No matter how much you spend on a microphone, its ultimate performance depends on how it interacts with the preamp it's plugged into. Many high-end mic preamps can effortlessly amplify the slightest sonic nuance, creating an aural panorama that's breathtakingly realistic, excitingly vivid, and truly 3-dimensional in scope. For years they've provided fidelity that just hasn't been possible with the "stock" mic preamps built into mixing consoles. Until now.
To develop the new XDR (eXtended Dynamic Range) mic preamp, the engineering team started with blank paper, concerned only with matching or exceeding the performance of $500 to $2000-per-channel esoteric preamps. They went through hundreds of iterations and revs and spent countless hours subjectively listening (and arguing). They started all over again several times. They scoured the world for rare parts. Then they spent more time critically listening and evaluating the design with every high-end microphone you can think of. Then they brought in veteran recording and live sound engineers for more exhaustive listening tests.
What they ultimately ended up with is not just an awesome sounding design. XDR is also a) highly resistant to damage caused by "hot patching" (caused by routing a phantom powered mic through a patch bay); b) remarkably independent of cable-induced impedance variations; and c) able to reject extremely high RF levels without compromising high frequency response.
Because a mic preamp must amplify faint one millivolt input signals up to a thousand-fold (60dB), its rectification components can also pick up radio frequency interference (RFI) from AM and FM stations, cell phones, and pager transmitters - even microwave ovens - and amplify them to audible levels.
Mackie assaulted RFI on 3 fronts. First, they incorporate bifilar wound DC pulse transformers with high permeability cores that reject RFI but don't attenuate the sound at 15kHz and above. Second, they use carefully matched, high-precision components for critical areas of the XDR preamplifier. Third, they direct-coupled the circuit from input to output and used pole-zero cancellation constant current biasing (which also avoids increased intermodulation distortion at high common mode signal levels).
Bottom line for the non-technical: you can use the new XDR mic preamps at the end of extremely-long cheap mic cables in an RFI-saturated urban environment while talking on your cell phone...without hearing a trace of RFI.
If a mic preamp isn't designed right, it will actually sound different depending on the impedance of the microphone and the cable load! XDR's Controlled Interface Input Impedance system accepts an enormous range of impedances without compromising frequency response.
0.0007% Total Harmonic Distortion. The lowest ever in any compact mixer.
Flat response. Not only are XDR mic preamps flat within a tenth of a dB across the bandwidth of any known microphone, but are also only 3dB down at an astonishing 192kHz!
Super-low intermodulation distortion at very high operating levels thanks to instrumentation-style balanced differential architecture, linear biasing, and use of DC-coupled pole-zero-cancellation constant current that frees the mic preamp from power supply fluctuations.
Think of the 1604 as an ultra-premium, esoteric mic preamp... that just happen to have really excellent compact mixers attached.
Ultra-low noise, highest headroom in its class
16 new precision-engineered XDR Extended Dynamic Range premium studio-grade mic preamps with: Ultra-wide 0-60dB gain range, 130dB dynamic range for 24-bit, 192kHz sampling rate inputs, +22dBu line input handling, distortion under 0.0007% (20Hz-20kHz)
Advanced DC pulse transformer RF rejection
4 subgroups with left and right assigns and direct outs
16 line inputs, 16 channel inserts
60mm long-wearing logarithmic-taper faders
Constant-loudness pan controls
Switchable AFL/PFL Solo
6 aux sends per channel with 15dB gain above Unity
Aux 1 and 2 pre/post
Aux Send 1-2 Master section with level controls, Solo switches, and Solo LEDs
Level, pan; -20, Solo and OL LEDs on each channel
RUDE solo light doubles as a mini-tanning booth
4 stereo aux returns, 8 direct outs
3-band active EQ with sweepable midrange
18dB/oct. 75Hz Lo Cut filter on each channel
Control Room/Phones outputs with multi-input source matrix
RCA tape inputs and outputs
Tape input level control and Tape To Main Mix switch
Balanced 1/4 in. inputs and outputs (except inserts)