Bass direction is audible

[dlaloum]

On the other hand, many "full range" speakers are not achieving those distortion numbers in the bass frequencies at the necessary SPLs either. "SOTA" ones maybe, but then I wouldn't compare those against subs that are anything but "SOTA".

Sure, but the distortion that localises the speaker, is localising it - to the speaker... which in localisation terms is relatively innocuous!

And speakers typically are held to much higher standards in distortion terms.... I ran Quad ESL's of various models for years, and they are circa 0.5% within their rated frequency range (yes they are and always have been one of the lowest distortion speakers on the market.... after circa 40+ years, it is becoming slightly more common to see speakers with THD within their spec range at 1% or less...)

Still any speaker that reaches 10% THD within its rated frequency spec, is going to get a whole lot of stick for it! - whereas subs for some reason don't!

 

[kyuu]

Still any speaker that reaches 10% THD within its rated frequency spec, is going to get a whole lot of stick for it! - whereas subs for some reason don't!

Well, it's not as though it's not true that distortion is less objectionable the lower you go. I think the fact that some subs, particularly probably the small, lower cost, heavily DSP'd subs chasing the last 10Hz are approaching 100% distortion at the low end is probably the most problematic part.

 

[sigbergaudio]

Sure, but the distortion that localises the speaker, is localising it - to the speaker... which in localisation terms is relatively innocuous!

Sounds reasonable, but in practice we don't really want our sound to come from the speakers either. On the contrary one of the main qualities of good speakers is the opposite - that sounds appear within and around room seemingly without coming from the speakers. So distortion that anchors the sound to the speakers is not good.

And speakers typically are held to much higher standards in distortion terms.... I ran Quad ESL's of various models for years, and they are circa 0.5% within their rated frequency range (yes they are and always have been one of the lowest distortion speakers on the market.... after circa 40+ years, it is becoming slightly more common to see speakers with THD within their spec range at 1% or less...)

Still any speaker that reaches 10% THD within its rated frequency spec, is going to get a whole lot of stick for it! - whereas subs for some reason don't!

Reaching 10% in the low end is very common for most speakers when you turn up the volume a bit. Most speakers aren't better at producing bass with low distortion than subwoofers. Most speakers are even worse.

 

[Sokel]

Well, it's not as though it's not true that distortion is less objectionable the lower you go. I think the fact that some subs, particularly probably the small, lower cost, heavily DSP'd subs chasing the last 10Hz are approaching 100% distortion at the low end is probably the most problematic part.

Bass distortion is not so bad as people say, at least with bigger speakers.
Have a look at his post, this is a nearfield of speakers woofer.

(I'll post a pic for ease, thread has more, we of course forget anything out it's range, that is below 30Hz and above 250Hz. It may be visible but it's because the rest of the drivers are playing too )



Between 0.5% and 1% at his range.

And now the fun stuff.
Bellow is the same speaker, same amp technology and brand, both amps WELL into their linear operation only one is far more powerful.
3 meter distance and go:





Most powerful one benefits lows (at my rig at least)

With all the above I'm trying to say that its more than distortion that makes subs localizable.

 

[sigbergaudio]

Bass distortion is not so bad as people say, at least with bigger speakers.
Have a look at his post, this is a nearfield of speakers woofer.

(I'll post a pic for ease, thread has more, we of course forget anything out it's range, that is below 30Hz and above 250Hz. It may be visible but it's because the rest of the drivers are playing too )

View attachment 450814

Between 0.5% and 1% at his range.

And now the fun stuff.
Bellow is the same speaker, same amp technology and brand, both amps WELL into their linear operation only one is far more powerful.
3 meter distance and go:

View attachment 450815

View attachment 450816

Most powerful one benefits lows (at my rig at least)

With all the above I'm trying to say that its more than distortion that makes subs localizable.

These graphs don't show THD(?), only 2nd and 3rd harmonics, and the fundamental is at a very low level (82dB) ?

 

[Sokel]

These graphs don't show THD(?), only 2nd and 3rd harmonics, and the fundamental is at a very low level (82dB) ?

Go to the posted thread I linked, I have posted sweeps up to 100dB from 3 meters at the first page.
Of course THD is not that low up there

Edit: I realized you talk about the amp test, that yes, you're right.
It's 3 meters at 82dB but the point there was testing the amps, not the speaker (it's semi-active)
So I made sure both used a few W to be well-well into their linear range despite the fact that are rated at 1200W and 300W respectively.

 

[LionIT]

When I listen to music, I always have the correlator in sight in the DAW and I have never seen signal below 100hz with ITD.
Sometimes very light ILD, or hard panning, but they are more artistic choices than intentions to place something in space.
Even with the Dolby Atmos tracks, I see that the bass is entirely on the LFE (therefore deliberately non-directional) or on L+R without side content. Sometimes it is spread on all channels, but still in phase...
To me there is no need to worry too much about directionality since it is almost never deliberately intended in the productions.
But maybe it was accidental that I haven't found it so far with my songs.
Has anyone found musical or cinematographic productions with intentionally directional content below 100 / 150hz?

 

[Sokel]

When I listen to music, I always have the correlator in sight in the DAW and I have never seen signal below 100hz with ITD.
Sometimes very light ILD, or hard panning, but they are more artistic choices than intentions to place something in space.
Even with the Dolby Atmos tracks, I see that the bass is entirely on the LFE (therefore deliberately non-directional) or on L+R without side content. Sometimes it is spread on all channels, but still in phase...
To me there is no need to worry too much about directionality since it is almost never deliberately intended in the productions.
But maybe it was accidental that I haven't found it so far with my songs.
Has anyone found musical or cinematographic productions with intentionally directional content below 100 / 150hz?

I don't know if the movie score has been translated to soundtrack but here's Interstellar's Mountains.





Or. spectrum, L R .



Delta of spectrum



Spectrum of Delta



Delta of phase.

It seems much different (disclaimer stands though, someone must compare the original movie content)

 

[LionIT]

I don't know if the movie score has been translated to soundtrack but here's Interstellar's Mountains.

View attachment 450863

View attachment 450864

Or. spectrum, L R .

View attachment 450865

Spectrum of Delta

View attachment 450867

Delta of phase.

It seems much different (disclaimer stands though, someone must compare the original movie content)

Sorry I don't know DeltaWave too much, but are you sure it is a good tool to detect ILD/ITD?
I mean, it should properly show the differences between two stationary signals, or constant differences on non-stationary signals.
To determine directionality you need to compare L and R with a relatively small window to detect how ILD/ITD behave during the whole duration.

 

[Sokel]

Sorry I don't know DeltaWave too much, but are you sure it is a good tool to detect ILD/ITD?
I mean, it should properly show the differences between two stationary signals, or constant differences on non-stationary signals.
To determine directionality you need to compare L and R with a relatively small window to detect how ILD/ITD behave during the whole duration.

Deltawave is the best tool on the planet for comparing recordings, try it.
Author is @pkane and here's where to download it.

DeltaWave Audio Null Comparator | DeltaWave documentation

deltaw.org

There's also a thread about it:

Beta-test: DeltaWave Null Comparison software

Folks, Only for the brave: I'd like to solicit your feedback and suggestions on DeltaWave null-testing software. It's an early preview, so please be gentle! Details and software download are available here: https://deltaw.org An example report produced by DeltaWave comparing two USB cables...

www.audiosciencereview.com

 

[LionIT]

Deltawave is the best tool on the planet for comparing recordings, try it.
Author is @pkane and here's where to download it.

DeltaWave Audio Null Comparator | DeltaWave documentation

deltaw.org

There's also a thread about it:

Beta-test: DeltaWave Null Comparison software

Folks, Only for the brave: I'd like to solicit your feedback and suggestions on DeltaWave null-testing software. It's an early preview, so please be gentle! Details and software download are available here: https://deltaw.org An example report produced by DeltaWave comparing two USB cables...

www.audiosciencereview.com

ITD and ILD are values which continually vary over time.
The graphs you attached do not seem to show the delta as a function of time.
To me they seem to show delta in function of frequency, I assume with a window equivalent to the duration of the song.
Furthermore, I understand that the software seeks the alignment between the two signals so the phase shown in that way is not pure.
Maybe I'm wrong?

 

[Sokel]

ITD and ILD are values which continually vary over time.
The graphs you attached do not seem to show the delta as a function of time.
To me they seem to show delta in function of frequency, I assume with a window equivalent to the duration of the song.
Furthermore, I understand that the software seeks the alignment between the two signals so the phase shown in that way is not pure.
Maybe I'm wrong?

You can set any duration of the rec you want, see my trims for example, I cut 20 sec from the start and 60 from the end.
You can set it to 1 sec if you like or whatever duration you want.

It will align if you ask for it, but will also show you all the raw values, you can filter, or whatever you want.
Have a look at its settings (on chart and the global functional ones ) and you'll see, both FR and time.

You can even listen to the difference.

 

[levimax]

When I listen to music, I always have the correlator in sight in the DAW and I have never seen signal below 100hz with ITD.
Sometimes very light ILD, or hard panning, but they are more artistic choices than intentions to place something in space.
Even with the Dolby Atmos tracks, I see that the bass is entirely on the LFE (therefore deliberately non-directional) or on L+R without side content. Sometimes it is spread on all channels, but still in phase...
To me there is no need to worry too much about directionality since it is almost never deliberately intended in the productions.
But maybe it was accidental that I haven't found it so far with my songs.
Has anyone found musical or cinematographic productions with intentionally directional content below 100 / 150hz?

The question of the value of stereo bass may have more to do with "timing cues" than "directionality" https://assets.swoogo.com/uploads/4646601-673c03ab61c93.pdf

 

[Oddball]

Has anyone found musical or cinematographic productions with intentionally directional content below 100 / 150hz?

As far as HT Atmos soundracks, what comes to my mind first would be Masters of Air. Some battle scenes are mixed amazingly and explosions are actually spread in 3D bubble. Recall Patriot is also pretty good but more 2D and front stage centred.

Fury is also good, but only heard 5.1 original with upmix. There are probably other examples, but agree that generally it is not very common.

There might be some directional bass threads on other forums with additional movies. And I do not run directional bass, so potentially missing some additional impact on some titles.

 

[olieb]

Has anyone found musical or cinematographic productions with intentionally directional content below 100 / 150hz?

This happens quite frequently with Decca tree recordings of (big) orchestra, in particular with "outriggers" that are far out left and right. The double basses will be much closer to the right channel mics and this typically will end up in the mix too (and intentionally so).
One example are the Boston Symphony recordings of Shostakovich (obvious in No 8 , Movement III). This is in Atmos and Stereo.

 

[Chr1]

I would be very interested to hear from anyone familiar with the production of modern electronic music.
It seems to me that this genre is where directional/stereo bass is going to be common.

 

[thcdru2k]

Distortion can be decreased in two ways. You can brand chase and get a very expensive three-way speaker / the most expensive subwoofers or you can get as many subwoofers as you can and distribute bandwidth amongst the subwoofers. If a subwoofer is only responsible for a very specific range it is going to have less excursion. Less excursion means less distortion. It also makes it more practical to deal with room nulls. Something as simple as a couch, coffee table, or that box of new speakers you haven't opened yet. I dislike the idea of room correction for subs to deal with room nulls simply because I believe it's making it sound good in the microphone position but makes it sound worst in a different position. When we go to clubs or concerts do we just stand in one spot or do we move around. The best way to deal with localization, nulls is honestly just buy more subs. When you have more subs you can distribute the bass and run each sub with more headroom and a lower noise floor because your gain knob is not anywhere near max. I dislike hearing the hum of large subwoofers so I think its better to boost the signal slightly if needed than to turn the volume knob and introduce the hum of a transformer. I know CEA is generally used more to see max SPL output but attached is a CEA run that shows how low you can get distortion by using multiple subwoofers with each subwoofer responsible for a specific range. I use two 15in for low end and two 12in specifically for midbass. The attached photo is four subs and two bookshelf speakers played together. Higher SPL with less power to each driver means less overall excursion per driver and less distortion. Less than 8% total harmonic distortion and less than 1% high order harmonic distortion at a real world SPL listening level.

 

[sigbergaudio]

Distortion can be decreased in two ways. You can brand chase and get a very expensive three-way speaker / the most expensive subwoofers or you can get as many subwoofers as you can and distribute bandwidth amongst the subwoofers. If a subwoofer is only responsible for a very specific range it is going to have less excursion. Less excursion means less distortion. It also makes it more practical to deal with room nulls. Something as simple as a couch, coffee table, or that box of new speakers you haven't opened yet. I dislike the idea of room correction for subs to deal with room nulls simply because I believe it's making it sound good in the microphone position but makes it sound worst in a different position. When we go to clubs or concerts do we just stand in one spot or do we move around. The best way to deal with localization, nulls is honestly just buy more subs. When you have more subs you can distribute the bass and run each sub with more headroom and a lower noise floor because your gain knob is not anywhere near max. I dislike hearing the hum of large subwoofers so I think its better to boost the signal slightly if needed than to turn the volume knob and introduce the hum of a transformer. I know CEA is generally used more to see max SPL output but attached is a CEA run that shows how low you can get distortion by using multiple subwoofers with each subwoofer responsible for a specific range. I use two 15in for low end and two 12in specifically for midbass. The attached photo is four subs and two bookshelf speakers played together. Higher SPL with less power to each driver means less overall excursion per driver and less distortion. Less than 8% total harmonic distortion and less than 1% high order harmonic distortion at a real world SPL listening level.

A couple of things here.

1. It's typically not recommended to fix nulls with EQ, but rather peaks.
2. Is EQ making the sound worse other places? To some extent, but not necessarily so. But you are right that more subs is a good approach, though not practical for many people.
3. "If a subwoofer is only responsible for a very specific range it is going to have less excursion." <- This is generally not true. What will require excursion are the lowest frequencies. The excursion doesn't increase meaningfully because the driver is also reproducing higher frequencies. You would get significantly lower distortion if all of your subwoofers reproduced the lowest frequencies.
4. You seem to (in)directly bash the idea of expensive speakers/subwoofers. 8% THD at 84dB is not a great result unless you have a very large room - and likely would look quite different with higher quality subwoofers.

I suggest you try to allow all four subs play all the way down, and measure THD again.

 

[thcdru2k]

A couple of things here.

1. It's typically not recommended to fix nulls with EQ, but rather peaks.
2. Is EQ making the sound worse other places? To some extent, but not necessarily so. But you are right that more subs is a good approach, though not practical for many people.
3. "If a subwoofer is only responsible for a very specific range it is going to have less excursion." <- This is generally not true. What will require excursion are the lowest frequencies. The excursion doesn't increase meaningfully because the driver is also reproducing higher frequencies. You would get significantly lower distortion if all of your subwoofers reproduced the lowest frequencies.
4. You seem to (in)directly bash the idea of expensive speakers/subwoofers. 8% THD at 84dB is not a great result unless you have a very large room - and likely would look quite different with higher quality subwoofers.

I suggest you try to allow all four subs play all the way down, and measure THD again.

Greatly appreciate the response; I just want to create a nice system as best I can while respecting older equipment

The system is in an open living room that flows into a kitchen, dining area, piano area, and hallway. The right side of the room has glass patio doors and a stone fireplace. There’s also a low-profile chaise positioned close to the right sub stack. Placement is somewhat limited by aesthetics, but overall alignment is good considering the space.

I’m running three sealed subs and one ported, the CHT-15. Each one is focused on a specific range. No eq. Just delay, gain, crossover management, and limited placement.

The 15s are not high passed. They run full range down to below 30hz. I've included SPL/phase/GD to show that there is response down to 10hz. I’m just keeping them from dominating the upper bass while blending the smaller subs into the midbass. Crossover points and placement help avoid unnecessary overlap at shared frequencies.

The visible null around 70 hertz looks like interaction from the chaise. It does not seem to cause any issues in use but it shows up in the measurement.

Signal to noise was low during the CEA test, which makes the THD appear higher than it probably is. It measured just under 8 percent at 22.5 hertz with everything playing, which seems about right for this setup and room.

I’ll run a proper burst test soon when I can get my dogs to my in-laws and push it up to 10 percent THD. If it falls short of what I want for music playback, I’ll look at upgrading one of the 15s if my wife allows She's already upset

 

[thcdru2k]

I like calibration but I don't want to live and die by the graphs and charts. There are some perceptual advantages with a multi subarray like decrease localization. Having dedicated mid bass components create better transients then asking my larger subs or speakers figure out the mid bass. And I want to clarify I am definitely not against expensive equipment I would love to have four sigberg audio 10Ds ) , I just think that a lot of people are not getting the most of what they already have