Abstract: A method of compensating audio frequency response characteristics of a portable sound system can be performed using acoustic characteristics of a user measured in real-time. The method of compensating the audio frequency response characteristics can be used by a portable sound system. The method includes generating an acoustic characteristics curve of a user based on a minimum perception level of a user with respect to audible audio frequency bandwidths, generating an acoustic compensation curve of the user based on the acoustic characteristics curve of the user and a predetermined frequency characteristics target curve, and compensating the audio frequency response characteristics of a sound based on the acoustic compensation curve of the user.

Abstract: A portable speaker of a portable multimedia device includes a digital amplifier to receive a digital audio signal from the portable multimedia device and to digitally process and output the received digital audio signal to a speaker unit, and a battery to supply electric power to at least one of the digital amplifier and the portable multimedia device.

Abstract: A method and apparatus to control an operation of a multimedia device includes detecting an input tapping, detecting a pattern of the detected tapping, and controlling an operation of the multimedia device according to the detected pattern.

Abstract: A method and an apparatus to record an audio signal use a beam forming algorithm for at least two microphones. The method includes disposing a plurality of microphones at a plurality of predetermined locations to generate audio signals upon receiving a sound signal output from a sound source, forming a beam from the audio signals by adjusting a delay and a level of the audio signal of each of the plurality of microphones, and adjusting an angle and a width of the beam by a user.

Abstract: A method of compensating audio frequency response characteristics of a portable sound system can be performed using acoustic characteristics of a user measured in real-time. The method of compensating the audio frequency response characteristics can be used by a portable sound system. The method includes generating an acoustic characteristics curve of a user based on a minimum perception level of a user with respect to audible audio frequency bandwidths, generating an acoustic compensation curve of the user based on the acoustic characteristics curve of the user and a predetermined frequency characteristics target curve, and compensating the audio frequency response characteristics of a sound based on the acoustic compensation curve of the user.

Abstract: An earphone frequency characteristic compensating method and apparatus to compensate for a frequency response characteristic of earphones by selecting a target curve. The method includes measuring the frequency response characteristic of the earphones considering a frequency characteristic of an ear canal, extracting a filter coefficient by comparing the measured frequency response characteristic of the earphones with a frequency characteristic of a target curve, and compensating for the frequency response characteristic of the earphones based on the extracted filter coefficient.