Specific audio analyzer

Hello everyone.
I have a task to analyze a sound level on 8 frequencies (63, 125, 250, 500, 1000, 2000, 4000, 8000)Hz.
I need a hardware realization of the task. It would be like https://www.dfrobot.com/index.php?route=product/product&product_id=514, but with my list of frequencies.
There is a solution using of MSGEQ7 and FFT, but FFT is sufficiently demanding to hardware. I have only 8-bit DFrduino FIO.
What can you advise to me?