Understanding Dynamic Range

[MichaelFremer]

My understanding is that the dB SPL scale describes actual volume levels and the dBFS scale describes relative volumes such that if I have a room with an ambient noise level of 35 dB SPL I can play a 16-bit audio file with a dynamic range of 96 dB and, as long as my amp and speakers have their level set such that the quietest sound from the file, -96 dBFS, is played at 36 dB SPL, then I can hear the entire dynamic range of the file from 36 dB SPL to 132 dB SPL. Leaving aside the fact that those upper volumes are a problem for humans, is that the right understanding of how dynamic range works?

[Kal Rubinson]

dB is always relative as it is defined by a ratio between the measured/specified value and a reference.

 

(The real MF would have known this.)

[davide256]

Assuming that the ambient noise is white noise, you need a db difference of at least 3 db in signal to be aware of a difference and 6db for a marked difference.  Looking at the  link from Purdue below, I doubt many performing groups intend a dynamic range of more than 70db but we audiophiles

do get tickled by hearing the chair scrapes and music stand rattles in a recording.

 

https://www.chem.purdue.edu/chemsafety/Training/PPETrain/dblevels.htm

 

[esldude]

You've gotten good answers already.  As said db is always a ratio of values.  I could give the weight of a full vs empty dump truck in db if I wished to do so.  

 

db SPL is db sound pressure level

db FS is db relative to maximum (Full Scale) level in a digital file.  

 

SPL by convention is the ratio relative to an arbitrary 0 db SPL which is why numbers are positive. 

 

FS is relative to a max level as 0 db which is why all numbers are negative.  

 

Your understanding of having the lowest signal in a 16 bit signal above the noise floor and hearing the full dynamic range above the noise floor is correct at least in simplified form.  

 

In more complex form, our hearing can hear 10-15 or even sometimes 20 db below a noise floor.  Plus the level of noise varies with frequency such that often in your room in the area of our hearings most sensitivity (3-5 khz) the in room noise level can be around 0 to 5 db SPL.  So for most purposes playing no louder than 100 db SPL you might mostly hear a dynamic range of 96 db or so.  

[Superdad]

On 10/26/2018 at 5:12 AM, MichaelFremer said:

My understanding...

 

I see you are a new member here, so welcome to CA!  

 

But I have a question back for you:

Unless your real name is actually Michael Fremer, why would you choose to a screen name identical to that of the well-known Stereophile  reviewer?  Just for kicks?  Or to be sure that people click on your posts?

 

I guess CA does not have a policy against users choosing screen names of other people in the real world, but it does seem odd.  Will we soon see CA members Vladimir Putin or Richard M. Nixon (well at least he is passed away)?  But to "spoof" a prominent audio reviewer here on an audio forum...

 

Unless of course you are Mikey F. himself, in which case never mind (and also a hello and thanks for that fun overnight at your house over a decade ago; I still remember your great dogs). 

[esldude]

My guess is this is his name. 

 

FWIW, I early on used my own name on some forums.  It was the name of a Monty Python skit character.  That show was never aired where I lived so I never heard of it.  People didn't think it was my name and made references I didn't get related to it.  I didn't use my name anymore.  

 

Of course in some forums people thought my current moniker was English Second Language Dude.  I received PM's in Spanish apparently assuming I was Mexican. I would only know what it said using google translate. 

 

At least he did not choose Mark Levinson.  At one point he was legally barred from using his own name in public.  It belonged to the Mark Levinson company he founded and lost control of along the way.  Now it belongs to Harman international which belongs to Samsung.  

 

He could have used Michael Remerf I suppose.  But he probably feels entitled to his own name.  

[jhwalker]

1 hour ago, esldude said:

My guess is this is his name. 

 

FWIW, I early on used my own name on some forums.  It was the name of a Monty Python skit character.  That show was never aired where I lived so I never heard of it.  People didn't think it was my name and made references I didn't get related to it.  I didn't use my name anymore.  

 

Of course in some forums people thought my current moniker was English Second Language Dude.  I received PM's in Spanish apparently assuming I was Mexican. I would only know what it said using google translate. 

 

At least he did not choose Mark Levinson.  At one point he was legally barred from using his own name in public.  It belonged to the Mark Levinson company he founded and lost control of along the way.  Now it belongs to Harman international which belongs to Samsung.  

 

He could have used Michael Remerf I suppose.  But he probably feels entitled to his own name.  

 

My name is John Walker.  All my life, people have called me "Johnny Walker", and I never really got the joke because I'm not a drinker and came from a family where no one drank.  It took me several years into college before I finally understood why people found "Johnny Walker" so entertaining 

[Doak]

Just an FYI:

Not that it at all matters, but, my real name is “Doak.”

 

[esldude]

I knew an engineer named Richard Head.   

[MichaelFremer]

No, I'm not the well-known Michael Fremer and I didn't think anyone would read that into a handle. When I posted my first question here a couple of years ago I had fairly recently been at the Rocky Mountain Audio Fest and in one of the rooms had seen this rather pretentious attender grilling the exhibitor about something. I don't remember how, but I eventually learned it was MF. I had never heard of him. When I needed a handle that's just what popped into my head.

 

Anyway, thank you for your answers.

[Milt99]

19 hours ago, esldude said:

My guess is this is his name. 

 

FWIW, I early on used my own name on some forums.  It was the name of a Monty Python skit character.  That show was never aired where I lived so I never heard of it.  People didn't think it was my name and made references I didn't get related to it.  I didn't use my name anymore.  

 

Of course in some forums people thought my current moniker was English Second Language Dude.  I received PM's in Spanish apparently assuming I was Mexican. I would only know what it said using google translate. 

 

At least he did not choose Mark Levinson.  At one point he was legally barred from using his own name in public.  It belonged to the Mark Levinson company he founded and lost control of along the way.  Now it belongs to Harman international which belongs to Samsung.  

 

He could have used Michael Remerf I suppose.  But he probably feels entitled to his own name.  

Mark Levinson was not barred from using his own name in public for godsakes.

He was barred from using the brand name Mark Levinson on gear after he left the company as Madrigal owned the brand name.

FWIW, I think using MF as a forum name unless it is your name is retarded.

I call BS on your explanation that no one would read into it. Please.

Fremer is a well-known analog evangelist and this is a digital music web site.

Yeah, you're right. Nothing there at all.

[Kal Rubinson]

2 hours ago, MichaelFremer said:

When I needed a handle that's just what popped into my head.

If you have a name, you don't really need a handle.

[esldude]

1 hour ago, Kal Rubinson said:

If you have a name, you don't really need a handle.

So what's your real name Kal?   You are not Tom Gillette are you??

[Superdad]

1 minute ago, esldude said:

So what's your real name Kal?   You are not Tom Gillette are you??

 

LOL!  That’s Sam to you sir. 

I knew Tom, and Kal is not.  But there might be a few here at CA who are cheapskate enough to stand in.   

[Kal Rubinson]

56 minutes ago, esldude said:

So what's your real name Kal?   You are not Tom Gillette are you??

Sam I am......................................................not. ?

[wgscott]

6 hours ago, MichaelFremer said:

No, I'm not the well-known Michael Fremer and I didn't think anyone would read that into a handle. When I posted my first question here a couple of years ago I had fairly recently been at the Rocky Mountain Audio Fest and in one of the rooms had seen this rather pretentious attender grilling the exhibitor about something. I don't remember how, but I eventually learned it was MF. I had never heard of him. When I needed a handle that's just what popped into my head.

 

Anyway, thank you for your answers.

 

It might be a good idea to ask Chris if he can change your username. 

[esldude]

56 minutes ago, wgscott said:

 

It might be a good idea to ask Chris if he can change your username. 

Should we have a poll to pick his new name if Chris gives him one?

 

I suggest Lee de Forest or John Bardeen or Jack Kilby. 

 

 

[wgscott]

He asks really good questions, and I think the username is a distraction.  If he feels similarly, I am just suggesting that this might be an option, for the same reason I wouldn't want to be stuck with a name like Michael Behe, even if I thought it was funny at some point.  (That is what Avatars are for.)

[Bob Stern]

@wgscott:  Are you perchance related to Alice Sara Ott?  If so, how do you pronounce your first name "wgsc"?

[esldude]

10 hours ago, Bob Stern said:

@wgscott:  Are you perchance related to Alice Sara Ott?  If so, how do you pronounce your first name "wgsc"?

I think he pronounces it Bill.  

 

NOUN  /bɪl/