PS Audio sent Erin their speaker??!!

[tmtomh]

As a reviewer, doing anything else is irresponsible (feeding people unreliable and misleading information). I know some audiophiles love the sense of soundstage but go and listen to some live music and you will notice that the band's sound is diffused and there is no precise imaging, etc.

That's one reason I prefer home listening for hi-fi. Live music can of course be incredibly fun and exciting, but when it comes to amplified live music played indoors (as opposed to in an amphitheater or similar), most live venues sound like absolute sh*t.

 

[restorer-john]

And yet the test tracks used for single speaker evaluations are stereo, contain individual left and right content, precisely placed and moved objects and contain deliberate phase, level and other manipulations- all of which disappear when summed into mono for a single speaker "evaluation" of spatial qualities. It's hilarious.

 

[amirm]

And yet the test tracks used for single speaker evaluations are stereo, contain individual left and right content, precisely placed and moved objects and contain deliberate phase, level and other manipulations- all of which disappear when summed into mono for a single speaker "evaluation" of spatial qualities. It's hilarious.

I don't do any summing. Just play one channel. Today's music has usually equal spectrum in each channel. We are not talking 60's rock music.

 

[restorer-john]

I don't do any summing. Just play one channel. Today's music has usually equal spectrum in each channel. We are not talking 60's rock music.

You don't sum to mono for a single speaker test of a piece of music recorded in stereo when you are assessing the spatial qualities of a track you know, such as the one linked a few pages back?

Go actually listen to it and repeat your claim about there being an equal spectrum in each channel. In fact, if there is any stereophonic content whatsoever in a recording, that precludes the spectrum being equal in both channels.

 

[CleanSound]

On a lighter note, I am happy that we went to page 15 and have kept the discussion civil. This rarely happens on the internet and I really appreciate having this discussion with you gents.


And to that one guy who called this place toxic, that's because he is toxic and brought his toxicity here.

 

[Duke]

... go and listen to some live music and you will notice that the band's sound is diffused and there is no precise imaging, etc.

Researcher David Griesinger claims that there is a distance within which precise localization occurs, and beyond which it does not occur. Most seats in most concert halls are too far away and localization is not possible due to the excess of reflections. From the abstract of one of his AES presentations:

"... During this time I was also experimenting and writing about the perception of reflections and reverberation, both on recorded music and in live concerts. I found that they are beneficial only up to a certain level, which is often exceeded in halls and rooms. My current scientific work is developing models and measures that can explain why and where localization and proximity are lost due to excess reflections and reverberation. This loss of localization happens abruptly at a particular distance, which we call the Limit of Localization Distance (LLD). The LLD can be easily found by walking forward and back from the stage with eyes closed while musicians play."

Link: https://www.aes.org/events/147/presenters/?ID=8425

I don't think I could get away with walking forward and back from the stage with eyes closed while the musicians are playing so I'm making a leap of faith in trusting his observation about concert halls, BUT I have at times observed something similar with listening distance in home audio settings.

This is an earlier lecture of his, I think the content is probably similar [link goes to the correct lecture now]; he describes the Limit of Localization Distance in the first two or three minutes:

 

[ctrl]

The very complex differential graphs show many things interacting, but not in any way that could be called compression. It is just what an electromechanical system is going to do. You can't look at this graph and talk about "compression."

Amplitude compression is always the SPL difference between the frequency response at a certain voltage and the frequency response of a reference voltage from the "small signal domain."

Here is a technically accurate definition:



Any difference in the frequency response is compression. The causes for this can vary greatly, some of which I mentioned in the previous post.
Klippel distinguishes between two main causes of amplitude compression: thermal (e.g., heating of voice coil, magnet...) and nonlinear effects (limited displacement, resonances,...). In addition, active systems also involve influences from limiter and DSP.

Especially short-term compression is interesting, as it shows the nearly instantaneous change of FR with rising signal. Whether the signal length should be 0.25s or 2s is certainly open to discussion.

You need to show it as I did above for that Genelec speaker and Dr. Toole shows in his book?...Notice the large differential on the graphs on the right. That is compression.

That the results are normalized to a reference frequency response for better comparison is common practice and even slight deviations are referred to as compression (see definition above or in the video below).

Take a look at Prof. Klippel's presentation, where the exact definition of amplitude compression is given and various types (short-term and long-term amplitude compression) and measurement methods (from 0.2s signal measurement to 1h measurement) of compression are discussed.

 

[restorer-john]

~20seconds (1M FFT@48k)of the first part of that reference track a few pages back. As anyone can see, the spectrum is not the same in each channel is it? Not even close.

Frequency domain (left channel = yellow, right channel = red)

Time domain, 5s to 6s. (left channel = yellow, right channel = red)

 

[napilopez]

I know some audiophiles love the sense of soundstage but go and listen to some live music and you will notice that the band's sound is diffused and there is no precise imaging, etc.

This is very true. I'm sure some will come away with different impressions, but I listen to live and often unamplified music very often and whenever I hear speakers that's are too pinpoint precise, I find I'm taken out of the experience.

Of course, depends on how the music is recorded and mixed too.

That is OK, I myself have never experience this kind of 3D soundstage until within this past year when I got my Perlisten, Neumann and Ascend LX. Even the speakers I thought was great of the likes of Revel didn't even do that.


Thank you for confirming what I said.

Even with the same exact speaker, equipment, facility and environmental condition, it would never, ever be the same. That is the nature of sound waves. So you now mean to tell me that somehow you can predict how two speakers sound waves' construct, destruct and interact with each other by only measuring and listening to one speaker?

Curious, what do you think causes that impressive soundstage, from an engineering perspective? I've listened to and measured myriad speakers of all price points and designs, so I don't think that not listening to the right models is the problem.

And am I misunderstanding or are you saying that taking a frequency response measurement of the same exact individual speaker (as opposed to a match pair) in the same position, with the same equipment, will not yield identical results? This is easy to disprove, and if you're genuinely interested in seeing this I'd be happy to do so.

It is true that a stereo pair will exhibit a dip around 2 khz from interaural crosstalk. There will be some other measured interference that does not necessarily correlate to what the ear hears. But I don't think this interference of sound waves you are describing has much to do with creating a realistic soundstage beyond what is already present in the music. I don't think evidence to suggest that.

But again, it doesn't hurt to listen in stereo too. I think we're just disagreeing on the degree to which spatial quality in stereo depends on elements that are not also assessable in mono.

 

[HairyEars]

But you questioned the idea of having a woofer close to the floor like the FR10 based on the lack of recommendation of the same from Genelec. How is that feasible with a typical studio monitor (and especially in a studio)?

I wrote in my original post the monitor in question was a Genelec main, not a "typical studio monitor." Take for example the 1238A. It's height is 81cm and the vertical acoustic axis is 65cm. If the ear level in the seating position is 81m, then the monitor stand height should be 16cm. That's pretty close to the floor.

 

[HairyEars]

Don't think about it in terms of floor bounce "reduction" or "increase". That can only be done via absorption. What you're doing when you move the driver higher or lower is changing the frequency at which the first and strongest cancellation occurs. When you move the driver further from the floor the frequency goes down; when you move it closer the frequency rises. The strategy is then to carefully place the drivers (bass elements and midrange) such that the floor bounce frequency is pushed out of the driver's passband. I would guess that Genelec's recommendation is based on the understanding that frequency response aberrations are less audible the farther you push them out of the critical midrange where human hearing is most sensitive.

You can try playing with this calculator:

Floor/Ceiling Reflection Calculator

I would be skeptical of claims of hearing this phenomenon or absence of without a controlled experiment.

That's super helpful. Thanks!

 

[CleanSound]

Curious, what do you think causes that impressive soundstage, from an engineering perspective? I've listened to and measured myriad speakers of all price points and designs, so I don't think that not listening to the right models is the problem.

I don't know. But I do know a very tight tolerance pair matching is one aspect.

And am I misunderstanding or are you saying that taking a frequency response measurement of the same exact individual speaker (as opposed to a match pair) in the same position, with the same equipment, will not yield identical results? This is easy to disprove, and if you're genuinely interested in seeing this I'd be happy to do so.

Yes, I am. You don't have to prove anything, just show me two separate measurements of the same exact speaker where you can overlay and the measurements are identical. That simply does not exist.

 

[napilopez]

Yes, I am. You don't have to prove anything, just show me two separate measurements of the same exact speaker where you can overlay and the measurements are identical. That simply does not exist.

By proving, I mean simply taking the very measurements you speak of. Since I see you have REW, have you tried this yourself?

I've done this many times as has I think anyone who's ever taken spent a meaningful amount of time taking anechoic or quasi-anechoic measurements.

 

[restorer-john]

Differences in impedance sweeps in a pair should tell you they cannot be truly identical in terms of output.

 

[CleanSound]

By proving, I mean simply taking the very measurements you speak of. Since I see you have REW, have you tried this yourself?

I've done this many times as has I think anyone who's ever taken spent a meaningful amount of time taking anechoic or quasi-anechoic measurements.

Let's be clear, I said identical, not very close.

I have never gotten identical measurements with REW, and I wouldn't expect to. I am also saying you won't get identical even with the same speaker, with the same equipment, in the same facility with the same environmental condition.

 

[amirm]

You don't sum to mono for a single speaker test of a piece of music recorded in stereo when you are assessing the spatial qualities of a track you know, such as the one linked a few pages back?

No I don't. I am listening to one speaker that would normally be playing that channel. Spatial qualities as we have discussed are properties of one speaker and can more certainly be ascertained.

 

[napilopez]

Let's be clear, I said identical, not very close.

I have never gotten identical measurements with REW, and I wouldn't expect to. I am also saying you won't get identical even with the same speaker, with the same equipment, in the same facility with the same environmental condition.

Hmm okay, you did say "very very close" in an earlier post, so just trying to see what your expectations are. I'll share some measurements probably over the weekend. Weather permit I was thinking of making a spinorama of my new center channel anyway.

 

[CleanSound]

Hmm okay, you did say "very very close" in an earlier post. I'll share some measurements probably over the weekend. Weather permit I was thinking of making a spinorama of my new center channel anyway

Very very close, in the sense of the overwhelming vast majority of the graphs are identical, maybe something like within 1/64th of a dB for 80% of the graph.

Try all you want. It simply doesn't exist. Microsoft has the world quietest anechoic chamber, they hold the Guinness world record. And even they can't produce something that is almost identical. I don't know the exact science, but I suspect it has to do with the characteristics of soundwave.

Also, even if one can produce identical explain to me the science of how that can accurately predict spatial sound characteristics of stereo by ONLY evaluating mono?

 

[napilopez]

Very very close, in the sense of the overwhelming vast majority of the graphs are identical, maybe something like within 1/64th of a dB for 80% of the graph.

Try all you want. It simply doesn't exist. Microsoft has the world quietest anechoic chamber, they hold the Guinness world record. And even they can't produce something that is almost identical. I don't know the exact science, but I suspect it has to do with the characteristics of soundwave.

Also, even if one can produce identical explain to me the science of how that can accurately predict spatial sound characteristics of stereo by ONLY evaluating mono?

Okay, fair enough then. If those are the parameters then I guess I've never investigated a match with quite as much scrutiny. I find it highly unlikely that having such an identical match will make a difference acoustically, vs something that's say, within 1/4db, but it's something to investigate.

Where did you read about Microsoft not being able to do so?

As for the second part, we already determined earlier we were talking about spatial qualities for different purposes (comparison and review in my case) so I'll leave that for someone else to address if they wish.

 

[MAB]

I don't know. But I do know a very tight tolerance pair matching is one aspect.

I'm not sure two matched speakers in a room will still be matched.
Even if you have two speakers matched to within 0.01dB, the typical room makes them mismatched by more than 3dB above transition, and more than 10 or 15dB below, unless you have a magical room. And even worse, the early and the reflections by large amounts as well. The room bends the speaker's response dramatically. So how can exact matching even be a criteria? I have always heard it's even smooth dispersion that allows speakers to provide a reasonable sound-field, creating the illusion of an image. I keep reading this, and I see it in good speaker's measurements.

Here are a left and right pair of well-matched speakers in a room.

These pair are within 0.5dB of each other, but are a mess in my room.
The smoothed response post room-correction isn't so bad:

You seem to have noticed the same issues in your REW measurement thread on your own speakers. Don't despair! You have great speakers, it's your room. The good news: these good speakers in a reasonably controlled room, even with the large room-induced imbalances will still energize the room in a way that allows a good image on the right recoding. I invest zero time on left/right, I do invest time on trying to tame room modes and reflections. I think I showed these effects of the room in the Perlisten thread you started. In my experience the reflected sound is even more variable, and those interactions are critical in the trick of imaging. Amir and others mentioned this earlier. There is an entire thread on imaging where this is discussed. Probably better to just read Toole and the literature.

One parting quote from Toole:

It is an interesting trait of the human ego that most of us, most of the time, know how certain things should be. Stereo is no exception. In spite if the fact that recordings are created, by and large, from multi-track tapes (or at least multiple microphones in acoustically foreign environments), many folks persist in believing that two speakers in a room are capable of rendering positions, dimensions, and ambience that, to them, should be perceived as realistic. Fortunately, humans have good imaginations, because occasionally this miserably imperfect system works amazingly well.

Yes, I am. You don't have to prove anything, just show me two separate measurements of the same exact speaker where you can overlay and the measurements are identical. That simply does not exist.

Hopefully the above L/R response graphs help show that even matched L/R pair are going to be mismatched in a room. I would be irritated if I got a pair with a large mismatch for sure. I even measure my speakers out of paranoia, but more for defect rather than L/R since I have had drivers with issues (new drivers with VC rub, a new TOTL Seas woofer with surround delaminated from the cone, etc...)