How to set the Crossover on Your Subwoofer


Whatever the specs on your speaker say they are, in many cases they’re put out by very fine companies telling you the absolute scrupulous truth, and if you were measuring in their anechoic chamber you would achieve exactly the same numbers. Your living room, your listening studio is not their anechoic chamber. When you see a loud speaker that claims, for example, to go down to 34 Hertz, which is extremely deep bass.


In many cases it’s not because the manufacturer can’t do that, or the speaker can’t do that. It’s because your room, even with the speakers perfectly set up, can’t support that. Rooms are enormously destructive and particularly of bass. It’s important to realize that while the manufacturer’s being scrupulously, honest, that speaker in your space set up the way it’s set up, may not be able to support that. But let’s say the speaker’s claims it’s 32 hearts. Wow. That’s a huge pipe in a pipe organ.


Well, the reality is the way it’s set up in your room and your room is not an infinitely large chamber. It’s good for maybe 48 or 50 Hertz. Why? Because that’s the nature of physics. If you’ve got a room that’s only 14 by 20 feet long, it literally physically cannot support the wavelength of 32 Hertz. So we end up making compromises. We get the speaker sounding as good as it can. It falls off at 48 Hertz at 50 Hertz, and that’s a full octave, octave, and a half of music that’s missing.


It’s not just the music. It’s the hall it was recorded in, it’s the recording studio it was recorded in. All that information evaporates and your brain listens to it and goes, yeah, that’s not a high end system. That’s not real life. What we wind up doing is we come in well below the speaker. Why? If you take the typical, perfectly designed speaker, which basically looks like a flat line until it goes away, and you take the perfect theoretical subwoofer, which also looks like a flat line until it goes away at the upper end of its peak. What you need to do is actually separate them by a certain amount.


Because the area under the curve, where they both can join is actually additive. I’ll just make it simple. That area under the curve is additive flips and inverts, and you get a perfectly flat response between the REL and the main speaker all the way from the lower end of the REL, all the way to out as far as that tweeter can work.

June 23, 2020 - Posted in: Sound Insights