A bender bar is presented. The bender bar includes at least two pairs of piezoelectric elements arranged on an inert element to adjust the response frequency of the bender bar. In some embodiments, the piezoelectric elements can be stacked on the inert element. In some embodiments, the piezoelectric elements are symmetrically arranged with respect to the bender bar such that a gap is formed between piezoelectric elements arranged on the inert element.

An acoustic transducer includes a substrate element having a first side, and a second side opposite the first side. The acoustic transducer also includes first and second piezoelectric elements coupled to the first side, and third and fourth piezoelectric elements coupled to the second side. The first piezoelectric element has a first polarity, and the second piezoelectric element has a second polarity different than the first polarity. The third piezoelectric element has a third polarity, and the fourth piezoelectric element has a fourth polarity different than the third polarity.

a Downhole Acoustic Measurement Tool that Includes a Transducer Operable for Emitting and/or Receiving Acoustic Signals to Perform Downhole Measurements. The Transducer Includes Multiple Piezoelectric Elements. Each Piezoelectric Element May have a First Axial End and a Second Axial End, and the Second Axial End May be Wider than the First Axial End in a Direction Along a Circumference of the Transducer. The Piezoelectric Elements May be Irregularly Pitched Azimuthally Around One or More Portions of a Circumference of the Transducer. The Piezoelectric Elements May be Spaced Apart by No More than the Distance Defined by W1*f1/F.sub.UL, where F.sub.UL is the Upper Limit of the Frequency Band of Interest, W1 is the Width of the Transducer Interelement Spacing that Produces Parasitic Mode at Frequency f1.

Methods and systems herein may be configured to utilize a downhole tool comprising: a transmitter configured to transmit an acoustic signal into at least part of a conduit string, wherein the transmitter is a first downhole element. In addition, receiver configured to measure an incoming signal from at least part of the conduit string, wherein the receiver is the first downhole element or a second downhole element. Further, disposing a downhole tool into a wellbore, wherein the downhole tool and transmitting an acoustic signal into at least part of a conduit string with the transmitter; and receiving the incoming signal from at least part of a conduit string with the receiver.