What measurements/parameters tell you to NOT use a subwoofer for mid range frequencies?

[Chrispy]

I don't think the topic relates to specific transducers, only the frequencies they produce, feel free to call them what you like.

Not usually the same range of effectiveness, thus my question. The equivalence is so misleading in general.....

 

[Ron Texas]

you seem to be referencing the driver and not the actual subwoofer?

Anyway above ~120Hz or so it becomes increasingly difficult to maintain phase coherence between a subwoofer and a speaker, which is 'measurable'.

Could you flesh this out? I'm crossing over at 160 hz. Maybe that comes under the "or so". I realize as frequency goes up the waves get shorter, so bit more care is needed. My measurements say there is no timing problem.

 

[dasdoing]

my ears can't confirm the not localizable bass theory. I throw 30Hz at my sub and I clearly hear it form it's direction.
does the theory realy work for you guy in the real world test? Do you guys hear the soundwave emerging form all sides or something like that?

I also tested my setup steep-crossed at 200Hz for stuff like male voice. without the mains I can obviously hear it coming from the sub, as soon as the mains come in the other frequencies simply overpower it.

I can also mute the left channel of a upright bass like this, and it will sound like it is coming from the right main only:

the only problem would be stuff like synth bass, but no engenier would ever pan them out of center anyways

 

[Chromatischism]

my ears can't confirm the not localizable bass theory. I throw 30Hz at my sub and I clearly hear it form it's direction.
does the theory realy work for you guy in the real world test? Do you guys hear the soundwave emerging form all sides or something like that?

I also tested my setup steep-crossed at 200Hz for stuff like male voice. without the mains I can obviously hear it coming from the sub, as soon as the mains come in the other frequencies simply overpower it.

I can also mute the left channel of a upright bass like this, and it will sound like it is coming from the right main only:

the only problem would be stuff like synth bass, but no engenier would ever pan them out of center anyways

An upright bass has a string pluck that includes much higher frequencies than 30 Hz. That is telling you where the sound is coming from.

There are also harmonics, resonances in materials, etc.

With pure tones, there is no chance of you localizing the source of a 30 Hz wave.

 

[dasdoing]

An upright bass has a string pluck that includes much higher frequencies than 30 Hz. That is telling you where the sound is coming from.

There are also harmonics, resonances in materials, etc.

With pure tones, there is no chance of you localizing the source of a 30 Hz wave.

for the 30Hz I use https://www.szynalski.com/tone-generator/

 

[dasdoing]

If that theory was true, you could throw in a 30Hz in the living room, and if you hear it at the other side of the house you would think the source is there. it makes no sense.
it might be true in an anecoic chamber

 

[Honken]

To me, pure bass tones don't really seem to come from anywhere, they simply exist around me. As I move around in my room their loudness changes but that's it. If I move farther from my listening room I still can't really perceive from where the tones eminate, but at the very far edges I start to get some intuitive idea of where the sound comes from thanks to the fact that the sound become more and more attenuated when I move in a certain direction.

As soon as I listen to an actual instrument, like a bass guitar, it becomes easy to discern the source - it's the highpassed speaker.

I'm crossing my speakers at 160Hz, above that and things start to sound funky to me. I assume it has to do with the size of the woofers, their orientation (down) and how the tones start to interact with the room, moreso than me being able to identify from where the sound comes from. But I am a mere layman so I might be wildly wrong.

 

[dasdoing]

If I move around and find a standing wave it sure comes from all sides. but that makes sense since the mode is overpowering the sub

 

[Honken]

I have two subwoofers though, perhaps that is what is causing it? It's getting a bit too late here for playing with my subwoofers but I could play some pure tones tomorrow to see if that changes it.

 

[abdo123]

my ears can't confirm the not localizable bass theory. I throw 30Hz at my sub and I clearly hear it form it's direction.
does the theory realy work for you guy in the real world test? Do you guys hear the soundwave emerging form all sides or something like that?

I also tested my setup steep-crossed at 200Hz for stuff like male voice. without the mains I can obviously hear it coming from the sub, as soon as the mains come in the other frequencies simply overpower it.

I can also mute the left channel of a upright bass like this, and it will sound like it is coming from the right main only:

the only problem would be stuff like synth bass, but no engenier would ever pan them out of center anyways

I cross my subs at 110Hz with really sharp slopes (24db/oct) and I'm very sensitive to visual cues when it comes to localizing sub-bass.
if i'm looking at my TV then it's coming from my TV, if i look at the speakers it's the speakers.

Truth be told I run multi-sub so the sub-bass is really coming from all around if I try to focus on where it's coming from.

 

[dasdoing]

sharp slopes (24db/oct)

that's not sharp. this is a 24db/oct low pass at 80Hz compared to the one I am using.
again: it is a FIR filter

 

[abdo123]

that's not sharp. this is a 24db/oct low pass at 80Hz compared to the one I am using.
again: it is a FIR filter

View attachment 143280

why? Isn’t it making the phase messy?

I noticed my response was better at 24db/oct vs 48db/oct

 

[dasdoing]

why? Isn’t it making the phase messy?

I noticed my response was better at 24db/oct vs 48db/oct

that's why I said I use FIR filters. they don't produce phase shifts.
If I would cross with 24dB/oct at 200Hz I would be hearing 500Hz-ish stuff from the sub

 

[abdo123]

that's why I said I use FIR filters. they don't produce phase shifts.
If I would cross with 24dB/oct at 200Hz I would be hearing 500Hz-ish stuff from the sub

a room is not modal at 200Hz, do you hear audible directivity mismatch?

 

[dasdoing]

audible directivity mismatch

sorry?

 

[abdo123]

sorry?

it's difficult to match the phase at the crossover region when the room is not minimum phase / modal anymore.

Do you hear any artifacts as a result? Some tones / instruments may sound larger in the sound stage than others.

tubas typically play at ~200 Hz. if you're curious if that's what actually happening.

 

[dasdoing]

it's difficult to match the phase at the crossover region when the room is not minimum phase / modal anymore.

Do you hear any artifacts as a result? Some tones / instruments may sound larger in the sound stage than others.

tubas typically play at ~200 Hz. if you're curious if that's what actually happening.

I dialed in the delay of the mains using trail and error and FR after rouphly matching on the excess group delay graph.
I use this setup since january and never heard any artificts.
but my setup is also DRC mixed-phase corrected

 

[abdo123]

I dialed in the delay of the mains using trail and error and FR after rouphly matching on the excess group delay graph.
I use this setup since january and never heard any artificts.
but my setup is also DRC mixed-phase corrected

it's difficult to tell from measurements at such regions whether things are 'correct'.

when the room is not modal anymore what you measure is not what you hear.

 

[dasdoing]

it's difficult to tell from measurements at such regions whether things are 'correct'.

when the room is not modal anymore what you measure is not what you hear.

are you talking about the Schroederfrequency?

mine is around 203Hz acordig to https://amcoustics.com/tools/amroc?l=408&w=293&h=243&r60=0.3

anyways

what you measure is not what you hear

is around 800-1000Hz afaik

 

[Vladimir Filevski]

I tried crossing several subwoofers "too high" and they all sounded very bad.
However I cannot see anything in the measurements or specs that suggests so, the FR looks flat but it still sounds terrible. it's not just beaming, it sounds "boomy" and "slow" and "muddy" in every direction.
e.g. this Seas L26RO4AY has usable FR up to 800hz per the manufacturer, and is even recommended up to 1Khz. yet it sounds really bad starting as low as 200hz.
...
What in the specs or measurements tell you to not use this driver at, say, 500hz?

High peak at 800 Hz and sharp dip at 900 Hz indicate cone breakup - very listenable with 300 Hz crossover point, even with 200 Hz (depending on the low-pass slope) as you noticed. "Muddy" is the tell-tale sign for too high crossover point.
Manufacturers routinely quote usable response up to the first highest peak (cone breakup), which is a shame.