Axiom Home Page Forums General Discussion Technical Questions Reference Level Sound

This is one of those stupid questions, but Ive seen lots of people talk about listening to movies/music at "reference level". What is reference level? Is it different for movies and music?

90 db if I remember correctly.

Actually it is 85dB or 75dB depending on where you get the info.
75dB is the most common version and certainly an adequately loud point for listening.

Hi LazyJ,

This is a term that is tossed around with little clarification. It really depends on what you are referencing it to. . .real-life sound levels? If real life, measured at what distance from the source? The front row in Carnegie Hall, or the first Tier halfway back? The levels the audio engineer mixed at? (Usually excessive, and much louder than life, in my experience.)

If memory serves, the THX level for movie theater playback is an average of 85 dB SPL measured in a mid-audience location. Subjectively, that's termed "quite loud" (and it is). It's also routinely exceeded in lots of cinemas. I fled a press showing of one of the Star Wars movies at the Zeigfeld theater in New York because the peak levels were away above 100 dB SPL (and I was at least halfway back in the movie theater).

Amplified rock in concerts reaches levels of 110 dB and louder (there are bylaws to control this, seldom enforced) but levels like that, if it's cleanly amplfied, are far more tolerable outside or in a club than in your living room at home.

The loudest peaks I've ever measured in concert halls with a 150-voice choir and full orchestra are about 106 dB SPL in the first ten rows of the orchestra section. From a first tier balcony seat at the side of Carnegie Hall, peaks of 96 to 100 dB SPL are not uncommon with large choral/orchestral works.

At home, I often listen to music peaking between 85 and 90 dB SPL at my listening position. It's realistic and enjoyable at those levels, even thrilling at times, and occasionally, at the risk of offending neighbors, I'll up the ante with peaks between 95 and 100 dB.

Listening-level tastes vary quite a bit from one person to another. Colleagues of mine routinely listen at levels at least 3 to 6 dB louder than my preferred levels.

Regards,

Thanks for all your help. Its interesting to see that reference level is widely used but seldom understood. I seldom listen to movies/music that most would term quite loud. I guess Ill have to get myself a sound pressure level meter and see where I would like to be at (loudness wise), and make adjustments to my speaker selections to accomidate it.

Since Alan's already seriously answered your question, I don't feel bad posting this.

Reference Levels by job title:
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Director : The soliloquay I'd like to be really "present"... kind of "coeval", you know! Idiots!

Audio Engineer : (incomprehensible jargon)

Audio Tech : I don't care long as the IOC doesn't flash

Lighting tech : Stop that ****, my HMIs are vibrating!

First camera : Dee-Bee?!?

Bren R.

Bren, i think you've been nipping a little too much of grandma's secret hooch.

Time to get out of the house. It is actually mild out there (only -14 C today with light snow).

In reply to:

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Bren, i think you've been nipping a little too much of grandma's secret hooch

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My grandma's secret hooch is made from milk, believe it or not.

Milk? That's got to be SOUR! Does milk have enough starch in it to be the main fermentable? Or are you just pulling our collective legs with old-world references?

Easily fooled and rising to the bait -

Tom

In reply to:

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Bren, i think you've been nipping a little too much of grandma's secret hooch.

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Nah, it's the dry reading I've been doing lately... last night - the Crown Com-Tech 1600 Power Amp manual... today - the Peavey Architectural Acoustics "Systems Approach to Sound" tome. Gotta brush up on my constant voltage distributed speaker systems theory.

Though some of Peter's grandmother's rheumatizz medicine is starting to sound better.

Bren R.

Milk is just the base ingredient. It's more of a milk cordial. It starts out with whole milk, lemons, oranges, and vanilla. You let is sit long enough for the curd and whey to separate (a few weeks I think). You get rid of the curd, then you dump in everclear.

It's actually quite delicious. Old Polish recipe.

That sounds so interesting that I'm almost ready to try it.

Is that the whole recipe?

It's really, really freakin' good. :-D

As far as I know, that's the recipe. Removing the curd can be tricky. I believe pouring through cheesecloth is involved. Also, when you first start with the milk/citrus/vanilla mixture stir it every few days and keep it in a cool, dark place.

There is no reference level for music. Reference level for movies is listening with your processor set at 0db if you have calibrated your system properly with a sound level meter at 30db below reference with your receiver's test tones (75db) or 20db below reference (85db) if using an Avia test disk.

This will give you peaks of 105db at the loudest portions of the movie, and 115db from the LFE (if your sub can produce those levels). Many processors offer a bass peak limiter to protect subs that can't produce that output.

Listening at reference will allow you to hear in your home what the sound engineer intended. Whether you want to reproduce those levels in your home is a separate issue.

Regarding music, I have measured peaks at Symphony Hall, Boston of over 100db in a mid-hall position of the orchestra. Most of that energy is provided by the bass, but the rest of the orchestra can get pretty darn loud. I try and replicate those levels at home when I'm in a crazy mood and my wife's away.