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What makes speakers "disappear " and can it be measured?

Tangband

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With respect to active speakers, you can have a range of solutions. I used to have active filters for both 3 kHz and 80 Hz, but have left the 3 kHz active solution many years due to space saving and simplicity. A good passive filter is good enough, IMO. I think a real benefit of active comes when you adapt the amplifier for the specific drivers such as ACE-Bass, current drive or servo feedback. I don't know how many manufacturers use this now.

https://www.current-drive.info/disto/68
Maybe interesting to you - It seems that both the Genelec 8330a and Kef ls50 Meta is stereo system- compensated - they both have a small peak of 2 dB at 1,7 KHz .
I dont think its a coincident.
https://www.audiosciencereview.com/...elec-8330a-review-studio-monitor.25704/page-2

https://www.audiosciencereview.com/...eview-studio-monitor.25704/page-7#post-880535
 
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headshake

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"Sound Spectrum Influences Auditory Distance Perception of Sound Sources Located in a Room Environment"
https://www.frontiersin.org/articles/10.3389/fpsyg.2017.00969/full

Free to read.

My take, there are certain frequencies that we over-estimate or can exactly guess the distance from our ears. If a baffle really mucks up 1.5khz-4khz your ears will tell you "hey, there is a small box making a sound" instead of hearing the room.

I also think that there are things that can bother us in mono that we won't hear in stereo.
 

Thomas_A

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"Sound Spectrum Influences Auditory Distance Perception of Sound Sources Located in a Room Environment"
https://www.frontiersin.org/articles/10.3389/fpsyg.2017.00969/full

Free to read.

My take, there are certain frequencies that we over-estimate or can exactly guess the distance from our ears. If a baffle really mucks up 1.5khz-4khz your ears will tell you "hey, there is a small box making a sound" instead of hearing the room.

I also think that there are things that can bother us in mono that we won't hear in stereo.

Thanks,

interesting, have not seen that one. Will read in detail.
 

Thomas_A

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Maybe interesting to you - It seems that both the Genelec 8330a and Kef ls50 Meta is stereo system- compensated - they both have a small peak of 2 dB at 1,7 KHz .
I dont think its a coincident.
https://www.audiosciencereview.com/...elec-8330a-review-studio-monitor.25704/page-2

https://www.audiosciencereview.com/...eview-studio-monitor.25704/page-7#post-880535

Yes, there are some speakers with variations that could be interpreted to be somewhat compensated for the timbral change caused by stereo comb filtering effect. Also a few of the smaller Revels have variations in the same frequency region.
 

kyle_neuron

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Yes, matching of drivers an tweeters are important, at least within 0.5 dB.

I’ve yet to meet anyone that has a perfectly symmetrical hearing system - physically, and measured response. With almost any speaker, moving your head an inch will produce offsets greater than 0.5 dB at some frequencies.

That’s not to say it’s not something that should be done, but there are often bigger battles to pick. Especially when you don’t have the luxury of a parts bin or warehouse that allows the testing of hundreds of drivers to get matched material tolerances.
 

Thomas_A

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I’ve yet to meet anyone that has a perfectly symmetrical hearing system - physically, and measured response. With almost any speaker, moving your head an inch will produce offsets greater than 0.5 dB at some frequencies.

That’s not to say it’s not something that should be done, but there are often bigger battles to pick. Especially when you don’t have the luxury of a parts bin or warehouse that allows the testing of hundreds of drivers to get matched material tolerances.

I agree that there are bigger issues to adress, having perfectly symmetric rooms is one for sure. Matching can be important though especially in crossover design. I have measured some cheap but good sounding cone tweeters and matching gives better crossover consistency.

1629106842497.png
 

Tangband

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I’ve yet to meet anyone that has a perfectly symmetrical hearing system - physically, and measured response. With almost any speaker, moving your head an inch will produce offsets greater than 0.5 dB at some frequencies.

That’s not to say it’s not something that should be done, but there are often bigger battles to pick. Especially when you don’t have the luxury of a parts bin or warehouse that allows the testing of hundreds of drivers to get matched material tolerances.
Its much easier with active loudspeakers with digital crossovers and dsp to match the performance individually L and R , even if the drive units is 2-3 dB different . You dont have to match the drivers, just use dsp and compensate.
 
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JWAmerica

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I agree that there are bigger issues to adress, having perfectly symmetric rooms is one for sure. Matching can be important though especially in crossover design. I have measured some cheap but good sounding cone tweeters and matching gives better crossover consistency.

View attachment 147764
But if you're cheap and lazy, perhaps a lower order crossover hides the imbalance a bit better?

I just use EqAPO and REW to compensate for differences.
 

HighImpactAV

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it's false regarding the Non environmental design as practiced by Northward Acoustics and of course with my room.
I think Thomas Jouanjean (Northward Acoustics) is one of the premier acousticians in the world. He calls his design front-to-back, but it is a subset of non environmental. His recording studios, Dolby Atmos studios, and home theaters are the current leading edge of acoustic design. I was hoping to visit a couple of his studios last year, but COVID prevented that.

in my opinion, the non-environment room isn’t one that makes a lot of sense and ultimately misses the forest for the trees.
In a proper non-environment room, the room is anechoic to the speakers, but the listener isn't anechoic to the room.
 

Matthew J Poes

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I think Thomas Jouanjean (Northward Acoustics) is one of the premier acousticians in the world. He calls his design front-to-back, but it is a subset of non environmental. His recording studios, Dolby Atmos studios, and home theaters are the current leading edge of acoustic design. I was hoping to visit a couple of his studios last year, but COVID prevented that.


In a proper non-environment room, the room is anechoic to the speakers, but the listener isn't anechoic to the room.
That’s impossible. If a room is anechoic to a speaker then the speaker can’t interact with the room and the listener is effectively anechoic to the room.
 

Wseaton

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My .02$

I dont care how perfect your speakers are. If you have a rear wall close to your listening position transparency will suck.

Room acoustics aside driver design has a lot to do acoustical transparency. There's a trend in today speakers towards waveguides in some aspect to increase efficiency and improve dispersion matching with midrange drivers. It also, IMO decreases speaker transparency.

Im not a B&W fanboy, but their midrange and tweeter designs in the 90s like their Matrix 800 series could get up and vanish as good as any speaker I ever heard. I attribute this to B&Ws aggressive design goal minimalistic front baffle area.
 

BrokenEnglishGuy

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My .02$

I dont care how perfect your speakers are. If you have a rear wall close to your listening position transparency will suck.

Room acoustics aside driver design has a lot to do acoustical transparency. There's a trend in today speakers towards waveguides in some aspect to increase efficiency and improve dispersion matching with midrange drivers. It also, IMO decreases speaker transparency.

Im not a B&W fanboy, but their midrange and tweeter designs in the 90s like their Matrix 800 series could get up and vanish as good as any speaker I ever heard. I attribute this to B&Ws aggressive design goal minimalistic front baffle area.
and which distance is that?
 

dasdoing

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whoever had a phase issue in one of the speakers knows the answer.
when the phases match the speakers disapear.
any slight variance smears the center image (e.g. voices coming partly from the right, partly from the left), and "compresses" the location panned stuff (e.g.: a 70% left panned signal will sound like 100% panned in a given frequency. in that range you will "hear" the left speaker)
 

ernestcarl

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whoever had a phase issue in one of the speakers knows the answer.
when the phases match the speakers disapear.
any slight variance smears the center image (e.g. voices coming partly from the right, partly from the left), and "compresses" the location panned stuff (e.g.: a 70% left panned signal will sound like 100% panned in a given frequency. in that range you will "hear" the left speaker)

This may be a bit off-topic — though it is related — but have you ever tried something like the “pano shuffler” where one very deliberately introduces phase differences between the left and right main channels to improve the stereo phantom center and left-right tonal balance for voices?

In theory, that might make the front stereo speakers “disappear” even more.

https://www.diyaudio.com/forums/multi-way/277519-fixing-stereo-phantom-center.html

One can use preset settings in rePhase to apply the effect. But apparently you need to also apply some tailored post-equalization adjustments to balance things out based on what you hear afterwards.

Unfortunately, and try as I might, there is the loss of the sense of “depth” and spaciousness with the soundstage imaging in many recordings for some reason… so I haven’t continued using it.
 

dasdoing

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This may be a bit off-topic — though it is related — but have you ever tried something like the “pano shuffler” where one very deliberately introduces phase differences between the left and right main channels to improve the stereo phantom center and left-right tonal balance for voices?

In theory, that might make the front stereo speakers “disappear” even more.

https://www.diyaudio.com/forums/multi-way/277519-fixing-stereo-phantom-center.html

One can use preset settings in rePhase to apply the effect. But apparently you need to also apply some tailored post-equalization adjustments to balance things out based on what you hear afterwards.

Unfortunately, and try as I might, there is the loss of the sense of “depth” and spaciousness with the soundstage imaging in many recordings for some reason… so I haven’t continued using it.

I have seen that topic before, but didn't read very far. I don't see the issue, not for music. the engenier will EQ it until it sounds good. For movies might be a problem, not sure
 
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ernestcarl

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I have seen that topic before, but didn't read very far. I don't see the issue, not for music. the engenier will EQ it until it sounds good. For movies might be a problem, not sure

Yeah, I remember Earl Geddes also argued strongly against it. Though, the convictions of other proponents did make it sound as though the dips in the response were something one might find irritating enough to want to "solve" with additional processing. I did feel that there was an improvement in some vocal tracks, but occasionally the vocals became slightly too strong/harsh -- since again, as you say, engineer likely would have already anticipated and/or compensated for the expected changes in the phantom center vocals.
 

dasdoing

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Yeah, I remember Earl Geddes also argued strongly against it. Though, the convictions of other proponents did make it sound as though the dips in the response were something one might find irritating enough to want to "solve" with additional processing. I did feel that there was an improvement in some vocal tracks, but occasionally the vocals became slightly too strong/harsh -- since again, as you say, engineer likely would have already anticipated and/or compensated for the expected changes in the phantom center vocals.

the topic rises an instresting psychoacoustic topic, though. since it sugests that the phantom center of a reverbant room, will be diferent from a treated one.
 
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