Belles Ondes : Creative Engineering

Test procedure for XR18 vs MR18 measurement.

A couple of disclaimers starting by a general statement: Measurements are done as close as possible to what would be a scientific measurement process (Configuration and tests are documented, they are reproductible by a third party, results are published, known assumptions and limitations are mentioned).

• Statement #1 : Measurements are done in recording studio environment. Namely, there is no control on CEM/EMI interfering with measurements apart from standard studio installation best practices in terms of proper ED grounding and shielding. This is not EMI controlled environment lab tests.
  • As a consequence, comparing the results is more important that dealing with the RAW value.
• Assumption #2 : One input and one output are used on each unit, there is only one interface sample. Statistically processing those measurement among several units/interface is out of scope of this measurement.
  • As a consequence, these results are prone to specimen bias.
• Statement #1 : XR18 has two high impedance instrument inputs which MR18 does not have. For the sake of comaparing apples with apples, Input 9 and Output 1 are used as references on both units

Measure loopback RTA THD (+N) @1khz + total dynamic range.

• REW in loopback mode,
• Double shielded XLR as connection
• on both units, use In-9 and Out-1

Loopback diragram: