Want to cross your eyes this morning?
There's always a lot of questions when it comes to how we at Octave Records make our recordings. Why? Because we don't do what most everyone else does.
When we record in DSD256— a format that runs at an incredibly fast data rate of 11,289,600 bits per second—people's eyes cross. "Man! That's fast!"
Compared to the lowly data rates of CD—44,100 bytes per second, DSD256 is light years faster and with more data than you can throw a stick at.
A few other high-end labels record in DSD256 but then when it comes time to mix and level adjust all those channels of DSD256, they convert the DSD to analog by running it through a DAC, process it through a lot of analog amplifiers and EQ stuff, then back again through an A/D converter returning to DSD256.
This method works and sounds great, but at Octave, we prefer to keep it purely in the digital domain and not go through the extra D/A, analog op amps, A/D. Instead we move the DSD256 data to DXD, then back again to DSD.
DXD is PCM running at 352,800 bytes per second. "Whoa Nellie!" you might say. Don't you lose a lot of data going from DSD's data rate of 11,289,600 bits per second down to a lowly 352,800 bytes per second? I mean, that 32 times less information, right?
The data density and resolution and sample rates are identical. The difference is found in the two types of data capture. DSD is a 1 bit stream while PCM uses multibit chunks. Both express the same things.
Let me give you the quick math.
DSD256 is calculated by multiplying the CD rate times 256. So, 44,100 bytes per second x 256 = 11,289,600 bits per second.
DXD is calculated as 8 times faster than CD. 44,100 bytes per second x 8 = 352,800 bytes per second.
Notice the difference. DSD is calculated in bits per second while PCM is calculated in bytes per second.
A byte is a group of bits. PCM groups together bits in to bytes (words) to describe what it records while DSD uses the same number of individual bits to record.
Think of DSD like a single long line of cars on one lane of a freeway and PCM like an adjacent freeway lane of a long line of trucks carrying 32 cars each.
If we need to move the same number of cars in the same amount of time in both lanes, how fast do they have to travel? Well, the single line of cars has to move 32 times faster than the lane with trucks carrying 32 cars. Make sense?
Here's the math again.
DSD 256 is a single line of 11,289,600 bits per second.
DXD is a single line of bytes running at 352,800 32-bit bytes per second. 32 x 352,800 = 11,289,600.
See? The data are the same. DXD is not "downsampled" as if we're trimming away bits from the DSD.
Same bits, same speed, same data, just rearranged into a different form.
Sorry for the long email on Sunday morning but I hope this helps people understand what's really going on and why we at Octave Records have chosen our path.
It sounds better.