This article presents a new method of audio quality assessment to solve the bottlenecks of new audio product development-low efficiency and deficient benefits. In order to solve these long-lasting constrictions stemmed from the new audio product development, a new approach is needed. This new method starts with the preparation of a set of tailor-made test signals; then we send all those specially made test signals to multiple sets of speakers. The third step is to use SoundCheck system to measure the sound quality on DUT (Device Under Test). Upon the completion of FFT analysis, we can directly pinpoint all the exact timbre differences from speaker to speaker. Our new tailor-made test signals are harmonic signals, while the traditional signals are pure tone signals (Sine wave). In fact, harmonic signals are the key elements that contribute to the variations in timbre. Therefore, by sending harmonic signals through SoundCheck system to complete FFT analysis, we can precisely locate every single difference in timbre between different speakers.    Concerning new product development in the audio industry, acoustic engineers conduct audio quality assessments through two different ways-Subjective Listening and Objective Measurement. These two standard tests are the decisive factors to determine all the new audio product development. Objective Measurement explains how the audio device sounds and performs typically in Physics. Physical data like THD, Frequency Response were being collected for evaluation and presentation. As for Subjective Listening, the process starts with a set of specification designated by the clients, and then the project team needs to come up with a new audio device to satisfy the requirement. Follow by a series of music signal listening tests on the DUT (Device Under Test), to confirm all the required specifications were met and satisfied by the newly-developed products. Some routine checks were also included to see: (i.) If the treble parts are crispy, crystal clear and free from unfavorable, annoying or sharp outputs; (ii.) Can the median parts deliver gentle and warm music signals, not the thin and hollow feelings; (iii.) The bass performance should be solid, exempt from any weak and powerless presentation. In other words, every single new audio product development project always involves with significant manpower doing trial-and-error types of repetitions; plus, some extensively time-consuming efforts to come up with the ideal new audio devices to meet the exact audio quality requirement instructed by the clients.