Martin Audio WLXGS manuale d’uso

The Martin Experience WLX, WLXGS User ’s Guide PREMININARY INFORMA TION All material © 2007. Martin Audio Ltd. Subject to change without notice.[...]

Wavefront WLX and WLXGS Hybrid™ Subwoofer Preliminary information Introduction The powerful WLX Hybrid™ subwoofer is designed to complem ent Wavefront W8L Series tou ring systems to provide deep bass with maximum efficiency. WLX Rigging options Standard WLX subwoofers are equipped with integral flying hardware. A non-flyi ng version is availabl[...]

A combined WLX/W8LM grid (ASF20003 – not shown) ha s been designed to enab le W8LM miniature line array elements to be flown ben eath standard WLX subwoofers. Rear connector brackets (ASF20005) are also available for flying W8LC compact line arrays below WLX subwoofers. ASF20005 connector brackets enable WLX subwoofers to be a ngled downwards wit[...]

Pin-outs and cabling WLX Input N L 8 W L X -1 Driver – (& link -1) +1 Driver + (& link +1) -2 Driver – (& link -2) +2 Driver + (& link +2) - 3 l i n k - 3 + 3 l i n k + 3 - 4 l i n k - 4 + 4 l i n k + 4 All material © 2007. Martin Audio Ltd. Subject to change without notice.[...]

Cable and panel connector part numbers Please note the following part numbers when orderi ng loudspeaker connectors to m ake up cables and patch panels Neutrik NL connectors NL8FC 8 pole cable (female) NL8MPR 8 pole panel (male) NL8MM 8 pole inline coupler (male-male) Connectors should be kept in good, clean, uncorroded condition to ensu re full, u[...]

Sub-woofer crossover and alignment Crossover frequencies The original factory controller se ttings for W8L, W8LC and W8LM sy stems are intended for use with sub- bass systems such as the W8LS, WLX or W SX. As a consequence LF high pass filt ers should be set as follows: Loudspeaker Type Default (with subs) Full-range (without subs) W8L 35Hz* 24dB/8[...]

W8LM presets include the WLX sub-woofer so they ha ve two (mono) or four (stereo) unlocked delays. The WLX channel defaults to zero because the WLX has the longest horn. The W 8LM LF/Full-range and HF reference delays default to 3.931mS and 3.829mS respectivel y to time align the W 8LM to the WLX when the grilles are aligned. W8L, W8LC & W8LM r[...]

Main to sub-woofer delays Reference settings The following table shows system delays to align various combinations of W 8L Series main and sub-woofer system. These should be treated as im portant initial settings and will work without further adjustments where grilles are alignm ent. They are a good starting point for f urther time align ment. The [...]

In all cases, set the main (W 8L, W8 LC or W8LM) and sub-woofer contro ller output parameters as follows, making sure that controller inpu ts are initiall y set flat (no equalisatio n), 0dB gain, 0ms delay. Flown WLXs Side-by-side arrays Similar length (height) sub-woofer arrays shou ld be placed beside the m ain system for consistent performance a[...]

4 x WLX + 8 x W8LC mixed array fo r orchestral applications using Connector Brackets – ViewPoint™ Rigging View Stacked WLXs or WLXGSs WLX or WLXGS subwoofers may be ground stacked be low the m ain system. Ground stacked subwoofers can be up to 6dB more efficient than flown systems – assuming an acoustically solid floor - thanks to half spaced[...]

Stacked system alignment A stacked subwoofer system should be placed di rectly be neath the main system with the subwoofer and m ain system grilles vertically aligned. Subwoofer grilles and main sy stem grilles should be closely aligned so that they are at equal distances from a central audience area – preferab ly a well positioned mix position. [...]

WLX sub-woofers may be time aligned without test gear as follows: 1) Start with t he controller out puts delays se t as per th e above t able 2) Use a laser tape mea sure to measure the distance to the main system grille and the WLX sub-woofer grille 3) If the WLX sub-woofers are closer than the main system, increase the WL X controller output dela[...]

overpowered models - with suitably set controller limiters - without risking uncontrolled power bursts. The MA series power amplifiers’ regula ted power rails also ensure maximu m performance under the real-world concert conditions of less-than-optimum ma ins supplies and low impedance loads. Amplifier load tolerance An efficient subwoofer system[...]

have been checked and controllers have been set to suit the power amplifiers to be used. Music should be used to check that controllers are receiving and sendi ng the ap propriate signal bands and then each power amplifier level control advanced in sequen ce to check system operation and patching. Assuming that controller output leve ls and limiter[...]

Symmetrically coupled 2-wide columns show a sli ght im provement in mid-bass am plitude and polar response - but the effect becomes insignifican t in large, flat fronted arrays or widely spaced stage apron systems. 2-wide symmetrical columns of WL X/WLXGS m ay be horizontally arrayed to improve mid-bass coverage. Array shapes vs coverage WLX or WLX[...]

Array Approx Boost Horizontal Vertical ( w r t s i n g l e u n i t ) coverage coverage - Wide Wide +12dB Wide Narrow +12dB Narrow W ide +24dB Narrow Narrow In these examples “wide” means th at there are no coverage nulls w ithin the forward 180º at m id-bass crossover frequencies. Wide covera ge arrays have significant output be yond 180º mak[...]

Coverage angle for tightly packed flat fronted arrays -6dB Coverage Here is a simplified formula for calculating the m ain c overage angle of a tightly packed flat fronted array. * = approximate speed of sound in m/s. Va ries with temperature (see Section 2a). Arcsin means “the angle whose sin is ...” Flat fronted cluster coverage pattern s wil[...]

The medium sized array (left) has significant ou tput to ±90º wh ereas the large array’ s ±90º output is dramatically reduced. A note on coverage nulls It is useful to be able to calculate where these first response nulls will occur for various frequencies as they indicate areas where coverage, transient response a nd directional information [...]

For instance, an 8 high ground-based stack of WLX/WLXGS subwoofers will act like the top h alf of a 16 high stack. It is possible to reach higher seati ng areas whilst retaining a tall vertical stack by electronically “tilting” the system - see later. Note that flexible floors may actually absorb sound at some frequencies so the situation isn?[...]

Again, a flexible side wall may absorb sound at certain low frequencies. Boundaries should always be treated with caution. Spacing It is possible to space out W LX or WLXGS subwoofers to provide a larger frontal area with fewer units but care must be taken to avoid irregular c overage at higher, mi d-bass frequencies. The following formula gives th[...]

Far field polar patterns can be quite complicated - even for a simple pa ir of subwoofers driven in unison. Wide spacing will cause off axis irregularities (com bing) because time off sets start to become significant. An odd number of half wavelengths will cause nulls along the line of the loudspeakers (the 90º lines) - see the 2½ wavelength exam[...]

Horizontal splays Splaying WLX/WLXGS arrays horizontally will widen their mid-bass coverage. The following sketch shows an 8 wide x 3 high WLX/WL XGS array arranged in four symmetrical pairs for smooth mid-bass coverage. WLX/WLXGS Wide Horizontal coverage (Splayed with Radius = width) 43Hz 86Hz 172Hz 2 Wide 90º 60º 4 90º 60º 30º 8 60º 30º 36[...]

Stacked WLX/WLXGS application examples The following sketches show how WLX/WLXGS arrays may be deployed for a wide range of productions and types of venue. All productions and venues present their own unique requirements and these examples are intended as a template or starti ng point for your own specific design. Examples 1 and 2 show typical set-[...]

(3) WLX/WLXGS set-up for very high power dance/rock production in narrow arena Gives narrow horizontal & vertical co verage up to 120Hz - allowing for ground effects. Example 3 shows a very high power da nce or rock set-up for a narrow “shoe box” venue. Note the four-wide left and right WLX arrays for tight horizontal control and the m ore [...]

(5) Alternative set-up for wide venues Splayed WLX/ WLXGS array s for wide horizontal coverage. Example 5 shows a set-up for a TV shoot in a similar wide venue where sight-lines are critical. Note the lower profile, splayed arrays. Thrust stages Examples 6 show a typical set-up for a larg e, thrust st age productions. (6) WLX/WLXGS set-up for high [...]

Island stages (not shown) Island stages are simply four-sided versions of exam ples 3 and 5 and should be aligned using the same process. Tutorial on spaced systems Whenever two or more loudspeaker systems are fed w ith the sam e signal and thei r coverage overlaps, sound addition and subtraction will take pla ce depending on the listener’s posit[...]

Addition & Subtraction The above shows how two pairs of sine waves (with identical am plitude and frequency characteristics) will sum. Pair (a) are in phase and add. Pair (b) are out of phase and cancel. All material © 2007. Martin Audio Ltd. Subject to change without notice.[...]

Polar variations with frequency Whether particular frequency components add or subt ract in the far field will depend on the louds peaker system spacing, the angular offset of the listener with respect to th e centre line, and the wavelength. The following polar responses show what happens when subwoofers are placed 8.6m apart and are driven in uni[...]

These lobes could cause low freque ncy feedback problems on stage with the high microphone gains used for orchestral low string (cello, double bass) se ctions or for “unplugged” perform ances. 60Hz At 60Hz the spacing is an odd number of half-wav elengths again so we see side nulls again. 40Hz When the frequency drops to 40Hz, the 8.6m spacing [...]

40 Hz reduced spacing The above shows what happens at 40Hz if we reduce the spacing between the subwoofers to 4.3m. We get better central coverage without 40Hz side lobe s - adequate for long, narrow “shoe-box” venues but wider coverage would be required for most arenas. 40Hz close coupled Close coupling would give a wider coverage at that freq[...]

Listeners in the 60º zone will hear th e note at a reduced leve l and may be more aware of room reverberation because the direct-to-reverberation ratio would be poorer for that note. Other notes would give d ifferent effects. In practice, these peaks and troughs can be smoothed out with additional fill systems. Electronic steering It is possible t[...]

Note that it is important to keep th e subwoofers tightly packed to avoid polar anomolies caused by spacing. Procedure The normal procedure is to measure the angle from the t op of the vertical subwoofer stack to the highest/most distant seats (using an inclinometer) and to calculate the required delay increm en t with the formula shown. Example We[...]

The following delay line taps would be required for the above system: t0 = 0m s t1 = 0.83mS t2 = 1.66mS t3 = 2.49mS t4 = 3.32mS t5 = 4.15mS t6 = 4.98mS Going further It is possible to apply electronic sh aping to horizontal array s. For instance, it is common to use curved m ain clusters for smooth mid and high frequency coverage. Ground-based s ub[...]