I should add that early in the video, there's an error regarding the claimed output voltage for the miniDSP unbalanced 2x4. Its maximum output voltage is 0.9 Volts RMS, not 2 Volts RMS. There is an input jumper that allows the user to switch the input sensitivity of the device between 2.0 Volts RMS and 0.9 Volts RMS. With the former setting, an input voltage of 2.0 Volts RMS results in an output voltage of 0.9 Volts RMS, which implies a loss of 6.9 dB. With the latter setting, an input voltage of 0.9 Volts RMS results in an output voltage of 0.9 Volts RMS, implying a 0.0 dB loss. Regardless of the input jumper setting, the maximum RMS output voltage of the unbalanced miniDSP 2x4 is 0.9 Volts RMS. This is very important, because it means that if you want to drive your subwoofer amp to full power, that amp must have an input sensitivity of 0.9 Volts RMS or less. This is not very common, but can be found with careful selection.\n\nThe balanced miniDSP 2x4 puts out a maximum of 4 Volts RMS in the balanced mode, so those who use pro amps for their subs will have no problems with maximum output.\n\nAnother alternative is the recently released miniDSP 2x4 HD, which is unbalanced, but has a maximum output voltage of 2.0 Volts RMS, plenty to drive almost any pro amp one might use for a subwoofer. It also solves a problem with the standard miniDSP 2x4, which is a maximum delay of 7.5 msec. This is too low for many, perhaps most multi-sub applications. The HD version has a maximum delay of 80 msec, which is far more in line with what might be needed in practical installations, especially those with fairly large rooms, in which the subs have a distance difference from the main listening position of more than 8.45 feet.\n\nOne needs to be very careful with the choice of miniDSP products, especially when considering the unbalanced 2x4 (non-HD version). This has been the subject of many posts over several years. Even the balanced miniDSP 2x4, which has plenty of output voltage for any application, is nonetheless handicapped by the 7.5 msec maximum delay limitation.