Tag: speaker

Choosing Speakers by Reading Spinorama Charts!

Hello! this is Jooyoung Kim, an engineer and music producer.

Today, I’d like to explain Spinorama, a concept anyone interested in sound and speakers should know. Let’s get started!

Example of a Spinorama Graph

First, let’s briefly look at the history of how Spinorama measurements were developed.

Spinorama was created in the 1980s by Dr. Floyd Toole, a leading authority on speaker acoustics, while he was working at the National Research Council of Canada. In the 1990s, it was further refined in collaboration with Harman International. It has since been incorporated into standards issued by the American National Standards Institute (ANSI) and the Consumer Electronics Association (CEA).

Standard Method Of Measurement For In-Home Loudspeakers

The measurement process, as shown above, involves taking measurements every 10 degrees horizontally and vertically in an anechoic chamber, resulting in a total of 70 data points.

This looks intense…

The collected data is represented in six frequency response graphs known as Spinorama charts.

KEF R3 META

Let’s look at the Spinorama graph for my recently purchased KEF R3 META. The vertical axis is dB SPL (the unit we often use to measure sound levels, like airplane noise), and the horizontal axis is Hz (the unit of frequency).

  1. The top blue line is the On Axis response, representing the frequency response directly in front of the speaker. Manufacturers commonly provide this graph, but it lacks comprehensive information.
  2. The second orange line is the Listening Window response, which averages the frequency responses from ±10 degrees vertically and ±30 degrees horizontally, totaling 9 measurements. This approximates the expected response in a typical listening environment.
  3. The third red line represents Early Reflections, showing the response of early reflected sounds. It averages 8 measurements taken at ±40, ±60, and ±80 degrees horizontally, and ±50 degrees vertically. A significant difference from the On Axis and Listening Window responses helps distinguish between direct and reflected sounds.
  4. The light blue Sound Power response averages all 70 measurements. The more this graph parallels the other graphs without significant fluctuations, the better the speaker’s acoustic performance.
  5. The green Early Reflections DI (Directivity Index) is the difference between the On Axis and Early Reflections responses. This graph helps to quickly understand the difference between direct and reflected sounds.
  6. The brown Sound Power DI is the difference between the On Axis and Sound Power responses. Research suggests that smoother changes in both DI graphs are preferred by listeners (I’d provide the exact study, but finding it would take some time… I’ll update if I come across it later).
Genelec 8351B
  1. The On Axis chart shows the basic frequency response.
  2. The closer the Listening Window response is to the On Axis response, the more similar the sound will be for the listener and those around them. This indicates good off-axis performance, meaning the sound remains consistent even if the listener moves slightly.
  3. The more aligned the Early Reflections, Sound Power, and On Axis graphs are, the higher the preference among listeners. If it’s hard to judge, check the DI graphs for a consistent slope.

This gives a basic understanding of Spinorama charts.

Of course, Spinorama charts have their limitations. As the title suggests, you shouldn’t choose a speaker based solely on these charts. However, they are a fundamental indicator for understanding a speaker’s performance, making them valuable knowledge for anyone in music or sound.

In future posts, I’ll discuss near-field measurements by the German company Klippel.

Finally,

https://www.spinorama.org/

This site offers Spinorama charts for many speakers measured so far. Since it aggregates data from various sources, make sure to choose highly reliable sources in the settings tab for accurate information.

I hope this post is helpful for you! See you in the next post!

Basics of Mixing – 2.4 Speaker Placement and Listening Techniques

Hello, This is Jooyoung Kim, a mixing engineer and singer-songwriter.

To mix effectively, you need to listen to sound accurately.

What does it mean to listen to sound accurately? It can be a long discussion, but let’s focus on two main points:

  1. Minimize distortion (from the room, objects, speaker baffle, speaker unit limitations, etc.)
  2. Listen from the correct position.

These two principles form the foundation.

Generally, stereo speakers are arranged in an equilateral triangle. The angle marked as 30 degrees in the diagram above is called the Toe-In Angle. This angle can be adjusted slightly based on personal preference.

Additionally, the tweeter, which reproduces high frequencies, should be positioned close to ear level. This is because high frequencies are more directional and may not be heard well if the tweeter is placed too high or too low. Various stands are used to achieve this positioning.

However, recommended angles and placements can vary by manufacturer, so it’s best to start with the manual and then adjust as needed.

When changing placements, it’s important to measure and identify where the issues are. With some training, you can listen to a track and identify boosted or cut frequencies, giving you an idea of where the problems lie. Measurement, however, makes it easier to pinpoint specific issues you might miss by ear.

One of the simplest and free measurement programs is REW (Room EQ Wizard), which I introduced a long time ago.

Room EQ Wizard

You can use an affordable USB microphone like the miniDSP UMIK-1 for easy measurement, or, if budget allows, a measurement microphone like the Earthworks M50.

By measuring, you can understand various factors beyond just frequency response, such as phase, harmonic distortion, and reverberation time. This helps you identify and solve problems in your workspace.

Doing all this ensures you hear the sound as accurately as possible, allowing you to understand what proper sound and mixing should be.

So, you’ve set up your speakers correctly. How should you listen to the sound?

Of course, you listen with your ears, but I’m not just saying that. I’m suggesting you listen to the sound in layers.

In a typical 2-way speaker, the tweeter is on top, and the woofer is on the bottom, so high frequencies come from above and low frequencies from below. Consequently, low-frequency instruments seem to be positioned lower, and high-frequency instruments higher.

If your listening distance and room support it, well-made hi-fi tallboy speakers can make mixing easier.

That was about the vertical plane. Now, let’s talk about the front-to-back dimension.

When someone whispers in your ear versus speaking from afar, there are noticeable differences:

  1. Whispering sounds clearer (more high frequencies, less reverb)
  2. Whispering sounds louder.

These principles determine whether instrument images appear in the front or back. Panning also moves them left and right.

If you’re not familiar with this concept, try closing your eyes and identifying where each instrument is located in a mix.

Since stereo images vary with different speakers, it’s crucial to understand how your speakers reproduce images. Reference tracks are essential for this.

For example, I always listen to Michael Jackson’s albums and the MTV live version of “Hotel California” when I switch speakers. Michael Jackson’s songs are well-mixed for their age, and the live version of “Hotel California” is superbly mixed except for the vocals.

Let’s wrap it up for today. Creating the best acoustic environment in your room is essential for effective mixing.

My environment isn’t perfect either, but I’m continuously improving it..!

See you in the next post!