Should you Calibrate the Dolby Pro Logic (DPL - REFERENCE) DVD mode?

If you want your DVD to playback accurately, the answer would be YES!

Why?    SPL output thru your 5 separate Amp's  (FL / C / FR / SL & SR) will vary between each channel due to the integration with the DSP / Decoding chips, used for Dolby Digital & Dolby Pro Logic (DPL).       It's an easy enough test to verify using Video Essential DVD and or Delos DVD Spectacular.      Just run your DPL mode @ your Calibrated Dolby Digital 5.1 REF Level, . . .watch your SPL meter readings, . . .it will be different when the DPL test signals starts playing.

If it is Not, . . .your set and go no further.   You've got an high-end Rec/Pre-Amp control setup. BUT, . .if there is difference, . . .then you NEED to also establish your DPL REFERENCE Calibration mark.      I actually go one step further.  I have Calibration REFERENCE Marks for:

1) Dolby Digital: via DVD signal source using Video Essentials or Delos DVD Spectacular 2) Digital 2.0 DPL: via DVD signal source using Video Essentials or Delos DVD Spectacular (could be same setting as #3-Analog) 3) Dolby Pro Logic / Analog: thru REC/AMP Internal pink noise (for DPL TV Broadcast & VHS THX / DPL tapes) NOTE: If your AV Receiver / or Pre-AMP does not have memory for these three modes, then you will have to write down the differences between all 5.1 channels.      My Yamaha RX-V995 does not, but, fortunately for me, the established DD & DTS -5.1 surround settings, is IDENTICAL when I switch to a DPL DVD, VHS THX Hi-Fi, etc. source.

My Technic's SA-TX30 has separate memory, so each mode automatically changes when I enter that playback selection.

Technic's SH-AC300 Dolby Digital 5.1 Processor

Using the SA-TX30 as an example: Final Result: CHANNEL.........DPL / DD-5.1 Front Left:.....-6  / -4 Center:.........+2  / +2 Front Right:....-5  / -3 Surround RT:.....0  / +3 Surround LT:.....0  / +3 LFE:............+6  / +6

If you examine my results above, you will notice that if I did not compensate for the differences between the two modes (DPL vs. DD 5.1), . . .while playing my DPL DVD's, . . .the center channel dialog would be lost to the overbearing Front Left & Right Channel outputs.  Notice that the Rear Surround channels would be also too loud!      Of course, if you don't buy DPL DVD's, . . then this is a moot point!  But if you watch regular TV DPL Stereo programs and every once in a while, put in your "Jurassic Park" or "Men in Black" THX DPL VHS Hi-Fi Tape, . . .then you will 'want' to Calibrate your DPL playback mode via your internal test signal generator so "you can enjoy a much more faithful reproduction of motion picture program material"!

Some "Dolby Pro Logic" DVD Movies "Earth Girls are Easy"/Special Edition - Gena Davis, Jeff Goldblum "Infinity"/with Commentary - Matthew Broderick, Patricia Arquette "Labyrinth"/with' Making of' - David Bowie, Jennifer Connelly "Matinee" - John Goodman, Simon Fenton "Maverick" - Mel Gibson, James Gardner, Jodi Foster "Radioland Murders" - Brian Benden, Mary Stuart Masterson, George Burns "Romancing the Stone" - Michael Douglas, Kathleen Turner "The Three Amigos" - Steve Martin, Chevy Chase, Martin Short "Tremors"/Collector's Edition - Kevin Bacon, Fred Ward

Click to see entire VE Calibration Settings

Why 75 dB Calibration Recommendation?? From my "Technic's" SA-TX30 Owners Manual: "When  your speakers are set to 75 dB SPL, you can enjoy a much more faithful reproduction of motion picture program material by setting volume control to "REFERENCE".  This will recreate the same field of sound as in the film recording studio."

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PI - Dec. 8, 1999

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