This article is a repost of the two-part series originally published as Where did my music go? Signal loss.

Signal loss is causing your system to sound 30-40% less good than it could. That’s my estimate, and I think it’s conservative.

The loss begins at the source and continues through a bog of electronic parts, EMI, connectors, and cables, a long process of loss that doesn’t end with your speakers, but your room. Everything in the chain up to your ears will cause some signal loss to occur that will take you one step further from hearing the full potential of your system.

Uncontrolled, signal loss will impair all the things we love about great audio: imaging, transparency, bass, resolution, clarity, you name it. Signal loss might be the number one reason why some people are never happy with their sound and constantly feel the need to upgrade, when perhaps all that’s needed is some judicious use of signal loss prevention to make their system sing.

And that’s the good news—that there are ways to help prevent signal loss and preserve the sound quality that’ll make us keep coming back for more. And I believe that the vast majority of hi-fi systems could be optimized against signal loss to sound better by up to 30-40%.

This article outlines my surprising journey for the last 10 years, that helped me unlock the hidden potential of my hi-fi system, and will hopefully help unlock that of your system as well.

To start with, you need a great source—the one that sounds best to your ears. Using a poor source will always be a bottleneck to getting the best possible sound from your downstream components. You can’t make up for a poor source by upgrading your electronics or speakers, just like you can’t use poor quality food ingredients to make a 5-star gourmet meal. Obviously, better electronics and speakers will make your system sound better, but you’ll always be limited by your source, so always start with a great one.

Room Acoustics and Music Loss

Poor speaker placement and room acoustics will mask or degrade musical notes before they reach your ears. Muddy bass is especially toxic. It will prevent you from hearing some of the highs and mids, even though they’re in the room. Or they’ll overpower them, distorting images, details, harmonies, and musical timing.

When positioning speakers, small adjustments, even those of a few millimetres, forward or backward, can make a profound difference in how the sound is propagated. Also important is finding the right distance between the speakers. Generally, speakers need room to breathe and should be kept away from walls.

Adjusting toe-in can tame sound reflections based on the principle that the more the speakers are facing you, the more direct sound will reach your ears. I sit approximately 3 meters from my front speakers, which are toed-in 22 degrees. This gives me a big, deep soundstage, with excellent imaging. That said, every setup is different and some speakers are designed for no toe-in, so experimentation, as usual, is key.

Bad acoustics will also cause signal loss. Reflections of sound off furniture, windows or other hard surfaces will excite highs to the point of sounding shrill, a sure recipe for listening fatigue. But careful with damping. Too much will rob the life out of the music, making it sound uninspired.

The ideal situation would be that all the music coming from your speakers goes directly into your ears, as with headphones. That’s not going to happen with speakers, as the music bounces around the room first, creating a series of inter-colliding reflections. Bass is especially problematic, because not only will you hear bass directly, but again a fraction of a second later after it has bounced off the walls, floors, and ceilings, then again as it bounces around the room. This affects the timing and rhythm of the music, and reduces your ability to clearly hear the voices and instruments as they were meant to be heard.

If you want high-end rather than mid-fi sound, it’s crucial to optimize speaker placement in relation to the walls and toe-in (assuming toe-in is needed). Use bass traps to prevent secondary and tertiary reflections from bouncing around the room and muddying the sound. Room absorption panels and diffusers can further control the sound bouncing around the room, so that you can hear the music as directly as possible from the speaker drivers, with the least amount of signal loss.

I use Vicoustic extreme traps, Primacoustic absorption panels and diffusers, and some absorption panels from ATS. But if you want to experience with makeshift acoustic treatment using household products, bookcases and plants can act as diffusers, while area rugs, window coverings, wall-to-wall carpeting, and cushions can act as absorption devices. It’s also possible to build your own Helmholtz resonators to address bass issues.

Cables and Power Bars

Every cable and cable connector—a banana plug, spade, and RCA connector—will cause some signal loss and colouration to the sound, due principally to the cable’s connectors, the soldering, the design, or its materials of construction. Signal cables in close proximity to power cords are always a bad idea, as EMI is notorious for marring the bass, soundstage, mids and highs, resolution, and details.

Ethernet cables are most susceptible to the destructive effects of power cord generated EMI. Other sources of signal loss include a noisy power supply and vibrations in the electronic components.

Based on my having tried out dozens of different power cords, RCA, Ethernet, HDMI, and speaker cables, from inexpensive to top-of-the-line ones, I can say emphatically that not all cables are equal, not even those that cost the same. They certainly don’t all sound the same. Design and build quality matter. So do cable designers. Some designers are just better than others, or have better equipment at their disposal to help them design better cables.

I’ve heard extremely expensive speaker cables and other cables that cost more than some people’s whole stereo system’s electronics and speakers. While there’s no question that some expensive cables provided significant performance in sound quality, I’d be more tempted to use the money to upgrade the electronics and speakers. I’d choose mid-range cables from a manufacturer—their sweet spot in their lineup. The sweet spot are cables that provide some of the best qualities of the company’s most expensive cables, at a fraction of their cost.

Better quality cables generally use higher quality components, materials, and more effective designs than does their cheaper counterpart. They mitigate signal loss and colour the music less. They’re designed and engineered to provide a cleaner and more efficient electrical flow by minimizing the effects that can come from exposure to radio waves and EMI— not a simple matter, as cables can act as antennas.

Many people I know use cables by Blue Jeans, which are moderately priced, but these can be bettered if you’re willing to spend more money. I currently use a mix of Cardas and Shunyata cables in my system, but there are many choices available, from myriad manufacturers, that offer excellent sound quality.

The best option, if possible, is to audition different cables in your own system to see if you like them. Online retailer The Cable Company offers an extensive cable lending library that will lend you cables for two weeks to help you decide which complement your system best. The company also offers component-cable synergy advice they’ve accumulated over many years and have a try-before-you-buy programme for headphones, line conditioners, and isolation devices. You can’t go wrong with that kind of an arrangement.

EMI Mitigation

I’ve spent a lot of time exploring possible ways of reducing the effects of EMI on the sound quality of my hi-fi system. While doing this, I’ve been astonished by how much EMI affects the music.

The worst possible scenario is to have your expensive stereo plugged into a cheap power bar along with noisy electronics such as a TV, HD Box, and other video equipment, as well as network switches and switched-mode power supplies (SMPS), as all of these will pollute your system’s power source with noise that impacts musical detail.

EMI can come from a variety of sources, from inside and outside your components, including from neighbouring components, power cables, and other cables that pick up radio signals. Power supplies generate high frequency noise, especially from SMPSs.

The best products use internal EMI shielding around their power supplies or completely isolate them to block EMI from reaching the more sensitive parts on a circuit board. As I’ve mentioned elsewhere in the virtual pages of PMA, the judicious use of copper tape around the areas of a signal cable closest to a power cord, which is one of the worst emitters of EMI junk, works in maintaining the integrity of the music signal as it moves from one place to the next. Beyond shielding, EMI can be eliminated by connecting your system to an isolated, low-impedance ground, or a power conditioner designed to block EMI, such as iFi’s PowerStation, which promises to do exactly that.

I’ve also lately experimented with Synergistic Research Tranquility PODs, a product designed to reduce EMI inside an audio component, with very good results.

Speaker Crossovers And Phase Distortion

Every speaker with multiple drivers uses a frequency crossover to send the appropriate signals to the proper drivers, e.g. the bass driver, midrange driver, and tweeter. Unfortunately, all crossovers smudge the signal to some extent. The problem is two-fold. Due to air compression, the parts on an internal crossover will violently vibrate, causing signals to distort. Another issue is phase distortion, which occurs when two different speaker drivers are creating music in the same frequency range at the same time. For example, a bass driver may create musical notes from 20Hz to 340Hz with some bleed into higher frequencies above 340Hz. If the lower midrange driver creates music from 290 Hz-1200 Hz, the overlap between frequencies in the 290Hz-340Hz region and higher is creating phase distortion that muddies the music, making vocals and instruments sound less focused and lyrics harder to understand.

If you already own speakers with internal crossovers, i.e. most on the market, there’s not much you can do against phase distortion. But if you’re in the market for speakers, you can choose to buy a model that uses an outboard crossover, and as such is impervious to inner-cabinet vibrations, or one that’s designed to mitigate or even completely eradicate phase distortion. Options for the latter include speakers that are crossoverless, single-driver (or full-range) designs, such as those made by Omega or Cube, or electrostatic, panel types, such as those from Magnepan. While these speakers won’t deliver the same frequency extension as from a full-range multi-driver speaker, what you forfeit in the lowest bass or airiest highs you gain in a midrange clarity and transparency that can be intoxicating. Or, if you’re not in the mood to sacrifice too much low bass, you could opt for a horn or electrostatic model that incorporates a separate dynamic bass driver, such as the models made by MartinLogan and Avantgarde. Another option is to buy a speaker that uses a digital crossover, such as Linn’s Exakt speakers. A well-designed digital crossover can more evenly and precisely distribute frequencies among drivers and, consequently, will produce less phase distortion.

If you get a chance to compare similar models, one with and one without an internal crossover, or one with and one without phase distortion, I’m sure you’ll be surprised by how much an internal crossover and phase distortion impairs the sound.

Vibration Control

Vibration control is one of the most misunderstood aspects of stereo optimization. Many people simply can’t believe that vibrations can affect the sound of their components, especially ones with no moving mechanical parts. Sure, gear with moving mechanical parts will probably benefit most from vibration control, but I’ve heard dramatic improvements using anti-vibration devices with all sorts of electronics and speaker cabinets.

A real-world example of using vibration control to tweak performance can be found on a nuclear submarine, whose electronic equipment has to vibrate the least amount possible, both to better hear the enemy outside the vessel, and, more crucially, as far as we’re concerned, to reduce the sonic signature of the submarine—the playback system—so its superfluous sounds aren’t detected. In this sense, a playback system is no different—it should produce the least amount of superfluous sounds to avoid detection.

To begin with, our systems have to contend with three kinds of vibration: airborne, which, ultimately, originates from our speakers; structure-borne, which enters the equipment via its resting place; and self-induced, which comes from the unit itself, such as from a CD tray or transformer. In other words, our electronics and speakers vibrate due to a combination of external and internal forces, and if these aren’t addressed, they will invariably corrupt the signal and reduce the sonic fidelity of our playback systems.

Luckily, there are many effective products on the market, in the form of footers and hi-fi stands, designed to keep vibrations away from our components’ more delicate and vulnerable-to-noise parts, i.e. resistors, capacitors, transistors, chassis, and cabinets. Benefits of using them include a tightening up of the sonic image, and better focus, resolution, and transparency, along with firmer bass. I can’t stress enough the importance of having a good stand or shelf to put your equipment on, such as those made by Solid Steel, Quadraspire, Salamander, Stillpoints, Silent Runnings, and Naim, among others. You don’t have to spend an arm and a leg to get something good, but I suggest you buy a stand you can check out pre-purchase for its stability and solidity—you don’t want one that sways from side to side—and, if possible, whose shelves are decoupled from the frame so that vibrations don’t travel through the whole of the unit. You want your electronics to be as inert as possible on whatever they’re sitting.

A turntable should get special attention when it comes to vibration control to prevent vibrations from feeding back into it and being audibly magnified. Solutions include using specialized turntable platforms from specialized companies such as IsoAcoustics, or, if you want to spend less, a combination of butcher blocks and footers.

Other low-cost solutions include using silicon-rubber pads and IKEA Gunstigs. In an earlier article, I listed a variety of footers for components and speakers that I’ve had personal experience with and found effective, including IsoAcoustics Gaias, Iso-Pucks, Oreas, Nordost Sort Kones, and Synergistic Research MiGs.

The Listener and Listening Position

Once you’ve optimized your system so that it preserves the musical signal as faithfully as possible, it’s then your role to make sure the signal reaches your ear, from the speaker, as faithfully as possible. That’s why it’s important that you neither sit too far away from the speakers nor too close to the back wall, otherwise what you’ll hear most are reflections bouncing off hard surfaces. Room treatment can also be immensely helpful in keeping the sound in your room organized. It’s also generally a good idea to sit so that your ear is level with the tweeters. If the goal is to become immersed in the music, it’s always preferable to hear direct sound over reflected sound, just as it’s preferable to watch a TV show directly from the TV rather than from a reflection in a mirror.

Another good idea is to remove any sources of noise independent of the listening room, such as from a nearby fridge or heating system, that will encroach on your ability to fully enter a state of suspended disbelief. Think of that nuclear submarine. It won’t work if it’s detected.

Life is full of noise. Don’t you want to hear less of it from your system?