what is "headroom?"

  • Thread starter Thread starter Daisy
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Daisy

Banned
i keep hearing that expression used to describe mixers and preamps.

just curious if anyone has a clever "homerecording.com" definition?

thanks!

daisy :)
 
Every piece of audio gear is designed for a specific usable range of signal voltage level... it's especially critical for pres or mixers because these device are used to adjust or change signal levels.

Especially mixers - which are designed to combine multiple signals together - which is mostly summing the voltages... if you exceed the design limitations of the handling of the voltage levels, the result is excessive noise, and distortion.

Headroom is the definition of the range of that usable signal level area in the circuitry.

A bit of an oversimplification, but hopefully, it gives you an idea....

Bruce
 
Okay, I've got a Joemeek VC6Q. I use it for tracking electric bass a lot. So the headroom of that unit would be what in terms of dB?

If you can't answer that question, then I understand completely. But why is 'headroom' a useful term?
 
Let's say the maximum output is +28db... now if you run a mic signal in and get it to to sit around 0db, you then have 28db of headroom to work with -- meaning your signal source has 28 db of "space" in which to peak, so if you're recording drums, if that cymbal splash causes a 30db peak, you ate into your headroom by 2 db....

Headroom is not so much an absolute reference as a relative one dependent on the dynamic range of the device and the signal level being sent thru it.

So I can't answer your question with numbers without knowing 1) the overall dynamic range of the unit, and 2) the signal level you're applying.

Bruce
 
Let me try my layman's approach.

A long time ago my band headlined a political function which meant I provided the pa and did sound for all the other music. The country band was fronted by an older guy with few and 5 strings on his strat. I asked him how he wanted the sound and he said, "Son, crank 'er up till she squeals 'n back 'er off a hair."

Headroom is the space between your setting and the squeal. A hair in this case.
 
very interesting. no wonder they have schools for this stuff.

so in other words, if something has a lot of headroom, it can handle louder noises before you get that nasty distortion. something with less headroom will distort sooner? am i close?

thanks, sweeties!

daisy
 
Another analogy would be a bathtub.

When filling said bathing device with solvent it is prudent to not fill it all the way to the rim because when a bather steps into the tub, the volume of the bather is combined with the volume of the solvent to produce a new level. Leaving enough room in the tub so you can step in without overflowing the tub is "leaving enough headroom". Further extrapolation of this analogy to a similar device- a swimming pool, leads one to the conclusion that while keeping many other variables the same (e.g. depth of the tub, temp of the solvent) the swimming pool intrinsically provides more headroom due to the larger size of the vessel. Better design of the circuit can also leave more headroom.

Throwing this out: is this difference in headroom from one circuit to another mostly due to a lower noise floor in the circuit with the larger headroom?
 
I predict Daisy's next question will be..........what is "noise floor".

:)
 
Great analogy Doctor!

And as far as ... is this difference in headroom from one circuit to another mostly due to a lower noise floor in the circuit with the larger headroom?...

That's probably true given that a lot of studio gear has a relatively fixed output level, so the only way to improve headroom is better circuit design (ie, better components with higher specs) and a lower noise floor.

Bruce
 
They're all wrong Daisy!!!!!

It's the distance between the top of your head and the roof of your car!
 
headddddroommmm

Now we are getting somewhere Q. I've been tring to get them to raise the headroom on golf carts. I keep bumping my head tring to get in and out in a drunken stupper.
dtb
 
Hey Bruce!

I guess you are completely right but I thought that headroom was the amount of extra dB's over the Standard Operating Level SOL of 0dBs before saturation, in mixers and equipment. I mean, for example the Behringher Eurodesk has 22dB's of headroom and so on... To put it in a very raw form... It's the amount of dBs the master peakmeter shows above the zero (positive shown dBs +3, +6...)
Am I entirely wrong?

Peace

PC
 
Well... that's the refined definition, I guess! But I was trying to keep the 'splanation more basic for our floral friend here!

You're technically right though...........

Bruce
 
"Headroom is the space between your setting and the squeal. A hair in this case."

Headroom is hairroom in this case.

Headroom's how much you've got to play with before it clips.

When I record, I set the levels so the peaks are hitting somewhere between -6 and -3 dB. Which means I've got about 3-6 dB headroom.

Did I use the word correctly?
 
If you're talking mixers - if you're peaking between +3 to +6db, how much headroom you've got left depends on what the upper limit of signal level is for the mixer.

The idea is that you need to know your gear's limitations and ideal levels. You need to know headroom not only to watch for distortion, but also to move your levels as far away from the noise floor as possible. It will vary with every piece of gear and will be different for every studio depending on how it all has been interconnected!

Bruce
 
when a bather steps into the tub, the volume of the bather is combined with the volume of the solvent to produce a new level...

... what if the solvent dissolves the bather somewhat? Does that increase headroom?
 
No, it increases the room left in his pants.
 
thanks fellas for the . . . ahem! . . . INTERESTING responses!

you boys are not only educating, but you add a flare of humor also.

thanks 2 the blue bear for the information, and thanx to powercouple, track rat, others, for cracking me up! :)

and i know what a noise floor is! i have one of those in my kitchen. when all the girls come over on a sat. night (before a night on the town), we likes to wear our high heels and the otherwise quiet floor becomes a "noise floor." :)

take care, sweeties! :)

- your daisy
 
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