· By Yerko SEPULVEDA
Hi and welcome to update #8!
Components are slowly starting to trickle in
USB charging cables are shown below:
The charging connector on BackBeat is USB-C with the other end being USB-A connectable to a standard USB port.
We've set up the maximum charging current to be 1.5A which balances charging speed and battery life.
The Voice Coils have also arrived:
These voice coils are 4.2ohms DC resistance. The class-D amp has an impedance range of 4-8ohms.
For the BackBeat system 4.2ohms provides the best balance between current draw (directly proportional to the electromagnetic force which drives the magnet), wire size, power, and battery charge life.
The springs that provide the restoring force and centering for the magnet assembly have been completed, and are being incorporated with the magnets.
The magnet assemblies themselves are almost complete (expected to be completed by the end of this week), we should have some photos to share soon.
Bluetooth module testing
As mentioned in a previous update, due to component unavailability we had to switch manufacturer for our Bluetooth module. This set us back significantly due to time taken for redesigns and testing.
As well as providing Bluetooth capability, the module serves as the microprocessor "brain" for all BackBeat operations.
We've received sample revised circuit boards with this module, and have used them for testing to prepare for mass manufacturing.
Over the last several weeks we have been testing this new Bluetooth module and are happy to say the module has passed our requirements.
As such, we immediately secured orders for the modules and have them in hand for the full circuit board production.
Again as mentioned in a previous update, we added the through 1/4" connection which provides a similar signal chain path as the original G1 BackBeat:
And just like G1, these 1/4" connections are hard-wired. So should the battery die mid-performance, your signal path remains unchanged.
So you can use your own cables or have the option to use the BackBeat-specific cable, more details in a future update.
Note: although the functionality is the same, this is a sample touchpad we received months ago and is not the final controller.
Mode Button - cycles through different modes:
1. pressing the logo turns the unit on. The initial state retains the same levels as the previous settings. This is equivalent to taping the G1 knobs in place that we have seen some folk use!
2. battery mode - green LED blinks showing current battery state of charge, which in the video shows about ~90%.
3. pad setting. No green LEDs means no pad (used for setting input levels for passive and active basses).
4. Signal Input. Bass input thump strength, indicated by green LEDs from mute to max (LEDs from video indicate approx. 20% power).
5. Input Headphone. Bass signal headphone volume, indicated by green LEDs from mute to max (LEDs from video indicate approx. 30% volume).
6. Auxiliary Input. Aux input thump strength, indicated by green LEDs from mute to max (LEDs from video indicate approx. 10% power).
7. Aux Headphone. Aux input headphone volume, indicated by green LEDs from mute to max (LEDs from video indicate approx. 80% volume).
With these controls you can see that a big improvement over G1 is being able to individually mix the Auxiliary input, whether it be the rumble or the headphone output.
Here's another video demonstrating the step control for the rumble and headphone output:
For those interested, here's the block diagram showing the main circuit board components and signal paths:
All the major blocks and interconnecting signal blocks have been proven out as functional with the new Bluetooth module/microprocessor.
We have some small details to iron out but as you can see from the videos, the firmware is mostly completed. Details include adjusting dB steps for each button push, plus setting maximum dB for the thump and headphone volume.
Thats it for now! We're still expecting to start shipping in October. Thank you for your patience, and as always if you have any specific questions, you can email us directly at firstname.lastname@example.org.
From the Low End