stereo amplifier with bass booster

Hi everebody! First of all i need to apologize on my english, it's not very good
and if i make some mistakes i hope you will understand it
I'm interested on some ideas about this project.
(all solutions and diferences among them)
I have allready started this and i have some problems.
The basic idea is to create audio amplifier which amplifies
all audible frequencies, and add some circuit which will
amplify bass frequencies. (few decibels). All with op-amps.
So, the (ideal) amplitude characteristic will look like this -->(picture 1)
(gain in bass range must be adjustable)
I have create this circuit --> (picture 2, this is
just one block, not stereo),
but this don't work properly! I tried to place filter
circuit in other part of feedback (parallel with R1, of course
with changed values for R-C), but
still it's the same result...--- no bass frequency change!
I'm using LM1877.
(I put these values just for the testing, so the critical
frequency is set to 1 KHz. In real circuit i need to
amplify frequencies from 30 Hz to 170 Hz, without loss of
high frequencies and overall volume).
What solution do you have about this theme, and how can i built this circuit.
I'm very grateful on all answers, ideas and explanations.

Well, first of all I see that you don't know how to uses opamp.
Your circuit must be supply from symmetric power supply, or if you want single-supply opamp you needed to add the virtual ground.
#1058329

Your circuit will work as follow: (assuming correct supply)

For low frequency the gain is equal
A_low=1+(R1/R2)=101[V/V]=40dB
When the frequency is rise the reactance (Xc) of capacitor in being decrease.
When Xc=R3 at F=0.16/(C1*R3)=10.6KHz (C1 is 10nF ? or 10uF)
So gain is equal
A=1+(R1/(R2||(R3+Xc)=106[V/V]=40.5dB
As frequency rise even more (Xc<<R3), the gain will be equal
A_h=1+(R1/(R2||R3)=107.66[V/V]=40.64dB

The "correct" circuit will look like this

R3 and C2 determine the F1=30Hz=0.16/(R3*C2)
POT and C1 determine the F2

Thank you for this answer. I will do this modification on my circuit. Can you give me more tips about this theme? Something like fundamentals? I'm doing a project for school and i need to make documentation in which I have to show more realizations
and choose one of them to develop. Also i have to explain the diferences among these ideas. This doesn't have to contain values, just block-diagrams, or something like this.
I've tried some ideas with two op-amps, one for boost and second for amplification.
But i need more. What is your opinion?

Can you give me some explanations about yours calculations?
What is your way for finding values for R's and C's? I understand it for R, but i have
a problem with C...
How can I determine values over a transfer function?
I'm having a problem with a mathematical aproach. What is the easiest way to build
this circuit to behave as asign in amplitude plot? (Generaly, for all kinds of amplitude characteristic,
not just this, which is in my case).