Mis à jour le 4 November 2021.
Are 3-way hi-fi and home theater speakers really superior to 2-way models? Incidentally, what does “way” refer to? Here are some answers.
What are frequency bands?
When a speaker is only equipped with one wideband driver, it only has one channel, which means the totality of audible frequencies are delivered by the same driver. This is the case with the Cambridge Minx Min 12 compact speaker for example. Its older sibling, the Cambridge Minx Min 22, is also a 1-way model, despite the presence of two drivers. When both drivers cover the same frequency range, the speaker only has one channel.
Note that this type of speaker, which is very rare, has the advantage of having perfect tonal coherence.
In which instance is a speaker considered 2-way?
When two drivers are each in charge of a different and complementary frequency range. Most compact and center speakers fall into this category. One or several identical drivers handle the same low and mid frequencies (first frequency band), while the tweeter restitutes the highs (second frequency band).
In which instance is a speaker considered 2.5-way?
It’s a rather specific case, found with certain floorstanders and central speakers with three drivers. One of the low-mid drivers is prevented from restituting mid frequencies, firstly to make it more efficient in the lows, and secondly to be able to modify the speaker’s response curve more easily.
In which instance is a speaker considered 3-way?
Very simply, when three drivers each restitute different frequency ranges.
Sometimes these speakers have multiple woofers that all deliver the same frequency band.
How are frequencies distributed over multiple drivers?
This is the role of the passive crossover filter, integrated into the speaker. Inductors, capacitors and resistors are associated to each driver, filtering the frequencies coming from the amplifier.
Are three channels better than two?
On paper, the more frequency bands you add, the more efficient each driver becomes. If the lows are handled by a large driver, the mids by a smaller one and the highs by a tweeter – which is a 3-way setup – you get better results than you would with a 2-way speaker. It’s logical: in a 2-way setup, the woofer(s) must restitute mid frequencies, often up to 2 or 4 kHz, which means they have to cover a wide frequency range. However, there are certain requirements that need to be met.
Truly distinctive drivers
For a 3-way system to be efficient, each driver must be different. However, we can sometimes find speakers whose midrange driver is identical (or almost identical, with the addition of a bullet phase plug) to the woofer. An example: two 6” woofers, a 6” midrange driver and a 1” tweeter. On the contrary, the main advantage of a 3-way system is being able to use a smaller midrange driver, with a lighter cone and a more solid surround.
A good 3-way speaker must have three distinctive types of drivers.
A high-quality crossover filter
It’s often said that a good crossover filter is a filter with few components. There is a reason for this: the more components there are, the more the signal coming from the amp is degraded. But here’s the thing: less components means shorter crossover slopes between the different drivers. In other words, the drivers have a tendency to get in each other’s way. Also, the separation of frequency ranges isn’t as good, and ultimately, the perceived sound isn’t as precise. Furthermore, multiplying crossover points interferes with the audio signal’s phase as well as the coherence of the soundstage. Sometimes certain pairs of speakers have difficulty centering mono sounds.
Are there any good 3-way speakers?
Of course. As the price range gets higher, the number of 3-way and even 4-way floorstanding speakers multiplies. Their price tag is notably due to the development of the crossover filter which is particularly complex, but it is also due to the use of quality components, which are very expensive.
How to choose a good 3-way speaker
Choosing a model with completely different drivers (low, mid and high) is a good starting point. Next, it’s a good idea to choose a speaker from a company that makes their own drivers. The reason is simple: this way the manufacturer creates drivers for a very precise frequency range, or even to match another driver perfectly. We can therefore take a look at Focal, B&W, KEF, JBL, Klipsch, Dali or Tannoy, for example. However, some brands work closely with driver manufacturers and have their drivers made to meet certain specifications. This is the case for Jean-Marie Reynaud, Sonus Faber or Elipson for example.
Ultimately, is it less risky to have a 2-way speaker?
Because a 2-way speaker’s filtering is a lot simpler, with few components, this type of speaker has an undeniable advantage as the amplifier’s signal isn’t as deteriorated. There’s a catch, however. The crossover frequency between the tweeter and the midrange driver(s) is usually around 2 or 3 kHz.
The bad news is that our ears are extremely sensitive to this frequency range.
The electronic components disrupt the sound in this range (phase, delay). It’s also very difficult for a manufacturer to move this crossover frequency. Any higher and it means making a large driver cover even higher frequencies – something that it isn’t made to do – resulting in a muddy sound (delay, distortion). Move it any lower, and it means making the tweeter go lower, which is something it can’t do because of insufficient power handling capacities (they’d be a risk of it blowing at high volume). This is why some manufacturers, like Klipsch or JBL, horn-load their tweeters so that they can restitute lower frequencies, all whilst requiring less electrical current.
Verdict: is it best to choose 2-way or 3-way speakers?
As you will have understood, a 3-way speaker can be superior provided that it features distinctive drivers and quality filtering. Additionally, it has the advantage of being able to move the speaker’s crossover frequency two channels higher in frequency (often around 5 kHz) and doesn’t interfere with the listening experience. However, when compared with a cheaply-built 3-way speaker, a 2-way model is a better choice.