To appreciate how each component in your setup—plus your room itself—greatly affects sound quality, let's walk through a loose hierarchy of what impacts quality. This isn't an exact science, so don't take the order too seriously.
Again, this is just my best stab at a hierarchy—don’t take it too seriously.
Let’s start with my personal rules for speaker setup.
For floorstanding loudspeakers, I often read (and have personally experienced) that an ideal room size is around 17ft wide x 10ft tall x 23ft long (5m x 3m x 7m), but this is not critical. It’s just a good starting point.
For rooms smaller than this, you should consider buying smaller floorstanding speakers or switch to bookshelves and mounting them on stands.
For rooms larger than this—say, 32ft x 20ft (9.5m x 6m)—buy larger, full-range floorstanding speakers. Ideally they’re at least around 5ft tall (1.5m), but there’s no hard rule. The bigger the better to get sufficient soundstaging and unstrained loud volume.
For floorstanding speakers to reach their full dynamic potential, use vibration isolation underneath them. By decoupling speakers from the mass of the floor, sound clarity and bass grip are noticeably increased—as reported by even the most skeptical hifi reviewers: video, video (notoriously skeptical of audiophile snake oil), video, article, article, article.
Why does this work? Sound traveling through a dense medium (the floor) arrives faster than sound traveling through the air, so floor coupling creates sound phase problems. Further, vibrations rattle furniture in your room, increasing the room's noise floor and decreasing the perception of dynamic range. Plus a shaking speaker will produce a less accurate soundstage.
The speaker manufacturer's included feet often do nothing except secure speakers into carpet. They're not adequate vibration isolation. So, third-party accessories are needed. Many people use the IsoAcoustics products. They work well (shown here), and you can read through their patent here. A potential upgrade is EVP (article, article, video), which appear to work better according to their research (scroll down their page).
Tweeters are more vertically directional than the other drivers in a speaker and are the most sensitive to height relative to your seating position. In short, they should usually be parallel with your ears.
If you’re using bookshelf speakers, raise them with stands. If you have floorstanding speakers, use the provided foot spikes to tilt the speaker slightly forward if necessary and if safe to do so. Or just switch to a taller chair.
Avoid placing furniture next to speakers. They may absorb side and rear sound waves, which can collapse the soundstage and produce other acoustic effects. Similarly, if your electronics are on a rack between your speakers, try to place them closer to the ground so they’re below the lowest driver on the speaker. Although admittedly this is a micro-optimization.
Even the best and biggest speakers can benefit from added subwoofers. It's why the high-end brands still make them. By placing two extra bass drivers in your room's corners, you can smooth out the bass response throughout the room. This is worth considering if you're aiming for a wide acoustic sweet spot for multiple listeners (think home theaters).
Listen for thick, bloated bass. That's wrong. The notes within proper bass sound distinct—like the rest of the frequency range. It's not supposed to sound like a low drone underlying the music.
Further, bass is more enjoyable when you have extra woofers vertically stacked up to ear height. It becomes more immersive—particularly for cinema. Because even though bass waves are omnidirectional, our ears are still sensitive to the location those waves are projected from.
The universally respected high-end bass company is Rel. You can match their units with any high-end speaker brand.
Direct sound from the speakers accounts for only 12% of the sound that reaches your ears at your seated position. The rest is room reflections. That means your room plays a huge part in how your system sounds, and it is absolutely critical that you treat it properly. This is not optional. I cover this topic later on this page.
If you don’t adhere to a speaker positioning process such as this—and just place your speakers wherever they look good—your speakers will sound much worse and your money will be wasted. Don’t be lazy with placement.
If your speaker manufacturer provides specific instructions for placement, feel free to follow those. Otherwise, the following process is a great place to start.
Start by placing your speakers alongside the longer wall of your room—assuming your room is rectangular. This can produce less indirect (reverb) sound at the seated listening position due to the speakers' greater distance from the side walls. This can improve soundstage and tone. The hifi stores I've visited prefer this orientation whenever they can use it.
Here's how we'll initially set up speakers before optimizing their position:
Next, we optimize from here. That was just our starting position. To optimize, choose a song that's repetitive and play it on repeat while you run the following process. I use Never Gonna Let You Go.
Repeat this optimization process as many times as necessary with even smaller increments until you find your favorite position. If you want to be super accurate, you can use a laser meter (discussion). For instance, identical toe-in across speakers helps maximize soundstaging. (You can align toe-in by matching the distance from the wall behind the speakers to the outer rear corners of the speaker.)
Ultimately, this process might not work for you. Especially if it greatly contradicts your speaker manufacturer's own recommendations. So if you don't like how your speakers sound after this process or your manufacturer's, consider restarting using one of these alternative methods:
Don't place bookshelf speakers on bookshelves—or any other furniture. You must mount them on stands (see if your speaker manufacturer sells stands or buy from a third-party on Crutchfield).
Once mounted, follow the same instructions detailed in the previous section for floorstanding speakers.
Allow components, such as your source and amplifier, to ventilate by not stacking them directly on top of one other. Overheating can affect performance and electronics longevity. Use racks or place components side by side.
If your room is an echo-y mess—clap your hands to hear the echo—your speakers will sound worse than they could and should. (That said, some rooms won't need additional treatment if there's a lot of furniture near the walls with variable depth.)
Acoustic treatment is necessary to avoid reflected sound waves on your side walls from interacting with—by canceling or strengthening—the direct sound waves from the speakers. This effect, when completely untamed, often makes sound considerably worse.
Acoustically treating a room entails placing paneling on your walls (and potentially ceiling) to dampen sound reflections. Paneling dispurses soundwaves so they do not reflect uniformly into each other. When they do, they cause dips and peaks in volume at different frequencies. This makes music sound worse.
It’s typically most important to treat the wall behind the speakers and your side walls. You don’t have to treat your floor, ceiling, and the wall behind you. In fact, you don’t want to over-treat a room, otherwise it deadens the sound and removes the concert-like liveliness ambience that helps music come alive.
Below are room treatment steps to consider. The goal is to maximize how in focus and clear music sounds at your listening position—across low to high frequencies.
Place diffusion panels on the side walls between your speakers and your listening position. Use the mirror trick to identify placement:
If you don’t want to hang these, bookshelves or open cabinets are a lesser but often acceptable alternative. (You just want a lot of varying 3D texture on the walls.)
Next up in importance is placing bass traps in the two corners nearest the speakers. Bass traps absorb bass, which requires thicker materials like those pictured below. Without these, you'll have non-linear bass throughout the room, resulting in high variance in bass quality depending on where you're seated. In some places, it'll sound muted and in others it'll sound too overpowering.
You can buy bass traps here.
The wall behind your speakers doesn't necessarily need acoustic treatment. Sometimes it sounds better when it's acoustically reflective—creating a greater sense of liveliness and spaciousness. But it's worth trying and deciding on your preference.
Similar to front wall acoustic treatment, your mileage will vary. But it's absolutely worth testing.
With dipole (e.g. Magnepan) speakers in particular, you might not hear much benefit from ceiling treatment as they don't project much sound upward or downward. But most other (cone) speakers do, and that does have an effect on the sound.