MartinLogan Dynamo 800X controlled subwoofer
In the last part of the 1980s, when I started assessing very good quality subwoofers, they were huge and weighty, hard to move or track down space for in a room. Their controls were consistently on an awkwardly situated back board, and there were no inherent programmed room-streamlining choices or parametric equalizers. Velodyne's 105-lb, downfiring ULD-18 ($2570), ca 1989, was run of the mill: Two individuals were expected to unload and move it; it was fueled by a detachable 400W intensifier, associated awkwardly with a speaker link and a RCA-ended interconnect for its servo control; and its controls were on the lower part of the bureau. Changing its hybrid recurrence included patching new resistors onto a printed circuit board inside the amp.
From that point forward, subwoofers have become more easy to understand. Eight years prior, JL Audio's Fathom f113 offered worked in, robotized room improvement actuated from a board on the sub's front. Three years prior, with the SB16-Ultra, SVS presented its own cell phone application for remote control of subwoofer settings from the listening-room seat, including room advancement and a parametric equalizer.3 And in 2018, MartinLogan acquainted remote sign associations with take out the requirement for long, exorbitant runs of interconnect from preamp to sub. As I do with any such new innovation, I contemplated whether remote network would be sans clamor and dependable. At the point when MartinLogan's Devin Zell offered a couple of their Dynamo remote subwoofers for audit, I chose the center model, the 800X, which Zell suggested for my new, more modest listening room.
Remote subwoofing
The Dynamo 800X gauges 30 lb and has a descending terminating 10" woofer with upset encompass, housed in a generally cubical (13.7" high by 12.4" wide by 13.1" profound) nook, cross-supported to tame bureau resonances. Its feet, connected by screws, can be moved to one more surface to change the 800X to a front-terminating sub, the last direction valuable for establishment in a bureau. Its implicit class-D speaker (300W RMS, 600W pinnacle) utilizes MOSFET semiconductors constrained by a restrictive opposite numerical balance (IME) channel to convey more precise low-recurrence reaction.
The 800X accepts its line-level transmission from the preamplifier by means of MartinLogan's discretionary SWT-X remote pack ($199.95), which incorporates a transmitter and a pre-matched recipient that plugs into an enormous port on the 800X's back board; its 50' scope of activity doesn't need view situating.
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Arrangement is dealt with ML's Subwoofer Control App, liberated from the internet based Apple and Google Play stores. Tapping on the suitable symbol opens a Discover page that recognizes any close by ML Dynamo subwoofer, sets its result level, offers different listening modes (Movie, Music, Night), and ships off the sub's drive-unit a test tone that breadths from 20 to 120Hz. The range can be halted at a specific recurrence to examine and distinguish a wellspring of undesirable vibration in the room.
Likewise accessible is the new Anthem Room Correction (ARC) Mobile application, which gives programmed room streamlining to the 800X. This prompts the subwoofer to create signal tones, records low-recurrence room-reaction information, analyzes them to put away ideal reaction bends, and changes the sub's result to diminish room-explicit abnormalities. Curve can be run by means of a Bluetooth (cell phone) or USB (PC) association. I utilized my iPhone's implicit mike.
Since those two applications incorporate the vast majority of the 800X's controls, the sub's back board has just an IEC power gulf, two uneven information jacks (RCA), a LFE input (RCA), a power-on status LED, a 5–24V trigger jack, speaker-level data sources, a switch for App or Local control, a Micro-USB port for firmware updates, and ARC, an enormous port for the SWT-X remote beneficiary module, and a level control.
Arrangement
The Dynamo 800X's little size and 30-lb weight made it simple for me to convey both of them, each in turn, up two stairwells to my listening room. Also the elastic tipped feet that cover the spikes implied that I didn't need to utilize Super Sliders to secure my listening room's hardwood floors.
The 800X was intended to be utilized with a sound framework's principle speakers running full reach, which clarifies its absence of an inherent high-pass channel. Be that as it may, I involved Quad ESL-989 electrostatic amplifiers for this survey in light of the fact that their restricted profound bass reaction and dynamic reach can be increased by subwoofers. What's more, supported pedal harmonies from pipe organs and bass-drum whacks can over-burden the Quads' electrostatic boards and trigger their assurance circuits. To stay away from this issue, I restricted their bass trip by utilizing the high-pass channel in JL Audio's CR-1 outer electronic hybrid.
Arrangement was supported by the 800X's guidance manual and by ML's incredible video instructional exercise, "Subwoofer Setup and Optimization." I suggest this video, however my own arrangement contrasted: I utilized the JLA CR-1, and estimated SPLs and the room's recurrence reaction.
The subsequent stage was to combine the Dynamos' remote transmitters with the comparing recipient modules, to set up the subs' remote sign associations. LEDs on the transmitter and collector modules gradually streaked red while connecting, then, at that point, a consistent green when combined. The right-channel transmitter and beneficiary matched quickly; the left-channel continued squinting red, declining to combine, however I attempted every single imaginable design. Devin Zell sent me a substitution remote unit, and that matched immediately. I was exceptionally happy that the remote collector wasn't designed to the 800X, for what it's worth in some different subwoofers.
The time had come to actually look at the remote associations. Attempt as I would, there was no solid. Re-perusing the manual uncovered a switch on the back board that chooses among App and Local control. Flipping the change to App woke up the Dynamos, later which the Subwoofer Control application immediately identified both 800Xes.
Setup was aided by the 800X's instruction manual and by ML's excellent video tutorial, "Subwoofer Setup & Optimization." I recommend this video, though my own setup differed: I used the JLA CR-1, and measured SPLs and the room's frequency response. (See sidebar, "Using the MartinLogan Dynamo 800X with an External Crossover.")
The next step was to pair the Dynamos' wireless transmitters with the corresponding receiver modules, to establish the subs' wireless signal connections. LEDs on the transmitter and receiver modules slowly flashed red while linking, then a steady green when paired. The right-channel transmitter and receiver paired immediately; the left-channel kept blinking red, refusing to pair, though I tried all possible configurations. Devin Zell sent me a replacement wireless kit, and that paired instantly. I was very glad that the wireless receiver wasn't hardwired to the 800X, as it is in some other subwoofers.
It was time to check the wireless connections. Try as I might, there was no sound. Re-reading the manual revealed a switch on the rear panel that selects between App and Local control. Toggling the switch to App woke up the Dynamos, after which the Subwoofer Control app quickly detected both 800Xes.
I moved the two 800Xes into my room's front corners, one next to each Quad speaker, and played through both "Cosmo . . . Old Friend," from James Horner's film score for Sneakers (CD, Columbia CK 53146). I used this track's endlessly repeating bass-drum beat to optimally set the phase and the physical distance of each sub from its corner, one sub at a time, listening for the drum beat while adjusting the app's phase control between 0° and 180°—the latter position produced the loudest bass. To determine the subs' optimal positions, I moved each a short distance out of its corner on the diagonal, equidistant from the front and sidewalls, listened, then pulled them out a bit more and listened again. About 2' from the room's corner to the sub's rear panel, the drum beat became solid, heavy, and loud. That's where I left them.
I then ran the Anthem ARC app's wireless, semiautomatic room-analysis and -correction routine, beginning by pointing my iPhone's mike at the sub to be optimized and tapping the Continue button on the phone's screen. This caused the sub to generate five two-second beeps. This was then repeated at four other positions. The app then averaged the five room measurements, calculated corrections to the sub's output, and transmitted them wirelessly, one sub at a time.
The ARC Mobile app now run and shut off, I restarted the Subwoofer Control app, to match the output levels of the subs and Quads. Playing a digital file of uncorrelated pink noise, I adjusted the preamplifier's volume control until each Quad delivered a sound-pressure level of 75dB at my listening chair. I switched off the Quads, then turned on the subs and used Subwoofer Control to adjust the sub's output to deliver an SPL of 75dB. For all measurements, I used the SPL Meter module of Studio Six Digital's AudioTools (v.10.5.6) in conjunction with their iTestMic, a professional-grade test and measurement microphone for iPhones
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