Let’s say your ratio is set at 2:1. The higher the ratio, the more the compressor will turn the signal down. Petropedia explains Compression Ratio Generally, cylinder pressure for common automotive designs should at least equal 10 bar , or, roughly estimated in pounds per square inch (psi) as between 15 and 20 times the compression ratio, or in this case between 150 psi and 200 psi, depending on cam timing. Resistance factor is defined as the ratio of measured pressure drop across a compressor valve to the pressure drop that would be predicted in flowing the same quantity of the same gas at identical upstream pressure and temperature conditions through a round hole (an orifice) having a discharge coefficient equal to one and an area equal to the valve pocket opening. For example: A compressor with a threshold at -10dB and a 3:1 ratio is a nice starting point for vocals. If we want to compress more, we could set the ratio at 4:1, meaning 1 dB is heard for every 4 dB over the threshold. Often misunderstood, compression ratio simply specifies the amount of attenuation to be applied to the signal. You will find a wide range of ratios available depending on the type and manufacturer of the compressor you are using. For every signal that goes over the threshold, it gets compressed according to a certain ratio. n. In an internal-combustion engine, the ratio of the volume of the combustion chamber measured before … For every 2 dB above the threshold, only 1 dB will be let through. Compression Ratio is an important variable in building a performance engine. A ratio of 1:1 (one to one) is the lowest and it represents “unity gain”, or in other words, no attenuation. 17.9.The figure also shows the trend in the maximum to minimum cycle temperature ratio, T 3 /T 1.It has been stated that the increase in specific work results in an increase in turbine entry temperature, T 3.Since the ambient temperature, thus the compressor inlet temperature, T 1, is constant, T 3 /T 1 will increase. If you have a semi-constant level of the vocal at -1dB it will become compressed so that it only reaches -7dB. Compression ratio, in an internal-combustion engine, degree to which the fuel mixture is compressed before ignition.It is defined as the maximum volume of the combustion chamber (with the piston farthest out, or bottom dead centre) divided by the volume with the piston in the full-compression position (with the piston nearest the head of the cylinder, or top dead centre). The increase in compressor pressure ratio is shown as a trend in Fig. Compressor Pressure Ratio synonyms, Compressor Pressure Ratio pronunciation, Compressor Pressure Ratio translation, English dictionary definition of Compressor Pressure Ratio.