Ultrasonic speeds u have been measured in [2-(2-(2-methoxyethoxy)ethoxy)ethanol + di-n-butylether], [2-(2-(2-ethoxyethoxy)ethoxy)ethanol + di-n-butylether], and [2-{2-(2-butoxyethoxy)ethoxy}ethanol + di-n-butylether] systems across the entire composition ranges, at the temperature 298.15 K, using a sing-around technique, at a frequency of 4 MHz. The values have been combined with those of the excess molar volumes to obtain estimates of the product K-S,K-m of the molar volume and the isentropic compressibility kappa(S), and the excess values K-S,m(E) were also calculated. The deviation u(D) of the ultrasonic speeds from their values in an ideal mixture were also evaluated for all measured values of x. These values are compared with the mixing function delta u calculated in the paper. The behaviour of u, u(D), and K-S,m(E) with composition and the number of carbon atoms in the aliphatic chain of the alkoxyethanol is discussed.