System Calibration

OK, everyone agrees that a decent decibel meter is needed for system calibration ... but what else do Gunslingers like to use? What source material(s)? Computer software? Test gear? Methods?

C'mon and tell your stories!

For routine level calibration, the RadioShack analog SPL meter is the standard. In fact, movie dubbing stages use this very meter to do their calibrations! For more in-depth analysis, there are many RTA applications available. A good measurement microphone can be fashioned for a reasonable cost with a mic capsule from Digikey electronics. The required preamp is easy to construct.

For really accurate calibration of levels, full bandwidth pink noise should be used. This is available on the Avia DVD test disc. The problem with the "test tone" in preamps like the 950 and on most test discs is that they only exercise a very narrow slice of the audio spectrum. This makes frequency response of the speakers at that particular frequency a determining factor in the ultimate calibration. Full bandwidth pink noise averages the entire audio band and allows a more accurate calibration. This is how it is done professionally.

i picked up chesky's 'ultimate dvd surround sampler/5.1 setup' disc while at ces.

the sub and sub/sats in phase, out of phase section is an important calibration.

also, though i believe the RS spl meter is an easy way to calibrate channel levels, i found the chesky disc delay setting 'clicks' to be a great final tweak tool.

though i measured placement with a ruler to the 1/16", this section of the disc caused me to change the rear surround delay setting slightly and the front right level setting. this ever so slightly shifted the image centerstage to perfect center from just off to the left and forward position.

this makes me think SH is right on suggesting the use of full bandwidth pink noise (vs. the narrower band that comes in the 950). also, the room acoustics can play tricks on you and your equipment.

test discs are helpful in that they tell you what to listen for and how to correct a wrong image (placement, phase, delay, LF routing, etc.).



[This message has been edited by bossobass (edited May 02, 2003).]

Stryke & Autosounds 2000: discrete test tone CDs.

Avia, VE, & the S&V disc: DD/DTS/DD EX audio and video DVD test discs.

Chesky Ultimate: DVD-A set up disc.

My favorite:

http://www.etfacoustic.com/

All along with a trusty Radio Shack sound level meter.