As many of you know, the best thing is to compare different speakers in my environment and choose one that suits my taste. Even if it’s not actually a good product, it’s something that suits my taste. However, it is very difficult for ordinary people who do not have enough money to test like this in reality. In the end, you have to go to a speaker store and listen to it and buy it, but most stores can’t hear it properly.
Today, we will look at objective indicators and find out how to select good monitor speakers more objectively and accurately.
Measurement graph in an unscented chamber
Many companies do not provide measurements in these unscented rooms, showing only product specifications. But with such simple specification, it’s hard to evaluate the speaker. In fact, you’re right to say you don’t know anything.
There’s already a lot of research and data that we’ve studied about how to design and what measurements should be made to make speakers that people feel are generally good.
People can’t be 100% good for me because of their taste, but we need to pay attention not only to subjectivity but also to objectivity because we can’t hear all the speakers in the environment we want.
That’s why I write down a few things to look at when choosing a speaker.
- On-Axis Frequency Response
On-Axis refers to the directional axis on which the speaker’s sound is radiated. It’s the front of a regular speaker. It’s the direction we listen to the speakers. Of course everyone knows this is the most important thing. If it’s not intentional, it’s a good speaker that can play sound flat across the entire band.
When reading all frequency response graphs, you should note the scale of the graph and Octave Smoothing. Octave Smoothing is a way to correct how dull the graph is. It is expressed as 1/n, and the lower the n value, the more dull and smooth the graph becomes. Non-Smoothing or high n-value smoothing can make the graph squishy and difficult to see at a glance, so it converts it into an appropriate Octave Smoothing.
Therefore, it is recommended to compare graphs in the same Octave Smoothing. But if this is different, we should refer to it and compare it. Companies that do not indicate which Octave Smoothing has been applied should be suspicious. This is because deliberately gentle octave smoothing can be applied to deceive enough to have a flat response.
Also, there are companies like Ampion that provide measurement graphs such as measurements in Half-Space rather than unscented measurements, so be careful when you read them (Ampion clearly notifies you of this).
What’s interesting is that in modern times, even low-cost speakers have a flat frequency response on On-Axis. With the application of DSP technology to speakers, more speakers can easily get a flat frequency response and produce a lower frequency sound.
But if the frequency response is flat, why aren’t all speakers the same? There must be other factors, right?
- Off-Axis Frequency Response
I don’t think there are people who listen to music and work in an unscented room. That’s why we’re always listening to the reflection of the room and the direct sound, so what’s very important is this off-axis frequency response. It is the sound that radiates off the axis and off the axis at another angle, not the radial axis at the front of the speaker.
This greatly affects the resolution, propensity, and staging of sound. It’s a very important indicator for evaluating speakers. You all know the nature of sound orientation. Hard work has a strong straightforwardness. The more you go to the lower station, the more ignorant you become.
Therefore, of course, speakers also have this orientation characteristic. But wouldn’t it be impossible to expect a good sound because there’s less reflection in the high and low reflections, so there’s no balance between direct and reflective sounds? And if you’re a speaker with an inconsistent orientation, the sound will be very different even if you move your head a little bit. I think I’m going to get a disc just thinking about it. It’s sad.
That’s why it’s a good speaker, designed to have a moderate radial angle (usually 90 degrees forward) and a certain orientation across the entire band. This is called Constant directivity.
And to do this, many speaker manufacturers are doing a lot of R&D on technologies such as wave guidelines and cardioid design. Any company that doesn’t consider this orientation design…I don’t think I can say it’s a proper speaker production company.
First of all, the ideal orientation design is an ideal orientation in which a very flat sound is made within a constant (90 degrees) radiation angle as shown below, and then a strange shape that is impossible to hear when it is out of the radial angle.
But as I said before, it’s still impossible in the real world. Therefore, as shown in the picture below, the speaker will be directed towards a smooth sound reduction across the entire band as it goes out of the axis.
The K model line of Kii Three from Kii Audio and 8C from Dutch & Dutch, and ME-G, which are speakers built with cardioid designs, is receiving this response from the cardioid design.
Polar Map and Out-of-Axis Response Graphs in Dutch & Dutch 8C
Shows near-perfect orientation patterns up to 100 Hz
The Polar Map of Kii Audio Kii Three
Kii is great, too.
Polar Map and Out-of-Axis Response Graphs for ME-Geithain RL901K
It’s a little squishy.
In general, this orientation is very challenging, so most speaker manufacturers aim for the following orientation:
It’s a pattern of orientation that has a certain orientation and gradually changes to directionlessness as it progresses to low regions.
To achieve this orientation, speaker manufacturers do a lot of R&D on wave guide designs.
There’s no wave guide, but it’s not a cardioid design. Is it a product that has made no effort to design the Constant directivity above? If you say so, you need to be suspicious at least once.
Speaker design considering sound diffraction
Sound has the characteristic of diffraction when it hits obstacles and corners. As I said before, the sound emitted from the speaker is not completely straightforward.
That’s why we need to avoid the diffraction of sound caused by the front bepples of the speaker enclosure.
Why is Genelec’s speaker ugly? It was a reasonable design to minimize this diffraction!
This distraction caused by the speaker’s front bepples causes unintended distortion of sound and also affects orientation control. The diffraction from the corner of the speaker creates another sound source.
Diffraction caused by speaker front bepples is most likely to occur in angular speaker front bepples design.
It is said that such diffraction can be greatly improved by making the edges of the front bevel slightly round. Some companies even remove the screws on the front of the speakers to do this.
The diffraction of sound by speaker enclosure is easily explained by the animation provided by Genelec below, so it will be easier to understand if you look at it.