Tag Archives: sound

Asheville, Walnut Cove, Biltmore Forrest and Western North Carolina’s Audio and Home Theater specialists present Cane Creek AV and Paul McGowan – PS Audio, Intl.

We went to see Andy McKee last night and talk about dynamics!!

Unlocking dynamics

Dynamic range describes the difference between soft and loud. What’s not defined is how soft or how loud—only the magnitude between the two—which is a problem if the softest sounds fall below the threshold of audibility. When that happens the range of dynamics is truncated, a fact not apparent when quoting dynamic range figures.

I’ll give you an example. The threshold for hearing is defined as the minimum amplitude the average person can detect sound. This level happens to be around 15dB for a middle-aged male. If we want to be able to listen to the full range of a CD, which is 96dB, we have to adjust the system’s loudest peaks to be 111dB (15dB + 96dB). That’s pretty loud and beyond the capability of most speakers to comfortably hit those levels. Which means we aren’t going to get the full dynamic range possible out of a CD.

But, wait a minute. A CD is 16 bits limited in dynamics (96dB). Higher bit depth, like 24 bits, can theoretically go as high as 144dB, though noise and other factors set the practical limit at about 123dB. How then can this greater dynamic range from greater bit depth matter, if we’re already losing dynamic range to the threshold of audibility?

It can’t, at least not by much.

And vinyl? Heck, we’re lucky to get 70dB from well-pressed vinyl, forcing the mastering engineer to compress the presentation into that smaller space. That said, vinyl’s the only medium that actually scales pretty easily. You get it all at most volume levels, though the price is the compression.

So, the bottom line in this ramble is simple. Even though a CD is limited to 96dB of dynamic range, by making sure to turn the level up so the softest passages can just pass the threshold of audibility, we can get close to the dynamics of live music. Deeper bit depth makes it easier, but not by a lot.

 

Asheville, Walnut Cove, Biltmore Forrest and Western North Carolina’s Audio and Home Theater specialists present Cane Creek AV and Paul McGowan – PS Audio, Intl.

Thought plum

Some puzzles are quick to solve while others take a lifetime. I like to think of the long-term puzzles as thought plums.

And, while I love plums, I am always sad to eat one because the longing for its pleasures is never as sweet as its fruit.

One such plum has been with me for as long as I have been aware of recorded sound. Live sound from mechanical means.

Just yesterday I sat in the quiet of the hotel lobby noodling on this problem. It was early morning, just after 6. I sipped hot coffee in the 100-year-old Benbow Inn with its disparate collection of furniture, windows and doors. It’s a large room with wooden floors and tall ceilings. In the far corner, ironically next to a beautiful grand piano, is mounted a pair of crappy speakers playing some attempt at classical mood music. As the recorded piano played in its muddled version of music—unable to leave the speakers—I imagined how that same music would have sounded in this room on the grand just below the speakers. It would have pierced the silence. It would have rung like a bell. It would have lifted itself out of the quiet and made itself known. Its notes would have lingered in the air, separate and apart from the room and the wooden box the strings were amplified by.

Those little speakers could never compete and I wondered if any speaker could. Yes! came the answer. Somehow we can make this happen. We are so tantalizingly close, yet miles from the grail.

I figured one test that might give us a clue. A step response. I don’t know if this yet exists but I want to create a low-level continuum and intersperse stepped volume bursts of increasing levels and record the results to see what is disturbed and what is maintained. I can see it in my head. Now we just have to figure out a means to make this happen. It’s what engineering is all about.

It excites me.