This document describes the system built by the SPL-IT-UC team from the Signal Processing Lab of Instituto de Telecomunicações (pole of Coimbra) and University of Coimbra for the Query by Example Search on Speech Task (QUESST) of MediaEval 2015. The submitted system filters considerable background noise by applying spectral subtraction, uses five phonetic recognizers from which posterior probabilities are extracted as features, implements novel modifications of Dynamic Time Warping (DTW) that focus on complex queries, and uses linear calibration and fusion to optimize results. This year’s task proved extra challenging in terms of acoustic conditions and match cases, though we observe the best results when merging all complex approaches.