May I ask when this was? Just wondering. RME dacs are pretty good, yet IME there is better...
Last fall. I have an Audio Note DAC5 Special so I have a high bar and the RME running high rez was impressively good in that system. It’s a local audiophile who hosted for the Las Vegas local club event. Not many things impress me anymore and this did.
The short answer to the original poster's question is: Yes, DSP can be used to adjust the dB level across the entire range of audible frequencies. In fact, DSP is the means by which simple multi-band equalizers work. DSP is also the means by which all digital audio recordings are produced, mastered, etc. Some other posters have mentioned the Fletcher-Munson Equal Loudness Curves and an understanding of these curves, and what they represent, is key to understanding how our hearing really works and why bass, for example, at the same dB level, does not sound as loud as a higher tone. But it's also true that frequencies from around 4K up need to be louder to be perceived as equally loud to lower frequencies. It's an interesting topic and well worth digging into if you are into hifi.
This is a topic that is close to my heart. Some years back, after a scare with near total (but temporary) hearing loss in my right ear, I came to understand that at the age of 67, my hearing was not what it was when I was much younger and that it was quite different in each ear. In both ears my hearing sensitivity to higher-frequencies - above 1500 Hz - were significantly reduced. The right ear is much worse. I found that I could use a DSP-based equalizer from my UAD Apollo Duo to compensate for this modest but, to me, distressing hearing loss. Because I love quality audio - like everyone on this Forum, and because I have some skills with electronics and software, I decided to build a simple system that has programmable DSP at its core and that can be used to: a) take a hearing test and create a custom equalization profile based on the way that you hear such that you can hear the kind of bass, midrange, and highs that you may have been missing. b) apply AutoEQ profiles for a range of 3000 or so headphones to subtly tune your headphones for optimal sound quality. This also involves using the same hearing-profile based equalization to add another level of customization to the sound. c) do some very basic realtime EQ to tune your speakers to a given room - room equalisation. I'm still tweaking the software for this, especially the hearing test, but my early results are very motivating. I'm hearing my music in a way that I had forgotten. This project is just for my own learning and use but if anyone else here has any interest in what I'm doing please let me know - especially if you have tried to do something similar. My own current prototype is using the HiFiBerry DAC+ DSP + HiFiBerry OS as the foundation. Out of the box it provides some very nice DSP capabilities. I am not particularly happy with the DAC, however, but it's still better than the DAC in your PC/Mac. Anyway, DSP rocks!
This is a topic that is close to my heart. Some years back, after a scare with near total (but temporary) hearing loss in my right ear, I came to understand that at the age of 67, my hearing was not what it was when I was much younger and that it was quite different in each ear. In both ears my hearing sensitivity to higher-frequencies - above 1500 Hz - were significantly reduced. The right ear is much worse. I found that I could use a DSP-based equalizer from my UAD Apollo Duo to compensate for this modest but, to me, distressing hearing loss. Because I love quality audio - like everyone on this Forum, and because I have some skills with electronics and software, I decided to build a simple system that has programmable DSP at its core and that can be used to: a) take a hearing test and create a custom equalization profile based on the way that you hear such that you can hear the kind of bass, midrange, and highs that you may have been missing. b) apply AutoEQ profiles for a range of 3000 or so headphones to subtly tune your headphones for optimal sound quality. This also involves using the same hearing-profile based equalization to add another level of customization to the sound. c) do some very basic realtime EQ to tune your speakers to a given room - room equalisation. I'm still tweaking the software for this, especially the hearing test, but my early results are very motivating. I'm hearing my music in a way that I had forgotten. This project is just for my own learning and use but if anyone else here has any interest in what I'm doing please let me know - especially if you have tried to do something similar. My own current prototype is using the HiFiBerry DAC+ DSP + HiFiBerry OS as the foundation. Out of the box it provides some very nice DSP capabilities. I am not particularly happy with the DAC, however, but it's still better than the DAC in your PC/Mac. Anyway, DSP rocks!
