The initial 'dull' sounding impressions may be due to the lowering of noise. Noise, as opposed to the intended signal, sounds 'louder' than music of the same measured dB level.
So if you reduce noise levels, you are reducing the APPARENT loudness of the transmitted signal by more than just the drop in noise level.
This is why noise is added (or at least used to be) added to radio signals so that the station 'sounded louder' when changing stations in the car. It is also why live music, even when at high SPLs, does not present itself as loud as for reproduced music with more noise at the same SPL.
The thing that really sealed it for me was when I changed to UltraClear/CT-1 cables from other cables and would stand up to lift the tonearm at the end of a song. When I first changed cables I would go over to the TT when I was expecting the song to be over and I would hear an additional 5 seconds of low-level music coming through the speakers that I hadn't heard before. The CT-1 cables allowed more music to come through, whether through a reduction in noise or the ability to transmit lower level signals better than IC cables from the usual companies.
So if you reduce noise levels, you are reducing the APPARENT loudness of the transmitted signal by more than just the drop in noise level.
This is why noise is added (or at least used to be) added to radio signals so that the station 'sounded louder' when changing stations in the car. It is also why live music, even when at high SPLs, does not present itself as loud as for reproduced music with more noise at the same SPL.
The thing that really sealed it for me was when I changed to UltraClear/CT-1 cables from other cables and would stand up to lift the tonearm at the end of a song. When I first changed cables I would go over to the TT when I was expecting the song to be over and I would hear an additional 5 seconds of low-level music coming through the speakers that I hadn't heard before. The CT-1 cables allowed more music to come through, whether through a reduction in noise or the ability to transmit lower level signals better than IC cables from the usual companies.