Unfortunately AVR manufacturers haven't been very innovative when it comes to improving sound quality in areas where it would really matter, namely bass management. On the other hand the surrounds have to work harder which can push them over their electrical or mechanical limit. Often a hole in the frequency response of the surround channel caused by an inappropriately low crossover point is perceptually better than selecting a high crossover and the sub becoming localizable. If any of this isn't possible then one needs to experiment with different crossover settings for that speaker. If the speaker itself isn't capable of going deeper then it's time to get a better speaker. Rerun Dirac Live and check whether the response improved or not. The early fall off could be caused by room effects. In such a case the first step is to change speaker and/or listening position. Furthermore the subwoofer wouldn't support it anyway (max. The subwoofer would most likely become localizable. In the example above a 80Hz crossover would work for all speakers except the side surrounds which would require a crossover at 180Hz. So ideally the target is a crossover point of 80Hz. On the other hand the sub(s) shouldn't become localizable which requires a crossover frequency of about 80Hz or lower. Generally speaking the crossover frequency should be as high as possible in order to benefit from spatially optimized, monophonic bass. In any case moving the sub to a different location might eliminate the hole. boost is 10dB, which is a lot) or that no boost is possible (response is non-minimum phase). The hole around 90Hz indicates that either Dirac Live couldn't boost enough to reach the target curve (max. This allows a crossover frequency of 130Hz (260Hz / 2 = 130Hz) or lower. The upper cutoff point for the subwoofer is at around 260Hz. This allows a crossover frequency of 180Hz (90Hz * 2 = 180Hz) or higher.
The lower cutoff point for the side surrounds is at around 90Hz. This allows a crossover frequency of 130Hz (65Hz * 2 = 130Hz) or higher. In order to avoid it use 65Hz as the lower cutoff frequency. The dip at around 60Hz is wider and potentially audible. The narrow dip at 95Hz is probably not audible. This allows a crossover frequency of 80Hz (40Hz * 2 = 80Hz) or higher. The lower cutoff point for the center speaker is also at around 40Hz. The lower cutoff point for the left and right speaker is at around 40Hz. The highest usable crossover frequency is 1 octave below. Then find the high frequency cutoff point for the sub (remove target curve break points above that frequency). The lowest usable crossover frequency is 1 octave above. This is the low frequency cutoff point (remove target curve break points below that frequency). Examine the green "Average Spectrum (after) curve" for each satellite speaker (or group of satellites) and locate the frequency where the green curve starts to fall off from the orange target curve at low frequencies. Run Dirac Live, set target curves (make sure you're using the very same target curve for all speakers, including the subwoofer) and optimize. The crossover frequency in this example is 100Hz. Here's a graph showing how the low frequency portion (red) and the high frequency portion (blue) ideally combine (green). The overlapping frequency region where there is significant interaction typically extends from about 1 octave below the crossover point (half the frequency) to about 1 octave above (double the frequency). both the subwoofer and the satellite speaker contribute to the response around the crossover frequency. High and low pass filters found in common AVRs aren't brick wall filters, i.e. The crossover point is the frequency where the resulting two frequency response curves cross each other. Then a high pass filter is applied to the channel that should carry only higher frequencies (signal going to a satellite speaker) and a low pass filter is applied to the channel that should carry only lower frequencies (signal going to the subwoofer). First the signal is split into two different channels. Basicsīass management in AVRs provides crossovers that separate low and high frequencies. NAD T758v3) or standalone Dirac Live room correction device (e.g. RequirementsĪVR with Dirac Live room correction (e.g.
DIRAC LIVE IMPULSE ROOM CORRECTIONS HOW TO
This tutorial shows how to set crossover frequencies in an AVR/pre-processor for subwoofer and satellite speakers based on data captured by Dirac Live room correction. Setting crossovers in an AVR/pre-pro with Dirac Live room correction
Note: There's an updated version of this tutorial for Dirac Live 2.