Here we see some common dispersion patterns found in HiFi Loudspeakers. Recall that the bass range is omnidirectional for all except the dipoles.
Those of you who have invested in a high fidelity musical playback system for your listening room probably already know a thing or two about the various categories of loudspeaker type. How about a quick refresher on two of our favorites, and then some discussion about why different types may work better in certain rooms than others?
Part 1: Direct Radiator Loudspeakers
These are probably the most common type of speaker, and have many upsides and a few down sides. To be clear, we are referring here to speakers in cabinets; sorry, open-baffle folks.
They can range from compact KEFs..
…to huge Status 8T’s…
…to tiny little subwoofers.
What do they all have in common? To keep it simple, the mids and highs project in a forward direction, focusing the upper frequency acoustic energy toward the listening position. As mentioned, the bass output is mostly omnidirectional, projecting equally in all directions.
What do we love about these speakers? The punchy bass delivered by a woofer in acoustic suspension is about as good as it gets. The pinpoint imaging communicated by metal, fabric, or ceramic dome tweeter is hard to beat.
But… Where Does the Sound Go?
We like to think that most of the speaker output reaches our ears. Sadly, this is far from true, even in the treble range.
Furthermore, the buildup of bass and midrange in the plane of the speaker and in the corners behind the speaker are particularly strong. As the frequency drops, the dispersion pattern spreads, and instead of moving down the room toward our listening position, the sound gets bottled up around the speakers.
How Do I Control This Beast?
Hmmm, let’s see. What sort of portable, adjustable device can we think of that we could simply set in a corner or against a wall that could reduce the energy of this bottled up sound?
What’s that you say? You also want to add some treble diffusion to control the front-to-back flutter echo and improve the room ambience?
Well, I think we know where this is going. You want some TubeTraps.