What Causes the Sudden Disappearance of Bass in BMW Harman Kardon Systems?
1 Answers
BMW Harman Kardon systems may experience sudden bass loss due to issues in three main components: the audio head unit, speakers, or amplifier, requiring inspection or adjustment at a repair shop. Below is relevant information about car subwoofers: 1. Principle: The internal amplifier circuit divides sound into several wavelength segments via a crossover. Mid-to-high frequency ranges (mid-high tones) are output to satellite speakers, while mid-to-low frequency ranges (mid-low tones) are directed to the subwoofer. Typically, subwoofers produce long-wave sounds between 20-200Hz, which are easily audible but difficult to localize due to their long wavelengths. These long waves exit through bass reflex ports, resonating with satellite speakers. The combined weak bass from the subwoofer and satellite speakers is then re-amplified by the satellites, creating an intense bass effect that perceptually seems to originate from the satellite speakers. 2. Function: Subwoofers enhance the bass frequency range, specifically amplifying long-wave audio components (below 100Hz, including infrasound which, though inaudible, still has an effect). Since standard speakers have limited size and cannot produce long-wavelength low frequencies, larger subwoofers are necessary to generate impactful low-frequency effects. Additionally, bass waves, being the longest, exhibit low efficiency in energy conversion, making their production highly energy-intensive—requiring greater input power to achieve equivalent output levels.
