The Off-Axis Truth About Speaker Dispersion

Loudspeaker companies love throwing around impressive dispersion specs and angles in their marketing. But getting wide sound dispersion right is a lot trickier than their sales pitches may make it seem.

The hard truth is, as soon as you step away from being straight in front of a speaker, you’re hearing its off-axis performance. And no matter how pricey the speaker is, its off-axis response will always be different from what you hear head-on. Those highest frequencies absolutely beam straight out, but physics crashes the party as you move off to the sides. Think of having a conversation with someone standing to your side instead of facing you directly – their voice doesn’t reach your ears with the same clarity and projection. 

The thing is, with speakers we expect that off-axis performance to still sound great. That’s what we paid for, after all. But replicating an even, coherent soundstage from any seat in the room has been an age-old quest for sound engineers. Some have cracked the code through intense study of radiation patterns, driver integration, waveguide design, and all sorts of industry magic. 

But others fell back on fudging the numbers, getting those coveted wide dispersion stats through overly simplistic approximations and modeling. Their cone drivers might hit the right measurements on-axis, but ask those tweeters to disperse sound outwards and comb-filtering or beaming becomes impossible to tame.

Those might look great on paper, but audition them in a real room and you soon hear what’s amiss. See, a huge portion of the sound isn’t coming directly from the speaker – it’s bouncing off walls, floors, ceilings before hitting your ears. If those reflections are coming from erratic, unpredictable off-axis output, it demolishes the seamless, anchored imaging you want. That incoherent reflected sound won’t blend nicely with the direct audio reaching you.

Needless to say, the best speakers keep it consistent both on and off-axis across the full frequency range. So next time you see a shiny dispersion stat, push for the real off-axis polar maps. Those will give you an honest read on what you’ll actually hear once the speaker is pumping in your room –  top to bottom, no matter where you’re sitting. A speaker with truly uniform dispersion talents is the only way to get realistic, anchored sound everywhere you want to be. Otherwise, no amount of room treatment can properly tame the lobbed acoustics.

The off-axis dispersion performance is a crucial, yet often overlooked aspect of loudspeaker design. While marketing claims of wide dispersion look enticing on paper, the real-world listening experience hinges on achieving smooth, consistent radiation patterns across the entire frequency range – both on and off-axis.

Only then can the direct sound from the speaker correctly integrate with the reflected energy bouncing around your room. Get it right, and you’re rewarded with a lifelike, anchored soundstage no matter your listening position. Get it wrong, and you’ll hear a disjointed, diffused audio spectacle.

So push past the simplified dispersion specs and dive into those polar map measurements. They’ll expose whether a speaker genuinely serves up an enveloping, coherent performance worthy of any setup. Before making any buying decisions, it pays to remember – the truth is in that off-axis data.