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Radically upgrade your sound and music experience with this 100dB HiFi Bluetooth speaker/portable audio monitor. 50 hours playtime!
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Bluetooth (4.1 LE) pairing for single and stereo FS-X speakers + battery level indicator

Posted by Frankenspiel Ltd. (Creator)
Hi Everyone!

Bluetooth pairing for single and stereo FS-X speakers + battery level indicator
We’ve spent a lot of time doing hands-on pairing and stereo pairing, testing it with an array of Bluetooth devices (e.g. Macbook, iPhone 3S, iPad Mini, HTC One, Samsung Galaxy S3, etc.).

For the tech-minded, the implementation is now based on Bluetooth 4.1 LE.

The tests showed that our system is reliable, robust, and above all extremely simple i.e. intuitive, in fact, stereo pairing is automatic and the master and slave speakers identify themselves with different LED colours.

This is how our single button works for power on/off and pairing:

Single speaker operation
1. To power on, press the button for 2 sec. 
2. When switched on, speaker will enter twin pairing mode for 10sec. Since there is only one speaker it will automatically change to single speaker pairing mode after 10 sec. 
3. Your Bluetooth device finds the FS-X, makes it discoverable (as Frankenspiel FS-X) and you can pair it to your Bluetooth device in the normal way. 
4. To power off the speaker, press the button for 3 sec. 

Stereo Speaker operation
1. To power on, press the button on both speakers for 2 sec. Note: this doesn’t have to be done simultaneously.
2. Both speakers will then enter twin pairing mode for 10sec. Note: the pairing of master and slave is fully automatic, the LED on the slave will be a constant colour, and the LED on the master, instead, will be a flashing colour.
3. If these two speakers haven't been connected, each of the speakers will change to single speaker pairing mode.
4. Your Bluetooth finds the master FS-X speaker, makes it discoverable (as Frankenspiel FS-X) and you can pair it to your Bluetooth device in the normal way. Note: the flashing LED will become constant.
5. To power off the speaker, press the button for 3 sec. Note: you only need to do this on one of the speakers and the other one will automatically switch off.

Battery level indicator/warning
Here’s a snapshot of the new battery level indicator which will appear on your phone: 

The battery indicator symbol is located next to the normal battery indicator of your phone (the example shown is on an iPhone).

In addition to this there is also an audible warning (beep) of low battery state which comes from the speaker.

We said we would also update on SPL this week, but we’ve overrun a bit on the issue.
We’ll update on that when we’ve done some more testing and can be totally sure of our data. 

Enjoy the rest of your weekend!


The Frankenspiel Team

Phil Hunnisett, Paul Clarke, and 18 more people like this update.


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    1. Missing avatar

      Dave Fowler-Timms on

      You show an image of an iOS screen showing a 2nd battery indicator for the FS-X but will Android do the same? Also will this 2nd battery indicator be the battery level for the master speaker only or the lower of the 2 speakers in the stereo pair? Thanks.

    2. Missing avatar

      Kevin Jacoby on

      same question about the test with nexus 5?

    3. Edward Wilcox on

      Did you test this with a Nexus 5?

    4. Missing avatar

      bsl100 on

      Further to my earlier comments......

      Bluetooth 4.1 enables multipoint device connectivity. You can have two devices connected simultaneously, but might require to pause or stop play from one and then let the other start playing. Bluetooth 4.1 also enables auto-reconnection as an added feature.

    5. Missing avatar

      Giles Smith on

      Thanks for the update!
      How do we know which speaker is left and which is right? Once paired, will the master and slave / L&R relationship stay the same when subsequently turned on and reconnected to the same device?

    6. Missing avatar

      bsl100 on

      Excellent update. The stereo speaker pairing was an important pending issue from the time of launch of the project. I like that its simple.

      There are some good concerns raised and as Marsha has rightly mentioned, an FAQ should address all these.

      From my understanding of the update and how other BT speakers work, I would assume that:
      1. The 10 sec time is given to ensure you put both speakers ON in this stipulated time. Its upto the two speakers to communicate and form a stereo pair.
      2. The master and slave combo normally ensures that if one goes off, the other works as an independent unit. If one does go off, you might have to repeat the process as you would for a single speaker. Its all about the hardware and
      whats written in the software, and it would be great if the single speaker (which has the battery remaining) switches to single mode automatically. I assume this would be difficult if they are planning to have one go OFF if the other is switched OFF.
      3. Unlike Airplay, in BT, if one device is paired and connected to a speaker, another already paired device cannot override the existing connection. You would generally need to disconnect one device to connect another.

    7. Kirill on

      @Andreas Hamm
      what do u think about if one looses power, the other becomes mono (maybe legs come out of it transformers style and flip it so its blasting music to the top) . or if both speakers loose connection the same thing will happen. both go into mono and if possible, move closer to each other and flip upwards

    8. Kirill on

      Love the comment @Marisha :P umm ya another thing im curious about what if my friend and i have 4 speakers could we have a surround sound effect? i know you guys are thinking about releasing a Sub in the future.
      or what about just stacking 2 speakers on or next to each other and 2 more that will function as the other sound channel, can that be equipped?. lets have an upgrade for LCD screen and stuff to make this easeyer :P

    9. Marsha Tyszler

      @ Frankenspiel, I like what I'm seeing and hearing!

      I have one suggestion, but I'm not sure whether it's possible to implement. For those of us with a pair of speakers, would it be possible to have the phone's BT connection indicator say "Frankenspiel FS-X Single" for one connected speaker and "Frankenspiel FS-X Pair" when both speakers have been connected to the phone? Or something like that? I know you have the lights to help differentiate what's connected/paired, but it'd be nice to have that visual to help confirm it as well.

      @Tom Davies, you don't have to wait a full 10 seconds. I think they just meant that you don't have to press both buttons at once since it might be difficult to press and hold both at once. So you'd press and hold the master's speaker's button, and once that's ready, you'd immediately press and hold the slave's button. My question is what happens if you don't finish connecting the slave before the master's 10 seconds are finished . . . .

      Kirill and Andreas Hamm have also asked some interesting questions. Frankenspiel is telling us the basic instructions, but what happens with the various other possibilities that could occur outside of that? I'd love to know if they've tested other scenarios and how they might be dealt with? It's probably be helpful if they made some kind of troubleshooting and FAQ's guide to help advise everyone on various other possible situations and/or problems that could arise during pairing and general use.

    10. Jay on

      I really appreciate the effort you guys are putting into making it simple and easy. Of course there are edge cases, I'm sure you'll get it right =)

    11. Missing avatar

      Tom Davies on

      Does point number 2 for single speaker configuration mean that we must wait 10 seconds before paring a single speaker?

    12. Missing avatar

      Andreas Hamm

      And to add some more concerns about the 1-button solution and synching of FS: What if the master loses its power? Will the slave be the master or will the slave turn off? And in this situation how to get them running into stereo mode without going through BT pairing again? What happens if the speakers lose the connection to each other? It's a nice effort to keep it simple, yet you should mind all those incidents, that might happen and provide a solution that does not include automatically turned off speakers or interruption of sound output.

    13. Kirill on

      *My friends speaker

    14. Kirill on

      @Frankenspiel So.. what if my frinds speaker is in range or next to my speakers? How will the BT pairing thingy know which speakers are mine lol. there should be some kind of switch? (like dip switches on dj and stage lights, or something) between the 2 speakers so it looks for the speakers whos pattern matches ones.

    15. Steven Rowe on

      Update. Support should be there it just looks different. Nice add on!!

    16. Steven Rowe on

      Does that battery symbol show on ios7 soon to be 8?