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Radically upgrade your sound and music experience with this 100dB HiFi Bluetooth speaker/portable audio monitor. 50 hours playtime!
1,083 backers pledged £84,768 to help bring this project to life.

Reviews Incoming / Operating Instructions

Posted by Frankenspiel Ltd. (Creator)

Hello everyone,

The backers ‘First Look’ will be sent tomorrow and we are still on target to deliver all of your units this month. They are likely to be shipped 2 to 3 weeks from now so expect to receive your units towards the end of the month.

Reviews Incoming

Along with the Backers ‘First Look’, we will also be sending out our first batch of FS-Xs for test and review.

The first to be published in the next few days will be from Andrew Everard, Audio Editor of Gramophone with over 30 years experience as a consumer journalist.

Some of you may remember Andrew, he was the very first reviewer of the original FS-X. And it was his review which inspired the name of our project: ‘Frankenspiel FS-X: the Bluetooth speaker that can!’.

Andrew reviewed the very first FS-X prototype so we thought he’d be a perfect critique who’ll likely answer the question on everyone’s lips - has the wait been worth it?

Operating Instructions

We’ve been working on the operating instructions for the FS-X, we’ve included plenty of detail and lots more information about the FS-X’s user experience, stereo mode, buttons, and a health warning!

Please read this carefully before you operate your units for maximum effect, efficiency, and safety.


Before operating for first use, it is recommended to make sure your FS-X's battery is fully or near fully charged. Use the micro USB charging cable and charge for at least one hour @ 1A.

Most laptop/computers will only charge @ 0.5A or less.

Bluetooth discovery

Pairing and switching between wireless and cabled operation are automatic with the FS-X.

To start, depress and release the button to power ON and make FS-X discoverable for your own device.

The visible sign will be that the button LED flashes red, and the audible sign is a beep "doo, dah, dah, dah, ping, ping" followed by a short pause and two more pings. The FS-X is now discoverable for your own device and the button LED is now blue.

If you wish to operate with a cable, simply insert the 3.5 jack in the socket, and the FS-X will automatically know what to do.

If instead you want to operate FS-X wirelessly, switch Bluetooth ON on your own device, where you will see FS-X single appears in the list of devices, and tell your own device to connect. On connection you will hear another fast double "ping" and you are ready to go.

Dual, enhanced Stereo mode

First, make sure both FS-Xs are off. (See Power Down)

Then depress and release the button on both FS-Xs.

You do not have to try to do this exactly simultaneously, but within 10 secs.

Each will emit the audible beep sequence and the button LED of each FS-X will change from red to blue.

At this stage if you wish to use a cable simply insert both 3.5 jacks of the Y cable, again the FS-X will automatically know what to do.

If you wish to use wireless enhanced stereo dual mode, switch Bluetooth ON on your own device, select ‘FS-X Dual Mode’, and you will hear the audible beep sequence indicating pairing is complete.

Button controls


Single quick button press. Repeat to un-mute. During mute the LED reverts to red, on un- mute it goes back to blue.

Power Up

Two button presses in rapid succession the LED flashes. From default power (each time you power ON) There are two stages of power boost.

Power Saving

Three button presses in rapid succession. From default power (each time you power ON) There is one stage of power saving.

Power Down

A prolonged button press (note, this can require several secs) LED flashes red until power off.

Behaviour of Dual Mode

The above listed controls are LOCAL meaning that they apply only to the unit itself. So, in the case of dual mode, you have to remember to adjust each unit separately.

The exception is power down. If for whatever reason either right or left speaker is powered down, the dual mode will automatically cease. The remaining unit will revert to single mode.

Note that slightly more power will be used on the master (left channel) in dual mode, this is because it has to both transmit and receive. This means battery playtime will be reduced slightly.

For this reason, wireless range will decrease when dual mode is in operation.

Also note that the battery indicator shown on your own device when connected wirelessly, is only indicating battery status for the left-master-FS-X.

Positioning your FS-X

You can place your unit(s) wherever you wish. However, for optimal results we recommend you place your FS-X on a surface in front of a wall (boundary reinforcement). This especially applies to dual mode, in this case try to ensure the left/right units are about 80 cm apart. You will find that this enhances all frequencies, but in particular it gives much more bass depth.

Setting up your FS-X for the best results

Use your free stand to try and position the FS-X against wall, if you’re using dual mode, ensure the pair are around 80 cm apart. For the best results, use a phase tester which is easily downloadable on most smartphones.

The FS-X is powerful and even at high power settings, unlike other speakers, it does not distort. This means music still sounds pleasurable even at very high volumes, which in normal circumstances would screech or squawk, making listening uncomfortable.

However, be aware that listening for prolonged periods at high SPL levels can seriously damage your hearing.

Health warning and disclaimer

The FS-X is not a low power speaker.

The FS-X gives great sound, without distortion, even at high power levels. At its highest power setting, dependent on the music playing, it's as loud as a rock concert, and prolonged listening may damage your hearing.

The factory default power setting is set at 80 dB (the limit of what's comfortable for most people for normal home listening). It can however go up to 110dB, this is similar to standing near a speaker at a rock concert. At this level it's recommended to limit exposure to no more than 30 mins.

70 dB is the normal level for listening to radio or TV

90 dB is 4 x louder, (equivalent to a power mower)

100 dB is 8 x louder, (equivalent to a jackhammer)

110 dB is 16 x louder, think of live rock music, or a car horn @ 1 M

120 dB is 32 x louder, think of a thunderclap overhead, or a chainsaw

“Do you HAVE to run your FS-X from the battery?”

No, if you so choose, you can operate the FS-X on a desktop tethered with a USB micro charging cable. Either way is ok, and absolutely fine for the battery life and performance. In this case, when the battery is full, the FS-X will only be charged when the level falls to around 90%, it will then trickle-charge back to full.

Our batteries, Li iOn polymer, are not like a niMH battery (where it remembers a charge level). With Li iOn polymer this trickle-charge back from 90% does not amount to a full cycle. In fact, one of the characteristics of this type of battery is it doesn't like to be fully discharged.

So in other words, it will not degrade the battery.

On the contrary, using the FS-X in this way, it is quite handy. If you wish to pick up your FS-X/s and go out and about, you are assured of sufficient charge and of course playtime.

Charging the FS-X

The FS-X will automatically check the voltage, if the level is low and sufficient current is available it will accept full charge (2.1A) up to 90%. After this level is reached, it will trickle-charge to full (so, fast if a current is available up to 90%, slower after that).

“What happens if charging current is lower?”

The FS-X is quite sophisticated. It will then back off and charge at lower rate, around 500 mA. If it detects a subsequent higher current it will start to raise charge rate.

Power management

There is an automatic power saving function implemented.

When no sound is detected for 15 mins, the FS-X will go into standby mode and power draw is extremely low.

Full power fastcharge time is 50 mins. Audio will run @ down to 2.9V (most batteries shutdown @ 2.8V). And the FS-X’s thermal management will ensure there is no significant heat build up.


Of course, we all have our favourite tracks, but in addition to checking these out and comparing (if you can) to other speakers you might be interested in doing the following:

1. Download an SPL METER (preferably a digital one)

With this you can verify

Loudness (@ 1M, but also check @ 2,3,4 M or more)

Dispersion, density.

Test SPL, not just at same height but also high and low.

2. Download a tone generator

With this you can test the low frequency range of the FS-X

Use this in conjunction with a digital sound meter, to see how low frequency passages in pieces of music compare in dB, mid, and treble passages.

We all look forward to hearing your feedback!

Here’s a reminder of our timeline. 


Backers ‘First Look’

Reviews (we'll share each one as soon as they're published)

Delivery of all units to backers

Your next update will be no later than a week from now, Wednesday 8th July.

All the best,

The Frankenspiel Team

Kirill, Chris Means, and 11 more people like this update.


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    1. Missing avatar

      Craig Trickett on

      They dont require a pin.

    2. Lee Gibson on

      @Creator something is missing, there should be a bluetooth pairing pin for the speakers?

    3. Missing avatar

      Alain on

      @Creators: lol @ "Testing" part of the update

      "Reviews (we'll share each one as soon as they're published)" -> Backers don't care that NOW !!

    4. Missing avatar

      Tyler Freeman on

      So of the items you said would be finished in June, are these all done?

      > Test & review of production FS-Xs by reputable blogs
      > Finalising project in Amsterdam
      > Final assembly of all FS-X units from components
      > Packaging of units and accessories in gift boxes to be sent worldwide

      I know the first item isn't complete, but what about final assembly and packaging? Have you finished these tasks or have you again missed your timeline and not bothered to say anything.

      Like last week when you said "The Backers ‘First Look’, and other units for review, are almost ready and they’ll be sent in the next few days."

      Now seven days later, you say you are sending them out 'tomorrow'. This would be fine if you bothered to acknowledge this slip and talk about what issues caused yet another delay.

      The consistent lack of frank communication from the project, even if you do deliver eventually, means I won't support any future kickstarter projects from this creator or team.

    5. Missing avatar

      Giles Smith on

      A little bit of detail at last. Still wondering how we will know which of the speakers will be the master and which will be the left or right channel when in BT mode. Am I missing something that may have been described already? Also, it would be nice to get an update on the accessories. The ones going with the first look kits did not look finished.

    6. Kirill on

      Nice guys. All its missing is a mini laser show and possibly a fog generator, maybe a cup holder. other than that, sounds good, can't wait.