Well, if you want to make something that goes down, to say 10 HZ, it needs to make 10 back-and-forths per second, but the problem is the wave needs to be much \'larger\' if you will for low frequency, so the travel on the woofer must be much larger (which is hard to do accuratly). Usually big woofers are made for big travel/power, but not super-accuracy, so a small woofer which can still go pretty damn low will do a \'better job\'.
You can get higher quality woofers over 10" but the price goes up really fast.
I disagree with you there. Having a subwoofer that can goes down to 10 Hz is overkill since that\'s beyond the the hearing level of the average human beings and unecessary. I disagree with you about bigger subwoofers not being super accurate compare to smaller subs.
Its true that higher quality woofers that are big with deep bass are expensive. But rightfully so.
Generally 15" and 18" drivers are only found at movie theatres and music concerts, you are giving up a \'good quality sound\' for earth-rumbling bass with such speakers.
i think you got confused here when you mention subwoofers with speakers...subwoofers are invented mainly for low frequency effects, aka bass because speakers can\'t pump out as deep bass since that can require very big speakers and they are very expensive which makes it uncessary to have such speakers. That\'s why subwoofers are invented to pump out those deep bass only and nothing else.
While speakers are mainly for middle frequency to much higher frequency response as much as 20,000 Hz, and I believe around 10 kHz - 20 kHz are the high frequency response, aka treble.
So, say a big speaker that have a frequency response of 50 Hz - 20,000 Hz, you can listen to musics and movies where it will playback most of the frequency that the human ears can hear. But what about low frequency response? Most human ears can hear as low as 20 Hz, but the speakers can\'t go that low though. So, you will need a subwoofer to playback the LFE. Most subwoofers don\'t go higher than 200 Hz because that is uncessary because subwoofers are invented to playback the low frequency effects.
If you have a subwoofer that can go down to 20 Hz as its deepest bass, and its highest frequency is 150 Hz. By doing crossover say at 50 Hz between the speaker and the subwoofer, you will get the frequency response of 20 Hz - 20,000 Hz. Where from 20 Hz - 50 Hz is created by the subwoofer, and 50 Hz - 20,000 Hz is created by the speakers.
You can do crossover between the sub and the speakers at any frequency that you like between 50 Hz - 150 Hz as an exmaple. since the example subwoofer can go up to 150 Hz, but don\'t do crossover lower than 50 Hz since that\'s where the speakers limit for deep bass is.
This will benefits both movies and music. I think many music weren\'t recorded with bass as deep as movies, but it wouldn\'t hurt to have a deep bass subwoofer.