He he well come to my world
I say that with the same gain on the I/O i loose about one db with the M23+PS1 (phantom supply)+Line6 output at 0db. Compared to a M23 straight on a wire.
Next im saying that the gain match between the Belt pack and the M23 is not IMO optimal, I can only in what i would consider normal conditions "hit" the belt pack with a low signal, one led lamp out of 5 (indicating signal). So if I used wired mic's I don't have to raise the output I could gain the balcony mic right? WIth the Line6 I can only boost the low signal hitting the mic 12db.
Ah, ok, makes sense now, essentially the gain stage between the specific microphone (the M23) and transmitter is not optimal, as can be seen by the low meter level on the transmitter. But in the work that we typically do in live sound, does it really matter? Let me elaborate...
In the context of live sound measurement, we typically deal with a very limited dynamic range in sound reinforcement systems (consider the noise floor of a typical shed with the ventilation system on, and the upper limit of the output of a system), so where do you think the noise floor has an *effect* on measurements when using the M23 with the line 6? Stimulus at 60 dBA, 70 dBA, 80 dBA, 90 dBA and so on? Perhaps the moral of the story is to measure with stimulus that is "loud enough" for the output of the microphone being used. Here's where dual channel measurements work extremely well, we can see how the noise floor influences our measurement by keeping an eye on the coherence curve and making sure it remains high enough to do our work.
To quantify this, find a *really* quiet room (eg recording studio), and with everything quiet, measure the noise floor with the microphone wired direct to your computer interface's preamp (take a snapshot in spectrum mode). Then measure it with the same gain on the computer interface, but now with the line 6 system inserted in the path. Now take a snapshot of the noise floor in the spectrum mode. This should give us an answer to the above question for that specific type of microphone and it's sensitivity rating, provided that the signal path remains linear with all our measurements. To test for linearity, feed a stimulus in the system, and increase it by 10 dB increments, take a snapshot of the transfer function of each, then offset the curves on top of each other. They should remain the same in frequency response as the level increases.