Question on AVIA disc and Sound Level Meter

[tjkahn]

I've been meaning to ask this for a while, and I know this is the right place to get it answered. I actually have 2 quesitons:

1) On the Avia disk, they say to calibrate to 85db, or lower if that's too loud. My question is, why does that even matter? Isn't the only important thing to have the same db reading for all speakers, and then you can listen to whatever overall volume you want by adjusting the master volume when watching a film or listening to music. Am I missing something here?

2) For my five main speakers (which are JBL's that I'm upgrading to Axiom's), it's very easy to get the needle to hold steady in the same place for all five speakers, but the needle tends to bounce around a little more on the subwoofer (M&K MX-125). I assume that this is normal because the lower frequency causes more vibrations and the needle is reacting to the vibrations on the wall/hardwood floor caused by the subwoofer? I'm taking a guess here. Input from someone who actually knows what they are talking about would be greatly appreciated.

Thanks!!

 

[schneiderdn]

I am by no means an expert on this matter, but I also use the Avia calibration DVD and a basic RadioShack sound meter. I believe Avia suggests the 85db level so that your calibration is set according to levels similar to actual movie watching volumes (room resonances become more evident at different volume levels and should be part of the equation)

As for your needle bounce, you should have an "A" and "C" weighting switch on your SLM; try both positions and see which works best (one accounts for very low frequencies, one does not).

 

[Unregistered]

Avia home theater setup DVD - subwoofer

Calibrating your speakers at 85db is supposed to be reference level (i.e. the volume used when mixing the movie in the recording studio). 85db reference is very, very loud in a home environment, and there is no advantage balancing your speakers at this level. Turn your volume control to a position you normally use when listening to movies, and calibrate your speakers at this level.

When you calibrate the subwoofer, the needle will move more than with the main speakers. Adjust it so that it does NOT move BELOW the level set for the main speakers. It's OK if it bounces ABOVE the level for the mains. Some people actually prefer to set their subwoofer 3-5db HIGHER than their main speakers.