Dolby Digital Test Tones



I want to calibrate my speakers using a SPL Meter and I need to generate some test tones.

All the tones that I get from the net are only stereo.

My question is what to do with the LFE and the Rear chanels in Dolby Digital?

Should I code the LFE and Rear chanels or leave them silenced? In my AV Reciver all the speakers are configured as small, an SW Otuput at Both, if I generate a tone at 40Hz and put it at the two main speakers then the AV sends that tone to the SW right? If so, if I put the same tone at the LFE chanel, is the bass is going to be stronger them if I leave the LFE chanel silenced?

How should I code the 5.1 chanel in my test tones? should I put the same tone in all the chanels or only in the 2 front speaker?


Distinguished Member

Why not buy a test disc such as AVIA or Video Essentials??

AVIA available from

Video Essentials from

At least you´ll know these test discs have all the their test tones recorded correctly and will help you balance your AV system properly.:)


Standard Member
Or if you got Star Wars Episode 1 or Monsters Inc on DVD they both have THX Optimizer on them which provides 5.1 channel test tones.


Standard Member
One thing puzzles me with test tones, to get 75db pink noise with Video Essentials requires a very high volume, to get 75db pink noise with The Ultimate DVD Platinum requires a lot less volume so which one is more accurate. I'd say the test tones at 75db that are closer to your listening levels are more accurate surely, your thoughts?

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