Information encoder for encoding an information signal, the information encoder comprising: an analyzer for analyzing the information signal in order to obtain linear prediction coefficients of a predictive polynomial A(z); a converter for converting the linear prediction coefficients of the predictive polynomial A(z) to frequency values f 1...f n of a spectral frequency representation of the predictive polynomial A(z), wherein the converter is configured to determine the frequency values f 1...f n by analyzing a pair of polynomials P(z) and Q(z) being defined as P z = A z + z − m − l A z − 1 and Q z = A z − z − m − l A z − 1, wherein m is an order of the predictive polynomial A(z) and l is greater or equal to zero, wherein the converter is configured to obtain the frequency values (f 1...f n) by establishing a strictly real spectrum derived from P(z) and a strictly imaginary spectrum from Q(z) and by identifying zeros of the strictly real spectrum derived from P(z) and the strictly imaginary spectrum derived from Q(z); a quantizer for obtaining quantized frequency (f q1...f qn) values from the frequency values (f 1...f n); and a bitstream producer for producing a bitstream comprising the quantized frequency values (f q1...f qn) characterized in that the converter comprises a zero-padding device for adding one or more coefficients having a value "0" to the polynomials P(z) and Q(z) so as to produce a pair of elongated polynomials P e (z) and Q e (z); the converter comprises a limiting device for limiting the numerical range of the spectra (RES, IES) of the elongated polynomials P e (z) and Q e (z) or one or more polynomials derived from the elongated polynomials P e (z) and Q e (z) by multiplying the elongated polynomials P e (z) and Q e (z) with a filter polynomial B(z), wherein the filter polynomial B(z) is symmetric and does not have any roots on a unit circle; wherein the converter comprises a Fourier transform device for Fourier transforming the pair of polynomials P(z) and Q(z) or one or more polynomials derived from the pair of polynomials P(z) and Q(z) into a frequency domain with half samples so that the spectrum derived from P(z) is strictly real and so that the spectrum derived from Q(z) is strictly imaginary. an analyzer for analyzing the information signal in order to obtain linear prediction coefficients of a predictive polynomial A(z); a converter for converting the linear prediction coefficients of the predictive polynomial A(z) to frequency values f 1...f n of a spectral frequency representation of the predictive polynomial A(z), wherein the converter is configured to determine the frequency values f 1...f n by analyzing a pair of polynomials P(z) and Q(z) being defined as P z = A z + z − m − l A z − 1 and Q z = A z − z − m − l A z − 1, wherein m is an order of the predictive polynomial A(z) and l is greater or equal to zero, wherein the converter is configured to obtain the frequency values (f 1...f n) by establishing a strictly real spectrum derived from P(z) and a strictly imaginary spectrum from Q(z) and by identifying zeros of the strictly real spectrum derived from P(z) and the strictly imaginary spectrum derived from Q(z); a quantizer for obtaining quantized frequency (f q1...f qn) values from the frequency values (f 1...f n); and a bitstream producer for producing a bitstream comprising the quantized frequency values (f q1...f qn) characterized in that the converter comprises a zero-padding device for adding one or more coefficients having a value "0" to the polynomials P(z) and Q(z) so as to produce a pair of elongated polynomials P e (z) and Q e (z); the converter comprises a limiting device for limiting the numerical range of the spectra (RES, IES) of the elongated polynomials P e (z) and Q e (z) or one or more polynomials derived from the elongated polynomials P e (z) and Q e (z) by multiplying the elongated polynomials P e (z) and Q e (z) with a filter polynomial B(z), wherein the filter polynomial B(z) is symmetric and does not have any roots on a unit circle; wherein the converter comprises a Fourier transform device for Fourier transforming the pair of polynomials P(z) and Q(z) or one or more polynomials derived from the pair of polynomials P(z) and Q(z) into a frequency domain with half samples so that the spectrum derived from P(z) is strictly real and so that the spectrum derived from Q(z) is strictly imaginary.