Rate this item
23 October

:Auditory Range:

Using higher bit depths during studio recording enables greater headroom to be left on the recording. This reduces the risk of clipping without encountering quantization errors at low volumes.

Bit depths by signal-to-noise ratio
bits - SNR - Possible integer value

4 -24.08 dB - 168 - 48.16 dB-  25616 - 96.33 dB - 65,53624 - 144.49 dB - 16,777,21632 - 192.66 dB - 4,294,967,29648 - 288.99 dB - 281,474,976,710,65664  -  385.32 dB  -  9,223,372,036,854,775,807 Floating point . Many audio file formats and digital audio workstations (DAWs) now support PCM formats with samples represented by floating point numbers. Both the Microsoft WAV file format and the Apple AIFF file format support floating point PCM and major DAWs support varied floating point processing capabilities.Unlike integers, whose bit pattern is a single series of bits, a floating point number is instead composed of several smaller bit patterns whose mathematical relation forms a number. This method of representation is similar to scientific notation and expands a binary system to more closely approximate real numbers. Floating point numbers still have upper and lower bounds that are fixed but the method of representation allows increasingly smaller integer values to include an increasingly larger fractional part. The most common standard is IEEE floating point which is composed of three bit patterns: a sign bit which represents whether the number is positive or negative, an exponent and a mantissa which is raised by the exponent. The mantissa is expressed as a binary fraction in IEEE base two floating point formats.IEEE single-precision (32-bit) floating point format:

For example, the 32-bit floating point bit pattern 1 01111101 00101100000000000000000 is interpreted as the following:

(-1)1 × (1 + 0.34375) × 2(125 - 127) = -1.34375 × 2-2 = -0.3359375

As a different example, the bit pattern 0 10010010 10110001010000000001000 is a larger number and shows the fraction become reduced in length:

(-1)0 × (1 + 0.004883766174316406) × 2(146 - 127) = 1.004883766174316406 × 219 = 526,848.5

Beats

Beat frequencies are produced when two different sounds are produced which are very close to each other in frequency. In such a situation the crests and troughs of each wave are generally slightly out of phase. But because the two notes have differing frequencies, after a certain repeating interval of time the crests of one wave will be aligned with the crests of the other, when a pulse or beat appears to the listener.Research has found that any two notes of different frequencies tend to sound good together (ie consonant) if there is an absence of beat frequencies between 8 and 50 Hz produced. Beat frequencies of 2-8Hz have been found to be pleasing, while beat frequencies above that level are generally though to be unpleasant.The beat frequency produced by any two notes is found by subtracting the value of the higher from the lower, ie Fbeat = Fhigher - Flower. Thus beat frequencies are a subset of difference tones -the 'beat' sensation occurring when the beat frequency value is low, say from 0.5Hz (1 beat every two seconds) to say 20Hz (the lowest frequency that has a pitch-like quality) J.Askill, in 'The Physics of Musical Sounds) says 'in general beat frequencies of 2-8Hz are considered pleasing, whereas if the beat frequency is above 15-20Hz, an unpleasant or dissonant effect is produced'. Personally I am curious about the range in the middle, say 8-12Hz which is also the frequency of 'alpha' brain-waves.

Read 3341 times Last modified on Monday, 17 November 2014 14:49

Latest from zik

More in this category: Music Tips 1 »