Difference between active and passive speakers

In this piece, we’ll explore the distinctions between active and passive speaker setups, debunk popular myths surrounding them, and offer guidance on selecting the appropriate option for a home audio system. Passive speakers Passive speakers,...

Difference between Active or Passive speakers
Difference between Active or Passive speakers

In this piece, we’ll explore the distinctions between active and passive speaker setups, debunk popular myths surrounding them, and offer guidance on selecting the appropriate option for a home audio system.

Active or passive acoustics. How do they differ and which one to choose

Passive speakers

Passive speakers, a concept well-known among Hi-Fi enthusiasts, employ filters made of passive components such as capacitors, resistors, and inductors to divide the audio signal into distinct frequency bands. The objective is to isolate specific frequency ranges from the broad-spectrum signal, with each range being reproduced by a dedicated emitter for high, mid, or low frequencies.

Active or passive acoustics. How do they differ and which one to choose

The hallmark of passive speaker systems is that the filters within them process a high-amplitude signal from the power amplifier’s output stage. This setup means the precision of the filters’ function is deeply reliant on the accuracy of their design calculations and the quality of the passive components in the crossover network. Sound quality can be influenced by a range of factors, including added impedances, the capacitance of capacitors, potential phase distortions, the reliability of connections, and more. Additionally, the amplifier is subjected not just to a reactive load from the speaker drivers but also faces the challenge of overcoming the resistance of the filter components. This is particularly true in the case of complex crossovers that include compensating networks or intricate control mechanisms like attenuators.

Active or passive acoustics. How do they differ and which one to choose

This collective scenario diminishes the efficiency of both the dynamic drivers and the amplifier’s output stages, consequently lowering the maximum achievable sound pressure level. However, passive loudspeakers come with substantial benefits, especially from a practical standpoint:

1. The user gains the flexibility to incrementally upgrade both the amplification and cabling aspects of their system.

2. When components of equal quality are employed, a passive setup generally costs less than its active counterpart.

3. DIY enthusiasts have a better chance of creating high-quality sounding passive speakers at home compared to active ones, making it a more accessible project for hobbyists.

Active or passive acoustics. How do they differ and which one to choose

Active speakers

First, it’s essential to clarify the terminology. The term “active acoustics” is frequently misinterpreted to mean any speakers with built-in amplifiers. However, this isn’t entirely accurate. In some of these speakers, amplifiers are connected to the drivers through passive filters, making their structural design similar to passive models. The defining characteristic of an “active” acoustic system isn’t merely the incorporation of amplifiers within the speaker housing, but the implementation of low-level crossover filters. These filters split the audio signal into separate frequency bands before it reaches the power amplifiers’ output stages, which are dedicated to each band. Nonetheless, it’s common for amplifiers in such systems to be housed in separate enclosures.

Active or passive acoustics. How do they differ and which one to choose

How it works

The process begins when either a digital or analog signal from the source is sent to a processor or active filter, which then divides it into the required number of bands. These could be two, three, or more frequency sections, each designated for reproduction by specific drivers. Following this segmentation, individual amplifiers, each linked directly to its respective speaker, are engaged. Each amplifier functions within its own frequency band, ensuring that the sound is accurately reproduced across the spectrum.

Active or passive acoustics. How do they differ and which one to choose

This approach not only maximizes the efficiency of the amplifiers but also offers great flexibility in configuring the system. For instance, to achieve clean and deep bass in the low-frequency band, it makes sense to utilize a powerful amplifier, such as one operating in Class D. Meanwhile, the mid and high frequencies can be managed by a less powerful, but more refined, transistor amplifier in Class A, or even a tube amplifier, to ensure rich and detailed sound reproduction. Professional active monitor manufacturers often develop specialized amplifier versions designed to operate within specific frequency bands for optimal performance. Moreover, digital or analog processors far exceed passive systems in terms of tuning precision. Modern high-end professional active crossovers allow for meticulous customization of each driver by implementing signal time delays, fine-tuning levels, phases, cutoff frequencies, and slopes, as well as integrating equalization curves. Consequently, each amplifier is fed a “pre-conditioned” signal that it then amplifies and delivers directly to its designated driver, ensuring a highly optimized and tailored audio output.

Active or passive acoustics. How do they differ and which one to choose

What are the advantages of active speakers over passive ones?

First, this configuration achieves a significantly higher sound pressure level while minimizing nonlinear, phase, and intermodulation distortions. This leads to clearer and more accurate sound reproduction.

Secondly, this design ensures that both amplifiers and drivers operate with maximum efficiency within their designated frequency bands. By doing so, it optimizes the performance of each component, ensuring that they contribute to the overall sound quality without straining or operating outside their optimal range.

Thirdly, if the crossover filter offers such functionality, it allows for the customization of sound within a specific room by considering its unique acoustical properties. This adaptability enhances the listening experience by tailoring the audio output to suit the environment, thereby optimizing sound quality for the specific listening space.

Active or passive acoustics. How do they differ and which one to choose

What active speakers are on the market today

Most commercially available speakers with band amplification are predominantly found in the professional market as near, mid, and far-field active monitors. Despite prevalent myths and misconceptions, there are no significant barriers to integrating these speakers into high-end home audio systems. Additionally, when considering the price-to-quality ratio, such speakers often represent a very cost-effective choice. This is partly because their design tends to be more functional than decorative; unlike studio monitors, you won’t find models adorned with fine wood veneer or coated in triple-layered Ferrari varnish. Furthermore, their pricing doesn’t include the substantial markups common among distributors and dealers of high-end audio equipment, who typically operate under the same business models as purveyors of luxury goods. This makes them an attractive option for audiophiles seeking top-tier sound quality without the premium price tag associated with high-end aesthetic finishes and brand prestige.

Active or passive acoustics. How do they differ and which one to choose

The home acoustics market also features a variety of active speaker systems, with numerous Hi-Fi and High-End audio manufacturers offering such solutions. Digital active wireless speakers, in particular, have surged in popularity in recent years. These speakers are designed to function both within traditional stereo setups and as components of multi-room audio installations, providing flexibility and ease of use for consumers. Furthermore, several companies have a footprint in both the professional and home audio sectors, producing high-end speaker systems for both markets. Notable brands like JBL, Dynaudio, Tannoy, and Focal have been joined by top-tier studio acoustic manufacturers such as Genelec, Westlake Audio, Backes & Muller, and Ocean Way in actively promoting their products for home use. This trend highlights a growing convergence between professional-grade audio quality and consumer audio products, offering audiophiles and casual listeners alike access to superior sound performance in their living spaces.

The main types of active speakers

These systems are usually compact 2-way active monitors featuring a main speaker ranging from 5 to 8 inches, with all the necessary electronics housed within the speaker cabinet. They are designed for listening to audio recordings at a close range of 1 to 3 meters, where the level of the direct sound signal is greater than or equal to that of the reflected sound. Typically, the use of such monitors is associated with a 2.1 setup, incorporating active subwoofers in separate enclosures to enhance the bass response. However, this configuration is not universal and may vary depending on the specific setup or user preferences.

Active or passive acoustics. How do they differ and which one to choose

Far field monitors

In the context of far-field listening, which typically occurs at distances greater than 3 meters from the sound source, the systems in use are often three- or four-way configurations. These systems may be housed in their own separate enclosures or built into specially designed niches to integrate seamlessly with the listening environment. In such setups, it’s common for all the electronics to be consolidated in a separate rack, away from the speakers themselves. This arrangement facilitates optimal sound reproduction over longer distances, where the listener experiences a balance between direct and reflected sound. At these distances, the ratio of direct to reflected sound in the signal perceived by the listener is either 1 to 1, or the reflected sound begins to dominate, affecting the overall audio experience.

Active or passive acoustics. How do they differ and which one to choose

Household active speakers

Large far-field speakers, designed for listening at distances greater than 3 meters, share a similar class and purpose with studio speakers. A key distinction, however, lies in their design: all large far-field speakers are equipped with their own enclosures. This characteristic ensures that they are specifically optimized for performance in open spaces where direct and reflected sounds play a significant role in the listening experience, providing a rich and immersive sound that can fill larger rooms effectively.

Active or passive acoustics. How do they differ and which one to choose

Who Should Buy Active Studio Monitors?

For musicians and DJs recording at home, the selection of professional active speakers is a clear and straightforward decision. The inherent design and functionality of these speakers make them ideally suited for capturing and reproducing the intricacies of music with high fidelity, a critical requirement for professional audio work.

For enthusiasts of heavy and electronic music genres, which demand high sound pressure levels while maintaining minimal nonlinear and intermodulation distortion, powered speakers are the optimal choice. These speakers are engineered to deliver powerful and clean sound, a prerequisite for accurately reproducing the dynamic ranges and bass-heavy tracks characteristic of these music styles. Achieving comparable sound levels and clarity from a passive home audio system would entail a significantly higher investment, making powered speakers a more cost-effective solution for fans of these genres.

Active or passive acoustics. How do they differ and which one to choose

For aficionados of a balanced and neutral sound profile, both studio monitors and high-fidelity (hi-fi) acoustics aim to fulfill a shared criterion: achieving the flattest possible frequency response at the listening position with minimal sound coloration. Despite the inherent variations in sound characteristics across different models, this common goal ensures that any audio playback through these systems is characterized by accuracy and authenticity. Consequently, listeners can expect a more consistent and predictable output across various phonograms, making these speakers an excellent choice for those who prioritize fidelity to the original sound recording.

Active or passive acoustics. How do they differ and which one to choose

Who doesn’t need to buy active studio monitors

For enthusiasts who enjoy regularly upgrading components, cables, and accessories as a key aspect of their passion for audio, an active system—particularly one designed for studio use—may not be the best fit. Such systems offer less flexibility for experimentation and tend to be less responsive to changes in cables, limiting the customization that some audiophiles relish.

Conversely, for those who seek a “live” sound characterized by mobility, plasticity, rich timbres, and a faithful reproduction of the composer’s intentions, the utilitarian nature of modern active monitors may not be appealing. These monitors are engineered with a focus on handling high volumes and ensuring reliability, rather than delicately balancing the nuances that contribute to the sublime aspects of music. As a result, while they excel in technical performance, they may not meet the expectations of listeners who prioritize the emotional and expressive qualities of sound.

Active or passive acoustics. How do they differ and which one to choose

For those who have a keen eye for design and wish to maintain a sophisticated interior aesthetic, active studio monitors, with their typically utilitarian appearance, might not align with your vision. These monitors are designed with functionality and performance in mind, often at the expense of visual appeal. However, if active acoustics are a must-have for your audio setup, turning your attention to products intended for the consumer market would be advisable. Today, there is a diverse array of active speakers available that don’t compromise on style, offering both exceptional sound quality and an appearance that can complement or enhance your living space’s design. This variety ensures that enthusiasts can find options that merge both their acoustic and aesthetic preferences seamlessly.