Okay then, the Ascends in your system will still be the bottleneck as it is only rated 500 W maximum short term peak. You will need about 660 W to hit reference level with one speaker from 15 feet.\n\nThe Monolith can output only a little more than 500 W average short term dynamic peak, that's 1,000 W peak, two channel driven into 4 ohms.\n\nCalculated results based on Ascend specs, for one single speaker:\n\n\n\nInput data required:\nInput data\nUnit\n\n\n1) Speaker nominal impedance (Ohms)\n4.00\nOhm\n\n\n2) Sensitivity in dB\/W at 1 Meter\n\n\ndB\n\n\n3) Sensitivity in dB\/2.83 V at 1 Meter\n90.00\ndB\n\n\n4) Seating distance (1 foot = 0.3048 Meter, 1 Meter = 3.281 foot)\n4.57\nMeter\n\n\n5) Room gain for speaker placement near walls\/corners, enter 0 to 3 dB max., to err on the conservative side\n3.00\ndB\n\n\n6) Desired additional amplifier headroom (dB) Recommended minimum is 3\n\n\ndB\n\n\n7) Target SPL - THX reference is 85 dB, with 20 dB of headroom\n105.00\ndB\n\n\n\n\n\n\n\n\n\nCalculated values from the input data:\nCalculated values\n\n\n\nSensitivity loss at seating distance (dB)\n13.20\ndB\n\n\nSPL\/W at seating distance calculated from the input data\n79.80\ndB\n\n\nAmplifier power output based on 2.83 V and the assumed impedance at 1 Meter\n2.00\nWatt (W)\n\n\nPower increase in multiples needed to achieve target SPL\n331.46\n\n\n\nPower increase in dB needed to achieve target SPL\n25.20\ndB\n\n\n\n\n\n\n\n\n\nCalculated amplifier output power required:\n\n\n\n\n\nFor the target SPL at seating distance\n663.66\nWatt (W)\n\n\nFor the target SPL at seating distance, with the desired headroom included\n\n\nWatt (W)\n\n\n\nBoom! Thanks Peng! \n\nI am going to conclude that scooting a little closer will definitely take a little heat off my speakers at high volumes. The folks over at Ascend have been a little bit hit and miss to contact lately, with everything going on but they always eventually get back to me. I think I'm gonna shoot Dave an email and ask him ask about max spl at 1 meter, like you suggested I do with Ed for my Ultras. \n\nYou know what's interesting, tho maybe not overly surprising? My Monolith runs MUCH cooler powering my 4 ohm Sierra towers than it does my "8 ohm" Ultra towers. It's gets good and warm with the Ultras, but barely more than lukewarm with the Sierras. Even after some some very spirited listening sessions.