What to do with my professional SPL meter...

I have to do a lab at uni where I take home an SPL meter (it is a Bruel & Kjaer type 2231 - made in 1983) and do some tests on transmission loss through walls using white noise.

I also wish to do some calibrations on my monitors so I can set them to 85dB for mixing, so I know how loud this sounds.

Can anyone think of any other little things I could use this for? Some interesting experiments or anything? I only have it for a week so would like to make the most of it. Thought it would be fun to see how loud my guitar amp goes... And just see how loud things are... I like sound

Hey Matt a few tips. Firstly you have got to know what your reference level is going to be in your track and master. -20 db FS is good. If you have got VU meters they should show 0db VU on the master buss when the track/master are at the reference level. Track and master faders are also all at unity. Substitute band limited pink noise (500 to 2K) at the same level and your VU's should be also at 0db VU. (People say VU meters are not necessary but in fact what they are good for is showing signals around 0db VU when the tracks and busses are at -20.)

Each monitor should show 83 db SPL with a C Weighting and do them individually. Both on is around 86 db SPL.  Mark your monitor gain so that you can go back to this point on call.

Sounds all a bit technical but its called calibrated monitor gain and its a good thing to do. You can always monitor mixing sessions 6 db louder and mastering sessions 6 db softer. Its important to able to go back to 83 db SPL when you want. And spend some time listening to music at this level and really start to appreciate how good it is.

There has been no standard for setting monitoring levels in the industry we are in (except for film of course and it has worked very well there) This goes a long way to working to a standard. But what is great is that sound pressure levels can reach 106 db in the room if the full range of the digital medium is extracted even for a short time.

Mark your monitor gain -6db and -8db down from the 0 db position. (and at +6 db for louder monitoring for mixing) Then you can master to the K14 and K 12 K System standard for mastering for other applications where louder masters are required but stopping short of pushing further and causing distortion.

You can do all this with your wonderful sound pressure meter.

After calibrating levels using a noise signal, if you play a swept sin wave (i.e. with a slowly changing frequency) through both monitors, you can check your room's acoustics (roughly) at the listening position. Sort of a poor man's room analyzer.

drewfx

Jose7822


Better yet, he can download these test tones of 1dB increments from 10Hz - 300Hz:

http://www.realtraps.com/test-cd.htm  (top of page)


Bring them into Sonar (I don't trust media players) and enjoy your room response.  You'll notice some frequencies will sound louder and others softer.  Those are your room's modes and nulls respectively.  It could be a disapointing experience though.  But the test requires setting up the included Pink Noise file at 70dB SPL (C weighted) for a reliable test.  Another excuse to use the SPL meter you have :-)


Take care!

That's a great link for this!

The only bad part is, the first time you see this you're going to be shocked how much level varies with frequency.

drewfx

You could do free breast exams.

   Play a continuous loop of pink noise (at say 85 db)
take the meter outside to different locations ( one being
3 foot from the outside wall) "from the room producing
the sound. And see what amount of "drop" there is in level.

   Could you somehow use it to test Insulation or
"r" factors?