For a future project (blue barrel infra sub woofer with ducted fan) I'm already looking for parts. I see most amplifiers and amp chips (like the TDA7294) have a frequency response usually 20 - 20,000 Hz. But I'm interested in a range from 0- ca 40 Hz. As far as I understand, the low cutoff is to protect the driver (speaker). Would it be possible to circumvent the low cutoff, or would I have to build from scratch? (I'm thinking in a 70 - 150 W RMS range).