If your domestic situation allows it, measure the MLP last and keep the microphone in place for when you do the final verification. The most important of these future tasks is to verify MSO's performance predictions against the final measured REW data with all DSP filters, delays and gain adjustments in place, and the subs all energized at once as they are in actual use. You can help make later tasks easier by planning ahead to accommodate them. Measure the MLP Last to Help With Verification The number of measurements is then ( N s + N m) * N p = (4 + 0) * 5 = 20. If you are optimizing, say, 4 subs at 5 listening positions, N s = 4 and N p = 5. This means the number of measurements you must perform is ( N s + N m) * N p.Įxample: If you're optimizing a sub-only configuration, then N m is zero. Suppose you are measuring N s subs and N m main speakers at N p listening positions. If you are using MSO to integrate the mains and subs, you must also measure the main speaker(s) at each listening position. This guarantees an incorrect result, not just an inconvenience as with the above delay example.įor each listening position you wish to measure, you need to measure the frequency response of each sub individually at that position. In the case of miniDSP hardware, exporting a biquad text file from MSO and importing it into a DSP channel that had some filters enabled during the measurements will cause those filters to be replaced, not appended to. To avoid such problems, it's much easier to simply zero out all DSP delay and gain/attenuation parameters prior to performing the measurements.Ī similar, but even worse situation can occur if the measurements were performed with DSP filters set to a non-flat condition. The maximum allowable delay that you would specify for the delay block in MSO for this case would need to be 5.5 msec, as the delay was 2 msec when the measurement was performed. Setting the maximum allowable delay of the applicable MSO delay block to 7.5 msec would be incorrect for this example, as that would allow for a final delay of up to 9.5 msec in the DSP device. Assume for this example that a non-HD miniDSP 2x4 device (which has a maximum delay of 7.5 msec) is being used. Second, it makes the task of preventing MSO from exceeding the hardware limits of your DSP for e.g. First, the non-zero initial delay requires tedious and error-prone manual calculation of the final delay value. It should be clear that performing the measurements with this sub's delay set to a non-zero value has caused at least two problems. 7.4 msec for a particular sub, and the measurements were performed with that sub's delay set to 2 msec, the correct final delay would be 9.4 msec, not 7.4 msec. It's important to realize that the filter parameters, polarity inversions and delay and gain values used by MSO represent changes relative to the conditions at which the measurements were performed. Multi-Sub Optimizer Reference Manual (page 3) Taking Measurements With Your Measurement Software First Clear Out DSP Filters, Delays, Gains and Polarity Inversions Taking Measurements With Your Measurement Software
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