Cypress Hill, Brixton Academy, London

It's been nearly two decades since their debut record, and Cypress Hill long ago cemented their reputation as one of the best-loved rap groups, even if their output since the turn of the millennium has been inconsistent at best.

In April the Los Angeles band released their eighth studio album, and first in six years, but tonight's show is an exercise in nostalgia. Fair enough – their self-titled debut, and follow-ups Black Sunday and Cypress Hill III: Temples of Boom, remain landmark LPs, and a blistering opening barrage takes heavily from them, with tracks including "Hand on the Pump", "How I Could Just Kill a Man" and "When the Shit Goes Down".

It is not just the music that is taking people back though – clouds of smoke are already rising above the crowd before the band take to the stage. It could only be a Cypress Hill show when such flagrant flouting of the smoking ban is taking place. It follows then that perhaps the biggest roar of the night comes when B-Real holds a suspiciously large roll-up above his head and "I Wanna Get High" – just one of their many paeons to marijuana – begins.

Yet it quickly becomes clear that, despite the energy coming from B-Real and Sen Dog, the PA is struggling to keep up with them; the beats frequently get lost in the mix and there are also problems with feedback. It is something of a surprise for a venue such as Brixton Academy, especially since the set-up (the two MCs mainly only have percussionist Eric Bobo and Julio G on the decks on the stage with them) is hardly complicated.

Still, the band don't seem too fazed, and although it is disappointing not to be able to appreciate B-Real's unique nasal rapping properly, during the gig's best moments – such as "Insane in the Brain" and "Pigs" – the crowd is more than happy to step in whenever the sound is found wanting. Not the most polished concert then, but a lot of fun nonetheless.