We have received several EQ/PEQ questions from PM, email, and forum discussion after we added this feature in the
v1.6 Firmware. To make our users understand the strengths and limitations of these new features, I have decided to consolidate related information into one post and pin this to the FAQ in Post#2.
We have prepared a short video to explain the PEQ features of N3Ultra, while we were referring to another DAP in this video, the concepts and steps are the same, so we can use this video as a starter for our PEQ explanation:
The new EQ/PEQ function is a system-level audio adjustment, the EQ/PEQ setting, once enabled, applies to all system or third-party applications such as music player app. or streaming apps, including but not limited to Neutron, UAPP, Spotify, Tidal, Qobuz, ....
The EQ/PEQ are processed entirely in the digital domain. To simplify the concept, you can consider the EQ/PEQ as adding one or more digital filters as pre-processing before passing the bitstream to the 1-bit DAC circuit in N7. Based on this assumption, we can now examine the limitations of our EQ/PEQ implementation.
(1) EQ/PEQ does not apply to the MQA format because MQA wants to deliver a studio experience to its users. To let the users hear the music as close to the original recording/mastering, they don't want any additional audio processing on top of the MQA playback. They have specified the digital filters in due course and users are not allowed to change the digital filters. So MQA format is not compatible with our EQ/PEQ functions.
(2) EQ/PEQ does not apply to the DSD format because DSD is a 1-bit-based format, it doesn't allow DSP processing like multibit formats. For this reason, Mastering Engineers will need to employ an interim format such as
DXD to perform their usual DSP or plugins during the DSD mastering session. That explains why you cannot EQ or PEQ DSD on the N7. This is the limitation of the music format, not a restriction of N7.
In other words, turning EQ/PEQ on or off will not do anything with MQA and DSD. There is no need to disable EQ/PEQ function in order to get "original" MQA and DSD playback.
On top of the frequency adjustment feature, we have embedded a pre-amp control in the EQ/PEQ interface.
During the adjustment of EQ/PEQ, if you set the gain (or level) in some EQ/PEQ frequencies or bands to be relatively high, you might introduce distortion in certain frequency ranges at occasional music passages. In our previous EQ functions, we try to compensate for this by reducing the output by 6dB "automatically" when you enable EQ. This -6dB procedure is applied, and this is regardless of whether you have increased or decreased the levels in your EQ setting.
The new EQ/PEQ function replaced the -6dB compensation with an unser-controlled Pre-Amp function. This will allow the user to adjust the compensated output level explicitly, and eliminate the need to reduce the output level. The EQ/PEQ becomes more transparent and you can hear the effect intuitively. This is a necessary "additional" audio processing to the EQ/PEQ function but you can bypass this control by setting the Pre-Amp to 0dB.