How do loud speaker manufacturers achieve frequency response ranges as low as 20Hz for its speakers and headphones?

Question

I'm in the process of learning about building speakers myself, and noticed that there isn't a single speaker driver that is marketed to have frequency response ranges that drop to as low as 20Hz. I think the lowest that I've seen is in the ballpark of 30Hz.

Sony markets their devices to have frequency response ranges to go as low as 20Hz.

I own two products of theirs, both having frequency response ranges from 20Hz, to 20kHz. I play a 20Hz tone, and sure enough, I can hear something.

But on my MacBook Pro, I don't hear anything. So, I guess Sony is doing something right. Or perhaps it's all marketing.

If I understand it correctly, as frequencies drop below a certain point, it's not like the volume cuts off abruptly. Instead, I believe that it's a gradual drop in volume, and we should have the opportunity to throw in an equalizer to boost the lower frequencies. But that's just a guess.

I'm new to building speakers, and I would like to learn more in the ballpark of what Sony (and others) is doing for them to confidently market their products to have such frequency ranges.

Answer 1

Engineering.

Speaker manufacturers have research and development departments staffed with engineers that spend a lot of time to develop crossovers (capacitors,resistors and coils) in conjunction with drivers that can be tailored to play a lot or a little of the sound wave spectrum.

Your Macbook is unlikely to have anything other then just a VERY small speaker, Very small speakers without a crossover in a VERY small space can not reach the low end of the spectrum.

Understanding Loudspeaker Frequency Response

Building a Do-It-Yourself Loudspeaker Design

The truth in spec sheets on speakers has long been very dubious.