Sound Reproduction: The Acoustics and Psychoacoustics of Loudspeakers and Rooms (Audio Engineering Society Presents)

Category: Engineering
Author: Floyd E. Toole
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by JohnBooty   2022-11-11

    Please cite actual research defining "objective audiophiles"
Sure, absolutely. Hope you've got time to read.

First, I want you to consider for a moment how remarkable it would be if we had no idea how to objectively measure "good" sound considering that this is a multibillion dollar industry that has existed for over a century. A world where we can calibrate televisions and movie screens objectively by automated means but not, for some reason, their audio counterparts. As rational minds might expect we don't live in such a world.

You'd want to look into research by Sean Olive, Floyd Toole. Here's probably your best starting point:

The TL;DR is that it turns out that most people prefer sound reproduction that (like video reproduction) is accurate to the source material, with a bit of a "house curve" that accentuates the bass frequencies that roughly corresponds to the Fletcher-Munson equal loudness curve. In the end, it's signal reproduction.

    Do you realize that all gear is tuned by ear - someone 
    listens to it to adjust how it sounds?
I don't realize it because it's not true. A person's hearing can change rather markedly from day to day due to factors like congestion, humidity, etc. This would be a remarkably laughable and irreproducible way to calibrate audio reproduction devices.

Audio technology companies that are serious about high quality sound reproduction make use of anechoic chambers:

...and/or measurement devices like the Klippel NFS to simulate anechoic measurements:

...and/or measurement devices like Audio Precision gear:

Of course, audio companies do tinker with their sound to some extent for subjective purposes. A lot of brands try to achieve a bit of a house sound. Ultimately though, audio reproduction is not wine tasting. We can objectively measure what is good and isn't good.

There is also room for subjective personal preference. Everybody's hearing is a little different. And even Floyd and Toole's research reveals average listener preferences. But ultimately...

    What is "objective" about sound?
Well, everything. As you know, "sound" is pressure waves in the air. Those pressure waves can be objectively measured in terms of frequency and amplitude. And those 1's and 0's in a digital audio stream for example have objective meaning. They are not a series of opinions. They represent frequency and amplitude. Anybody telling you otherwise is simply uninformed, or trying to pull the wool over your eyes and sell you something.
by JohnBooty   2021-06-05

    If you think this hobby is about the most precise 
    listening experience you would be wrong in my eyes. 
    It's more about the presence/power you get from a system
    that can saturate a 20A circuit with transients. 
Both things are true and the best systems nail both.

The research done by Floyd Toole and Sean Olive and others tells us that all other things being equal, listeners prefer speakers that accurately reproduce the input signal.

But, I also agree 100% that gobs of power and accurate reproduction of those transients is also key to listener enjoyment and that this is something that is currently (no pun intended) undervalued by the objective audiophile world.

In a modestly sized room one can have their cake and eat it too, with regards to studio monitors. My den music room is about 200 ft^2 / 19 m^2. In this room I have studio monitors crossed over to a pair of subwoofers and it's able to push some very satisfying output levels.

by apecat   2019-08-04
I'm glad you asked, and ideas are welcome! I'm not an audio pro and I suck at physics.

I'm at work but I fired up Skitch and made this ridiculous little drawing, which should explain the situation somewhat.

But back to business, with this nice house we don't really need to do much. The log walls absorb a lot, while leaving a nice little lively touch that makes it not feel like a padded room (one of my friends had a padded room before for music, and I've decided I definitely prefer a room that feels a little bit alive).

My friend has this DSpeaker Anti-Mode 2.0 for room correction

The same friend has two Genelec 8330A active speakers that could do room correction on their own

Then we have a previous model of the Genelec F One form factor subwoofer, I can't remember the model number, which is alphabet soup, even though it's connected to my system at home.

The Genelecs are both compact, durable and easy to transport, and we have telecope model stands for them. They have a super nice mid range for guitar and the human voice, and they're also quite nice to look at.

When we set up the space, we basically let the DSpeaker box do its frequency swipes for ten minutes or so. We'd be fine without it even, but it just clears up the bass so nicely.

by jasonwatkinspdx   2017-08-19
> Human beings don't listen to linear sine sweeps. We listen to music. ...

This is irrelevant. They're measuring frequency response, not trying to map the entire world of psychoacoustics. Log sin wave sweeps are a perfectly adequate way of measuring a transducer.

> Sine wave measurements of audio gear ignore impulse response, intermodulation distortion, phase shift, and a host of other real-world physical device responses to real-world musical signals.

No, when you do a sin sweep and measure the impedance you can recover all that. Pick up a basic textbook on loudspeaker testing.

> Scientific, reductionist thinking is inadequate to get an accurate picture of the factors that matter to human listeners.

You are completely mistaken. Here's the research itself:

Learning from it will require you to shed the chip on your shoulder, but it will put you miles ahead of your peers in understanding what's actually going on when we listen to music vs all the commonly repeated mythology.