Master Thread: Are Measurements Everything or Nothing?

[voodooless]

I upmix stereo recordings to surround. Is that 'touching' or 'accommodating'?

I’m pretty sure there are some gray areas, so who knows…

In terms of a painting, your cutting it up into pieces and arranging them into 3D space to create the illusion of more depth

 

[Newman]

I upmix stereo recordings to surround. Is that 'touching' or 'accommodating'?

I would say the latter. 'Touching' would be: overdubbing another instrument onto the recording. But one could argue....

(Good) upmixing is intended to reduce the inherent compromises of stereo playback in small (ie domestic) rooms. There is no intent to change the tonal balance of the music or instruments.

A painting analogy might be adding more angles of lighting, and more diffuse.

 

[Petrushka]

(Good) upmixing is intended to reduce the inherent compromises of stereo playback in small (ie domestic) rooms. There is no intent to change the tonal balance of the music or instruments.

A painting analogy might be adding more angles of lighting, and more diffuse.

Or lighting the scene while making a move, which doesn’t change the object, but compensates for the lack of dynamic range in photography, compared to eyesight.

There could be many analogies between photography and sound recording.

 

[MattHooper]

Any number of different analogies could apply depending on the point one wants to make.

Ultimately up mixing stereo to surround is another version of “ this is how I think it should sound” or “ I want it to sound this way” since it wasn’t heard that way in the mixing or mastering. And clearly the de-correlation, frequency dependent steering, ambient extraction enhancements or however, your up-mixer is handling it, is a departure from the original signal itself so you’re not preserving that with the highest accuracy. You’re basically saying that the original signal played back in its original form is not spacious enough for you, so you’re going to enhance it in the way you like.

Which is of course perfectly fine.

No apologies needed.

Personally I get enough room melting immersion from my two channel system that subtle ambience extraction and up-mixing for two channel doesn’t really do much for me.
(my surround system shares the same room as my two channel system).

So often enough if I’m going to upmix stereo it will tend to be some of the more aggressive surround modes. Especially for electronic music or some pop - I’m happy to hear some of the instruments showing up around me in the surrounds whipping around.

 

[krabapple]

(Good) upmixing is intended to reduce the inherent compromises of stereo playback in small (ie domestic) rooms. There is no intent to change the tonal balance of the music or instruments.

I don't upmix just for ambience or embiggening. I like when the occasional sound appears in the rear left or right channels...as they do in a 'real' surround mix.

 

[Rob_Gordon]

Hey everyone,

It's been a while since I posted. I don't know how far from the current topic this is gonna be but I wanted to share something that ultimately echoes a big chunk of the debates of this thread.

I've been doing music again and so, since time isn't expandable, the time I used to spend researching hi-fi audio gear (and reading posts here) was "relocated" to researching music gear (and reading posts on other forums). I got lost in an ocean of guitar amps, vintage pick-ups and boutique pedals.

A joke popped up here and there : "we painted this pedal in red, because it makes it sound better". And of course, there was the (reversed) debate "SS amps vs. Tube amps" with blind testing showing that nowadays SS amps can reproduce the same distorsion (!) as tube amps.

Obviously, I never saw one proper ABX test. It's all very unscientific. And I was thinking how much musicians are biased when they hear such amp or such guitar because of all the prejudices that come with it (the brand, the history, the looks...)

And so I thought that, obviously, the work they do in the studio, the instruments they play there, the effects they use (vintage or not), the location itself, all that color the way they hear the final mix.

And even though I still think it makes total sense to look for a hi-fi rig that does not introduce any distorsion on the source material, I still found it funny to realize that the musicians themselves might be the most biased of all. At least, they are probably hearing things quite differently than they would if they heard it blind!

 

[Cote Dazur]

Ultimately up mixing stereo to surround is another version of “ this is how I think it should sound” or “ I want it to sound this way” since it wasn’t heard that way in the mixing or mastering.

Very true, but when even in pure stereo, every time we move the speakers and/ or the seat, we change the sound and the stereo presentation, so we also do the “this is how I think it should sound”, even without EQ, CSP or up mixing.
At the end of the day, we all shape the sound of what we hear at home, one way or the other.
I have 3 systems at home in 2 dedicated listening space, one room is stereo only, the other is stereo and multi channel, different amps and speakers. They all present a recording differently, that is the way I want it.
To me, any up mixing of stereo is a step too far, that is how I fell, but I do not think I am correct or that other option are wrong, we all shape our system to match our preferences one way or the other. All that count is the pleasure we get from listening to the music.

 

[Mnyb]

Very true, but when even in pure stereo, every time we move the speakers and/ or the seat, we change the sound and the stereo presentation, so we also do the “this is how I think it should sound”, even without EQ, CSP or up mixing.
At the end of the day, we all shape the sound of what we hear at home, one way or the other.
I have 3 systems at home in 2 dedicated listening space, one room is stereo only, the other is stereo and multi channel, different amps and speakers. They all present a recording differently, that is the way I want it.
To me, any up mixing of stereo is a step to far, that is how I fell, but I do not think I am correct or that other option are wrong, we all shape our system to match our preferences one way or the other. All that count is the pleasure we get from listening to the music.

+1 even the most pan potted mono sourced stereo recordings have some kind of ”soundstage” effect ? So even stereo is a kind of illusion.

And for better recordings up mixing may actually reveal more of the soundscape, bypassing stereo’s limitations I would not consider it an effect if used correctly it’s another tool to better audio illusions at home .

 

[Romario]

I don't know if this is the right place but I have a question. I purchased a used analog class a/b amplifier with 70 W at 8 ohm/100 W at 4 ohm. I'll connect a DAC with volume control (zd3) and have two options. To Line in or directly into the Power Amp in. According to the manual the Signal to Noise specification (IHF-A, 8 ohm load) for line in is 104 db ( >100 db good enough?) but for the Direct input is a whopping 125 db. Line input is 20 kOhm vs 15 kOhm for Direct input. I read that above 10 kOhm the input impedance is enough but what about the S/N? Is there a benefit to opt for the Power Amp input instead of line in? Or are the differences to small to notice?

 

[antcollinet]

Is there a benefit to opt for the Power Amp input instead of line in?

Measureably? Probably.

Audibly - no.

Just use whichever is most convenient and suits your use case best.


EDIT - the benefit of using line in, is you can use the amp volume control as a high level limit. Run your DAC closer to maximum volume and protect your system in the unlikely event the DAC loses its marbles and outputs full volume.

 

[Romario]

True, with hdmi arc the DAC will turn on when the TV does. But I don't know yet if the 12v trigger from the DAC functions on the A/B amp. ( I have to just try) if it works I'll select line in. Thanks

 

[Eddie_Vanjovi]

A sound wave is rather complex. I've never understood why not record an instrument and try to replicate that sound wave perfectly with a driver. You completely remove the psychoacoustics and any biological bias. If you can get a driver to replicate that instrument, in all its complex sine wave function perfection, you'd be good to go. Many times I've heard the exact same FR graph on two different drivers and it does not sound exactly the same.

 

[kyuu]

A sound wave is rather complex. I've never understood why not record an instrument and try to replicate that sound wave perfectly with a driver. You completely remove the psychoacoustics and any biological bias. If you can get a driver to replicate that instrument, in all its complex sine wave function perfection, you'd be good to go. Many times I've heard the exact same FR graph on two different drivers and it does not sound exactly the same.

Because that's not how it works. The notion that an instrument's (which instrument at what SPL btw?) series of sine waves are somehow more complex or more difficult or more meaningful in a technical sense to reproduce than test tones is not accurate.

If you heard something different from different drivers with the same FR, then you were either hearing different distortion performance (if you were at a level where it was audible), different dispersion interacting with the room differently and/or your positioning relative to it, or you were perceiving differences that weren't actually there.

Edit: Or the drivers weren't SPL matched.

 

[voodooless]

Many times I've heard the exact same FR graph on two different drivers and it does not sound exactly the same.

So, which two drivers have the exact same frequency response?

 

[solderdude]

A sound wave is rather complex. I've never understood why not record an instrument and try to replicate that sound wave perfectly with a driver. You completely remove the psychoacoustics and any biological bias. If you can get a driver to replicate that instrument, in all its complex sine wave function perfection, you'd be good to go.

We will need 'holographic' microphones and holographic speakers with near perfect performance.
Recording would need to be done in an acoustic dead chamber to prevent acoustics playing a role.
And even when that problem is solved it would have to be mixed in a holographic way and even when that would be possible it still won't sound the same in each room simply because of the acoustics in a room.

Many times I've heard the exact same FR graph on two different drivers and it does not sound exactly the same.

That's because no 2 speakers are 'the same'

 

[Sal1950]

I upmix stereo recordings to surround. Is that 'touching' or 'accommodating'?

I would say the latter. 'Touching' would be: overdubbing another instrument onto the recording. But one could argue....

I guess I'd agree but I hate these word games. I've been very happily out of school for 60 years now.

I don't upmix just for ambience or embiggening. I like when the occasional sound appears in the rear left or right channels...as they do in a 'real' surround mix.

Same here. If all I wanted was a little ambience I could have just stayed with a Hafler circuit like I played with in the very early 70s

 

[voodooless]

So, which two drivers have the exact same frequency response?

Coincidentally:

BLINDTEST: Midrange 360-7200hz, NO audible difference whatsover.

Just realized no proper thread was made to explain in a simple way the blindtest I organized a little while ago: So here it is: Blindtest. Rotating cube (enclosure) with 2 different drivers per round, one driver at a time, on-axis to the listener. Bandpass crossover 360hz @ 7,200hz (48db/oct...

www.diyaudio.com

 

[antcollinet]

You completely remove the psychoacoustics and any biological bias

No you don't. Perceptive bias is aways at play - no matter the quality of reproduction. That is sort of the whole point.

And from an engineering perspective, sound waves are not complex at all in the electrical domain. A simple one dimensional voltage varying with time, and at frequencies that are trivially easy to deal with.

 

[Mort]

Many times I've heard the exact same FR graph on two different drivers and it does not sound exactly the same.

Stick around and stay open to having your mind changed.

 

[ahofer]

I've never understood why not record an instrument and try to replicate that sound wave perfectly with a driver.

A null test is definitive (IMO) in electronics. With speakers we have the microphone inaccuracies to take into account.