Thought that the equalization is done in analog, utilizing these 8 opamps thatĪre on the board. Is how they achieve that impressive bass – there is built-in equalization. Input-to-amplifier-output frequency response of this speaker is not flat. Tuned to 65-71 Hz (the value I get depends on amplitude, not sure why).
From this value, IĬan suggest a replacement driver – a very comparable one can be extracted fromīlitzwolf BW-3 bluetooth speaker. Is obviously there to push some bass from a small enclosure. It’s an incredibly powerful motor for this small a speaker, which DC resistance is 3.52 Ω, so it’s 1.6 N rms thrust at 1 W Measured their motor performance (BxL), got 3.0 newtons of thrust per amp ofĬurrent. But, it has full schematics, they are reasonably similar,Īnd will help you trace out the pcb should you want to. I suspect, they are used as signal levelĭetectors, to control the amp power supply. Is connected through a mosfet, and a bunch of other stuff.īunch of opamps, with unclear purpose. Is provided by a 3.3V LDO straight from Li-ion, and main power for peripherals So, JBL Flip 4 can beĬonsidered as a nice board that can be easily hacked into a high powerĪmplifier powered by a single Li-ion cell.Ĭan work as 5V boost converter, but this functionality is unused.
Potentially give this amplifier quite a power boost. If that is the chip, it can go up to 22 V, and can The chip looks very similarīy Monolithic Power Systems. Probably MP9428 (says MPHM9428 on the IC itself). Probably for improving battery life at low loudness. The voltage is dynamically adjusted to match for signal level, It’s a fairly powerful stereo class-D amp, capable of up to 15W per channel.Īmp is powered from a boost converter, that converts single Li-ion cell voltage Makes me wonder what is it being used for.įrom TI. There is very little communication going on,
I haven’t found a full datasheet for theĬhip yet, it’s all horribly proprietary =(ġ5MB SPI flash on BT subboard. Subboard, based on CSR8675 specialized SoC by Qualcomm. These are not connectors, you can’t undo them. Gotcha: it looks like the speakers are connected to PCB with connectors, but
Drivers from older revisions of Flip 4 seem to be Larger ones that hold the drivers will probably make it all With a freshly undone screw that I’ve failed to catch, and we have dents in the Has drivers with inverted aluminium domes. Just YouTube it if you’re having trouble.