NEW UPDATED Room Calibration for Film and TV Post

[dr sound]

New LINK
http://www.prosoundweb.com/studyhall.../slm/slm.shtml

It's posted at the very top Link Page

Thanks Minister!

[abluesky]

Hello All:

We just updated our website, so the link to our calibration files and instructions has changed. Below is the new link:

http://www.abluesky.com/asp/catalogu...asp?linkid=143

Cheers!

[doctorsunshine]

Hi everyone,

just a little question : which brand/ model of device do you use to tweak your surround system ( eq, delay, phase and so on ... ) ? I've seen some products from dbx , behringer.... or maybe most of you use Dolby CP650 ....

Thanks,

Jerome

[abluesky]

Hello All:

We just updated our website, so the link to our calibration files and instructions has changed. Below is the new link:

http://www.abluesky.com/asp/catalogu...asp?linkid=143

Cheers!

Just a quick note about our test files:

The calibration test files, available for download on the above linked page, have recently been updated and improved. Changes include; reduced hum & distortion, which although it didn’t negatively impact the accuracy of the previous version of the test files, the noise was somewhat annoying. Additionally, the crest factor on the 40 to 80 Hz test file has been reduced to help improve accuracy when measuring this test signal with a SPL meter.

Cheers!

[Chief Technician]

Here's a question about speaker placement (because without proper placement, a calibration is worthless).

I am setting up our rooms as close to the ITU spec as I can. I keep hearing other people say "Well so-and-so at such-and-such has the speakers in his room above his head and angled down." I am thinking this is only useful if you are working in cinema/dub stage/printmastering environments. If you are working in radio and TV environments, I think the ITU spec is a better setup. I know some people I have queried about this in the past use the ITU spec.

So, is there a right and wrong answer to this? Should the rear speakers be above you, behind you, and angled towards you? Or should they be in an equidistant circle around you? The question is for a non-printmastering environment. Inquiring minds would like to know.

Thanks for reading!

[minister]

when i did my room, the center channel placement determined everything; there were few places it could go. once set, everything was adjusted to that. this meant, i needed to angle the speakers down.

i would not say that this is ideal or not ideal, except in that given the placement, it was the only way to get all speakers on the same plane to hit the mixer and clients ears in the sweet spot. we adjusted the monitors so that the tweeter were all at the same hieght. that, angle and relative distance are the most important things. the L&R 30degrees off of center. and the surrounds 110 of off center (with a plus or minus 10 dgree tolerance.) measured off what is regarded as the center point of the monitor (depends on manufacturer, genelec says it is the area on the housing between the tweeter and woofer). angled or not only depends on room geometry. the rule of thumb we used was a typical seated person's ears are 4 feet off the ground. all speakers are the exact same angle to that spot.

do you have a laser line generator device? they are very handy for this sort of thing. set it in your focal point and you can mark exactly where things need to go.

[Charles Deenen]

Many smart folks here, so I thought I'd ask since it's bugging me for months already:

First off, I'm not a noobee when it comes to surround calibration, but I must be doing something wrong consistently.
We have a center channel volume problem in several studios (if not all).

- I'm calibrating my surround speakers like most other people. Radio-shack meter, C, bluesky/M+K tones etc.
- using direct outputs on protools (no panning)

result: center channel comes out too quiet in comparison to a prologic 2 downmixed version (setup with factory defaults).

Thoughts ?

-charles

[Arno Peeters]

Can it be tied to 'Nominal Pan' or some other panning-law? I ran into questions on that with a Yamaha 01V96 (see some answers here )

[Charles Deenen]

hi,

No, it runs straight from protools into Control 24. No panning in there.

But, last night I noticed that the Radio shack meter is directional (it even says in the manual), so once I didn't keep the meter pointed 45 degree upwards and didn't place it between me and the speaker... magically, it all fell in-line, and worked out good.

So for me at least, the directions posted in the links above, resulted in badly calibrated center speaker.

(update): here are the directions which ended up producing a proper calibrated room for me. Took some time out to note them down:

Link to PDf for calibration

-charles

[dr sound]

Poster: Charles Deenen
Subject: Re: UPDATED Room Calibration for Film and TV Post
SNIP
But, last night I noticed that the Radio shack meter is directional (it even says in the manual), so once I didn't keep the meter pointed 45 degree upwards and didn't place it between me and the speaker... magically, it all fell in-line, and worked out good.

So for me at least, the directions posted in the links above, resulted in badly calibrated center speaker.

dr sound replies,
Charles,
Since I can't be there to see or hear what your doing it makes it difficult at best. As for my links resulting in a badly calibrated center....
I don't think so!