TEST: Mackie TH-15A

 Maybe it's just a subjective perception on my part, but it's slowly starting to seem to me as if the days of passive loudspeaker designs in the small P.A. and vocal systems sector are numbered. It definitely makes sense if you take a closer look at the design-related peculiarities of the fused power amplifier/loudspeaker combination in one housing.

Not only is there no need to transport the external power amplifier in the 19-inch format, along with cabling, but the space required both in the transporter and on stage is also significantly reduced. Especially in the area of discreet sound reinforcement at private parties or company anniversaries, where every case more or less represents a visual faux pas, minimizing the tools on stage is a must!

In order to still be able to offer a voluminous sound with the appropriate air movement, fully-fledged multi-way constructions have recently appeared more and more often, sometimes with a 15-inch model in the bass range, but these also often have to deal with the problem of transport weight have to beat.

In order to overcome this problem, Mackie has consistently focused on the issue of weight in its TH-15A product and tried to ensure the fusion of performance with low weight using various components. That makes you curious.


construction

The Mackie TH-15A is an active two-way box. In terms of performance, the product generates 200 watts sine wave with a peak of 400 watts, with a 15 inch bass speaker being operated with a 150 watt Class D power amplifier, while the 1 inch tweeter driver is operated with a Class AB power amplifier. Separation occurs at 3 kHz. In order to support the bass a little more, the construction is designed as a bass reflex.

In addition to the comparatively small Class D power amplifier, the very light housing made of polypropylene ensures that the product only has a total weight of 16.3 cm despite the above-mentioned performance specifications and the housing dimensions of 68.9 cm x 42.7 cm x 40.1 cm kilogram!

The area of application ranges from the classic vocal system to the floor monitor area (trapezoidal shape!) to the full-fledged club P.A. with appropriate daisy chain operation of several individual components. The box can even be used as a moderate drum fill in a pinch, provided the drummer doesn't play in a Motörhead tribute band.


In terms of transport, the product has three handles or recessed grips, two on the outside and one on the top. Due to the convenient placement and the weight mentioned above, a man of average strength can easily transport this box alone without exposing himself to the risk of back pain.

The construction has four stacking troughs on the top and bottom, which should, however, be treated with a little caution. For a well-situated event, the tilting is sufficient to place two boxes safely on top of each other. However, if you are dealing with a throbbing mosh pit in front of the stage, with one or the other tumbling against a sound system, the individual elements must be secured with tension straps. The box also has the standard 35 mm flange on the bottom for stand operation.

A special feature, especially in this price range, is the three-band tone control, which is recessed on the back of the box. Two shelving filters at 80 Hz and 12 kHz, as well as a semi-parametric mid-band with a selectable frequency between 100 Hz and 8 kHz, ensure post-processing of the applied signal. If necessary, the equalizer can also be deactivated using a pressure switch.


Regarding the connection panel, the user has to make do with a single XLR socket, which he can loop through via another XLR socket if necessary. That's it, there's nothing more, but let's be honest, Speakon is eliminated and jack or even Cinch in the performance class? Go away....

Finally, the master volume controller, a power plug and the on/off switch are all located slightly inwards on the back of the housing. Oh, by the way, you can also easily connect a microphone directly. Despite the lack of a gain control, the result is quite usable. Barkers of all countries, unite ;-)



Practice

As soon as you activate the construction, several typical Mackie components catch your eye and ear. In addition to the characteristic blue LED on the front panel, it is the rather soft treble that runs through the entire Mackie speaker range, especially since the treble control is very tasteful.

In general, the sound control is pleasing. Even if the filters in this price range do not quite reach the culture of the more expensive Mackie consoles, the possibility of frequency correction can almost be viewed as a luxury in this segment. With the necessary sensitivity, spatial problem areas can be addressed and possibly sound-unfavorable source material can be processed. So everything is fine?

Well, where there is a lot of light, there is sometimes a bit of shadow. The weight advantages mentioned at the beginning are undoubtedly a relief for your back and your wallet, but they also have the disadvantage that, due to the reduced mass, low-frequency components easily cause the housing to vibrate. Depending on the sound material, you could notice that, especially with strong bass-heavy material and boosting of the same, the housing tends to make a slight drone and the quality of the radiation characteristics of the construction is somewhat reduced.

The fact that a 15-inch model can of course process more low-frequency components than the more commonly used 12-inch model also contributes to this. So, especially to the gentlemen DJ, be careful with the bass control, even if the loudspeaker seduces you.

As expected, there is a slight dip in the high-mid range, as the bass loudspeaker cannot manage the range between 2 - 3 kHz quite as well due to its sluggish mass until the high-frequency horn finally kicks in. I see real problems in this regard. but not because the Hochtorn horn in this design is very expansive and compensates for this small flaw well.

A small annoyance, as with many speakers of the same design, is the cable routing when using the product as a floor monitor. No matter which side the box is on, either the IEC plug or the XLR cable will be bent at an angle, which in the medium term can lead to a cable break or damage to the socket. Therefore, slightly rework the connector arrangement or housing shape and everything is in order. Oh yes, the controls are a bit wobbly because they are not countered on the outer plate. Not existential, but it would have been nice.


Conclusion

It happened as it had to, the active Mackie TH-15A construction is also a really valuable purchase in terms of price-performance ratio. For less than 300 euros you get a highly flexible sound system construction that covers a wide range of areas.

An additional tone control, good workmanship and a very low weight make the TH-15A an all-purpose weapon when it comes to being quick, light, uncomplicated and inexpensive.

Recommended!

—————————

Additional Informations:

Multi-way loudspeaker systems featuring a 1-inch compression driver and a 15-inch woofer have become a cornerstone in the professional audio (PA) industry. These systems are designed to deliver high-fidelity sound across a wide frequency range, combining the strengths of both high-frequency precision and robust low-frequency performance. This article explores the history, technological advancements, and impact of these versatile loudspeaker systems in the PA domain.

### Early Loudspeaker Technology

The origins of loudspeaker technology date back to the early 20th century. Initial designs were rudimentary and typically featured a single driver attempting to cover the entire audio spectrum. These early systems, often horn-loaded to improve efficiency, were limited in frequency response and sound fidelity. The single driver struggled to reproduce both low and high frequencies accurately, resulting in significant audio distortion and subpar performance.

### Emergence of Multi-Way Systems

The need for improved sound quality led to the development of multi-way loudspeaker systems. By using multiple drivers, each optimized for a specific portion of the audio spectrum, engineers could enhance sound clarity and minimize distortion. This concept laid the foundation for the multi-way systems that would later feature the combination of a 1-inch compression driver and a 15-inch woofer.

### Introduction of the 1-Inch Compression Driver

Compression drivers are specialized high-frequency drivers designed to produce clear and powerful high-end sound. The 1-inch compression driver, in particular, became popular due to its ability to deliver precise and articulate high frequencies. These drivers use a small diaphragm attached to a voice coil, which is driven by a powerful magnet. The diaphragm's movement compresses the air in a small chamber, which is then directed through a horn to amplify the sound.

#### Early Compression Drivers

The first compression drivers emerged in the 1930s and 1940s, primarily used in public address systems and cinema sound. These early models were relatively crude but laid the groundwork for more advanced designs. The introduction of the 1-inch compression driver marked a significant improvement in high-frequency reproduction, offering better clarity and higher output levels compared to previous technologies.

### Development of the 15-Inch Woofer

Simultaneously, advancements were being made in low-frequency driver technology. The 15-inch woofer became a popular choice for handling bass frequencies due to its ability to move a large volume of air. This driver size struck a balance between low-frequency extension and efficiency, making it ideal for PA applications.

#### Early 15-Inch Woofers

The first 15-inch woofers appeared in the 1950s and 1960s. These early woofers were typically used in large speaker cabinets and were designed to provide powerful bass response for live music and public address systems. Over time, improvements in materials and engineering led to more efficient and robust woofer designs.

### Birth of the 1/15 Multi-Way Loudspeaker System

Combining the strengths of the 1-inch compression driver and the 15-inch woofer, the 1/15 multi-way loudspeaker system emerged as a powerful solution for PA applications. These systems typically feature a two-way design, with the 15-inch woofer handling low and mid frequencies and the 1-inch compression driver covering the high frequencies.

#### Early 1/15 Systems

The first 1/15 multi-way systems appeared in the 1960s and 1970s. These systems used passive crossovers to divide the audio signal into separate frequency bands, directing each band to the appropriate driver. The passive crossover networks were relatively simple, consisting of capacitors, inductors, and resistors, but they marked a significant improvement in sound quality compared to single-driver designs.

### Advances in Crossover Technology

Crossover technology quickly became a focal point for innovation in multi-way loudspeaker systems. Early passive crossovers had fixed crossover points, limiting their flexibility and performance. As technology advanced, more sophisticated crossover designs were developed, allowing for adjustable crossover points and improved frequency band separation.

#### Active Crossovers

The introduction of active crossovers in the 1970s and 1980s revolutionized the design of 1/15 systems. Unlike passive crossovers, active crossovers are placed before the power amplification stage and use active electronic components like transistors and operational amplifiers. This placement allows for more precise control over the frequency division and offers the ability to adjust crossover points more accurately. Active crossovers also enable independent amplification for each driver, improving overall system efficiency and sound quality.

### Driver Technology and Materials

The evolution of driver technology and materials has been integral to the development of 1/15 multi-way loudspeaker systems. Early drivers used paper cones and metal diaphragms, which had limitations in terms of durability and sound fidelity. Over time, new materials such as polypropylene, Kevlar, and carbon fiber were introduced, offering improved performance characteristics.

#### Woofer Development

Woofers in 1/15 systems are designed to handle low and mid frequencies, typically ranging from 20 Hz to 1.5 kHz. Advances in woofer design have focused on improving cone materials, motor structures, and suspension systems to enhance low-frequency response and minimize distortion. Modern woofers often use materials like treated paper, aluminum, or composite materials to achieve the desired balance of strength and lightness.

#### Compression Driver Development

Compression drivers, particularly the 1-inch variety, are responsible for high frequencies, usually from 1.5 kHz to 20 kHz. The development of new diaphragm materials such as titanium and mylar, along with improvements in magnet structures and phase plug designs, has significantly enhanced the performance of these drivers. Modern 1-inch compression drivers offer higher output, greater clarity, and improved reliability compared to their predecessors.

### Integration with Digital Signal Processing (DSP)

The advent of digital signal processing (DSP) in the late 20th century brought about another wave of innovation in 1/15 multi-way loudspeaker systems. DSP allows for precise control over various aspects of the audio signal, including equalization, crossover settings, and time alignment. This technology enables engineers to optimize the performance of 1/15 systems in real-time, compensating for acoustic anomalies and ensuring consistent sound quality across different environments.

### Applications in Professional Audio

1/15 multi-way loudspeaker systems are ubiquitous in professional audio applications due to their balance of performance, cost, and complexity. They are commonly used in live sound reinforcement, installed sound systems, and studio monitoring.

#### Live Sound Reinforcement

In live sound applications, 1/15 systems offer the clarity and power needed to deliver high-quality audio to audiences of various sizes. They are often used in combination with subwoofers to extend the low-frequency response, creating a full-range sound system capable of handling a wide variety of music and speech content.

#### Installed Sound Systems

1/15 loudspeakers are also prevalent in installed sound systems, such as those found in theaters, stadiums, and houses of worship. Their ability to provide even coverage and high intelligibility makes them ideal for these environments, where both music and speech reproduction are critical.

#### Studio Monitoring

In the studio, 1/15 monitors are essential tools for recording and mixing engineers. They provide accurate sound reproduction, allowing engineers to make precise adjustments to their recordings. The combination of a 15-inch woofer and a 1-inch compression driver ensures that these monitors can handle a wide range of frequencies, providing a clear and detailed sound.

### Conclusion

The evolution of 1/15 multi-way loudspeaker systems has been marked by continuous innovation and improvement. From their early beginnings as a solution to the limitations of single-driver designs, these systems have evolved into highly sophisticated and versatile tools in the professional audio industry. Advances in crossover technology, driver materials, and digital signal processing have all contributed to the superior performance and widespread adoption of 1/15 systems. As technology continues to advance, the future of 1/15 loudspeaker systems promises even greater enhancements, further solidifying their role as indispensable components in the world of professional audio.