Mackie earned a loyal following in the 90's with their original HR Series studio reference monitors for both their sound quality and affordability. As the demands for the perfect reference monitor become more stringent, Mackie followed up with the new-and-improved HRmk2 series, taking their tried-and-true technology to new heights.It's trademarked Zero Edge Baffle uses just one cast aluminum piece. Other than catching your eye with its sleek look, it minimizes diffraction and surface vibrations, keeping the sound crystal clear. Its integrated Optimized Waveguide accurately controls dispersion characteristics on- and off-axis, resulting in a wide sweet spot with smooth transitions from lows to highs.Unlike many other studio monitors which use simple ports to boost the bass response, the HRmk2 speakers have a passive radiator which reproduces the low frequencies at higher sound pressure levels (SPL) without as much distortion. The wood cabinet design with its strategically placed open-cell adiabatic foam material dampen any mid-range standing waves inside the cabinet.Mackie went to elaborate lengths to make sure each HRmk2 sounds as good as their experts intended. Each one is subject to rigorous testing and pre-screening during the production process, then calibrated and tuned with an environmentally controlled test chamber before final packaging. They go as far as to provide you with the speaker's "birth certificate" with a chart plotting the frequency difference between it and their "Golden Reference Unit", so you know exactly what this speaker can do for you. For unparalleled quality control for your next reference speaker, try the Mackie HR624 MK2 today.FeaturesUltra-linear frequency response for accurate mix translation6.7-inch high-precision, low-distortion LF transducer1-inch titanium dome, ferrofluid cooled tweeterOptimized Waveguide for wide, even sweet zoneTwin FR Series amplifiers — 100 W for LF / 40 W for HFCast aluminum Zero Edge Baffle minimizes diffractionFull internal damping eliminates mid-range artifactsPassive radiator provides tight, articulate bass extension down to 45 HzAcoustic Space, LF roll-off, and HF controlsOmniMount ready for easy wall/ceiling placement, and can be mounted vertically or horizontallyTHX pm3 certified for surround sound applicationsPerfect for High-Definition audio, cinema and gaming systemsLED power indicator turns red when input levels are too highBalanced XLR, TRS, and unbalanced RCA inputsSpecificationsEnclosure:3/4" thick MDF cabinet construction with internal bracingDie-cast aluminum exponential wave guide and Zero Edge BaffleOpen cell adiabatic "foam fill"Transducers:LF Driver: 6.7"Sensitivity: 89 dB SPLNominal Impedance: 4 ΩVoice Coil Diameter: 1.25"Power Handling (Long Term/Program): 50/150 WFrequency Range: 45 Hz - 6 kHzHF Driver:Sensitivity: 91 dB SPLNominal Impedance: 6 ΩVoice Coil Diameter: 1.0"Power Handling (Long Term/Program): 20/50 WFrequency Range: 1.6 - 22 kHzPassive Radiator: 6" x 9" mass-loaded elliptical flat piston with variable thickness filleted edge rubber surroundCrossover Section: Modified Linkwitz-Riley, 24 dB/oct. @ 3 kHzAmplifier Section:LF Power Amplifier: 100 W @ 4 ΩHF Power Amplifier: 40 W @ 6 ΩCooling: ConvectionInputs: Balanced differential (XLR, 1/4" TRS), unbalanced (RCA)Input Impedance: 20 kΩ balance, 10 kΩ unbalancedInput Protection: RFI and level protectedMaximum Input Level: +20 dBuLow Frequency Filter: 20 Hz, 2nd Order, ButterworthHF Equalization: Shelving ±2 dB @ 10 kHzDimensions (H x W x D): 13.1" x 8.6" x 12.6"Weight: 23.4 lbs. Mackie HR624mk2 6 2-Way Active Studio Monitor 140W, Single.