The software license of RAL costs just US$22, but RAL is more functional than the usual FFT analyzer. General realtime measurement function is entirely included. It has the signal generator and FFT analyzer for supervising distortion of the frequency characteristic, a S/N ratio, and a volume level. And it has the oscilloscope for investigating failure of equipments, polarity, and distortion. It can be used broadly from a home audio, and a car audio to a concert hall. Moreover, RAL can be used as a noise meter. You can measure the noise in the roadside, the airport, the factory, construction site, the office and home. With the test signal from the signal generator and the realtime analyzer, it is possible also to measure soundproof efficiency and sound insulation quality. It is possible to measure frequency characteristic of the speaker with pink noise and 1/3 octave band analyzers. You can use these functions for installation and adjustment of crossover network of the speaker and the amplifier. They can be adjusted in real time precisely. You can verify speakers in measurement of the distortion while looking at the oscilloscope. By inspecting the output of the mixer and the speaker by the oscilloscope, it is possible to prevent the destruction of the expensive equipment from error connection. When the electric sound engineer tries to get more acoustic gain and the improvement of the sound quality, he can LOOK the result of adjustment not only hear the sound. If it takes 20 minutes for the one quality curved line, now you will get it just in 20 msec and you can work more efficiently. It is one of the most useful audio measurement equipment! Abundant measurement example is introduced in the " Introduction to simple sound measurement using an notebook computer " () and " TURN YOUR PC INTO A SOUND MEASUREMENT LABORATORY! " (). You can download RAL freely and try it for 3 days to see its performance!