Small size speaker is often blamed for its lack of low bass at 100Hz. Subwoofer plays bass for the LFE (low frequency effect) channel which is usually in the range of 33-80Hz, leaving a bass gap of 70-120Hz.

Filling a frequency gap is not as easy as many people think. We found no audio systems can do it well at the moment. The challenging part is to seamlessly fill up the bass gap while not overlapping with the two ends of the gap. The critical part of bass-filling is exact timing : 
• Main speaker, center speaker and subwoofer must be absolutely synchronized 
• All speakers are of zero phase error 
• No non-linear group delay and phase delay in subwoofer 
• Subwoofer has wide and flat frequency response at 100-500Hz 

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We expertly managed all speakers’ characteristics and specially designed the subwoofer to match with the speakers. We then carefully measured the sound response and fine-tuned the system, making sure the filled mid-low bass are clean, clear and match with the main and center speakers. 

In the case of 2.1 stereo play, most small size speakers have a problem: the subwoofer bass is flowing at the floor level, separated from the main stream of music. The bass-filling technique can extend low frequency smoothly and continually, thus accurately produce the full frequency spectrum and merge the bass with the music. 

Let’s listen to the difference between “with” and “without” the bass-filling technique.