Questions & Answers

Studio 68: Linearity in loop measurement: Low- and high frequency cut/filters?

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asked Jun 30, 2018 in Studio Series USB Interfaces by michaellenz2 (220 points)
retagged Jul 11, 2018 by michaellenz2

Hello,

i use the studio 68 for some measurements of loudspeakers and pickups for electric guitars and basses.

In a loop measurement from output 1 to input 1 (line), i get at 192 KHz sampling frequency a serious drop above 30 KHz. So why buying a 192 KHz interface?


The effect still exists less pronounced at lower sampling frequencies. (-2dB@40 KHz@96 KHz sampling)

Even my measurement microphone is far more linear in this range (Earthworks M50, +/- 1,5 dB til 50 KHz) and i don't want to loose accuracy. I know that in the HiFi world, everything above 20 KHz is'nt so important but i have to so some measurements where it ist ;)

So it seems that there is a kind of high- and lowpass filters active. The question: Can i switch them off?

Second question: Is there a way to use at the same time Input 1 for a condenser Mic (with phantom power) and a line source on input 2? When ih switch Input 1 and 2 from Instrument to line, there's no more signal from the mic.
Thanks and best regards, Michael

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