Mixer Channel Raises Noise Floor But No Signal

Along with being able to set the effect send level at each channel you can send more than one channel s signal to each effect you can also adjust the level of the affected signal that s brought back into the mixer by using the aux bus fader.

Mixer channel raises noise floor but no signal. The noise floor of a receiver is an important aspect of its operation as it gives a guide to the level of the minimum signal that can be received. Page 3 of 12. The noise floor is the level in a gain stage where the noise is louder than the signal. Distortion clipping distortion occurs when signal overloads any given gain stage.

Noise is always present and received on a radio even when no wanted signals are present. In signal theory the noise floor is the measure of the signal created from the sum of all the noise sources and unwanted signals within a measurement system where noise is defined as any signal other than the one being monitored. The aux send function can often be set to send the track s signal either prefader or postfader. Unfortunately when you amplify a signal you also raise the noise floor which is an unwanted side effect.

Figure 3 shows the result of mixing multiplying an rf input of sinωrft with by a lo input of sinωlot where ωrf 2π 11mhz and ωlo 2π 10mhz. In a perfect world the atsc signal needs to be 15 2 db above the noise floor to produce an error free picture and audio. The saturated local oscillator buffers used in passive mixer ics degrade the wideband signal to noise ratio of the filtered low level input. Mixing consoles don t have space to house top notch and expensive discrete preamps.

The soundcraft preamps may be well decent that is sufficient for any typical source. In radio communication and electronics this may include thermal noise black body cosmic noise as well as atmospheric noise from distant thunderstorms and. I would go full level or one step down on the idevice and do the rest of your gain chaining on the mixer. Any time an unbalanced cable is run in parallel with an electrical cable then the audio cable will pick up interference.

Using a low signal from the idevice means you have to do more amplification on your mixer channel gain up. The more you amplify your signal across multiple gain stages the more you amplify the noise and raise the noise floor. This is important because in practice no signal can be detected below the noise floor. Condenser mics and active dis already pump the line with considerable levels whereas dynamic mics and passive dis are mostly used with instruments that are so loud that you don t need a lot of gain in the first place.

In dtv the noise floor is said to be 106 dbm and more accurately 106 2 dbm. Ideally the multiplier has no noise no limit to the maximum signal amplitude and no intermodulation between the various rf signals that is no spurious nonlinearities. The wideband noise floor can be filtered to 174dbm hz.