Though most people probably don’t realise it, the history of car audio is in fact almost as long as the automotive industry itself. It is nearly a century since the earliest examples of aftermarket installation first began to appear, and by the late 1920s radios had started being directly built into mass production vehicles. Back then the equipment involved was quite basic, consisting of an AM radio accompanied by a single speaker unit. During the decades that followed this arrangement evolved considerably - FM radio was brought in, with dual speakers permitting stereo output to be enjoyed by vehicle occupants. The addition of still more speakers eventually led to surround sound.
In terms of the storage media via which recorded musical content could be accessed, initially this was through the employment of chunky 8 track cartridges. These would be supplanted by sleeker reversible tape cassettes (in the late 1970s) and then CDs (in the mid 1980s) - closely mirroring what the consumer public were buying for home and portable usage. More recently, solid state and cloud-oriented arrangements have become prevalent.
Over the course of this progression in vehicle audio, innovations in the constituent amplifier technology kept improving output quality. The vacuum tubes incorporated into the earlier radio models would be replaced, with feature-rich sound systems that relied on microelectronics gradually coming to the fore. New opportunities, beyond music, opened up accordingly. These included making hand-free phone calls, as well as voice-based navigation, multi-media entertainment, etc.
With people spending a considerable amount of time in their cars these days, it is understandable that they expect the audio quality experienced there to be comparable with what they get when back at home. There are, of course, big differences when it comes to the operation conditions that must be dealt with though. Several factors need to be taken into consideration and ways found by which to circumvent them. Firstly, in a home setting, audio systems can utilise different speakers for each of the main frequency ranges (subwoofer, woofer, tweeter, etc.). However, limited available space means that this is not possible in an automotive context. Consequently, a different setup is called for - where speakers that cover different ranges are combined together to form coaxial speaker units which take up less room. The component costs also present major constraints, given the highly price-competitive nature of the automobile business. Then there are issues relating to the actual application environment. For instance, electro-magnetic interference (EMI) can have a detrimental effect on the ability of automotive-situated amplifiers to accurately reproduce analogue signals.
Ground-breaking development work by Toshiba’s engineers has now resulted in a new breed of audio amplifiers emerging. These Class TB amplifiers combine the key attributes of popular Class AB and Class D devices - offering elevated performance levels while still enabling a considerable reduction in the system power budget. They also exhibit strong EMI resilience, which means that heightened signal integrity can be assured. All this translates into a superior user experience, alongside substantial savings in respect to the both board real estate and bill-of-materials costs.
Toshiba’s automotive white paper gives a comprehensive overview over types of advanced amplifiers, including the benefits of Class TB amplifiers. To download the white paper, please click here: