[selfbuilt]

Warning: pic heavy, as usual.



4Sevens has updated its popular Maelstrom G5 build with an XM-L emitter, now known as the Maelstrom X7. Let's see how it performs compared to the original G5, and other recent XM-L-based lights in this 1x18650/2xCR123A class…

Specifications:

• Cree XM-L LED
• Total of 7 modes of output, split into 2 sets*]Regular: Moonlight, Low, Medium, High
• Special: Beacon, S.O.S., Strobe, High
• Power: (1) 18650 or (2) CR123A batteries (18650 button-top cells only)
• Operating Range: 2.7V~12V
• Typical Output and Runtimes*]Moonlight: 0.3 lumens, 6 days
• Low: 30 lumens, 21 hours
• Medium: 270 lumens, 2.8 hours
• High: 480 lumens, 1.3 hours
• Strobe (10hz, 480 lumens): 2.5 hours
• S.O.S.: 4.5 hours
• Beacon: 12 hours
• Dimensions: Length: 6.0 in, Body Diameter: 1.0 in, Head Diameter: 1.5 in, Weight (w/o batteries): 5.1 oz
• One-inch weapon mountable body
• Fine-tuned deep, smooth reflector
• Useful range of over 100 meters
• Waterproof to IPX-8 standard: 1 meter, 30 minutes
• Estimated MSRP ~$145

Included inside is the light, good quality belt pouch/holster and wrist strap, manual, two 4Sevens-branded CR123As, spare o-rings, tactical grip-ring replacement cover, and flat black bezel replacement cover.


From left to right: Redilast 18650, 4Sevens Maelstrom X7, Maelstrom G5, Lumintop TD-15X, Thrunite Scorpion, Armytek Predator.

X7: Weight 146.9g (no batteries), Length: 151.5mm, Width (bezel): 38.7mm
G5 : Weight: 145.5g (no batteries), Length: 156mm, Width (bezel): 38.9mm
Scorpion: Weight: 167.5g (no batteries), Length: 168mm, Width: 35.1 (bezel), 37.0mm (tailcap grip ring)
TD-15X: Weight 150.3g (no batteries), Length 147.3mm, Width: 37.8mm (bezel)

As you can see, the X7 is very similar to the G5 in its exterior appearance. The main difference is that the X7 is about half a centimetre shorter, mainly due to a reduction in the length of the head. Although the original G5 seemed slightly larger than the typical tactical 1x18650/2xCR123A light at the time, there are now quite a few lights in this size.





The interior of the light looks much the same as the G5 as well.

The Maelstrom lights have black anodizing (type III = HA). Lettering is minimal, but bright and clear. Knurling is not very aggressive, but does help somewhat with grip. Clip is removable, with a ring cover to hide the attachment point. Note the clip is not reversible.

The Maelstrom lights use a protruding forward tactical clicky switch (i.e. press for momentary on, click for lock-on), with good feel. All mode switching is done with the head, and the Maelstrom lights retain the novel 4-contact-point design (scroll down for a UI discussion). Also as before, the head's positive contact lacks a spring, meaning newer high-capacity flat-top 18650 batteries will not work.

The front of the bezel easily opens and you can directly access the reflector and the front of the emitter.

Note that due to the protruding forward switch, the light cannot tailstand. But tailcap screw threads (square-cut) are anodized allowing for tailcap lock-out.

I have not detected any obvious rattle on any battery type.




The reflector looks very similar to the Maelstrom G5, just not quite as deep (in keeping with the smaller head on the X7). The other obvious difference is the XM-L emitter sitting at the base of it now. My sample came with a smooth reflector, and I don't know if textured OP is offered (it was available as an accessory on the G5). Given the depth and shape of the reflector, I would expect pretty good throw.

Which brings me to the white-wall beamshots. All lights are on AW protected 18650, about ~0.75 meter from a white wall (with the camera ~1.25 meters back from the wall). Automatic white balance on the camera, to minimize tint differences.













The X7 throws well, although not quite as well as the G5. The overall beam pattern is good, although there were some artifacts in my the center of the hotspot of my X7 sample (i.e. not uniform). These were not distracting in actual use outdoors, but was noticeable inside the house on smoother surfaces.

UPDATE June 6, 2011: I have just posted a new 100-yard round-up beamshot review for 2011, showcasing all my current "thrower" lights. Below are a few animated GIFs showing some relevant comparisons for the BC40. Please see that round-up review for additional pics of other lights, taken under the same conditions.








User Interface

The X7 comes with the same interface as the revised G5 that is currently shipping.

Turn the light on/off by the tailcap switch (press for momentary, click for locked-on).

As before, the 4-point switch engagement in the head of the flashlight allows you to select the different outputs by simply loosening or tightening the head by ~90 degree turns.

The X7/G5 has 8 modes in total, split into 2 sets (referred to as Regular and Special mode). In order from tight to loose, you get the following:

Regular: Hi, Med, Lo, Moonlight
Special: Hi, Strobe, SOS, Beacon

One of the changes from the first batch G5s was the removal of the original Med mode, and the inclusion of the max output level on both sets (i.e. original Turbo became Hi, original Hi became Med, and original Med was omitted). This way, you don’t have to switch into the special blinky mode set for max output – you can have Hi on both sets.

Switching between Regular/Special mode sets is done by quickly loosening and tightening the head from tight 4 times rapidly (i.e. quickly switching between Primary and Secondary 4 times in a row). You have to do this pretty fast, or you won’t switch between mode sets. You also need to make sure you do the full quarter turn each time, or the switch won’t register (i.e. need to see the secondary mode).

Also, note that the position just below where a level switch occurs can be a bit unstable (i.e. light might flicker or jump back and forth from the lower to higher level if shaken). Best to make sure you are well within a given level’s position for stable operation (i.e. avoid leaving it set within a ~15 degree arc right around where the levels switch).

PWM/Strobe

I can detect no sign of PWM flicker by eye or with my sound-card oscilloscope on any level, leading me to conclude the X7 is fully current-controlled.

On the original G5, high frequency PWM could be detected on the Lo and Moonlight levels (by shinning on a fan), but I see no trace of that now on the X7.



Strobe is 9.6 Hz on my sample. Beacon mode was one ~850 msec pulse, every 10 secs.

Testing Method:

All my output numbers are relative for my home-made light box setup, a la Quickbeam's flashlightreviews.com method. You can directly compare all my relative output values from different reviews - i.e. an output value of "10" in one graph is the same as "10" in another. All runtimes are done under a cooling fan, except for any extended run Lo/Min modes (i.e. >12 hours) which are done without cooling.

I have recently devised a method for converting my lightbox relative output values (ROV) to estimated Lumens. See my How to convert Selfbuilt's Lighbox values to Lumens thread for more info.

Throw/Output Summary Chart:

Effective November 2010, I have revised my summary tables to match with the current ANSI FL-1 standard for flashlight testing. Please see http://www.sliderule.ca/FL1... for a description of the terms used in these tables.







Max output has increased on the X7 compared to the G5, and is generally comparable to the XM-L-based Thrunite Scorpion and Lumintop TD-15X. Note that there seems to be two versions of the TD-15X out there, and mine is the one with unusually high output on 2x3.7V Li-ion sources.

Throw is fairly good on the X7, measured here as roughly equivalent to the G5 and TD-15X when extrapolated from measurements at 5m. However, the X7 lux measure is something of an over-estimate, due to a small, unusually bright region in the X7's hotspot (that gets picked up by the lightmeter). In real life, the G5 easily out-throws the X7 – I will update this review shortly with 100-yard outdoor beamshots for comparison purposes.

Output/Runtime Comparison:









The X7 is certainly a good performer, as expected from 4Sevens. It is typically comparable in output/runtime efficiency to the Lumintop TD-15X, at all levels where output is similar. It matches the Thrunite Scorpion closely at the max output level, but clearly outperforms it at lower levels.

Performance of the XM-L emitter in this build is consistent with what I've come to expect for this emitter class. At higher drive currents, you get lot more overall light for equivalent runtime compared to the XP-G R5 in the G5 emitter. At lower levels, overall runtime efficiency is comparable to the XP-G R5-equipped G5.

Potential Issues

The 4x switching mechanism for Regular/Special mode sets can be a bit tricky to perform reliably. However, now that Hi is common to both sets, you aren't likely to need to do this frequently.

With the reverse polarity protection feature of the head, none of my newer high-capacity flat-top protected 18650 cells would work.

The light can't tailstand.

There were some minor artifacts in the center of the hotspot on my sample.

Preliminary Observations

The upgrade of the Maelstrom line with the popular Cree XM-L emitter gives flashlight enthusiasts another option for relatively high output in the compact 2xCR123A/1x18650 class.

I always liked the build of the G5, and find the X7 to be quite comparable in most ways (i.e. just slightly shorter). The intuitive interface is easy to use, and reliable in my testing. I am particular glad to see the mode level revision (introduced early in the G5 run) that keeps the max mode output available in both mode sets. IMO, spacing of levels is quite good on the X7.

So what's different from the G5? Of course, you get more output on Hi with the XM-L emitter. In this regard, the X7 is comparable to most XM-L-based lights I've reviewed in this size/class of light. Relative throw is of course reduced due to the larger size die of the XM-L, but the X7 still performs quite well for this class. It doesn't throw quite as far as the G5, though (despite what my lux measures say - some minor artifacts in the hotspot give the X7 a slighter higher reading here than it deserves).

Output/runtime efficiency is excellent, as usual for a 4Sevens light. Although comparable to the Thrunite Scorpion on Max, the X7 handily outperforms it at lower levels (although to be fair, the Scorpion is a continuously-variable PWM-based light). Actually, I find the overall performance of this light to be remarkably similar to the Lumintop TD-15X in terms of output, throw, and efficiency. What differs is the build and interface, of course - plus 4Sevens has been around a lot longer.

I fundamentally like the build and design of these Maelstrom lights, and am glad to see the mode output level arrangement on currently shipping lights - it is well layed out. The X7 is a solid addition to the line.

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X7 provided by 4Sevens for review.