Transducers are typically mounted at the back of one of the tubes or on a trolling motor. There is nothing inherently wrong with mounting in any other position but if you want it to read at speed, between the tubes is NOT the place to mount it. Transducers must be mounted where the least amount of turbulence is encountered. The water between the tubes is very turbulent. Next, consider the beam shape provided by the transducer. It looks like a cone shaped paper cup turned upside down. The shallower the water, the less area the beam covers. At speed for example, you would likely run aground long before the depth finder showed the shallow water and you had time to react. Locators cannot read forward except in deeper water and even then, there is little to no chance to react at speed to avoid a rock or stump.