RATIONALE The recently designed dynamically harmonized Fourier transform ion cyclotron resonance (FT-ICR) cell creates a more harmonized electric field for the detection of the cyclotron motion of ions and prolongs the ion transient from seconds to minutes. In order to achieve its best performance, phase correction was applied in the spectra, and new advantages of the absorption-mode were revealed. METHODS Spectra were acquired from both simple standard and complex mixtures using either narrowband or broadband mode, and the data were processed to compare the performance of the spectra in magnitude and absorption-mode. RESULTS The research shows that phase correction works well with data from Nikolaev's new cell, which produces the maximum improvement in resolving power (2×), and improves the match with the theoretical intensities of the isotopic peaks. In addition, the harmonic peaks can be diagnosed immediately in the absorption-mode. CONCLUSIONS The manuscript demonstrates absorption-mode spectra from Nikolaev's ICR cell, which will be of interest to the community. The improved relative peak intensities and immediate identification of harmonic peaks will facilitate data interpretation.