Why do larger subwoofers typically produce more output and deeper bass?

So this is a really simplistic, creation. Why do large physical volume subwoofers or for that matter, let’s link it to driver size tend to produce deeper bass. When you go to reproduce deep bass, and I’m going to define deep bass as let’s call it below 40 Hertz.


To give you an idea that we’re getting down into an area where there may be a dozen instruments in the entire world that their entire tonic range operates between say 20 Hertz and 40 Hertz.

Hertz, by the way is number of cycles per second. Mid ranges tend to be up in the hundreds to low thousands, high frequencies go from a few thousand on up to 20,000. Middle bass tends to be pitched around 60 Hertz. Just trying to give you guys a frame of reference for what you’re listening for when you hear it.


So, a kick drum is typically pitched between 48 and 55 Hertz to give you an idea, and most people think that’s low bass. Low bass actually exists below that. So, starting at about 40 Hertz and down, you’re, you’re really talking now about low bass, and the range from 20 to 30 Hertz and below 20 is where it gets very, very, very difficult and typically fairly expensive.


The advantage you have with just greater surface area, a 12 inch versus an eight inch. You’re talking about something on the order of two and a half times as much actual circular surface area. There are really only two ways to motions, right? You either have size or you have stroke. It’s either moving in and out a great deal and there are limits to how much that can do, but in and out movement.

And then the size of the driver itself. What people don’t understand is the smaller the cabinet, the more restrictive the air spring is.


I’m talking only are sealed box designs now. So, when you have a small type cabinet, the louder you are playing it, and typically it takes louder at lower frequencies for it to maintain its sense of loudness relative to the music. That’s just a function of our ears. They drop off in efficiency at very low frequencies. So, you are now fighting on the out stroke. You’ve got this huge room, you’ve got a room that’s a couple of thousand feet, 10,000 cubic feet. In the case of a small, say one foot and smaller sub as you stroke back and forth the out stroke, no problem.


You’re loading into 2000 to 8,000 cubic feet. The in stroke, you’re loading into a cubic foot or less, and that becomes an increasingly stiff resistance on it. So, you’ve just got to kind of balance those things out. And you’ve got to balance that out against your main speakers. If your main speakers themselves are really high quality, main speakers that go down into the 40 Hertz range or below, you’re going to have to have a really serious subwoofer.


Meaning it’s going to have state-of-the-art drivers, state-of-the-art amplifiers, and a cabinet large enough to take advantage of those of those things. There’s just no way around it. So some of this will come about naturally, as you start to define the needs of your system.

We’ve sort of made our name over the last 30 years building really, really high quality, small to medium sized subwoofers for the most part. At the moment, I believe we have 10 different models and seven of them would be described as medium or smaller.


We only have three up in our reference range. The 212, G1, and the No. 25 that are truly large subwoofers. Everything else is really scaled to fit into someone’s idea of a normally sized living room. Everybody has different definitions of that, but that’s the basic relationship between size, output and how deep it can go. You just, at some point, get into limitations of how much or how little cabinet volume you have available to yourself.


You know we’ve got different tricks for coaxing more out. If you have a relatively small space and you throw tons of power at it, like we just did with a range of ours, we can essentially force the driver to act a little bit better. But you really want to stay within sort of the natural relationships of driver size, stroke and cabinet volume to keep it all in balance.

May 13, 2021 - Posted in: Q & A With John Hunter, Videos