SRS, BBE, DOLBY, etc. We can call it sound effects, but HIFI should be a property name, such as this is a HIFI system. Any HIFI equipment (including HIFI self-described mobile phones) is based on high-quality components, such as high-resolution chips, large-capacity filter capacitors, high-power transformers, brand-name power tubes, and so on; Software alone won't do, and traditional HIFI devices don't even need software.