What Specs Really Matter?

[John Blankenship]

A lot of the 20-20kHz illusions people have were born in the advertising departments of consumer HiFi gear. This, along with the terms "Pro" or "Professional" are among the most abused concepts in audio.

So, I'll throw it out there: "What specs, and/or spec limits, actually make an audible difference in our industry?

Consider the "Academy Curve" that some of the greatest films ever made were molded to.

Consider how few speaker systems will ever reproduce our diligent work at frequencies above 10 or 12kHz.

Consider the percentage of people whose hearing barely makes it into the teens in this noisy world we live in.

What percentage of distortion is actually audible? Consider that many people's voices sound distorted even as the sound waves leave their mouth.

What signal to noise ratio is necessary for quality work?

Of course, real world blind testing is the only true way to achieve the real answers to these questions but we all seem to have plenty of our own theories, so this is where we can share them.

[old school]

I remember what an old mixer and web site host told me a long time ago. He said it didn't matter how much the meter moved, it just has to sound right for the picture. I thinks his signature on his posts says something along the same lines. I am always put into a coma when the conversation goes into specs as compared to the technique and tools used to record a shot, scene, film. Signal to noise, like life is all relative to the shot. What worked for one may be disaster for another.

CrewC

[bralleput]

Crew:+1 you are so right!

[bralleput]

Oeps I didn't read the manual of the new Zaxcom..don't bash me!!

[stevegrider]

We are a sub group of audio professionals that don't always work in a controlled environment. Even our "controlled" environments could be a soundstage with little or no effective acoustical treatments. One could address technical specs in earnest while working in an acoustically treated space recording with the finest preamps and EQ available. Me? Some days I am recording an acoustic guitar on a street musician with a Sanken CS3E while I am simultaneously hoping my three reality cast members don't walk out of wireless range before the song is over. On those shoots, the specs are "Can we hear them?" and "Can we understand them?" Sorry if my cynicism is showing

[John Blankenship]

A good description of the "Academy Curve" and its history is on Sweetwater's site:

 

http://www.sweetwater.com/insync/academy-curve/

 

Quote:  "The response is flat between 100Hz and 1.6kHz. Response is reduced 7dB at 40Hz, 10dB at 5kHz and 18dB at 8 kHz."

 

For almost 50 years this is the response curve used for motion pictures.  I saw some of these movies as a kid -- and have enjoyed others exhibited in their original format in revivals -- and my reaction is that they usually sound great.  Granted, that reaction is influenced heavily due to content, but the movies were mixed in a way that worked well for the times and still hold up today if movie enjoyment is your goal.

[Constantin]

We are a sub group of audio professionals that don't always work in a controlled environment. Even our "controlled" environments could be a soundstage with little or no effective acoustical treatments. One could address technical specs in earnest while working in an acoustically treated space recording with the finest preamps and EQ available. Me? Some days I am recording an acoustic guitar on a street musician with a Sanken CS3E while I am simultaneously hoping my three reality cast members don't walk out of wireless range before the song is over. On those shoots, the specs are "Can we hear them?" and "Can we understand them?" Sorry if my cynicism is showing

So why do you bother with CS3e? You could also hear them with a ME66

[Constantin]

A good description of the "Academy Curve" and its history is on Sweetwater's site:

http://www.sweetwater.com/insync/academy-curve/

Quote: "The response is flat between 100Hz and 1.6kHz. Response is reduced 7dB at 40Hz, 10dB at 5kHz and 18dB at 8 kHz."

For almost 50 years this is the response curve used for motion pictures. I saw some of these movies as a kid -- and have enjoyed others exhibited in their original format in revivals -- and my reaction is that they usually sound great. Granted, that reaction is influenced heavily due to content, but the movies were mixed in a way that worked well for the times and still hold up today if movie enjoyment is your goal.

Ok, I love nostalgic movies, too. I also enjoy watching (silent) family videos on Super8 or whatever and I am excited when I can listen to original wax cylinders, but none of this has anything to do with "good" sound quality

[VM]

I would like to know who said that  human hears sounds from 20 to 20k Hz ? It sounds so nice : 20 to 20 k, like a gimick !

I would like to know who said that we are able to hear until 0 dBspl at 4kHz...Under 30 dB spl sounds are very very difficult to hear.

Maybe a new study is necessary.

 

Anyway it seems to me that all the pro manufacturers give us some nice specs on our recorders and wirelesses. The difference is elsewhere.

[Constantin]

I would like to know who said that human hears sounds from 20 to 20k Hz ? It sounds so nice : 20 to 20 k, like a gimick !

I would like to know who said that we are able to hear until 0 dBspl at 4kHz...Under 30 dB spl sounds are very very difficult to hear.

Maybe a new study is necessary.

Difficult, but still audible.

It's actually the other way around: our hearing defined what 0dBspl means. It is relatively easy to measure our ears.

The 20/20k thing is measurable as well. But it's also fairly well known that our hearing ability weakens just a few years after we're born - and continues to weaken as we get older.

The specs of our ears.

[John Blankenship]

Ok, I love nostalgic movies, too. I also enjoy watching (silent) family videos on Super8 or whatever and I am excited when I can listen to original wax cylinders, but none of this has anything to do with "good" sound quality

 

If one considers "good" quality as defined by specs, then, no, it has no bearing. 

 

However, if you define "good" as what impact it has on the listener's experience, it's definitely relevant.   My point is basically that most people have no concept of what specs actually define what they enjoy.  Due to consumer hifi hype, a lot of people seem to think that 20-20kHz is some magical formula for quality.  That is so far from the reality of what we do, or don't, perceive as "good" that it's basically a joke. 

 

Taking into account what speakers most people listen through as they're watching TV, for instance, or the masking effect of the background noise in a typical home environment, or the erosion of hearing so common in our noisy world, and many many other factors, the numbers basically lie. 

 

So, the point I was making is that in a controlled environment (a movie palace), even the highly rolled off Academy Curve was perceived by thousands upon thousands of movie-goers as great sound.

[Matt Burgette]

"Consider that many people's voices sound distorted even as the sound waves leave their mouth."

QFT

[Constantin]

If one considers "good" quality as defined by specs, then, no, it has no bearing.

However, if you define "good" as what impact it has on the listener's experience, it's definitely relevant. My point is basically that most people have no concept of what specs actually define what they enjoy. Due to consumer hifi hype, a lot of people seem to think that 20-20kHz is some magical formula for quality. That is so far from the reality of what we do, or don't, perceive as "good" that it's basically a joke.

Taking into account what speakers most people listen through as they're watching TV, for instance, or the masking effect of the background noise in a typical home environment, or the erosion of hearing so common in our noisy world, and many many other factors, the numbers basically lie.

So, the point I was making is that in a controlled environment (a movie palace), even the highly rolled off Academy Curve was perceived by thousands upon thousands of movie-goers as great sound.

And I thought my old Honda Civic was a great car until I sat in a Porsche.

I get your point about the specs and hype and so on, and I agree with it, but I also think that the sound systems in cinemas really have improved, as have my speakers in my home, my car...

I know that, because I can compare it to "real" sounds, like when I go to a (classical music) concert, I can hear what it should sound like. And at home I can hear that in comparison it still sounds like crap, but it sounds better than on the old system I had, which was better than the one I had before that.

I don't mean to argue pro Spec-hype or whatever it's called. For my home TV system I didn't read a single number (other than "6" for the number of speakers). The bigger challenge was to get my wife to agree to any speakers at all ... "doesn't the TV come with speakers? Do we really need more?" Sorry, I digress.

But I think glorified memories of nostalgic days gone by are just as valid (or not) as reading specs to define "good" sound. I think both are the wrong approach

[Jeff Wexler]

The specs of our ears.

The tracks of our tears

[John Blankenship]

I agree with most of what you said, Constantin (although I owned a Honda some time after I owned a Porsche and still enjoyed the Prelude), but not the last part.  It's not just about nostalgia, it's about perception. 

[chris_bollard]

the specs are "Can we hear them?" and "Can we understand them?" Sorry if my cynicism is showing

How about trying "Can I make it sound better"

[old school]

What are the specs of a Nagra compared to a Deva or a Cantar or SD recorder? Did using one over the other have much to do with the final recording and how it worked with picture on the day? In the final mix?  Specs are what they are and I of course think we should use the best gear for the shot, scene, film, but the final product is so much more than the specs of any piece of gear. Mostly it is the content we capture that determines what "Really Matters" IMO.

CrewC

[ccsnd]

One of the things I run into a lot is people who buy top notch mics, top notch pre's, then run them through sub par converters and interconnects.

Your signal is only as good as your weakest link. You can have a mic pre that covers 5hz to 40k, but if your mic only covers 50 to 15k, that's all that's going to get recorded.

You can't just looked the specs of a single device. You have to look at the specs of all devices.

[old school]

And my point is that it is how you use the gear more than the gear itself.

CrewC

[syncsound]

How about trying "Can I make it sound better"

In reality TV, there is little, if any, allowance to make it sound better. "Can we understand them" is a win on that kind of shoot.

[Wandering Ear]

Great specs doesn't mean great sound, but that doesn't mean the specs aren't useful info.  The important specs to me include:

 

Self noise, Dynamic Range, Power Consumption, Max SPL

These specs matter.

 

There are many others that are always going to be better than I require, so I barely glance at them anymore, including; THD, Frequency Response, etc. 

[RPSharman]

Great specs doesn't mean great sound, but that doesn't mean the specs aren't useful info. The important specs to me include:

Self noise, Dynamic Range, Power Consumption, Max SPL

These specs matter.

There are many others that are always going to be better than I require, so I barely glance at them anymore, including; THD, Frequency Response, etc.

This is a good list.

But as has been said a great deal before... "How does it sound?" - And that's not considering the sound shot to shot with a specific choice of gear, but how it all sounds together.

Robert

[chris_bollard]

In reality TV, there is little, if any, allowance to make it sound better. "Can we understand them" is a win on that kind of shoot.

I don't want to start an argument but sounds like an excuse

[syncsound]

I don't want to start an argument but sounds like an excuse

It's a lament, actually. I've done my share of reality (Little people, big world; house hunters ; etc). I used to try to fight the good fight, but it's a losing battle. Now I save my energy to get good tracks on feature films and episodic TV. Reality TV simply is what it is: chop suey editing with a near - constant music bed.

[Christian Spaeth]

The point I was trying to make in the other thread by asking "What will post say?" is not so easy to brush away. There is one part of a production that can be called "what does it sound like" but there is the other part of "who says what and who listens to whom?". I once did an M/S setup using Oktava mics for recording car sounds for a commercial, and it ended up sounding great, but when post called me before the shoot and asked about the mics I'd use, their reaction to my answer was like "oh, really? not so good...". Now, imagine a studio person saying to a producer "he's recording voices at 32 kHz! In the studio we use 192!" and the producer, possibly not well versed in audio matters, believes that guy and next time maybe hires another mixer, regardless of what it really sounded like. Sometimes post folks are quite influential, and sometimes they can influence producers, even if they're totally wrong. I had this situation because I was using the Zaxcom file naming scheme where everybody else had scene/take no.s as their file names, and just because they weren't used to that system, post was kinda not amused.

 

I know it's a rather theoretical discussion that might never concern many of us, but there are people in our business who care a lot about appearance, more than actual performance, and sometimes your job depends on those people's opinions.