A question about room reflections

[Poco]

"First, on the analog side of the converter, just like with any other analog preamp, if you push the signal too hot, you get distortions"

Mr. Stephan, your experience notwithstanding, I would like to hear that from the designers of the A to D's in my MX2424. In essence, you are telling us that if we use this gear to its full extent and within its operational design we will get distortion? I find that difficult to believe. In fact, I don't believe it. If a clean analog signal goes in, I am thoroughly convinced a clean digital representation of that signal will be written to the disk, regardless of the level (assuming no clipping has occurred).

If our input devices generate noise when they are turned up (simple way of putting it), we need better input devices.

To those of us who's only analog output post recording is the CD player, the rest of your explanation does not seem to apply. For me, anything post recording is purely math.

Also,
If I set my loudest signal at some 70 to 80 percent of my equipment's potential, my quietest signal will surely fall off the scale altogether. I mean, a chief complaint of recording technology is not that it has too much dynamic range, rather, just the opposite. Ask anyone who has recorded an orchestra. What the human ear can hear, and what current technology can capture are two vastly different things. Why exacerbate the situation?

From the makers of Alesis digital recorders:

"Setting the correct recording levels is crucial to
making any recording sound its best. On any
digital recorder, the best resolution is found
when the maximum recording level of each track
falls just below the “Clip” point."

They said "any digital recorder" Did the Alesis engineers protest this statement? Did someone just miss this very important section of the manual?


I bought a device that records from 0 to 100%. I think I should be able to use it that way to no detriment. If that is not the case, there should be a professional disclaimer "Caution, you should only use 70% of this device's recording potential"

It's my dynamic range. I'm keeping it.

Thanks,

Poco

 

[SouthSIDE Glen]

my MX2424[/URL]. In essence, you are telling us that if we use this gear to its full extent and within its operational design we will get distortion? I find that difficult to believe.

First, call me Glen.

Second, you're taking that a bit literally. Can well-designed preamps be pushed a bit? Of course. Every mook knows that. Why do VU meters go to +3 and PPM meters to +12?

The point is that the further you push your average level beyond 0VU (and remember VU meters are reading averages, not peaks), the farther your pushing your analog circuitry past it's design sweet spot. You can get away with it for a few dB, but after a while it gets unwise (unless there's a distortion you're specifically looking for like overdriven tubes or something.) Furthermore, the higher you push your average level, the more you're taking away from the available dynamic range for your peaks.

In a 24-bit recording system like yours, you actually have 144dB of room between the digital "floor" and 0dBFS. Recording at 0VU on the analog side and coming in at, say -18dBFS RMS (with 18dB of crest factor left over for your dynamics) means that you're using a full 126dB for your average program material. You could push it hotter if you like, but the more you push beyond that, the less room you'll have for your dynamics.

If a clean analog signal goes in, I am thoroughly convinced a clean digital representation of that signal will be written to the disk, regardless of the level (assuming no clipping has occurred).

Exactly my point. I agree entirely. So as long as the signal is clean at 0VU/-16dBFS - which it had better be, that's the line level that the device is spec'd to - what's the point of pushing it harder? There is none.

To those of us who's only analog output post recording is the CD player, the rest of your explanation does not seem to apply.

Ummmm.....what? Nobody is talking post-recording here; lesat of all I. We're talking signal levels in the recording chain only.

I mean, a chief complaint of recording technology is not that it has too much dynamic range, rather, just the opposite. Ask anyone who has recorded an orchestra. What the human ear can hear, and what current technology can capture are two vastly different things. Why exacerbate the situation?

Wow, talk about a time machine back to the early 80s. Do you still wear 1" wide hand-painted ties and listen to Flock of Seagulls too? (I'm just kidding around, don't get pissed ). Dynamic range has not been an issue since the advent of 24-bit recording. Do the math. 24 bits give you 144dB of room, which is far beyond the capabilities of even good ears. Your average analog curcuit these days has low enough noise levels to be able to yield a good 105dB, which is 9dB better than the 16bits you get on your CD that you bought at the store.

They said "any digital recorder" Did the Alesis engineers protest this statement? Did someone just miss this very important section of the manual?

Yeah, the proofreaders/translators have missed the boat on that one since 1999, the last time it was accurate. And I'll tell you, Alesis is not the only one guilty of that. This is old nows, and has been analyzed and discussed repeatedly by the engineers and the pundits. Ask any electronics engineer or audio engineer - including the ones who design this stuff - or read any technical article written on the subject in the last 5 years or so, and you will hear that the "use every bit" theory died with 16 bit converters back at the turn of this century.

I bought a device that records from 0 to 100%. I think I should be able to use it that way to no detriment. If that is not the case, there should be a professional disclaimer "Caution, you should only use 70% of this device's recording potential"

It's my dynamic range. I'm keeping it.

Nobody is telling you to not push your gear to it's best or to sacrifice any dynamic range. At 0VU/-16dBFS (give or take a couple of dB amongst friends), you have a good 105 or more dB on the analog side (actually closer to 120dB when you include transient peaks not picked up by the VU meter) and 144dB on the digital side, of which 16dB is used for those transient peaks. Push it harder if you like, but all you're doing is taking away your peak headroom.

G.

 

[RAMI]

If a clean analog signal goes in, I am thoroughly convinced a clean digital representation of that signal will be written to the disk, regardless of the level (assuming no clipping has occurred).

I could have sworn that's exactly what many of us have been saying all along. I know I said it at least 3 times. If you're analog signal is "clean", that means it didn't clip. If it didn't clip, it was at or under 0. That means it will come into your disk as -18digital. (or whatever it is, -15???). That's exactly the point!!!!

Nobody said anything about post-mix analog gear.

 

[snow lizard]

Poco, especially in the early days of 16 bit converters and home recording tutorials, there is a mathematically valid argument for printing levels on the hot side. 24 bit makes it all irrelevant. Even in 16 bit DAW's, there are arguments against using every bit. I've read plenty of stuff that says use every bit you can, and I don't think those things are telling you the whole story. I'm not trying to attack YOU, but I strongly disagree with printing as hot as you can. Proper gain staging was never intended to be reduced to that, and the popularity of that kind of misinformation is overwhelming and curious. Also, the Alesis manual does have plenty of caveats to consider about the idea of printing levels too hot, and they do highlight -15 dB in red on the meter scales as an important target point for setting proper levels, for a very good reason.

If that's what works the best for you, that's fine.

I might get back to this when I have more time, but it seems like the thread was supposed to be about reverb and room reflection kind of stuff, not gain staging basics.


Anyway,

sl