Please help a Newbie to set up his new Surround System correctly...

Discussion in 'Home Cinema Buying & Building' started by blackpants, Sep 7, 2007.

  1. blackpants

    blackpants
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    Hi all,

    I hope that a) I can articulate myself enough to get my question out correctly. b) that this is posted in the right area, it is kind of a calibration question but relevant to the settings in my amp. Anyway, here goes.

    Today I have an RS SPL Meter coming and will be attempting a basic calibration of the system using the pink noise tones from DVE tonight.

    I understand that all speaker levels should be taken down to minimum, then master volume up to 0dB then individual speaker levels raised until 75dB indicated on the display of spl meter held at prime listening position.

    Now i have read that to calibrate the sub correctly the sub level set at the amp should be about -5dB (in order to prevent the sub from clipping the sub output at reference level), then the gain on the actual sub adjusted to give 75dB on the meter.

    Now, here is my question. The amp settings are set so that speakers are all small and all bass + LFE goes to sub. Now in the sub there is an option in the sound menu(SOUND MENU>3 LFE LEVEL>SP LFE LEVEL) to set LFE level between 0dB and -20dB. Then there is another option in the basic menu (BASIC MENU>2 SP LEVEL>SWFR) again adjustable from 0dB to -20dB. Now these are both separate, ie adjusting one does not adjust the other.

    Which of these settings, if either, is the one which needs reducing to prevent reference level clipping?

    Any other pointers from people that have done this would be welcomed aswell. I don't mind if this needs moving to any other sub-forum either, whatever gets me the best help would be appreciated.

    Thanks

    BP
     
  2. blackpants

    blackpants
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    Oh dear...

    Right, SPL meter arrived on time so last night SWMBO had a nice long bath, I drew the curtains shut the doors and sat down with a nice cold beer to start what I thought would be 30mins of fiddling about a bit with the amp. So I fire up the DVE disc, load trusty AV forums on the laptop and promptly become very confused.

    Firstly, with my amp set to 0dB (Reference level? my amp goes from -80dB to +16dB) and the Front left set to 0dB (cannot be driven higher than 0dB range is -20dB to 0dB) the SPL is only reading 72/73dB so I think ok I'll just balance the rest of the speakers to 72dB. Out of curiosity I use the amps test tone and that registers 75dB???? Any ideas why the DVE tones are not loud enough??? Any way I set all speakers to 72 on the DVE tones and then checked using Amps test tone and all were 75. So they are balanced atleast.

    Now the next problem I had was when it came to the sub. First off the tone sent the SPL off the scale and i couldn't turn it down any lower -20dB already!!! Then i remembered there was a knob on the back of the sub so I turned that down to get the reading at 75. However when i checked the sub with the amp test tone it was only registering at 60-65dB on the SPL. So i did a couple of searches on av forums and read several things about LFE levels on DVE being 8dB hotter than they should be. Also that the DD and DTS soundtracks have different reference levels for the lfe track.

    What I need to know now is what do I do.

    a) calibrate sub to 72dB on DVE test tone
    b) calibrate sub to 80dB on DVE test tone( to allow for the 8dB too hot)
    c) calibrate sub to 75dB on amp test tone

    Please help me.

    I am thoroughly confused ( and dying to whack black hawk down on with a bit of volume, the neighbours are out and SWMBO is at work!!!)
     
  3. blackpants

    blackpants
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    :lease:Oh dear...

    Right, SPL meter arrived on time so last night SWMBO had a nice long bath, I drew the curtains shut the doors and sat down with a nice cold beer to start what I thought would be 30mins of fiddling about a bit with the amp. So I fire up the DVE disc, load trusty AV forums on the laptop and promptly become very confused.

    Firstly, with my amp set to 0dB (Reference level? my amp goes from -80dB to +16dB) and the Front left set to 0dB (cannot be driven higher than 0dB range is -20dB to 0dB) the SPL is only reading 72/73dB so I think ok I'll just balance the rest of the speakers to 72dB. Out of curiosity I use the amps test tone and that registers 75dB???? Any ideas why the DVE tones are not loud enough??? Any way I set all speakers to 72 on the DVE tones and then checked using Amps test tone and all were 75. So they are balanced atleast.

    Now the next problem I had was when it came to the sub. First off the tone sent the SPL off the scale and i couldn't turn it down any lower -20dB already!!! Then i remembered there was a knob on the back of the sub so I turned that down to get the reading at 75. However when i checked the sub with the amp test tone it was only registering at 60-65dB on the SPL. So i did a couple of searches on av forums and read several things about LFE levels on DVE being 8dB hotter than they should be. Also that the DD and DTS soundtracks have different reference levels for the lfe track.

    What I need to know now is what do I do.

    a) calibrate sub to 72dB on DVE test tone
    b) calibrate sub to 80dB on DVE test tone( to allow for the 8dB too hot)
    c) calibrate sub to 75dB on amp test tone

    Please help me.

    I am thoroughly confused ( and dying to whack black hawk down on with a bit of volume, the neighbours are out and SWMBO is at work!!!)
     

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