Our special is about sound for the PC, with a focus on speakers. We will enlighten you on topics such as analogue and digital sound transmission, surround sound and the differences between active and passive loudspeakers. At the end you will find a market overview with 50 box systems that are intended for connection to a PC, including 20 so-called near-field monitors.
Sound can be transmitted in analog form, in simple terms in the form of power fluctuations, or digitally as a data stream. At the very end of the chain, however, it always remains analog: the loudspeaker membranes are made to vibrate by current fluctuations and generate sound waves. In order for digital data to be converted into such analog streams, there is a so-called D/A converter in one of the loudspeakers at the latest in the chain of devices involved. But how do you know whether the sound is or can be transmitted digitally or analogously? Basically, it’s quite simple: If you use a socket on the PC, as you know it from numerous mobile phones or MP3 players and fits into the classic portable headphones, then the sound flows analog in almost all cases.
In addition to the 3.5mm plugs and sockets, there is often also the 6.3mm format in professional devices or in the hi-fi sector. You can tell whether a plug and thus the cable is suitable for stereo or just mono sound by the number of isolating rings on the plug: If there are two rings, it is stereo because the plug then has two separate segments for the sound signal “Left ” and that for “right” and as the third segment the grounding.
With mono, there is only one ring and thus two segments: mono tone and ground. In addition to the jack plug, there are also cinch plugs – these are always mono and are mostly used in the hi-fi sector.
A cinch cable for connecting a CD player to a stereo amplifier, for example, has two plugs (left and right sound) at each end to transmit stereo sound.
Trust GXT 628 speaker set with two speakers and a subwoofer. Source: Trust With many PC box sets, the connections on the boxes are also two cinch sockets. The cable to the PC has two cinch plugs on one end and a 3.5 mm stereo jack plug on the other.
Of course, even with analogue transmission of the sound from the PC to the speakers, the data in the PC or in a CD player reading a CD is initially digital, i.e. it consists of data. Therefore there is the D/A converter mentioned at the beginning, which converts the digital signals into an analog signal in order to make them available at the output sockets.
The D/A converter on a PC is part of the sound module on a mainboard or a sound card. With many end devices, however, you can also send the sound digitally on the journey – from the PC, for example via HDMI, i.e. together with the image signal via the graphics card, or depending on what the mainboard or sound card offers, also as an optical or coaxial signal .
Of course, the receiving device must then always have a suitable input. An AV receiver, for example, is suitable for all three digital paths mentioned and represents a kind of control center for hi-fi sound. Of course, it also has a D/A converter and then outputs the sound in analog form to the loudspeakers connected to it further. A PC box set that also has digital connections also has a built-in D/A converter. But what are the advantages and disadvantages of analogue and digital sound transmission? We shall do this on the next page.