Eagle, an TPA3116D2 bridge design.
So I wanted to have a gain with this filter at 45 Hz 8dB peak high pass filter.
Off course all filters and sources are going to be isolated by opamps for cascading.
Because a third order low pass filter (over damped) should also be added.
So my question is actually if this is a good idea to make this peaking 2nd order filter for subwoofer us?
I am aware of the phase change and delay which it creates, but this seems to be equal to a subwoofer in a bass-reflex enclosure without filters attached.
I wanted to design this just with filter RCL, with 0805 resistor and a 1 uF film capacitor and a coil.

I did not ask this question on a hifi forum, because hifi enthusiast seem not very familiar with making the filter at the input of the amplifier.
And i wanted to have it before the input, so I could cascade filters with the help of opamps instead of getting nasty filter interference by cascading.