Heat exchangers and boilers are widely used in various applications. High-level sound generation and thermoacoustic instability in these systems can results in serious problems such as plant shut-downs. In this study the aeroacoustic characteristics of tube bundles typically used in heat exchangers was analyzed. The tube bundles can potentially act as a passive control system for instabilities as they can be designed to change the reflection, transmission and absorption of incident sound waves. This paper presents a fundamental experimental study of the aeroacoustic characteristics of two rows of tubes in In-lined and staggered configuration, respectively. The flow duct experimentation is done with multi microphone technique with and without bias flow (through flow). The experimental results are compared with earlier results from a single tube row.