Bass management is typically done in the digital domain. That is why early HT recievers could not handle the complex algorythms needed to do bass management for SACD when they first came out. Until now very few receivers can do bass management for SACD. Except for a few flagship reveivers that must often convert the immense DSD bitstreams into 5-channel PCM before they can bass manage, like what Denon does. Most bass management on the SACD are being done on the player while the signals are still digital. Because once they pass thru the player's D/A converter and into the receiver's 5.1 analog inputs (SACD can only be played via the analog 5.1 connection, unless the player and receiver has proprietary D-link or I-link Firewire connection) the receiver assumes that the 5.1 analog signals have already been digitally processed and no further digital processing is done.
If you use an audio editing software on the PC, like Goldwave, Nero or Soundforge, you'd realize how easy, effective and efficient it is to manipulate audio signals in the digital domain. And this manipulation is all done courtesy of the software programs I mentioned plus many more. You can equalize parametrically, filter out frequencies like the voice, shift keys and pitch, optimize dynamics, simulate stereo out of mono, interchange channels, remove DC offset, subtract Left from Right signals, sum them up, etc, etc all in the digital domain. Much of these can also be done in receivers. Those chips in receivers virtually make the modern receiver a computer in itself, using software programs hardcoded into firmwares that may or may not be upgradable, depending on the price points. Certainly flagship receiver firmware can be upgraded via an RS232 port like in an Onkyo or thru a CD-R playback thru its S/PDIF port.
Whatever you can do with analog signals, you can more effectively and efficiently do once you convert analog to digtal first and manipulate the signals in the digital domain. Thanks to software programming. Those DD and DTS Decoders, DSP and D/A A/D converters were first done in computers using programs that manipulate the digital bitstreams. Receivers today simply inherited the advances made in the computer world.
I agree. The advancement in technologies and software programming is really influencing the modern designs of
most electronic gadgets.
May I add, Since there's no dispute that CD is already in digital form. DSP techniques can be applied as compared to let's say analogue signal where you need ADC.
Before, unwanted electrical noise is removed via filter circuit. With the advent of digital programming
nowadays, the DSP software program takes care of filtering signals to improve signal quality.
As I said before in another thread, First audio consumer products to take advantage of this Program
Implementation is Celestion DLP-600 whereby sofware program acts as high pass and low pass filter
replacing capacitors, resistors and inductors in loudspeaker cross-over.
So I believe 0 sampling proponents that Upsampling Theory isn't really what's being implemented
in 20 bit 192kHz CD players since with Software programs, Digital datas are manipulated and
software programmer will keep their source code in secrecy. "Black or Gray ART" as commented by most audio reviewers.
At most, this are only marketing hypes made out of jargon such as "24 bit CD player" when in reality the last four digits are marketing bits and in reality it's only "20 bit CD player" and your redbook CD '16 bit'.
Most significant improvement in Upsampling Cd players are as you said Bass Management. Improved low level frequency and improved soundstaging is really noticeable which I suspect
is a result of Sofware Programming parang the much maligned anti-audiophile digital equalizer effect.
This chips are popular now in usage in cellphone, video cameras and other gadgets .