The perfect sub crossover point, does it exist?

Moderator AceRimmer (who used to go by another username – name changes should be prohibited in this forum because changes disrupt and distract from posting history) inappropriately moved my post from the original thread to this new thread. My post was a well reasoned potential solution to a specific situation, not a general discussion starter. Since my post was moved for no good reason, I have deleted it. I am taking my ball/post and going home.



I’m afraid I would have to disagree here I’m afraid.

If you truly want your subs to absolutely disappear you really need to be crossing over at 50hz or below.
Unless your using smaller stand mounts or similar that possess nothing much useful below about 60hz themselves.

This is borne out by my inhouse results with my Spatial Audio ob speakers and SVS sb13 subs.


And decades of standard AV setup protocol would disagree with you. Subwoofer(s) crossed over at 40-50 Hz “disappear” because they produce nary any output. Most music has little energy in the 20-40 Hz octave. Unless you are listening to pipe organ music or watching action movies in that scenario, you basically could do without the subwoofer(s).



I use subs, only for audio/2 channel on both of my systems. I have always connected them speaker level or from pre outs on the pre amp and set them to come in at the lower regions of my main speakers, usually 40. I have Dirac now that sets it up for me but I still use the same system.
Always sounded seamless and noticeable less bottom end when I turn them off.

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Not true at all IMHO in my systems.
I can generate room shaking bass with a bit more gain if required and still cannot tell the subs are where they are.
Not that I do but I can and have tested it.
Low E on the electric bass guitar is approx 40hz and with the crossover set at 50hz I can completely “hear” the individual bass guitar notes at will but without them standing out like a sore thumb in the mix.
And yes I have also used this crossover in my av system ( which is only 2.1) with much more satisfying results and less artificial feel to the bass.

It’s mostly a vast improvement in the quality of the bass response I “feel” with a lower crossover point.

But please note my last line…ymmv.


SVS recommendations

If you know your speaker’s frequency range, set the crossover point roughly 10 Hz above the lowest frequency your speakers can handle cleanly
The most common crossover frequency recommended (and the THX standard) is 80 Hz.
The numbers below highlight general guidelines for speaker/subwoofer crossover frequencies
On-wall or Tiny ‘satellite’ speakers: 150-200 Hz.
Small center, surround, bookshelf: 100-120 Hz.
Mid-size center, surround, bookshelf: 80-100 Hz.
Large center, surround and bookshelf: 60-80 Hz.
Very large center, surround, bookshelf: 40-60 Hz.
Tower speakers with 4”-6” woofers: 60 Hz.
Tower speakers with 8”-10” woofers: 40 Hz or Large/Full-Band (i.e., full-range).


And that’s probably why most AV systems recommend the crossover they do as not too many employ large floorstanding speakers with big a$$ drivers.

My AV is two Totem towers and a PSB 12" sub and they are seamlessly integrated at 55hz IMHO.

My main stereo rig is crossed over at 50hz as the mains have 15" drivers, I could possibly go even lower.

However as I said if I was using smaller stand mount speakers it would probably have to be a fair bit higher.

Nice information @ged_hickman1


Mine is set at 80 as I have small standmounts with 4.5 inch drivers.

Which would be just about right in line with recommendations.
But with my Totems anything much above 60hz just starts to sound a little unnatural and I “hear” the sub itself, it makes its actual location known to my ears.

That’s a one-size-fits-all approach but the use of well EQ-ed multiple distributed subs can allow for higher frequency crossovers.

Yes if you can swing to say a five sub distributed array you can likely crossover a fair bit higher.
One day I might get to that stage…lol

This is really sub/system/setup/room dependent, YMMV big time! The size of the main speakers may or may not matter.

In my setup, I’ve crossed over as high as 120hz without the sub being localized. I bet the sub distortion level is a significant factor.

If anyone asks me where they should set the crossover, I say 80hz is a good starting place, then experiment up and down from there.

YMWV! (Your mileage WILL vary!) :grin::+1:


Interesting and timely discussion as im in the process of dialing one sub into my 2 channel system.

Suspect is a Jl audio f112 v2, being integrated into the Jbl 4367 which uses a 15 inch two way design. The jbl frequency response is 30hz-6DB. I have the Jl audio cr1 crossover. Using the cr1, i set the crossover at 40 hz for both the sub and speakers. And the sub is placed beside the front left speaker. With a 24- db slope.

Using frequency sweeps from a cd, i assume and perhaps incorrectly, that the 40hz sweep should have a similar sound output level from both the sub and speakers. I adjust the damping controls on the crossover to that effect. And the gain of the sub also.

The result is that i think the sub is blended in nicely, but im kinda of at an impasse.

I dont really hear it and question if i have it on. Which i think is what you want in your integration. But on the other hand, there truly seems to be little information sub 40 hz for music that i listen to. So it gots me questioning if in my scenario, with my room and gear, is it money well spent? For movies, there is a visceral difference, but im not a big movie guy. For music im really in the fork of the road.

Perhaps if i cross-over at 80 hz, but that would be a waste of so much awesome output that the 4367 is capable off. And when i did try that crossover setting, i did feel that i was able to localize the sub. At 40 hz, the sub does not draw attention to itself…but again to the point that im questioning why i spent so much mula…

Other important info, the sub was chose for a few reasons. Chief among them was small footprint. The wife acceptance factor is high with it. So moving to something like a svs 16 ultra size wize will not work for me.

Any thoughts/suggestions welcome

Has your sub got its own volume control? If so turn it up a tad until it’s obvious then it will tell you how much it’s adding to the frequency range. Then turn it down again until it’s blended in. Then turn it off and see whether you miss it. A lot of it is trial and error.

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Yes it has its own volume or gain which i use.

Yeah it seems a lot more trickier that i thought. Lots of trial and lots more error got me here. …i know i had heard that dialing in a sub was tricky and i foolishly would think, 10 minutes and bang…but its definitely time consuming

Yes it is. On my main system I wire it speaker level set the crossover about 10hz above the minimum speaker (40 in my case) get it as close as I can by ear and use DIRAC to iron the bumps out. It has helped that NAD amps have that facility. I then turn it up very slightly for my taste.
It also helps to listen to the high frequency with the sub dialled in. It can make them sound better.

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A full sweep helps too to se what’s happening. I think tidal has one.

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In all honesty what I find to be the main addition to music using sub(s) is not so much to add to already present bass but a full “fleshing” out of the music.
If I turn mine off while listening I “feel” something has been lost, some warmth and depth to the music.
Sure I can make it deliver much louder bass with more gain but that is not what I was aiming for or enjoy as much as my present results.

Adding the SVS sub stopped me looking at new speakers…lol
It certainly helps that I can control and adjust everything from my listening position via the app so can get immediate feedback on any changes I have made instead of the “well is it different or not?”

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Use a tone sweep on a test cd to hear what low frequencies are doing.
Qobuz and Tidal have test albums including this one
“The Sheffield/ A2TB test disc”

Then look at the thread here for some music ideas


Listen to subs with high frequency? Im confused what do you mean?