1. Sign-up to become a member, and most of the ads you see will disappear. It only takes 30 seconds to sign up, so join the discussion today!
    Dismiss Notice

Reference level suprise.

Discussion in 'Archived Threads 2001-2004' started by Dan Kaps, Jul 17, 2001.

  1. Dan Kaps

    Dan Kaps Extra

    Joined:
    Mar 6, 2001
    Messages:
    16
    Likes Received:
    0
    Trophy Points:
    0
    Today, I wondered how close to reference volume (75db) my usual movie watching is. On my Outlaw 1050, I usually set my volume to 58 when viewing DD material (53 for DTS). This always seemed to have plenty of impact in my medium sized room and what I consider to be pretty "theater-like".
    So, out of curiosity, I got out my VE disc and my sound level meter and checked what reference level read on my dial since I didn't pay attention to the displayed number when I originally calibrated based on 75db. The display read 71! I then checked the actual db level at my normal 58. I was around 55 db, a full 20db short of reference!
    Of course my next step was to view a few minutes of TS2 at reference. Holy cow! I was a rock drummer for about 15 years so my tolerance for volume is pretty high I think. My speaks held their own pretty well and didn't sound as strained as I thought they might (NHT 1.5's and AC-1). My sub however, couldn't quite keep up (HSU VTF-2...still an excellent sub mind you). It never clipped or distorted but it got buried here and there.
    How many people actually listen at reference levels in the home?
     
  2. Will Ernst

    Will Ernst Agent

    Joined:
    Mar 12, 2001
    Messages:
    28
    Likes Received:
    0
    Trophy Points:
    0
    From reading a lot of threads on this topic, I think the concept of reference level is misrepresented. I don't think that movie theaters deliver 115dB to the seat. I believe that is what they put out near-field, but due to the large space of the theater, what you hear is a substantially lower. I went to a couple of movies this weekend for the first time in a long time, and I know that it was somewhat lower that what I listen at home. I normally listen between -10dB to -7dB.
    But, this is just my observation, so I'm probably wrong [​IMG]
    -will
    [Edited last by Will Ernst on July 17, 2001 at 09:09 PM]
     
  3. Jack Gilvey

    Jack Gilvey Producer

    Joined:
    Mar 13, 1999
    Messages:
    4,948
    Likes Received:
    1
    Trophy Points:
    0
    I believe it's reference level at the seats. I closed my eyes recently at a boring action flick to concentrate on just how loud it was, because it just didn't seem as loud (whatever that means). After a while, I concluded that it was actually much louder than I listen at home, which is about ref. -10db.
    [Edited last by Jack Gilvey on July 17, 2001 at 09:12 PM]
     
  4. Charbel

    Charbel Agent

    Joined:
    Feb 11, 2001
    Messages:
    44
    Likes Received:
    0
    Trophy Points:
    0
    I go to 74/75 on my dial. Whatever that is? I know that does`nt really tell you anything but maybe with this other info... Onkyo 787 (100wpc) Studio 40`s CC and Servo 15 sub. I like to listen pretty loud. Although I don`t have it that loud ALL THE TIME. I wish I could but my neighbors... I`m actually insulating the outside of my house so I can put the sound up without bothering the neighbors.
    I`m looking into more power like the Parasound 200+ wpc x5 amp. Can`t wait. btw my hearing is pretty good.
     
  5. Mario_C

    Mario_C Stunt Coordinator

    Joined:
    May 15, 2001
    Messages:
    83
    Likes Received:
    0
    Trophy Points:
    0
    I like listening to ref levels during the dialoge, but as soon as the action starts I back down to 5 to 10 decibles.
    ------------------
    My Music & Home Theater System
     
  6. DanG

    DanG Stunt Coordinator

    Joined:
    Nov 19, 2000
    Messages:
    140
    Likes Received:
    0
    Trophy Points:
    0
     
  7. Mario_C

    Mario_C Stunt Coordinator

    Joined:
    May 15, 2001
    Messages:
    83
    Likes Received:
    0
    Trophy Points:
    0
  8. Lewis Besze

    Lewis Besze Producer

    Joined:
    Jul 28, 1999
    Messages:
    3,134
    Likes Received:
    0
    Trophy Points:
    0
     
  9. Jack Gilvey

    Jack Gilvey Producer

    Joined:
    Mar 13, 1999
    Messages:
    4,948
    Likes Received:
    1
    Trophy Points:
    0
     
  10. Will Ernst

    Will Ernst Agent

    Joined:
    Mar 12, 2001
    Messages:
    28
    Likes Received:
    0
    Trophy Points:
    0
    Actually, Charbel's 75 dial reading doesn't mean much of anything other than a benchmark. He's referring to what the volume is set to.
    Charbel:
    In order to compare volume readings, you'd have to calibrate your speakers to reference level with either Avia or Video Essentials.
    Here is HTF's own Vince Maskeeper's guide . I suggest reading through it.
    -will
    OT:
    So the Edit times are displayed on posts finally!
     
  11. Jay Mitchosky

    Jay Mitchosky Producer

    Joined:
    Sep 6, 1998
    Messages:
    3,729
    Likes Received:
    0
    Trophy Points:
    0
     
  12. Mike OConnell

    Mike OConnell Second Unit

    Joined:
    Jun 14, 1999
    Messages:
    489
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Overland Park KS
    Real Name:
    Mike
    I have a Denon 5800, Paradigm Reference Series speakers, and a Velo HGS-18 sub. I have not calibrated the sound levels with VE or Avia, but have used the internal tests tones.
    That said, for TV viweing, I am usually at - 20 dB to -25 dB on the volume, and for movies, usually at -14 dB to -18 dB on the volume.
    I have tried reference level (0 dB on the volume) for brief periods on a few of movies - T2 dts, SPR dd, ID4 dd - and althought I had absolutely no distortion and very clear sound, it was WAY too loud for me in my home. (I have to admit the sound, or rather the feel, of the bass coming from the sub was really an experience).
    I have tried to turn the subwoofer volume up instead of the receiver volume to get the same feel during movies, but the sound field just is out of balance and have gone back to the calibrated settings.
    I feel that the sound is too loud when I go to movies and sometimes feel like I should be wearing earplugs, but then you could not hear the dialogue very well.
    Mike
     
  13. Vince Maskeeper

    Vince Maskeeper Producer

    Joined:
    Jan 18, 1999
    Messages:
    6,499
    Likes Received:
    0
    Trophy Points:
    0
     
  14. Lewis Besze

    Lewis Besze Producer

    Joined:
    Jul 28, 1999
    Messages:
    3,134
    Likes Received:
    0
    Trophy Points:
    0
    Vince,
    I should have said that Dolby[and THX] advocates that the avarage dialog level is around 75db,hence the -30db test tones that almost all THX certified products use including built in pink noise generators in receivers,and softwares.
    DVD spectecular which was a collaboration of Dolby and Delos,also use the same level.VE while isn't THX certied[not with Banned From The Ranch,on the cover],could be using the the same level,by coincidence,but some reason I doubt it.
    Also I didn't calculate any of the dialnorm off sets since it seems vary sometimes and it could have very well induce more confusion to the subject.
    ------------------
    "You Hungarians always disagree"
     
  15. Chip E

    Chip E Screenwriter

    Joined:
    Nov 25, 2000
    Messages:
    1,165
    Likes Received:
    0
    Trophy Points:
    0
    I have all this good equiptment but, i really am clueless how to calibrate any of it.. I do have Avia. Can anyone spell it out for me, lol.. (or direct me somewhere to find out how) My room is small -11'2" X 10'6"
    Thanks! [​IMG]
    - Chip
    Mitsubishi 46807
    B&K AVR-307
    Dish 6000 HD receiver
    Sony S900ES dvd player
    Sony M-333ES mega changer
    Panny junkbox vcr
    **************************
    PSB Stratus Silveri main's (gloss black)
    PSB Stratus C6i center channel (gloss black)
    Infinity QPS1 surround's (changeing to PSB Image 10S's)
    SVS 20-39PC [​IMG]
    ------------------
     
  16. Jay Mitchosky

    Jay Mitchosky Producer

    Joined:
    Sep 6, 1998
    Messages:
    3,729
    Likes Received:
    0
    Trophy Points:
    0
    Chip
    If you don't already have one go to Radio Shack and buy a sound pressure level (SPL) meter. It's around $30ish and is among the best HT dollars you'll ever spend. I would also recommend a tripod - it will make your life much easier.
    I'm an advocate of first balancing the channel levels using the receiver's internal test tones. The advantage is that it balances the system for your other sources, stereo w/ sub, etc. Once you're done this use Avia to calibrate DD channel levels for your DVD player (more accurate when coming from the source).
    Either way the process for the SPL is the same. Make sure you turn the SPL on to the '80' mark on the dial (if I recall - don't have mine handy), set weighting to 'C' and 'Slow'. The meter should be located at the main listening position, tilted slightly forward of vertical. Activate the test tone starting in the front left channel and turn the AVR-307's volume up until the readout indicates -00-. This will be reference in the future, but typically you will play back movies at around -10 as suggested above. You adjust each channel's output so that it reads (in the case of Avia) 85dB, or (in the case of your receiver's tones) 75dB using the channel level settings, not the volume control. Repeat for the other channels. Engage THX mode and do it again - in my experience everything will be the same except the surrounds will need a couple of additional dBs.
    Side note: Avia does not include tones for rear surround channels. Your AVR-307's internal tones do (I have to assume). In keeping with my strategy above you can either a) note the difference between the calibrated levels of the different channels from the receiver's test tones vs. Avia, and then add/subtract an average value for the rear surrounds, or b) once you've done the initial Avia calibration connect the rear channels to the side surround outputs and re-run the test tones for just those channels. I'm certain others in the same predicament could offer other suggestions.
    Once you have done that you will have a properly balanced system for channel levels. You also need to properly set the delay levels for each channel relative to the mains. Note your average distance to the main speakers. Compare the distance to the center, and average surround distances. Factor in delay at 1ms/foot difference in distance. Some receivers simply ask you to enter the different speaker distances and it calculates the delays automatically - the 307 may work the same way, check your manual. Measure from your ear to the tweeters. I haven't done this in awhile (equipment hasn't moved) so if I've missed something somebody please speak up. While a millisecond here or there may not seem like such a big deal, the end result is that one sound arriving earlier than another (regardless of the margin) will be perceived as louder. If the delays are off than channel balancing won't be as effective as sounds will be arriving at your ear too early or too late.
    Finally, the AVR-307 is unique among the current crop of super-receivers in that it allows you to properly adjust crossover points and slopes, as well as equalization for a problem frequency. Search out other 307 users and ask how they have adjusted these settings. You can make a huge difference in performance by defining the best crossover point where frequencies go to either the sub or the speakers, and how sharp/gradual the transition. Plus, if you have a nasty frequency spike at your listening position you can flatten it out for a more balanced sound (and more detailed as it may drown out the surrounding frequencies). The latter adjustment is reasonably easy to identify using your trusty SPL meter, a frequency sweep (series of test tones at different frequencies played back at the same volume), and some graph paper. Measure the output of each frequency at the listening position to graph a response curve and eyeball which frequency is most elevated compared to the others (you can't really fix dips effectively through equalization), how much is it elevated, and how many adjacent frequencies does it cover? That information can be thrown into your receiver and it will attenuate (reduce) the volume of the frequency every time it occurs. Regraph using the sweep, confirm the results, and fine tune. Avia has such a sweep but I think it only runs automatically top to bottom. You need one where you can manually switch from frequency to frequency with enough time to measure the output of each. It seems to me that the 307 offers this capability internally for just such an excercise - again, consult your manual. Remember that they were all recorded at the same level. Any volume differences you here are entirely the result of room interactions.
    Good luck.
    ------------------
    --Jay
    "No one can hear when you're screaming in digital."
    My Home Theatre Pictures...
    "You're no mesiah. You're, you're a movie of the week. You're a ... t-shirt, at best."
    [Edited last by Jay Mitchosky on July 19, 2001 at 09:01 AM]
    [Edited last by Jay Mitchosky on July 19, 2001 at 09:04 AM]
     
  17. Grady Hollums

    Grady Hollums Second Unit

    Joined:
    Oct 24, 1999
    Messages:
    440
    Likes Received:
    1
    Trophy Points:
    110
    Well I watch all my movies at reference level 75db calibrated using VE and my receiver Kenwood VR-407 is set at -21 sound level.
    When I do watch movies I have gotten the sub to reach 114db, and man in my small room it is amazing!
    All I have to do to watch a movie is ask my wife's permission and call my up stairs neighbors if they don't mind their floor shaking every now and then during the following 2 hours. (Man, I love my SVS)
    I wonder if I should calibrate my receiver to -30 sound level and then use VE and change the individual speaker levels?
    Does it matter what the should level(according to the receiver) is at as long as the Radio Shack Sound Level Meter says 75db for speakers and 80db for sub?
    ------------------
    In Him,
    GH
    My Home
    Theater
     
  18. Stevie B

    Stevie B Auditioning

    Joined:
    Jun 5, 2001
    Messages:
    9
    Likes Received:
    0
    Trophy Points:
    0
    Just out of curiosity I wonder if anyone has taken their SPL meter into a theater to see what they are actually delivering to the seats.
     
  19. Will Ernst

    Will Ernst Agent

    Joined:
    Mar 12, 2001
    Messages:
    28
    Likes Received:
    0
    Trophy Points:
    0
     
  20. Chip E

    Chip E Screenwriter

    Joined:
    Nov 25, 2000
    Messages:
    1,165
    Likes Received:
    0
    Trophy Points:
    0
    Thanks so much Jay... This is just the kind of help i needed. I'll head down to Radio Shack this weekend and pick up an SPL meter and give it a whirl. Thanks again.
    - Chip
    ------------------
     

Share This Page