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.

0:30

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.

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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.

1:30

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.

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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.

[Anthony-gqdk]

So brilliantly explained, I could listen to him all day explaining the physics of sound in a standard room.

[joeyroth]

Yup, spot on explanation on how room dimensions impact sound quality, simple, precise and informative. Makes perfect sense. Thank you REL.

[Sunrayman]

That graph was a great way to SEE what's actually happening with a Subwoofer added... Thanks!

[mroflynn]

Wow, I could listen you this guy all day long, love the science and the things they don't tell you in the manual . Wish it was much longer and took questions too.

[sammclean]

set up my new T9/X recently and.... whoa. I can't believe i listened to music without a sub for so long.

[cyberathlete]

I agree 100% with this. Even before I saw this video or knew about it, out of curiosity, I measured my B&W 804 D2 in my room (manufacturer specs rate them at 34Hz -6dB) but in my room they fell off pretty quickly after 54Hz. I can't tell you how many people buy their speakers and think they're getting that low end as specified by the manufacturer. They're not. And when they look at these REL subs that are rated at 30Hz, or 32 Hz and they think their speakers hit 34Hz, in their mind they're wondering why would they want to invest in a sub that only gives them 2 more Hz. In reality that sub is actually covering 20 Hz or more of a range in the low end. I use a pair of T5i's with my B&W, but now upgrading to T7x and I can tell you they work flawlessly with those speakers and bring out an experience in music that doesn't exist without subs

[samidebs]

Thank you John Hunter I love the way you explain sounds 🎸

[mjot]

Fantastic. Now how do we set the crossover? Where is part 2?

[beercanshooter]

Very good, now that I know how to do it, how do I really do it?

[Novilicious]

Keep these vids coming! Just bought myself dual ti9s! Can’t wait to get my hands on them :})

[XxtothmonsterxX]

Great explanation .. my two T/5X are ordered and shipped and I can’t wait to hear

[ronny]

So if my speakers go as low as 39hz am I right in thinking I need to set the crossover somewhere between 39 to 50hz Because of the room influence?

[shaymcdonald]

Hi, what is the recommended method to check there is a smooth transition between he subwoofer and speakers? Would you use a sine sweep and listen for peaks and dips in the output?

[DiegoSanchez-niex]

Thank you. does this principe apply to 6 pack as well?

[jasonfallon]

Hi I have the Mackie DML 12 S and the 12 tops. What should I set the built in crossover to on the subs? Thanks

[davidstein]

I just ordered 2 REL HT1003 MK11 subwoofers. & have a question for the forum.

I have a pair of Totem Acoustic Tribe floorstanders located at the front of my listening room.

Approximately what should the crossover point be on my 2 REL Subwoofers?
My Totem Tribe Floorstander speaker's Frequency Response is
30 Hz-30 kHz.
I will be using the RELs BOTH for watching movies & for listening to music.
I don't listen to most aggressive genres of music.
I listen to folk, classical & jazz...In other words, I listen to accousticly-oriented music.
The size of my listening room is small to medium
in square footage.

Thanks So Much!

[chrisengland]

Didn’t tell me how to set it up but like the understanding

[webman]

I just bought the Sony STR-DH190 receiver with a pair of Sony SSCS5 speakers and lasted two days before I bought the Sony SACS9 subwoofer because it needed more bass. Now if I can just figure out the best settings for the sub as I have never owned anything but passive subs in the past.

[paulstone]

REL recommends you set speaker to large in a home theater system with the LFE AVR output to REL LFE input so how would set the crossover on the mains in the AVR?

[jadilson_paiva]

My thanks. The biggest problem with adjusting subs is that our bass reference is oversized. We have to detoxify the exhaustion of bass and feel the immersion of the stereo image that the sub gives us.