A little tip for all you SPL meter users

[RLA]

Hi all
I wanted to pass along a little tip for all you SPL meter gun slingers out there that are calibrating your own systems Many of you know how to use an SPL meter but many may not.

I just returned from an install, the client had previously set up his equipment and calibrated his system with an spl meter his surrounds and EX channels were behind the listening position
I know many of you have this same type of installation the clients channel levels were off by a fair degree and here is the reason why

#1 The SPL meter should be set at ear level with the MIC end of the SPL meter pointed upward

#2 The SPL meter should be set to "C" weighting and Slow response range to +75dB or +85dB if Using AVIA

#3 This is the area that most make a big mistake calibrating. When the test tone is present in the front and center speakers stand behind the listening position or off to the extreme side
When the test tone moves to the side or rear surrounds stand in the front of the listening position And calibrate. Your body is a very good absorber and if you stand in the direct path of the meter and the speaker when the test tone is active your level setting will be off by as much as 4 dB.If you can’t stand behind the listening position then calibrate one speaker at a time and move your body to the opposite side of the meter. Never stand between the meter and the speaker.

#4 When your level calibration is complete you will notice that your center channel and your sub
Will most likely sound a little flat with all channels set to + 75dB I will often boost the level of the
Center speaker 2-3dB and the subwoofer +3-4 dB this is technically not accurate but you may find it sounds more appealing

Hope this helps
Ray

 

[mtrycrafts]

Hi all
I wanted to pass along a little tip for all you SPL meter gun slingers out there that are calibrating your own systems Many of you know how to use an SPL meter but many may not.

I just returned from an install, the client had previously set up his equipment and calibrated his system with an spl meter his surrounds and EX channels were behind the listening position
I know many of you have this same type of installation the clients channel levels were off by a fair degree and here is the reason why

#1 The SPL meter should be set at ear level with the MIC end of the SPL meter pointed upward

#2 The SPL meter should be set to "C" weighting and Slow response range to +75dB or +85dB if Using AVIA

#3 This is the area that most make a big mistake calibrating. When the test tone is present in the front and center speakers stand behind the listening position or off to the extreme side
When the test tone moves to the side or rear surrounds stand in the front of the listening position And calibrate. Your body is a very good absorber and if you stand in the direct path of the meter and the speaker when the test tone is active your level setting will be off by as much as 4 dB.If you can’t stand behind the listening position then calibrate one speaker at a time and move your body to the opposite side of the meter. Never stand between the meter and the speaker.

#4 When your level calibration is complete you will notice that your center channel and your sub
Will most likely sound a little flat with all channels set to + 75dB I will often boost the level of the
Center speaker 2-3dB and the subwoofer +3-4 dB this is technically not accurate but you may find it sounds more appealing

Hope this helps
Ray

This is a great reminder to all, thanks

 

[puertorro]

Now, that's a good tip.

 

[snakeyes]

yeah thanx

 

[race4aliving]

Thanks for the tip.

 

[mitch57]

Thanks for the tip. However it's my understanding that you should avoid boosting the level of any speaker but instead decrease the level of the other speakers to compensate. Doesn't a boost in db on the plus side equate to greater distortion?

 

[RLA]

Hi
A significant boost in levels can create problems. I would think it would be highly unlikely that you would induce any distortion into the signal path even with a moderate increase in gain, and it is most unlikely that this would occur With a 2-5 dB gain.

There is actually a -2 to -4 dB error when using the 33-2050 when reading lower frequency’s. The gain of +2 dB for the center is almost inconsequential but the benefit is a more ledgeable center channel.
Try it and let me know wht you think
Happy Listening