System design automation aims to manage the design of embedded systems with ever-increasing complexity. To the success of system design automation, there is still a lack of systematic and formal design process because an entire design process, from a system's specification to its implementation, has to deal with inherent concerns about the systems' different aspects and, consequently, inherent semantic gaps. These gaps make it hard for a design process to be traceable or transparent. Particularly, guaranteeing the correctness of produced implementations becomes the main challenge for a system design process. SynQ (Synchronous system design with Quantitative types) is an embedded domain specification language (EDSL) targeting the design of systems obeying the perfect synchrony hypothesis. SynQ is based on a component-based design framework and, by design, facilitates semantic coherency by leveraging the quantitative type theory (QTT) and language embedding. SynQ enables a semantically coherent design process, including formal specification and verification, modelling, simulation and code generation. This paper presents SynQ and its underlying formalism and demonstrates its features and potential for semantically coherent system design through a case study.