[Radium]

Karl Uppiano wrote:
Digital audio for high fidelity?

Digital audio for any application.

Why monaural?

Because I want both the L and R channels to sound the same.

Suppose I like stereo?

A sample rate of 44.1 or higher will
give you 20KHz audio bandwidth. That's nice for hi-fi listening, but may be
more than you need for "You Tube" sound tracks.

Any digital audio requires 44.1 khz or higher in order to sound
pleasant. Aliasing can be a real earsore.

Okay. What about dither? Does it need to be dithered? I think it needs to be
dithered at 2/3 LSB (that's my rule).

No need for dither.

Even if the compressed and uncompressed versions reside in different zip
codes?

Of course. What do zip codes have to do with this?

I assume that by this you mean you do not want to reduce the bit rate by
reducing the sample rate, but only by means of bit allocation using a
perceptual coder.

Exactly.

In-phase signals from left and right channels will increase by 6dB when you
sum them. In order to avoid clipping if left and right channels are full
scale, you would need to reduce the level by 50% You said reduce *by* 77.5%,
so I assume you mean drop the level *to* 22.5%.

You assume correctly.

If it was mono you wanted, you had it at step 4. If you really wanted
(0.725R - 0.275L), you could have done that all in four steps: Reduce the
right channel by 72.5%, reduce the left channel by 27.5%, flip the phase on
the left channel, and convert to mono. Try that and see if you don't get the
identical results you got with your 14-step plan.

The audio that was in the center channel [lead vocal, bass,
percussions] are too loud while the audio that was in the periphery
[paino, chours, guitar, synth-pads] aren't loud enough.

People have been mixing down to mono from stereo for 50 years or more. You
simply add the left and right channels. Listening in stereo in a room
actually does more or less the same thing too (left and right speakers
working in phase (panned to center) will sum 6dB higher in the room,
depending on the frequency, and where you're standing). Record producers mix
the stereo channels for the proper artistic balance in their professional
opinion. Mixing down to mono should not be a problem.

My technique usually ensures that the sounds that were originally in
the central channel are not significantly louder than the sounds that
were originally in the periphery [and visa versa].