Tkool Electronics

There's more computing horsepower in a DVD player than an Apollo moon rocket. Governments have launched missiles with computers less powerful than a Nintendo game. The average new car has more technology than entire universities did in the 1980s. There's no question that computer hardware is getting faster, cheaper and more ubiquitous. But it's the software that really defines the consumer electronics experience.

EEE-HA0J220AR

There's more computing horsepower in a DVD player than an Apollo moon rocket. Governments have launched missiles with computers less powerful than a Nintendo game. The average new car has more technology than entire universities did in the 1980s. There's no question that computer hardware is getting faster, cheaper and more ubiquitous. But it's the software that really defines the consumer electronics experience.

Room effects The effects of the third category of problem are well known. Almost every subwoofer installation is plagued by response irregularities that are habitually attributed to room resonances”.

A study of the situation reveals that the majority of serious problems are not, in fact, and strictly speaking, room resonance problems, but rather, boundary problems of cancellation and reinforcement. Even though the effects on performance are similar, the distinction is important because it indicates a quite different type of solution.

EEE-HA0J220AR

Room resonance problems cannot really be solved by any method other than physically changing the proportions and size of the room. Further, even mitigating the effects with equalizers can only be accomplished for one listener location, with the usual result of worsening the problems for other locations.

In contrast, boundary problems are fundamentally and importantly different. Boundary effects are substantially consistent throughout the room and therefore corrections are improvements for all locations. Also, the effects of nearby boundaries are predictable and therefore can be corrected without measurements.

SmartSub The most noteworthy features and benefits of the Thiel SmartSubs can be listed in four categories:

EEE-HA0J220AR

The first of the above mentioned benefits is implemented with the separate companion crossover unit, the SmartSub Integrator, that can be used to process 2 channels of information and deliver a signal to multiple subwoofer units. The other three are implemented in the subwoofer unit.

The Integrator is used if the subwoofer is required to reproduce the bass energy in channels other than the LFE channel, for example, in the left/right channels. Such a configuration is desirable if the main speakers either cannot reproduce the full range of bass or if they cannot play at sufficient sound levels without bass distortion.

EEE-HA0J220AR

The Integrator does not have traditional controls for directly controlling crossover characteristics such as slope or phase for either the subwoofer or the main speaker high pass filters. Instead, a different approach is taken. There are settings for telling the Integrator the characteristics of the main speakers being matched, if a main speaker high-pass is desired (crossover mode) or not (augment mode), and what crossover frequency is desired. With this information the Integrator calculates what filter characteristics will provide seamless integration of the sub with the main speakers.

The Integrator has speaker level inputs for use in augment mode and both balanced and unbalanced line level inputs and outputs for use in crossover mode. Signal is supplied to the subwoofer via balanced line level connections. All signal processing is done with analog circuitry. Digital circuitry is used for user interface, calculation and circuit control functions.

Related links: DSP drives Velodyne subwoofersSubwoofers get active room equalizationEngineer with a subwoofer500W subwoofer design using Class D amplifiersDesign considerations for 500W Class D automotive subwoofer amplifiers

SIMPLE Sometimes, the most revolutionary ideas are those that in hindsight appear quite obvious and simple. The technology behind the SpectraPulse ultra wideband wireless microphone system is just that ” revolutionary and simple in concept. Consider that something as simple as a miniature switch is part of what was behind the technology revolution of integrated circuits. The engineering skill and effort it took to implement this simple idea was extremely difficult, but this simple idea changed the world. Once it worked, it became ubiquitous.

The Audio-Technica U.S., Inc. SpectraPulse development has been such a project. Many companies have tried to implement ultra wideband (UWB) wireless into products, but we have been the first to succeed in incorporating UWB into the world's first commercially viable audio product.

Ultra wideband wireless is a naturally simple idea. It consists of very rapidly pulsed signals, each one a short burst over a very wide instantaneous bandwidth of frequencies. In early conception dating back to Marconi in the late 1800's, a UWB signal was a spark-gap transmission that was used for long range communications. These early communications systems were replaced by more efficient, longer pulse duration, narrowband techniques.

Short pulse technology was only revisited nearly 80 years later in the mid 1960's. At this time, as technologies, methods and materials allowed engineers to work in much higher frequency ranges, UWB began to emerge as a novel form of communications due to its low probability of detection characteristics. The successful use of UWB by the U.S. government and military led to the FCC's groundbreaking rule-making that permitted unlicensed commercial use of the technology for the very first time. They set the definition of an ultra wideband signal as having an instantaneous bandwidth of at least 500 MHz (where the spectrum is defined as the 10 dB down points from the center of the transmission) ” or ” a signal with a >20% fractional instantaneous bandwidth. (500 MHz is approximately 20% of a 2.4GHz center frequency signal. 2.4GHz is a popular wireless frequency with many available parts, and many engineers have experience working at this frequency.)

访客,请您发表评论:

Powered By Tkool Electronics

Copyright Your WebSite.sitemap