I don’t think that button combo is LFM Mode. Afaik it’s factory reset. The Go 3 would have been better if JBL allowed the feedback tone to be disabled/enabled by using a quick button combo or even through the JBL Portable App. Sadly they do not which makes this model very disappointing for me personally.
@larieespiloy2828 Bro LFM (Low Frequency Mode) is a mode which is used by developers to test speaker's capability where all the frequencies are boosted to full level ... As my message said that it won't increase bass but no it does increase bass as well as treble but if we use LFM for long time our speaker's driver ruin
