# Foursevens MMU-X3 (3xXM-L2, 1x26650) review: RUNTIMES, BEAMSHOTS, VIDEO +



## selfbuilt (Jan 11, 2014)

*Warning: pic heavy, as usual. *











The MMU-X3 is the latest member of the 1x26650 class from Foursevens (originally known as the X10, later the MMU-X). The MMU-X3 features the same basic build as the earlier 1xXM-L/XM-L2 lights, but now with 3xXM-L2s squeezed into the head. oo:

I have the original X10 – plus a good number of 3xXM-L2 lights, so there's a lot we can compare to here.  

*Manufacturer Reported Specifications:* 
(note: as always, these are simply what the manufacturer provides – scroll down to see my actual testing results).


LED: (3) CREE XM-L2
Voltage range 3V-4.2V
Spot Beam Angle: 12 degrees / Diameter at 3 meters: 620mm
Flood Beam Angle: 90 degrees / Diameter at 1 meter: 2 meters
Brightness Levels Low: 200 lumens, 11 hrs / High: 1600 lumens, 2.5 hrs
Reflector Smooth
Body Material Type-III hard-anodized aircraft-grade aluminum
Bezel Material Type-III hard-anodized aluminum strike-bezel
Lens Material Optical-grade glass lens, sapphire coating, antireflective coating
Current Regulation
Thermal Regulation
Smart Circuit for Rechargeable Batteries
Reverse-Polarity Protection
Dimensions Length: 5.6 inches/Body diameter: 1.3 inches/Head diameter: 1.8 inches/Weight (without batteries): 5.6 oz
Included Accessories Spare-o-rings, holster (Battery and Battery Charger NOT included)
MSRP: ~$120






















Packaging has recently been updated across the Foursevens line. Designed to show off the light, you can see the key characteristics are presented on the top half of the box. Inside, included with the light are spare O-rings and manual. My review sample also came with the current generation of Foursevens 26650 Li-ion battery (likely an optional extra).













From left to right: Foursevens 26650, MMU-X3, X10; JetBeam SRA40; Nitecore EA4; Sunwayman T45C.

All dimensions directly measured, and given with no batteries installed:

*Foursevens MMU-X3*: Weight: 172.0g (264.2g with 26650), Length: 135.8mm, Width (bezel): 46.0mm
*Foursevens X10*: Weight: 156.9g, Length: 135.5mm, Width (bezel): 46.0mm
*Foursevens MMX*: Weight 145.8g, Length: 153.3mm, Width (bezel): 38.7mm
*JetBeam SRA40 4xAA*: Weight 236.0g, Length: 126.1mm, Width (bezel): 48.5mm
*JetBeam PA40 4xAA*: Weight: 184.0g, Length: 183mm, Width: 40.8mm (bezel), 42.1mm (max width)
*Lumintop SD10*: Weight: 117.6g, Length: 120.3mm, Width (bezel): 40.1mm
*Nitecore EA4 4xAA*: Weight: 161.6g , Length: 117.9mm, Width (bezel): 40.2mm
*Olight S80*: Weight 162.5g, Length: 151mm, Width (bezel): 38.7mm
*Sunwayman D40A 4xAA*: Weight: 167.9g, Length: 120.4mm, Weight (bezel): 40.0mm


















Physically, the MMU-X3 doesn't seem that different from the original X10 - except for the labels, the lights appear identical. At least, until you look at the reflector … more on that in a moment. 

The light is wider than typical 1x Li-ion lights, due to the 26650 cell used here. But overall length is well within the standard range for lights that use this typical 65mm cell length, and the overall width is still smaller than typical 2x18650 lights. 

As before, the MMU-X3 is a solid light. Black anodizing (type III, aka Hard Anodized) is more matte finish now, like the rest of the recent Maelstrom line. Knurling is not overly aggressive, although there is more of it than typical on these sorts of lights. With all the cut-out details, I found the grip to be good. Lettering is bright - clear and sharp, and smaller than previous models.

There are a generous number of square-cut machinist threads (anodized for tailcap lockout). :thumbsup:

Note that like before, the switch is not an actual clicky, but a press switch. Pressing the plastic button simply pushes forward the contact plate slightly. This allows contact for momentary-on when the tailcap isn’t fully tightened (but close). When fully tightened, the tailcap is locked-on and the button has no effect (i.e. the spring is fully engaged). Scroll down to my interface section for a discussion.










This is probably the smallest 3xXM-L2 head I've seen. oo: As you would expect, reflector wells overlap a considerable amount. Coupled with the three XM-L2 cool white emitters, I would expect good output for the size (but with less throw than 1xXM-L2 lights of this size). Scroll down for beamshots and direct output measures.


















My review sample came with the latest version of Foursevens' own brand of 26650 3.7V Li-ion (blue-wrapped, as before). The rated capacity is 4000mAh.

*User Interface*

The MMU-X3 has exactly the same interface as the X10/S12 which preceded it.

The light use a pressure-style switch, not a clicky. When the tailcap is fully tightened, the light comes on and stays on. With the tailcap loosened a quarter-turn or so, you can press the switch button to activate the light in momentary mode (and release the pressure to turn off).

Mode switching between the two output modes is controlled by rapidly turning the light off and back on again within 1 sec. You can do this with either the momentary pressure switch or by twisting. If you wait longer than 1 sec before reactivating, the MMU-X3 memorizes the last mode you were in (i.e. comes back on in the last mode used next time you re-activate).

Although this is fairly straight forward, it can be annoying if you are someone who rapidly flashes your light off and back on (i.e. triggers mode switching if you do it under 1 sec). This means that momentary signaling is not possible with the light.

*Video*: 

For information on the light, including the build and user interface, please see my video overview:



Video was recorded in 720p, but YouTube typically defaults to 360p. Once the video is running, you can click on the configuration settings icon and select the higher 480p to 720p options. You can also run full-screen. 

As with all my videos, I recommend you have annotations turned on. I commonly update the commentary with additional information or clarifications before publicly releasing the video.

*PWM/Strobe*

As before, there are no strobe modes on the MMU-X3 – just Lo and Hi.

I didn't detect any sign of PWM. Like before, I believe the MMU-X3 is current-controlled.  Note that there is thermal control feature when running on Hi (scroll down for details).

*Beamshots:*

For white-wall beamshots below, all lights are on Max output on their respective 26650 or 18650 battery. Lights are 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.

Let's start with the 1x26650-class lights





























































As you would expect, the 3xXM-L2 MMU-X3 has more output than the single XM-L/XM-L2 lights 26650 lights above. The hotspot is broader and less sharply focused, due to the multiple emitters.

And now the typical 3xXM-L2 lights:





























































Overall output of the MMU-X3 is a bit lower than the typical 3xXM-L/XM-L2 light, due to the smaller build and single Li-on source here. It is also less throwy than a typical light in this class, due to the smaller reflector. But as you can also tell, it has one of the cleanest beam profiles for this group. :thumbsup:

Sorry, no outdoor beamshots – given that we are in a deep freeze here right now, and snow is not conducive to beam comparisons. 

Instead, here are some indoor shots comparing the MMU-X3 to the earlier X10 (1xXM-L) and Nitecore TM15 (3xXM-L). For your reference, the back of the couch is about 7 feet away (~2.3m) from the opening of the light, and the far wall is about 18 feet away (~5.9m). Below I am showing a couple of exposures, to allow you to better compare hotspot and spill.











*Testing Method:* 

All my output numbers are relative for my home-made light box setup, as described on my flashlightreviews.ca website. 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 devised a method for converting my lightbox relative output values (ROV) to estimated Lumens. See my How to convert Selfbuilt's Lightbox values to Lumens thread for more info. 

*Throw/Output Summary Chart:*

My summary tables are reported in a manner consistent with the ANSI FL-1 standard for flashlight testing. Please see http://www.flashlightreviews.ca/FL1.htm for a discussion, and a description of all the terms used in these tables. Effective July 2012, I have updated all my Peak Intensity/Beam Distance measures with a NIST-certified Extech EA31 lightmeter (orange highlights).






Consistent with what you saw in the beamshots, the max output and throw of the MMU-X3 is relatively low for a 3xXM-L2 class light. But of course, that is not surprising given the small head (with relatively small mass), and the single Li-ion source. And ~1700 lumens, by my estimation method, is nothing to sneeze at. :laughing:

The low mode of the MMU-X3 is reasonable, but I suspect some may like to see higher output. My lumen estimate is a bit lower than the Foursevens spec of 200 lumens.

*Output/Runtime Graphs:*

Like its predecessors, the MMU-X3 uses a thermal-sensor controlled management system for output on Hi. The best way to demonstrate this is to compare runtimes with and without cooling:






The MMU-X3 dynamically alters it max output, depending on internal temperature. This means you will get longer runtime, but at a somewhat reduced output level. 

The Foursevens runtime spec is clearly based on a non-cooled environment (as is appropriate, for everyday use). But since all my runtimes are done under a cooling fan for consistency and safety reasons, I will use that runtime for all the additional comparisons below.

Let's start with a comparison to other small lights, including the earlier X10:










There is clearly an increase in output on Hi for the MMU-X3, and improved efficiency overall, compared to the X10. There is also a runtime advantage over 1xXM-L2 lights, despite the increased capacity of 2x18650 (likely due to the 3xXM-L2 emitters on the MMU-X3 being run at lower levels to achieve the same output).

And now let's compare the MMU-X3 to other recent multi-emitter lights (high-output class):










Again, as you would expect – newer high output emitters and multi-emitters lights running on 3x or 4x 18650 will have a runtime advantage over the MMU-X3. And as already noted in the summary tables previously, max output of the MMU-X3 is lower than other 3xXM-L/XM-L2 lights (likely due to the smaller mass here).

*Potential Issues*

Pressure switch/twisty only, no clicky. Mode switching design prevents signaling (i.e. flashing the tailcap jumps between output modes) 

Beam is remarkably clean for a 3xXM-L2 light, although some minor emitter-well beam artifacts are unavoidable.

The light is not tightly regulated over its run, but uses thermal management to lower the output as necessary (which is actually a good thing, IMO). 

No primary battery option – 26650 Li-ion rechargeable only. Although in a pinch, you could use an 18650 IMR cell with something wrapped around it to create the appropriate thickness.

No wrist lanyard attachment point, and the light cannot tailstand.

*Preliminary Observations*

The physical build of the MMU-X3 is basically unchanged from earlier X10/MMU-X models. As before, I find this to be a solid little light, with a straightforward interface. 

Of course, overall output has increased over the earlier 1xXM-L models, although the MMU-X3 is not driven as hard as most 3xXM-L2 lights. It is still an impressive amount of light from such a small build: ~1700 lumens in my testing.

The beam pattern is also particularly pleasing. Most 3xXM-L/XM-L2 lights have distracting artifacts in their spillbeams, due to the overlapping reflector wells for each emitter. The MMU-X3 has one of the cleanest beam profiles I've seen. :thumbsup: Of course, the MMU-X3 is not a greater thrower per se - the 1xXM-L X10 had further throw, although it also had some artifact issues around the hotspot/corona. 

As before, the pressure switch is interesting. Since there is no clicky, there are no worries about handling the sort of current required here (i.e. the switch is just a press switch). As before, my only real complaint is the mode switching interface – whether you press-on (momentary) or screw-on (locked-on), flashing the tailcap rapidly switches modes. :shrug: I would have preferred a tactical two-stage pressure switch (i.e. Low comes on first, then Hi, as you press or screw tighter), but there may be patent issues around that. 

Output/runtime performance is very good, as usual for a current-controlled Foursevens light. Efficiency is excellent, and the 26650 Foursevens cell (4000mAh rated capacity) did very well in my testing. Regulation pattern remains the same as the earlier X10/MMU-X – there is a thermal sensor that regulates output in response to internal heat. Under typical conditions, I expect the Foursevens Hi mode output and runtime specs are accurate (although my MMU-X3 on Lo seems a little lower output and longer running than the Foursevens specs)

In terms of performance, the MMU-X3 is an impressive single-cell rechargeable light, and a nice update to the X10/MMU-X line. It is certainly a strong contender to consider in the compact/high-output class. :wave: 

----

MMU-X3 was provided by Foursevens for this review.


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## scot (Jan 11, 2014)

Wow!! Thankyou Selfbuilt. Was wondering if you'd be testing this version. I have the original X10 and it's seen quite a bit of use. Still undecided on this one though. 
I would prefer a UI that always comes on in low or high. I've noticed that my lights that get the most use are the ones that don't have mode memory.
Thanks again for your reviews, very helpful.


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## Ryp (Jan 11, 2014)

Thanks for the review!


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## xml (Jan 11, 2014)

Awesome light - thanks for the review! :thumbsup:


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## Alex1234 (Jan 12, 2014)

i have this light but not in stock form. Its a Vinh modded light. It has 3 dedomed xml2 leds and is direct driven and puts over 60k lux. My favorite light at the moment. I run it on mnke imr 26650 and it has to be around 3000 lumens. it blows my mind a light this size can put out so much light. even retains low mode after the mod


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## zs&tas (Jan 13, 2014)

good job SB :thumbsup: that is one sexy light imo, i dont really have a need for it though :-(

edit- if you have a minute  id like to see a picture of the x3 sat next to the olight M22 for a size comparison to a pretty standard sized 18650 light, looking at your hand shots this is a very compact light.


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## calamari (Jan 13, 2014)

Thanks for the review

This is one I'm interested in picking up (when they get back in stock)

Ryan


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## selfbuilt (Jan 13, 2014)

zs&tas said:


> edit- if you have a minute  id like to see a picture of the x3 sat next to the olight M22 for a size comparison to a pretty standard sized 18650 light, looking at your hand shots this is a very compact light.


I will try to remember to do that when I am back in town next week - I am currently away from my office.


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## hikingman (Jan 15, 2014)

I concur that the quality of the beam is a standout for this little light. I bought an S12 (SST-90) years back and 2 batteries. So the X3 was ready to go the minute it arrived! While I really don't care much for the interface, the trade off is simplicity and reliability, particularly when a long way from your car hiking in the dark. The low setting is more than bright enough for general use, and with Hi mode super bright for those rare moments when needed. In forest conditions that I walk in most often, it throws far enough for most situations. Being small and very light, it is one of the best hiking lights I own.

Dave


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## selfbuilt (Jan 16, 2014)

hikingman said:


> I concur that the quality of the beam is a standout for this little light. ... While I really don't care much for the interface, the trade off is simplicity and reliability, particularly when a long way from your car hiking in the dark.


Well put, I have much the same feeling for the light. I've always liked the build and size, but have never been crazy about the interface - but it is serviceable.


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## tonkem (Feb 10, 2014)

hikingman said:


> I concur that the quality of the beam is a standout for this little light. I bought an S12 (SST-90) years back and 2 batteries. So the X3 was ready to go the minute it arrived! While I really don't care much for the interface, the trade off is simplicity and reliability, particularly when a long way from your car hiking in the dark. The low setting is more than bright enough for general use, and with Hi mode super bright for those rare moments when needed. In forest conditions that I walk in most often, it throws far enough for most situations. Being small and very light, it is one of the best hiking lights I own.
> 
> Dave



Dave, which do you prefer, the S12 or the MMU-X3? Thanks for your comments.


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## ven (Feb 11, 2014)

Thank you for the excellent review selfbuilt, i really do love this little light,beautifully made and my 1st foursevens light i own(i am learning why they have such a strong following)





So cute.......next to the tm15




little size line up




Thanks again:twothumbs


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## 4sevens (Feb 11, 2014)

Ven the LED's in your look funny. Did you remove the domes or something?


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## ven (Feb 11, 2014)

4sevens said:


> Ven the LED's in your look funny. Did you remove the domes or something?



vinh- de-dome and 9.6A with the kinoko for around 3300lm ish


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## ven (Feb 11, 2014)




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## dj:litestick (Apr 1, 2014)

I really, really wanted to get this and it would have been perfect, except the UI as SB mentioned. For being advertised as a tactical light, I would have wanted it to always turn on in high mode then being able to switch to low mode with a secondary push of the push button within the couple of seconds.
All in all, very nice review by selfbuilt. Thanks again for a thorough excellent review.


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## UnderPar (Apr 2, 2014)

dj:litestick said:


> I really, really wanted to get this and it would have been perfect, except the UI as SB mentioned. For being advertised as a tactical light, I would have wanted it to always turn on in high mode then being able to switch to low mode with a secondary push of the push button within the couple of seconds.
> All in all, very nice review by selfbuilt. Thanks again for a thorough excellent review.



Plus 1 on the UI. After watching the review, I somehow changed my mind regarding this model. Was really waiting for this to be out until I saw how the interface was. But this remains an option to me considering its size and power.


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## bladesmith3 (Sep 9, 2014)

does anyone know how quickly this gets hot on high? I imagine pretty quickly. 160 lumens on low seems too low. is there a way to boost low to 400 lumens or so?


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## Swedpat (Sep 14, 2014)

bladesmith3 said:


> does anyone know how quickly this gets hot on high? I imagine pretty quickly. 160 lumens on low seems too low. is there a way to boost low to 400 lumens or so?



My experience is that this light does not become very hot at high. The mass of the head and the cooling fin design contribute to hold the temperature pretty low. Also the three emitter construction increases the efficiency and lower the temperature: instead of running one emitter to 1600lm it's more efficient to run three emitters to 533lm. 

Personally I find the low mode to be very good level. I guess it's possible to increase the low mode to 400lm, if one wants to modify it. That's beyond my knowledge, however.


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## Archangel (Oct 7, 2014)

I don't understand why the output takes a drastic hit and then recovers, instead of simply slowly scaling back as the temperature increases. Seems an odd design choice.


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## 4sevens (Oct 7, 2014)

Archangel said:


> I don't understand why the output takes a drastic hit and then recovers, instead of simply slowly scaling back as the temperature increases. Seems an odd design choice.


The output throttling using a formula to reduce the temperature.

By the time you cut back on the power tons of heat is being generated and it takes a bit of time for that heat to travel from the LED to the sensors - the distance isn't much but once the power is cut the temps actually continue to rise for bit - thats why you see that spike. In real like use you don't notice it. It's only with engineer's instruments can you detect this.


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