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"Better" speakers to begin with, or more "fixes" everyone knows?

amirm

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#41
It's not uncommon when these technical arguments go over audiophiles heads, like Fitz, that they side with the "personality" they can best relate to.
For example there is no way for Fitz to understand the conflict here:

The lateralisation type stuff is obviously insurmountable for the casual reader as well.
No problem really, this is all just discussion.
"Lateralisation type stuff?" This is what you read into I what I was saying? If so, the plot is completely lost. So let me make sure it is clear.

Above transition frequencies measurements of room acoustics can lie and lie big time. We have two ears and a brain that interprets a completely different picture than than what you see in a graph from a single microphone. You must, must incorporate science of psychoacoustics in analysis of what is going on in higher frequencies. And that science relies on listening tests. See this article for a taste of it: http://www.audiosciencereview.com/forum/index.php?threads/perceptual-effects-of-room-reflections.13/

I showed in my post one example of changing the displayed frequency response to better match how we hear. You do not want to "fix" problems that are not there. There are people who fixate on these graphs then a year or two later wake up and realized they have a prettier one but worse sound.

So before saying there is a problem to be fixed, you need to demonstrate that it is indeed a problem in the manner you envision. Mind you, I am not saying there is no problem. I am just saying you can't keep talking about this topic by ignoring psychoacoustics.

Bottom line, I don't think you are understanding my answers to you so to declare someone else confused seems quite wrong.
 

amirm

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#42
Providing references is normal in a technical discussion. It answered my question about where the term probably came from and that it means a more generalized multipole sound source. For what it is worth I do not have access to the journal from home but can get access to it should it be sufficiently interesting. In this case it is not.
I highly encourage providing such references. What I don't like to see is dropping links to AES papers without the person himself having read them, or having read them but can't be bothered to quote anything from them. Membership here cannot be expected to be members of AES and know how to read and understand the papers. If they did, they would not have much use listening to AJ telling them about it.

Vast majority of our members are audiophiles who like to learn and as such, it is our responsibility to quote and translate the relevant portions of research papers. Indeed that is "normal" in publication of papers. No paper provides a link in the references without explaining the reason they have done so.
 

AJ Soundfield

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#43
"Lateralisation type stuff?" This is what you read into I what I was saying?
No, I'm saying those type of concepts are completely unknown on typical audio chat sites. How many folks reading here do you think knew what that was, or what JJ was referring to specifically in the slide when he talks about down to 40hz?

Above transition frequencies measurements of room acoustics can lie and lie big time. We have two ears and a brain that interprets a completely different picture than than what you see in a graph from a single microphone.
Yes, that's why I use 1/6th oct when I post my own FRs. Who do you think was advocating for psychoacoustic scaling in REW? :)

So before saying there is a problem to be fixed, you need to demonstrate that it is indeed a problem in the manner you envision. Mind you, I am not saying there is no problem. I am just saying you can't keep talking about this topic by ignoring psychoacoustics.
To be honest, I was only poking a bit of fun at you pointing out a null at 480hz.:p
No more, no less. I never asked how/whether you proposed to "fix" this...

Bottom line, I don't think you are understanding my answers to you so to declare someone else confused seems quite wrong.
Well, my response to Andy(HG) was actually directed at Fitzcaraldo.....so I guess there is some confusion there.
In any case, as I've stressed, this is not for everyone. If folks are happy with their mono bass and room stuffed with "traps etc" to "treat" those "room" problems, more power to them.

cheers,

AJ
 

AJ Soundfield

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#44
I highly encourage providing such references. What I don't like to see is dropping links to AES papers without the person himself having read them, or having read them but can't be bothered to quote anything from them. Membership here cannot be expected to be members of AES and know how to read and understand the papers. If they did, they would not have much use listening to AJ telling them about it.
Maybe that's my ploy to get them to join AES. $100 spent there on a wealth of info, instead of some magic doo-dah or audio comic books.;)

Vast majority of our members are audiophiles who like to learn and as such, it is our responsibility to quote and translate the relevant portions of research papers. Indeed that is "normal" in publication of papers. No paper provides a link in the references without explaining the reason they have done so.
Actually I've copied several quotes from the papers themselves, like the McGill study. But would rather encourage folks to at least make some effort to read first, then have thing explained. Otherwise, they would never need to read it to begin with.
You don't honestly think I don't have these papers I link, for several years?

cheers

AJ
 

Purité Audio

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#45
My next obvious question is, how do you, in your loudspeaker designs implement these ideas?
Keith.
 

AJ Soundfield

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#46
My next obvious question is, how do you, in your loudspeaker designs implement these ideas?
Depends on which, but I make them directional using horns/waveguides for the high frequencies and then either piston diameter and/or various forms of gradients for the mid-low frequencies, with variability thrown in. For example, if you EQ a dipole woofer to have the same free field response as a monopole and combine them where they are correlated (not separated by >1/3 wavelength, easily done at LF, even 300hz is nearly 4' long), the result is a cardioid.
If you put a XO between them, you can have the low part of your range monopole, where modes are sparse and as all the research I've linked indicates, monopoles make sense (<40-50Hz). Above the crossover it will be dipole. But in between (around the XO frequency itself, where the responses slope away), the mixed radiation will be cardioid. Depending on the room/taste of the listener, you can slide the XO frequency up and down, so if you wanted that monopole pressure "punch" (dipoles are velocity sources, the net pressure change in the room is zero), you slide the XO up around 80hz. For more acoustic tye music jazz/classical etc, you may want more pitch and definition to the bass, so you slide the XO down to 4ohz, leaving >40 cardioid>dipole, which radiates 6db less power into the room reverberate/modal decay, something akin to "traps", except without the traps. If you make this all rotatable (ala the Revolution), then the nulls can be turned to better couple to the room modes. IOW, it's not a accident why JA and REG are swooning about the real in room response and the subjective result in the bass. The measures match the perception, which is always a good check for reality. You can still use EQ and even "treatments" if they fit your needs, but you've applied the greatest amount of 'fix" to the source itself, prior to doing anything obnoxious to the room.
As Toole said, you can't fix directivity with EQ.
It should also be apparent that preferences rule here. Some folks may actually prefer mono bass (with smooth amplitude only) and padded rooms. YMMV.
Btw, that's what I do just for the bass/lower mids area. The upper stuff also has variable indirect radiation capability from uppermid>highs, once again to adapt to rooms/preferences/"stereo" inadequacies.

cheers,

AJ
 

Purité Audio

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#47
It all sounds eminently sensible, why do not more manufacturers make speakers lke yours?
Is it simply because there is an element of adjustability ,which would mean extra work for retailers?
Keith.
 

amirm

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#48
It should also be apparent that preferences rule here. Some folks may actually prefer mono bass (with smooth amplitude only) and padded rooms. YMMV.
No one prefers "mono bass" in the way you are using it. That would imply taking any sound we consider as "bass" and summing it to mono.

Mono bass in the context of using subs means only the signals routed to the sub will be in mono. All the higher frequencies going to the main speakers will still be in stereo. Here is the first four seconds of track, "drum solo" from Chesky's album,

upload_2016-3-29_8-20-34.png


If we set the crossover to subs at 80 Hz, just the full spectrum of this drum extending to many kilohertz will play out of the mains and in stereo assuming that is how it is recorded.

Here is a track from Sheffield Drum Solo where it only has low frequencies (just like above):

upload_2016-3-29_8-30-53.png


So clearly there is a lot of spectrum in what we call "bass" and almost all of that will come out in stereo.

The links AJ has provided say we may, may be able to detect directionality of bass down to 40-50 Hz. Such a threshold detection does not come into play when you are playing the full spectrum of music with vast majority of spectrum in stereo.

So no, no one should be worried about "mono bass" as anyone who listens to music with subs can attest. No sense of channel separation is lost much less in Jazz, etc. that is dominated by mid to high frequencies anyway.
 

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amirm

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#49
If you put a XO between them, you can have the low part of your range monopole, where modes are sparse and as all the research I've linked indicates, monopoles make sense (<40-50Hz). Above the crossover it will be dipole. But in between (around the XO frequency itself, where the responses slope away), the mixed radiation will be cardioid.
AJ as you well know there is no such thing in real speakers as "cardioid." The correct term is "cardioid like." So that everyone can follow us, this is a cardioid:



This is an idealized, theoretical curve. Real devices do not create such perfect patterns. You mentioned the Kii speaker. I asked you if you had listened to it and I take it you have not. Stick your head to the back of that speaker and what you hear is an awfully distorted sound. That distorted sound bounces around the room and mixes with the good sound coming out the front. Maybe you have done a better job in which case let's see a frequency response and distortion measurement of your speakers from back angle. Without it you are selling a concept, not reality.
 

Purité Audio

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#50
I know a couple of actual customers with Kiis and neither has mentioned 'awfully distorted sound' from the rear, when I asked they simply said there wasn't a great deal of output of any frequency from the rear, I will certainly check when our first pairs arrive.
Keith.
 

AJ Soundfield

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#51
No one prefers "mono bass" in the way you are using it. That would imply taking any sound we consider as "bass" and summing it to mono.
So clearly there is a lot of spectrum in what we call "bass" and almost all of that will come out in stereo.
Amir, I am being very clear what frequencies I'm talking about, no need to strawman or red herring the discussion. When you talk "multi-sub", you mean mono. Whatever XO you select, 70, 80 or 90Hz, your processor sums that bass signal to mono. That's a fact. The "multi-sub" setup is always mono. Mine is too, just below 40-50hz, not 80-90hz, well above where lateralisation is possible.

Here is the first four seconds of track, "drum solo" from Chesky's album
That has zero relevance. That's a drum kit, most likely muti-mic'd in mono. It's clear you're not understanding the concept. This is regarding spatial information into the bass region captured in stereo recordings of orchestras, big bands, etc.

The links AJ has provided say we may, may be able to detect directionality of bass down to 40-50 Hz.
No. You are confusing localization (ability to detect apparent source direction) with lateralisation. Or maybe the fact that I say my speakers retain directivity characteristics below the transition frequencies, basically full bandwidth. Here is what my link shows, as JJ summarizes perfectly:

We can detect spatial effects from interaural phase differences, i.e., between the channels, if the material is so encoded, down to around 40Hz. We cannot localize down to 40Hz, i.e., tell direction, unless there are spurious distortions.
The links on DIYA I gave you clearly show stereo content, i.e differences between L-R channels in classical recordings..and many others. No question that many, if not all pop etc recordings are indeed mono bass, i.e. zero interchannel differences. HT/movies, forget it, all mono.
That isn't my concern. And obviously not the concern of the vast majority of audiophiles./listeners. I don't care.:)
That's not my target audience.

cheers,

AJ
 

AJ Soundfield

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#52
AJ as you well know there is no such thing in real speakers as "cardioid." The correct term is "cardioid like." So that everyone can follow us, this is a cardioid:
:rolleyes:
Then I guess your Revels are "monopole like".
Ray Dunzl stats are "dipole like" :rolleyes::p

You mentioned the Kii speaker. I asked you if you had listened to it and I take it you have not. Stick your head to the back of that speaker and what you hear is an awfully distorted sound. That distorted sound bounces around the room and mixes with the good sound coming out the front.
Seriously?:rolleyes:
And who listens from the rear? It ought to sound a mess given it's being electronically delayed over a small bandwidth. Won't even bother addressing how absurdly silly that is, how did it sound from the LP?

Why don't you face your Revels to the wall and then tell us how it sounds from the LP. That's about equally "logical".:D

cheers,

AJ
 

amirm

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#53
The links on DIYA I gave you clearly show stereo content, i.e differences between L-R channels in classical recordings..and many others.
Quote them please, showing that difference only exists in sub crossover frequencies and not above. I don't think you can but let's see it.

No question that many, if not all pop etc recordings are indeed mono bass, i.e. zero interchannel differences. HT/movies, forget it, all mono.
That isn't my concern. And obviously not the concern of the vast majority of audiophiles./listeners. I don't care.:)
That's not my target audience.
Your audience for your posts are all the members. And so far, despite reading all of your posts, your position here is as clear as mud. Are you saying that by summing the signal to subs reduces in any meaningful the separation in low frequencies as we hear in music? And by low, I mean the full spectrum of that instrument, not the subset between 50 and 80 Hz. Do you understand what I am asking?
 

NorthSky

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#54
And who listens from the rear?
AJ
Some of the best concert halls in the world have premium seats behind the orchestra, and on balconies on each side.
I could post few pictures if you want me to?

The science of music listening and sound propagation goes beyond the front sound stage, it's all around in a 360° polar sphere.

* We might experiment with omnipolar speakers in the center of a party room, and have party goers and dancers all around the musicians playing in the center.
 
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AJ Soundfield

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#55
Quote them please, showing that difference only exists in sub crossover frequencies and not above.
You would have quote your strawman since only he made such a claim. Anyone here reading those links can see than stereo, that is differnces between L-R channels, exist in many classical, jazz acoustic etc music, falsifying your claim only mono bass exists in recordings.

And so far, despite reading all of your posts, your position here is as clear as mud.
Nope, it's clear that I, the paper, Griesinger and JJs very precise words, are stating the same thing: your mono summed bass below 80-90hz has zero chance of reproducing spatial effects from interaural phase differences, which can exist to 40hz.
You don't like this new information you didn't know about, so you rail against it. That's ok, if mono bass with smooth amplitude meets all your needs, then you need not worry.
 

AJ Soundfield

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#56
Some of the best concert halls in the world have premium seats behind the orchestra.
Bob, that has zero to do with Amirs claim the Kii with it's DSP delayed bandwidth limited rear drivers to create cardioid speaker, sounded "distorted"...from the rear!!
Amir should and does know better than to make such silly comments.
 

AJ Soundfield

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#58
Amir, Dr Griesinger:


One of the common fallacies in this field is that the perceived sound quality depends only on the sound pressure at the listening position.

A corollary of this assumption is that optimum bass in a room occurs when the pressure at low frequencies is maximally uniform both with frequency and listener position. In other words, sound is best when a listener hears all low frequencies equally loudly regardless of where he or she happens to be.
In practice, bass does sound better when it is free of gross frequency response anomalies.
However the assumption that sound quality depends only on sound pressure is clearly untrue.


http://www.davidgriesinger.com/asa05.pdf
 

amirm

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#59
Nope, it's clear that I, the paper, Griesinger and JJs very precise words, are stating the same thing: your mono summed bass below 80-90hz has zero chance of reproducing spatial effects from interaural phase differences, which can exist to 40hz.
You still don't see the issue? I am asking with real music that has content well above those frequencies, what is the subjective difference of not hearing "interaural phase differences" in that narrow band. Do you have this data or not?

You don't like this new information you didn't know about, so you rail against it. That's ok, if mono bass with smooth amplitude meets all your needs, then you need not worry.
No, I just don't like people hiding behind links without the ability to paint a coherent story that hangs together. The world is full of people who have designed speakers around this or that acoustic theory. What is usually missing is that they don't have an integrated story as to why it matters. They used timber cut by virgins in a tropical island that doesn't resonate as such. That is where you are, while complaining about other people's work where such an integrated, demonstrated, verified point of view exists. Name throwing of JJ and such doesn't save you in this forum.

I mean you have not even provided a measurement to show your speakers do what you say they do. And of course we are never going to see any kind of blind test.
 

NorthSky

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#60
AJ, I just mentioned because all kind of people like all type of speakers, and the sweet spot varies from very narrow to very wide and depending of the amount of toe-in, the room's reflections, acoustic dispersion and absorption, plus the music type playing, and, stereo or multichannel.

Why be limited to the almost perfect speaker that measures almost perfect on and off-axis in an imperfect room of our imperfect world.
What we play is what we like listening to, and we buy the speakers that we think we like because they sound good in our listening room.
And when we buy another house we bring our speakers to that new room. We tune our life with our decor, with the acoustics of our room if it doesn't impede too much with our decor, and the speakers are part of the decor with their acoustic signature...smooth just the way we like to go with our smooth lifestyle and soul.

Science can measure all she wants, and science includes our preferred designs with that preferred sound.
Some folks treat their rooms first, then they pick some of the speakers that not only measures superb but also looks superb.
Depending of the room's size they can be big full range towers or small hi-res monitors matched with a good quality sub or two for more flexibility in the lows.
Or they can supplement large towers with large subs that can plat clean down to 16Hz for those organ pipes. ...Cross the towers @ say 40Hz.

Tune the room first, then tune the speakers...toe-in, amp matching, speaker cables, listener position, distance of the three points from that triangle of life.
Take Ethan's advice for room's acoustical treatments, then pick your speaker designer...AJ, Harman, Magico, or B&W. ...The others don't forget to look @...Sonus Faber, Wilson Audio, Triangle (French speakers), Rockport Technologies, Paradigm, PSB, KEF, ATC, PMC, Genelec, and about two thousand other speaker's companies. ...From Germany, Italy, France, UK, Sweden, Norwegian, Switzerland, Spain, Japan, USA, Canada, and Iceland.

...After you tuned your room first.

I was visiting Guatemala years ago, in the mountains and the jungles; the trees looked like they can make good sounding speakers. while I was playing my classical guitar made of rosewood (Paracho, Mexico - where I bought it). Someone stole it, years later, and the sound still resonates in my heart and soul.

It's not easy to live in harmony in a world of pain and tumults, but us the music passionate we search for peace, no matter what.
We fill our heart and soul with gas and we're good to go when the jet stream is uninterrupted with the passages of life.

What we measure cannot always be correlated to what we don't; and that's a fair measure too in our music journeys.

We tune our environment first (room) and then the speaker. When we design a great speaker we design it around a peaceful and pleasant environment.
Sound first form to match.
 
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