2.1CH calibration VS 5.1/HT. Am I accurate?

Discussion in 'Archived Threads 2001-2004' started by Steve_Ma, Jan 8, 2002.

  1. Steve_Ma

    Steve_Ma Second Unit

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    Education Needed:

    In a system being used for both movies AND 2ch Audio, what's the best way to calibrate for "accuracy" of CD based material? My music listening is done in 2 ch mode + the sub (LFE-out). I want to be sure my sub is optimized for both. Am I already there if I have calibrated my speakers?

    I understand the desire and need for a "reference level" in movies. But, since there is no such standard in the music industry, how do I know where/how to calibrate my setup for "accurate" audio? I want to make sure I have gotten the most out of my system and room before I start EQ'ing and looking at outboard bass mgt, and etc.

    I thought I read a comment recently where someone indicated that once your speakers are calibrated, you will be getting an "accurate" reproduction of the material as the engineer intended (movie OR music). That once calibrated, everything else is up to your hardware/room, but I do not know if this is "on target" or not?

    Any input appreciated.

    --Steve
     
  2. BruceD

    BruceD Screenwriter

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    DVDs have SPL sound guidelines to follow during production. The same is not true for CDs.

    In fact, I'm sure you've noticed some CDs are hotter (louder) than others. It almost seems mastering studios have been raising levels for the last ten years.

    I find that since I listen to my music about the same SPL level as movie soundtracks, that the same calibration volume works pretty good.

    Do you remember the "loudness" buttons on older stereo receivers ? These were used to boost specific frequencies when you listened at lower volumes (especially bass).

    You may or may not need to adjust the sub's calibration for music vs. movies. Depends on your preference and listening SPL level.

    BruceD
     
  3. Steve_Ma

    Steve_Ma Second Unit

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    Thanks Bruce. I appreciate you feedback. When one calibrates their system for HT, they adjust their overall volume level to match a "standard" for movies (reference) it's easy, right. BUT...

    They also are calibrating their speakers (and sub) relative to each other as well. Assuming one leaves their treble/bass settings alone, does this mean they are "accurate" for audio apps as well? (to the best of their system and room's capabilities anyway)

    If not, then it would seem that "accuracy" as it relates to music is irrelevant.

    --Steve
     
  4. BruceD

    BruceD Screenwriter

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    Steve,

    The only "accuracy" we are talking about here is the SPL level matching between main speakers and sub from a "pink noise" test signal. Accuracy is probably not the right term, "calibration level" is probably a better term.

    Pink noise test signals used to set these "calibration levels" are what we call broadband signals - i.e. lots of different frequencies simultaneously.

    Matching the main and sub SPL levels for a DD source may or may not be acceptable for 2-channel+sub CDs, here is why;

    1) Does the receiver/prepro do the digital decoding of PCM output from your CD player or CD on a DVD player? If yes, then does the manufacturer allow bass management to be used in the stereo mode? Do they provide for different bass management settings in different modes? i.e. Do they have double bass output (mains+sub) with Large mains?

    2) Does the receiver/prepro manufacturer implement bass management in the analog domain for CD players that are connected to it with L&R analog cables? This can sound different than the digital domain bass management for DD and DTS. Does it provide a completely transparent analog pass-thru (no bass management).

    It really depends on room acoustics (room mode bass peaks), speaker positioning, listener positioning and just plain what sounds good to you.

    I use the same settings for both HT (DD and DTS) and music because I have spent lots of time tuning my speaker placement, listener placement, and eliminating my room's bass mode peaks with a parametric EQ.

    That last one, bass mode peaks (from your room's dimensions) is what typically causes most people to get up and change the volume level on their sub for different DVDs or CDs.

    BruceD
     
  5. Steve_Ma

    Steve_Ma Second Unit

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    WOW, I guess this is the education I requested. lol.

     
  6. BruceD

    BruceD Screenwriter

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    Steve,

    Just a thought. Does your DVD player have two digital outputs (like one coax and one toslink)?

    If so, you might be able to use these two digital outputs on two different different inputs of your receiver/prepro. Then maybe can you adjust the bass levels for the 2-channel differently than the DD/DTS.

    What are you using to decode the DD/DTS signals from the DVD player?

    BruceD
     
  7. Steve_Ma

    Steve_Ma Second Unit

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    Bruce, You Rock! Light shines on great Marble Head!

    A Marantz SR7000 is the AV rec.

    A Marantz DV3100 is the DVD/CD player.

    I do not have an optical out, but DO have a second set of RCA audio outs (component, right?). I might be able to use the 2nd component out for CD play and assign it a different input on the REC. The only question that will remain will be can I indeed change the CH levels for a CD and not screw up the speaker settings for DVDs. If that does work, I'll probably still have an existing room issue, but at least it'll allow me to better isolate and manage it till I can afford an EQ/better sub/or something.

    I'll follow up with you/this thread and when I try this and let you know how it worked.

    --Steve
     

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