The sampling rate is the frequency at which a signal is sampled. At a frequency of 2 Hz, for example, 2 data points per second are recorded. The physical rule for the sampling rate is that it must be twice as high as the frequency to be sampled. As human hearing stops at approx. 20k Hz, a sampling rate above 40k Hz is sufficient to eliminate the losses caused by sampling. Today, 48k Hz is generally used. There are also 96k Hz or higher sampling rates. Whether this is audible is controversial. The hypersonic effect describes the phenomenon and it is claimed that the auditory bones perceive up to 50k Hz. We use ADC and DAC with 48k Hz.

Active noise cancellation uses microphones and speakers to filter out background and ambient noise. The technology is primarily used in over-ear and in-ear headphones. This means you can no longer hear background noise on an airplane, for example, and the flight is more pleasant. 

In addition to enjoying music with less noise, you can also simply ensure more peace and quiet. The transparency mode can also be used to mix in outside noises when jogging so that you can hear cars approaching from behind, for example.

Active speakers are characterized by the fact that the amplifier is already built in. This has the advantage that music sources, e.g. a CD player or record player, can be connected directly and no other devices are required. It is also normally possible to stream music directly from a cell phone via Bluetooth.

Another advantage is that each driver (i.e. tweeter, midrange or woofer) has its own power amplifier, which results in a more precise sound dynamic with rich bass. The bass in particular requires a lot of power.

For the same reason, the crossovers in the active loudspeakers are also better, as the power amplifiers are behind them and better filters can be built with active components.

Audiophile, or fidelity, is the high playback quality of music. An audiophile is therefore concerned with reproducing music as faithfully as possible and optimizes their music system in this way. Many people spend a lot of money on optimal or faithful reproduction of music. However, we all have a subjective sense of hearing, which is why not everything that pleases one person also pleases others. Just like the frequency response of loudspeakers, the frequency response of the ear also differs from person to person, which is why the perception of music or sounds is different.

Many audiophiles largely reject digital technology and prefer to listen to analog records, which are transmitted via tube amplifiers to speakers with an analog crossover. Special (and often very expensive) cables are also used for faithful transmission, which are intended to suppress various effects, such as the reverb effect. For this reason, much of what is described as audiophile is also relegated to the realm of the esoteric. Note: Digital systems can also have outstanding sound quality.

If a reproduction is audiophile, it is described as natural, in the here and now, realistic, detailed, analytical or realistic. Bass, mids and treble should be neutral and none of the three pitches should stand out.

Of course, nobody knows how the recording really sounded in the studio, and music recordings are also post-processed in the studio, so the piece of music can be very different from the recording situation. The room, e.g. a concert hall with its sound characteristics, can also play a major role in how an instrument sounded at the time of recording. This is another reason why "audiophile" is a subjective term.

In the documentary "Amy" about the life of Amy Winehouse, it is shown how she sings "Back to Black" and then it is cut to the later song. A good example of Marc Ronson's good studio work and this is where the argument about what was actually "original" can begin. Here is the trailer, for those who don't know the documentary. Very worth seeing.

In principle, the super-small balanced armature drivers work like a dynamic loudspeaker with permanent magnets and a coil. However, the structure is different to that of a classic driver. Here, a magnet floats freely and produces the necessary vibrations via a diaphragm. The structure is flat.

Several drivers can be installed in in-ear headphones. Each one is then responsible for a specific frequency range. Balanced armature drivers used to be relatively expensive, but are now used in inexpensive headphones. 

When it comes to transmitting data between devices over short distances, Bluetooth is the main technology used today. Transmission takes place in the 2.4 GHz frequency band. However, before data can be transmitted, the devices (up to and including Bluetooth 4.x) must be paired with each other.

With Bluetooth 5.0, both the audio data transmission rate and, subsequently in 5.2, the energy consumption during audio transmissions were changed to enable high sound quality with very low energy consumption. This led to the mass distribution of ear plugs.

Stereo audio formats are exchanged between devices using the A2DP (Advanced Audio Distribution Profile). Various audio codecs (pair of algorithms used to encode and decode data) are used. The Bluetooth standard is the Low Complexity Subband Codec (SBC), in which the original format is encoded, transmitted and decoded. This coding is theoretically done at 346 kb/s. However, this depends heavily on the strength of the Bluetooth connection. Generation losses are therefore possible in the inaudible range with a good connection. Nevertheless, other codecs have been developed, in particular mp3, AAC, FLAC and aptx (also LC2, LDAC, LHDC and UAT). AAC (265 kbit) and aptx (345 kbit/s) offer this bandwidth regardless of the connection strength. For both transmission types, both the transmitter and the receiver must support these formats. 

Here we are in an area where we believe that sustainability and compatibility with ever new protocols is not possible and have so far opted for the Bluetooth Out of the Box codecs, as good Bluetooth connections should be possible indoors. 

A digital analog converter (DAC, digital signal converter) converts a digital signal into an analog signal. This analog signal is ultimately processed by the loudspeakers and converted into sound. There are various methods for this conversion. Today, a DAC is of paramount importance when it comes to sound quality. 

DACs are used in almost all audio devices that deal with digital sound sources.

In the opposite direction, DACs are referred to as ADCs or analog-to-digital converters. They are used to digitize the analogue signal recorded by a microphone, for example.

Devices to which headphones or power amplifiers can be connected are often also referred to as DACs. The upwardly open price scale for these devices also shows esoteric tendencies here.

Unit of measurement for loudness. The decibel scale ranges from 0 dB to 120 dB and has a logarithmic structure. Hearing is damaged from approx. 85 db continuous exposure. The volume of a normal conversation is approx. 60 db, the rustling of leaves is approx. 30 db and a hair dryer approx. 90 db.

A digital sound processor or digital signal processor. It processes digital signals and modulates them. In loudspeakers, it is responsible for shaping the frequency response in such a way that the audiophile experience is optimized and errors in sound reproduction are minimized. 

Modulation can be used to completely change the character of a loudspeaker. It therefore functions as a digital equalizer.

The output stage is the last electronically active (i.e. amplifying) stage of a power amplifier. The signal then goes to the passive loudspeaker or, in the case of active loudspeakers, to the chassis.

There are different classes of power amplifiers.

Class A: Class A amplifiers are used in the absolute high-end range as long as high power is not required, as they are very energy inefficient and convert a lot of current into heat even without an input signal. A voltage is always present in Class A amplifiers and they become very hot.

Class B: Two transistors amplify the positive and negative signal. Distortion occurs where the signal crosses the zero line, as the transistors only kick in at a certain voltage.

Class AB: The most commonly built power amplifiers are Class AB amplifiers. These work like a Class B amplifier unless the power is very low, in which case it runs as a Class A amplifier.

Class C: Not used in audio applications due to distortion.

Class D: Class D amplifiers work on the basis of pulse width modulation. The amplification is controlled by high-frequency pulse widths, which switch the power transistors on and off and which then have to be filtered again. The high-frequency (far above the audible range) signals must match each other exactly, which makes the construction of these amplifiers very demanding. The process enables extremely powerful amplifiers with very small housing sizes.

Class G: Functions like a Class AB, but is designed to be more energy-efficient due to the different voltages required for different loads.

If you are interested, you are welcome to watch the following video. (In German)

Unit of measurement for the frequency. The number of oscillations per second is the number in front of the unit of measurement. 50Hz is the frequency of our power grid. The electrical voltage oscillates 50 times between 0 volts (V) - 220V - 0V - minus 220V - 0V 

Hi-Fi is the abbreviation for high fidelity. Hi-Fi is based on standards (e.g. EN61305) that define the conditions under which a sound device has high fidelity. These standards are met by almost all devices today (except perhaps clock radios or the cheapest playback devices). 

Although one should not consider the price, but the performance or the price-performance ratio, high-end is often understood to mean the most expensive, most luxurious or best product.

In terms of sound quality, high-end should actually be a synonym for "audiophile". A high-end loudspeaker should enable reproduction that is as true to the original as possible. Regardless of the price. 

The hypersonic effect is described in a controversial study by Tsutomu Oohashi, in which people were able to perceive frequencies above 25k Hz in individual cases. In many other (also "double-blind") studies, the participants were unable to hear the ultrasound either in isolation from or together with lower frequencies. There were also different test results for general perception by the body. However, it is assumed that the body can feel an ultrasound emission in the long term. 

With coaxial speakers, at least two drivers are arranged on one axis. This arrangement corresponds more closely to natural sound production than drivers arranged side by side, as the sound comes from a single point. Speakers with coaxial drivers therefore create a natural sound stage more easily.

A monitor speaker (also known as a studio speaker) is often active due to the advantages of active speakers and is used to listen to music without distortion and as accurately as possible. In the studio, of course, it is important that the finished song does not have any errors at the end, which is why the display must not suppress or distort the slightest crackle.

Studio monitors are interesting products for audiophiles, as they do exactly what counts when it comes to audiophile music enjoyment. They ensure a faithful reproduction of the music without altering it by boosting the bass or treble. For many listeners, however, these speakers are also fun-free.

Headphones that are inserted in front of the ear canal. The housing is smaller than the auricle. External noise is therefore not strongly attenuated. The advantage is that the headphones are not stuck in the ear canal.

Over-ear headphones are larger than the earcup and are worn over the ear. As a result, they press less than on-ear headphones. 

Due to the large design, the headphones can also accommodate large diaphragms for sound generation. Most reference headphones can be found in this category and active noise-canceling technologies can be used due to the good shielding of the ear from external noise.

Passive speakers receive the signal from an amplifier or a power amplifier. They usually contain an analog crossover that distributes the sound to the various tweeters, midrange and woofers (bass).

So you need a passive speaker and a corresponding amplifier. Audiophiles enjoy choosing the best combination of devices and have a soft spot for analog technologies, which is why passive speakers are more common in this area. However, there are also active speakers with DSP and outstanding audiophile sound, e.g. our soundbar.

Every room has its own audio characteristics. These have an extreme influence on the quality of the audio reproduction.

The audio characteristics depend on the proportion of direct sound, reflections and reverberation in the total sound level and the time delay and direction of reflections and reverberation.

A room with good audio properties reduces reflections and reverberation in such a way that a spatial impression of the sound is maintained and the room still has no unwanted influence on the sound.

Damping of reflections and reverberation can be achieved, for example, with carpets, curtains and special damping panels on the walls, which prevent reflections and reverberation by breaking up the sound. (Diffusors)

S/PDIF (Sony & Philips Digital Interface) is a specification for a one-sided (unidirectional), self-synchronizing and serial interface for the electrical and/or optical transmission of digital stereo or multi-channel audio signals. 

The same specification is used by the TOSLINK interface for optical transmission.

A subwoofer delivers very deep bass, usually with a frequency below 80 Hz. As humans cannot locate sounds below 80 Hz, a single subwoofer is sufficient. In home theater systems, the subwoofer often only delivers very deep sound effects.

There are downfire subwoofers and frontfire subwoofers. The first emits the sound downwards and the second emits it forwards.

Stereo comes from the Greek and means rigid, solid or spatial.  

From around 1930, attempts were made to improve the recording quality by positioning several microphones in the room, which ultimately led to stereo sound, i.e. the spatial reproduction of the recorded sound. The recording technique was initially called binaural. The term was then also patented, which hindered its further use and meant that "stereo" as a derivative of stereography, i.e. the three-dimensional representation of images, came to the fore as a word. In the early days, there was often no attempt at all to create a spatial representation of the recorded image; instead, different sounds, noises or instruments were distributed across the channels. However, the recording techniques and microphone types still used today were developed back in the 1930s. Stereo, as a spatial recording of music, did not become a real issue until the early 1960s. In the 1960s, radio was also converted to stereo.

In the studio, the individual audio tracks are usually recorded separately and can then be positioned in the room by the sound engineer to give the impression that the music has been recorded by a band. This process is called stick stereophony.

The stereo effect is created by the two loudspeakers playing sounds with differences in time and/or intensity, making use of the human psychoacoustic phenomenon that allows us to locate the origin of a sound source.

The stereo effect naturally only occurs in the so-called "sweet spot", the point where the sound waves from the two speakers mix. For optimum reproduction, the speakers are positioned in an isosceles triangle in relation to the listening position and ideally at ear level (or tilted accordingly, as with our soundbar). The installation location and the room architecture also have a significant influence on the listening experience.

TOSLINK is the optical version of the S/PDIF interface (Sony & Philips Digital Interface). It is one-sided (unidirectional), self-synchronizing and serial and transmits electrical and/or optical digital stereo or multi-channel audio signals. 

As a rule, fiber optic cables are used that are not disturbed by magnetic waves.

Wireless Local Area Network, or WLAN for short, is a radio standard that transmits in the 2.4 GHz and 5 GHz range and follows the IEEE 802.11 standard according to the WIFI Alliance.

WLANs play a central role (alongside the Internet connection in the home) in the area of multi-room applications. A wide variety of devices can communicate with each other via WLAN applications. In our opinion, however, Bluetooth has some advantages in terms of ease of use when connecting devices to devices. Setting up WLAN connections is still much more complicated than with Bluetooth.