SPL Test Question

mark4man

MoonMix Studios
hello again...

(haven't been here since 2017?).

The Yamaha monitors in my studio do not have graduated level controls...so when I set them up, I did so by ear. I've now moved to the mastering stage on my forthcoming CD; & really need to have those monitors calibrated correctly (I know I'm real close, but want them to be perfect). I've ordered an SPL Meter online (Galaxy Audio CM-130); & was wondering if anyone could give me advice on the audio tones necessary for a full/complete test (& where such a disk might be had)

thanx,


mark4man
 
Do you mean you want them absolutely identical to each other? What are you hoping for more than the free meter apps you can get for your phone. Or are you trying for some mythical magic pressure level at your ears? My local supermarket had meters for 9.99 the other day and I bought a couple.

Tone wise 1k is a popular frequency for measurement as it usually falls in the overlaps between LF and HF drivers so you can probably gentle that in your existing software.

What are you hoping this will do for you. If I turn the pan knob away from centre with my eyes closed I have to go quite a way before my ears detect movement in location on music, but it's easier on a fixed tone. I see it move on the meters but not in my head. As a consequence, my speaker level matching is probably with a couple of dB isn't that enough?
 
If I turn the pan knob away from centre with my eyes closed I have to go quite a way before my ears detect movement in location on music, but it's easier on a fixed tone.
This indicates there might be a bit of excessive cross-bleed in your system. IDK your room, but the most common culprit is suboptimal acoustic treatment. In my mix room I can hear fairly small changes and if one monitor is a little low or even just gets bumped and turned a little off axis or moved a half inch one way or another, it messes me up. This is also my living room, so about all of the shows and movies I watch come through the same speakers, and sometimes poor sound design will have me second guessing my monitors. Did something change or are they actually panning all the high frequencies to the left?!?
 
Nope, I have never had the special acuity to spot movement close to centre, and certainly for me and the hundreds of others I've worked with , this seems common -so common I assumed it was the same for everyone. Your ability to detect inches is pretty much a super power! What do you do when listening? Keep your head clamped in one place, as lateral pavement of your head surely creates the time and pressure difference in the same was as a monitor displacement? As most of us cannot detect changes in level that are less than a couple of dB and you can, I'm not sure how you move forward here? I suspect you're sensitive to things many of us aren't. Phase coherence is certainly some of use detect and find important, but narrow imaging like this is unusual. Maybe of course it's been me for over 40 years with something not normal, I hope not but you never know.
 
Took a while to find but that SPL meter DOES have a C weighting option. Need that for moosik!
At its most basic you calibrate youmonitors for a given SPL at the mixing position when the DAW is reading your Operating Level, -18 or -20dB fs with PINK NOISE not a sine tone. Pink noise can be generated by almost all DAWs including Audacity.

The 'classical' SPL is 83dBC IIRC but that is often too loud in a domestic setting and 75dB fs more common. You can set for both as long as you know. "Monitors do not have regulated controls". Do you mean the level pots have no markings? Make some with a Sharpie! N.B. Only THE most expensive and sophisticated monitors, $10kish, will have truly calibrated attenuators.

John, Massive Mastering has a blog about monitor calibration, might be in "stickies"?

Dave.
 
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