The other thing that attracted me to this particular review item was that it's made by Omaker, whose mammoth power bank I was so impressed by back in January and which I've continued to use ever since. The M4 is another terrific piece of design, essentially a meaty mono speaker mounted in a ruggedised plastic enclosure, clamped to be 'splash proof' (of which more later), with buttons sealed and ports behind a rubberised flap, and with a rubber membrane behind the main grille, protecting the speaker cone itself from spills and drenchings.
The M4 is also surprisingly light considering the sound output, which is significant, perhaps because of the use of light plastic rather than metal in the construction. On top sit the four main control buttons, sealed into the plastic:
- Call pickup/hang-up
- Next track/Volume-up
- Previous track/Volume-down
The last two buttons are a little controversial, since changing the volume requires a long press in each case, but it's a fair compromise. In the shower, for example, you're more likely to want to change the music track than fine tune the volume. And away from the shower, it's easy enough to apply volume changes via the smartphone - the actual volume emerging from the speaker is a product of both the volume setting on the phone and on the speaker, so you'll have to adjust both in order to get maximum sound output.
Pairing a smartphone is trivial with NFC, just tap the phone to the back of the speaker for a couple of seconds and 'Do you wish to pair' pops up on the phone screen. Done. Phones without NFC can still play, of course, pairing in the usual 'discovery' mode. Music can then be played immediately and the quality is terrific as long as the Omaker M4 is kept dry.
Dry? Eh? Surely this is a waterproof speaker? Well, yes, but physics gets in the way a little here, as you might imagine. Despite only being branded as 'splash proof', you can in fact submerge the M4 for short periods, as long as you've pushed home the flap over the electronic ports. But water's not a great conductor of sound, so if the speaker is underwater you'll naturally not hear much!
More sensibly, using it in the shower for vigorous morning rock(!), water drops tend to accumulate in the small gaps in the front grille and block the treble frequencies, making the speaker sound 'woolly'. Drying the grille off with a towel instantly restores the gaps and frequencies - though why the grille wasn't designed with a larger protective grid is something of a mystery. Surely a much coarser front grille (as in rock music speaker cabinets) would have been less subject to water drop blockage and could still have been almost as protective? Maybe the answer lies in a 'beach' use case, since the current grille looks small enough to keep (most?) sand particles out. Testing needed during the summer, I think...!
Playback time on a charge was about 8 hours, less than that specified but then I did tend to drive the cone quite hard - if you're gonna have a Bluetooth speaker for louder music then you might as well 'pump up the volume'!
Not shown in the photos but very handy are a waterproof lanyard (to hang the speaker from a shower rail, for example) and a 3.5mm male-to-male lead for plugging in other audio sources that may not use Bluetooth.
All in all, a flexible, rugged and high quality accessory that's very good value at £22 or so currently on Amazon UK.