Jump to content



Sign up for a free account!

Signing up for an account is fast and free. As a member you can join in the conversation, enter contests to win things like this Logitech Harmony Ultimate Remote and you won't get the popup ads that guests get. Click here to create your free account.

Photo

When calibrating should I point the SPL meter towards the speaker


This topic has been archived. This means that you cannot reply to this topic.
8 replies to this topic

#1 of 9 Jason Bell

Jason Bell

    Stunt Coordinator

  • 176 posts
  • Join Date: Apr 03 2002

Posted April 23 2002 - 07:58 AM

Should I point the meter towards the speaker that the pink noise is coming from or just leave it pointed towards the TV. The way I have it right now is the SPL meter on a tripod in my seating position pointing forward. When calibrating the surrounds it makes a huge difference if the meter is pointing forward or pointing at the surrounds. Which should I do, Forward or towards each individual source? Thanks

#2 of 9 jeff lam

jeff lam

    Screenwriter

  • 1,806 posts
  • Join Date: Jun 04 2001
  • Real Name:Jeff Lam
  • LocationSan Jose, CA

Posted April 23 2002 - 08:12 AM

Video essentials says to hold it in an upright angle pointed towards the cieling slightly towards the front. I would say adjust it till the display is perpendicular to the floor since it is angled slightly downward.
It might be a 45degree angle or so.

#3 of 9 KyleS

KyleS

    Screenwriter

  • 1,232 posts
  • Join Date: Jul 24 2000

Posted April 23 2002 - 08:18 AM

Jason,

Do you turn toward a speaker every time sounds come out of it when watching a movie? If not (like most of us I suspect) then I would do as Jeff stated above. Calibrate the speakers from a single location since that is where you will be sitting.

KyleS

#4 of 9 Mike_T_

Mike_T_

    Stunt Coordinator

  • 198 posts
  • Join Date: Oct 30 2001

Posted April 23 2002 - 08:46 AM

What about the rear speakers? I would suspect you would have to set them much higher then the fronts if your sound meter is facing forward, then wouldn't this be too much sound coming from the rears?

#5 of 9 Roger Kint

Roger Kint

    Stunt Coordinator

  • 161 posts
  • Join Date: Jan 02 2002

Posted April 23 2002 - 08:51 AM

Mike, good point. The SPL meter has somewhat of a cardiod pattern and this does not match exactly to the pattern of our ears. I prefer to point the meter directly at each speaker so that at a single point in space, all levels from all speakers will be exactly the same. Besides, everyone will hear differently, some have bad left ears, some can't hear low freq, some have hair on one side, etc. but if you calibrate by pointing at each spearker you won't have to worry about all that. And you can't really approximate the HRTF (head related transfer function) with the cardiod pattern of the SPL meter.
Always wanted to be a procrastinator, but never got around to it

#6 of 9 Phil Iturralde

Phil Iturralde

    Screenwriter

  • 1,868 posts
  • Join Date: Oct 07 1998

Posted April 23 2002 - 09:50 AM

Like Jeff, ... I do it so I can playback my DD 5.1 DVD's like it was Recorded/Encoded @ Dolby 5.1-Channel Recording Studio.

FYI:5.1-Channel Production Guidelines (PDF file)

Quote:
3.4.3 Taking a First Measurement (pg. 36)

3. Ensure that you are sitting in your normal, proper reference listening or mixing
position. Set the SPL meter to “C” weighting and “slow” response.

4. Facing the front speakers, hold the SPL meter at chest level, with the microphone facing up at an angle of approximately 45 degrees to the center speaker. Keep the meter at arm’s length to prevent measuring audio that may reflect from your body. You should be able to take SPL readings as you look down at the meter.

5. Keep the SPL meter in this position. Make sure that the meter is aimed at the center speaker as you take readings for the left and right speakers.

6. When taking the SPL readings for the left surround or right surround speakers, keep the meter at the same angle and position as you did for the front speakers. Turn your body 90 degrees from the center speaker towards the wall closest to the surround speaker you are measuring. This will minimize “shadowing” or obscuring the meter with your body.

If it's good enough for Dolby Labs, it's good enough for me! Posted Image I use a tripod, positioned ear height @ my 'sweet spot'! Works great.

Phil
My HT Enthusiasts Google Website
---- Toshiba 62HM196 62" 1080p DLP HDTV pic's (#1 in Consumer Reports)
DVD Aficionado (DVDAF) on-going list.
Acquisition Rule #59 “Free advice is seldom cheap.” (Quark @ DS9)
JBL S-Series + SVS 25-31PCi (SN: 00034) w/NSD Upgrade!

#7 of 9 Roger Kint

Roger Kint

    Stunt Coordinator

  • 161 posts
  • Join Date: Jan 02 2002

Posted April 23 2002 - 10:13 AM

Phil, thanks for the post. Coming from Dolby, that would be the definitive answer.
Always wanted to be a procrastinator, but never got around to it

#8 of 9 Rich Malloy

Rich Malloy

    Producer

  • 3,999 posts
  • Join Date: Apr 09 2000

Posted April 23 2002 - 11:19 AM

I put a cardboard box on my couch that's nearly the same height as my ears, and place the meter on top. Then, I stand aside with my remote (being sure to stay out of the way of the soundwaves from the speaker being calibrated and the meter), and commence calibrating.
"Only one is a wanderer;
Two together are always going somewhere."

#9 of 9 Jason Bell

Jason Bell

    Stunt Coordinator

  • 176 posts
  • Join Date: Apr 03 2002

Posted April 23 2002 - 09:39 PM

Thanks Everyone,

I ended up calibrating the Dolby way with the meter facing forward at ear level and tilted 45 degrees. This made my surrounds have to be 3db louder than the mains for everything to be even. When actually watching a movie I noticed the surrounds to be a little overpowering so I just backed em off to 2db louder than the mains and now it seems perfect to me. I'm so happy with the balance of my system I'm afraid to walk to close to my speakers and have one move a millimeter in any directionPosted Image. One thing I have learned from this calibrating experience is a tripod is a must it made it so much easier to get out of the way of the sound for whatever speaker was coming up next in the test and its also easier to adjust levels on my remote as I go.

Thanks again.