"O db"-Theory

claudek · Post by **claudek** » Thu Jul 01, 2004 7:55 pm

I see most audio apps ,like Live output at "0" db.
What is this all about and why.
I've been told its better to be hotter than this.
I'd like your thoughts.

suburbanbather · Post by **suburbanbather** » Thu Jul 01, 2004 8:25 pm

Its always been my understanding that in the digital world anything above -0db will produce clipping. Not the same case in the analogue world though. I don't know if is 100% true.

Machinate · Post by **Machinate** » Thu Jul 01, 2004 8:39 pm

suburbanbather wrote:Its always been my understanding that in the digital world anything above -0db will produce clipping. Not the same case in the analogue world though. I don't know if is 100% true.

you're right. In analogue, different quality mixers and such have different amounts of overhead, up to +18 db and beyond. ( - i think, i'm not an analogue master by any means).

claudek · Post by **claudek** » Thu Jul 01, 2004 8:42 pm

So do all these digital DAW's limit to 0 db then.
mean lower in Volume?

Guest · Post by **Guest** » Thu Jul 01, 2004 11:16 pm

http://www.homerecording.com/bbs/showth ... ost1111663

Guest · Post by **Guest** » Fri Jul 02, 2004 1:18 am

Most redbook CD master's - prefer the premastered material to be closer to -3db with as little 0db attenuation premastering as possible though.

suburbanbather · Post by **suburbanbather** » Fri Jul 02, 2004 3:33 am

I always go to great pains for mixes in Acid to hit that -0.1 mark in the master volume and it always comes out great sounding except for the fact that I have TURN THE VOLUME UP! when listening to the mix on cd.

ethios4 · Post by **ethios4** » Fri Jul 02, 2004 5:27 am

From what i understand of the digital world, its not possible for a signal to go above 0db. When an audio signal is sampled into the digital world there are a finite number of possible representations of the amplitude, similar to a piano roll where there are 128 possible note positions, bounded by an absolute maximum and minimum. The actual number of possible amplitudes is dependant on the bit-depth used. So when a signal goes beyond what can be represented (beyond 0db) the nice round wave shape is flattened at the top and/or bottom (take a look at waveforms that have clipped to see this). At best digital clipping results in degradation of the sound quality, more often you get horrible-sounding digital glitching (unless you like that sort of thing

) It seems counter-intuitive for 0 to be the maximum, but this makes more sense with time.
The other thing is that loudness does not always correlate with the amplitude of the waveform. The quest for the loudest mix is one the great challenges a digital producer faces. Many factors go into determining how our ears perceive loudness, such as the amplitude of the transients vs. the rest of the audio material, which is why compressors help to make a mix sound much louder (and can also make a mix sound fatiguing if overused). How well the entire frequency spectrum is mixed also plays a big part in the perception of loudness. If there's too much going on at, say, 350 Hz, its going to eat up all your headroom. Everything else has to be turned down to keep 350 Hz from going above 0db, which is why proper use of subtractive Eq can make a mix sound louder too.
Hope this makes sense. If i've got any of this wrong, someone please correct me, cuz i'm learning here too

claudek · Post by **claudek** » Fri Jul 02, 2004 7:48 am

So all this to say that when it is burned to cd it i best to be at 0 db?
Funny how many say the cd should be "hot" ,like peaking in the grid.
I never understood that as in mastering they would take care of all this.
I guess that is why I post this topic.

Another thing then , while on this topic, why Reasons' main mixer is limted at -3db? Is this for htis '0' db factor?
Many say it sounds dull this way and not very powerful or punchy..lacks character.
I even have some saying it sounds best /warmer to run Live out of the digital world, through an analog mixer..

Who knows maybe it is all in the head.I guess once our ears become more used to all these digiatl recordings we lose the comparison to the older anaolog days.?

ethios4 · Post by **ethios4** » Fri Jul 02, 2004 5:36 pm

i always put a limiter with soft clipping at the end of the Master Out chain, set to -.1db, to prevent digital clipping. Seems like i've noticed Live's output being at -3db also. I would guess that this is to make it harder to get the glitchy sound of digital clipping. I like the slightly softer output because it gives me a bit of room for mastering later on. Either way i always normalize to -.03db as the final step.
Here's some links to info on mastering for anyone that's interested:
http://www.digido.com/
http://www.soundonsound.com (Articles->Techniques->Mastering)
I don't know what to make of all this talk about summing busses and running each channel out to an analog board. It probably does sound better, but i can't afford that. Seems like getting studio acoustics under control would be of more immediate concern.
I read a post recently by a clarinetist who jams along with a DJ. He was talking about how a real, live, raw clarinet doesn't sound good to people anymore, beacause everyone's so used to the studio sound of a clarinet. So he has to run his instrument through a bunch of processing to get that "studio" sound live. Weird...

eduardo especial · Post by **eduardo especial** » Fri Jul 02, 2004 9:21 pm

So do all these digital DAW's limit to 0 db then.
mean lower in Volume?

i dont believe so. analogue 0 Db is somewhat different from digital 0 Db. they are not really the same in terms of "loudness" i believe. one thing with digital though, you want to try to get it as close to 0 Db as you can without going over, for the optimum sound quality. theoritically speaking, the bit rate resolution might not get all the "digital information" right at low recording volumes.

Vercengetorex · Post by **Vercengetorex** » Sat Jul 03, 2004 1:21 am

Analog and Digital gear use different Decibel scales. +6 dB (peak) is most often considered to be "nominal" level in the strictly analog domain, and on many (NOT ALL!) analog peices +6dB would correspond to OdB (peak) digital input value. Unfortunatly (or perhaps not) manufacturers deviate from the standard scales and specifications quite often for better or for worse. THIS DOES NOT MEAN YOUR SOUNDCARD IS QUIETER THAN YOUR MIXER. They are simply referenced to different voltage scales, and thusly for optimal recording and playback, they need to be calibrated to each other. I reccomend looking for some articles on a pro-audio aubject called GAIN STAGING. Researching this subject will give you a great deal of reference regarding the different dB scales out there, and how they correlate, as well as how to get signal into and out of your equipment at the best level possible. Hope this helps!!

007 · Post by **007** » Mon Jul 05, 2004 8:24 pm

ok not really but , ive read a very interesting article that basically explains why many are so unconfortable with digital... heres an analogy.... basically when we speak softly our voice produces an x amount of freq's, when we shout ,naturally we begin to distort our vocal chords, as in the natural loudness curve found in nature(when pushed to the max)...and this is how basically analog equip reacts as well , when overdriven it distorts and produces natural compression curves ,once again like found in nature...now heres the fun part , digital works exactly the opposite....meaning that when you speak quietly , the voice gets recorded at a low resolution and therefore distortion is present because of missing bits...but if we were to scream we would get a nice full sound ,but yet smooth missing the natural rage...get the picture? plus if your recording quietly you lose a lot of harmonics in digital, so that kind of explains why recently alot of records sound crappy, because all though you get crystal clear recordings with digital ,everything above(nasty cliiping) and below a certain threshhold sounds like shit, no dynamics... a digital recording is a one big compressor when you think about it..or a repressor? of course there are great benefits to digital, but it has a way to go , to give us that natural expression that we naturally crave for...

borg · Post by **borg** » Mon Jul 05, 2004 9:07 pm

im(very)ho... that's why they got us 24 and 32, integer/float, bit recording: bigger dynamic range, more headroom (especially noticable when adding fx during mixing/mastering.

then there's these things like micing (the voice issue), mixing skills (wish i had lots more)... craftsmanship... but also conditioning, flavor of the month, the radio sound (overcompressed),...

it's not the tools... nowadays definitely not.

007 · Post by **007** » Mon Jul 05, 2004 9:49 pm

it is the tools, because they are acting as our mediums/extensions of expression in modern music making...and this works even more for electronic based music.

24 or 32 bit/float still does not produce(physically) a natural loudness/compression curve or atleast does it poorly, even with all the high headroom. if you cross Odb you end up with unpleasant digital nasties, and pretty much everything below -60db+(were lots of harmonics would reside to creat sum and differences within higher levels, are distorted/corrupted or even cut out, one reason as to why digital misses warmth)

I agree that mixing skills and micing techniques are crucial, and everything can be made to sound good if need be, unfortuanately our conditioned mind thru the time of man to walk earth has been the other way around and so as the laws of physics.

im not bashing digital , its just i think understanding these subtle yet big differences is important to obtaining a good digital recording and understanding the philosophy of 0db.

If michealangelo was given chopsticks to paint mona lisa ,i doubt it would ever happen. A craftsman very much depends on his tools, as for an artist? ,thats another story.

"O db"-Theory

"O db"-Theory

why digital sucks