Quote:

Originally Posted by

**Ntchi** Oh thats very interesting, can you explain me more about this. I understand what you mean by before and after volume. But how does in tranlaste in my problem? When I monitor the mix without EQs I PERCEIVE the 3 to 6k range to be painful, or rather harh. So yes my statement was wrong according to what you've just said...

Thx!

as far as EQing go...I'm afraid that's up to you! A matter of mix and match equipment, to find the best combination and setting for a particular performer...and learning how to mix.

Now, the decibel... I'm referencing

Decibel - Wikipedia, the free encyclopedia :

"When referring to measurements of power or intensity, a ratio can be expressed in decibels by evaluating ten times the base-10 logarithm of the ratio of the measured quantity to the reference level. Thus, XdB is calculated using the formula:

where X is the actual value of the quantity being measured, X0 is a specified or implied reference level, and then XdB is the quantity expressed in units of decibels, relative to X

So:

dB(SPL)

dB (Sound Pressure Level) — for sound in air and other gases, relative to 20 micropascals (μPa) = 2×10−5 Pa, the quietest sound a human can hear. This is roughly the sound of a mosquito flying 3 metres away. This is often abbreviated to just "dB", which gives some the erroneous notion that "dB" is an absolute unit by itself. For sound in water and other liquids, a reference pressure of 1 μPa is used.[6]

As you were using it...which is ok!

dBu or dBv

dB(0.775 VRMS) — voltage relative to 0.775 volts.[4] Originally dBv, it was changed to dBu to avoid confusion with dBV (citation needed - I'm not sure that's totally right) The "v" comes from "volt", while "u" comes from "unloaded". dBu can be used regardless of impedance, but is derived from a 600 Ω load dissipating 0 dBm (1 mW).

this is used with +4dBv and -10dBu nominal levels ie pro and semi pro gear.

dBFS or dBfs

dB(full scale) — the amplitude of a signal (usually audio) compared to the maximum which a device can handle before clipping occurs. In digital systems, 0 dBFS (peak) would equal the highest level (number) the processor is capable of representing. Measured values are usually negative, since they should be less than the maximum.

−3 dB ≈ ½ power

A level difference of ±3 dB is roughly double/half power (equal to a ratio of 1.995). That is why it is commonly used as a marking on sound equipment and the like.

Another common sequence is 1, 2, 5, 10, 20, 50 ... . These preferred numbers are very close to being equally spaced in terms of their logarithms. The actual values would be 1, 2.15, 4.64, 10 ... .

The conversion for decibels is often simplified to: "+3 dB means two times the power and 1.414 times the voltage", and "+6 dB means four times the power and two times the voltage ".

6 dB per bit

In digital audio linear pulse-code modulation, the first bit (least significant bit, or LSB) produces residual quantization noise (bearing little resemblance to the source signal) and each subsequent bit offered by the system doubles the (voltage) resolution, corresponding to a 6 dB (power) ratio. So for instance, a 16-bit (linear) audio format offers 15 bits beyond the first, for a dynamic range (between quantization noise and clipping) of (15 × 6) = 90 dB, meaning that the maximum signal (see 0 dBFS, above) is 90 dB above the theoretical peak(s) of quantization noise. The negative impacts of quantization noise can be reduced by implementing dither."

Ok, so I'm just copying and pasting from the original page now. I did a degree in music + acoustics, so this is quite familiar territory...but I've forgotten quite a bit of it! it is useful to know...for example, if you're bouncing something dual mono (ie a stereo file but with identical signals L+R) through a buss to a mono track, the level will double - or go up by 6dB.