10 Audio Myths Debunked For Better Sound
Audioholics is famous for deflating audio myths whether they be sham acoustic ideas, snake-oil audio cable, illogical loudspeaker design, or pseudoscience in the electronics realm. It is one of the reasons why I came to be such a big fan of the site and its community, and I’d like to think Audioholics’ agenda of injecting more objectivity in audio has had an effect on the business at large, although it’s difficult to assess how much exactly. Bad ideas in audio are still a force to be reckoned with, and at times, Audioholics seems like merely a lonely island of rationality in a vast ocean of nonsense. The battle against balderdash is an eternal struggle. Here are ten audio ideas that seem to persist without any solid grounding, and so we will attempt to set the record straight to help thwart their persistence.
1. Myth: "Center speakers should be from the same product line as the left and right speakers to ensure a tonal match." The reasoning behind this is that having a center speaker from a different product line will not be timbre-matched with the front left/right speaker, and that will create a schizophrenic soundstage as panning sounds change tonality across the front speakers.
Truth: Often the center speaker will be very different due to using a fundamentally different design and cannot be a tonal match. Most centers are merely an aesthetic match with the rest of the front stage, not an acoustic match. The problem is that so many center speakers use an MTM design, which we have often written about (some examples: Vertical vs. Horizontal Center Speaker Designs, Center Speaker Design Alternate Perspective, and Center Speaker Design Additional Considerations). For whatever strengths or shortcomings this design type has, one thing it will not do is match any normal front left/right speaker. The reason is that the off-axis response is radically different on both the vertical and horizontal axis. Much of the sound that you hear from your system does not come directly from the speakers but is acoustic reflections from room surfaces. This being the case, in order for speakers to sound the same in-room, they have to have similar acoustic behavior at all angles, not just for the single direction facing forward. Many center speakers just don’t do this at all within their speaker line.
If you want the sound of a center speaker to be a true match that of your left and right speakers, look for similar behavior in measurement performance, both on and off-axis. Many manufacturers will have more luck getting a matching sound with a three-way center than a two-way center (although there are exceptions). The reviews here at Audioholics can often examine the center speaker from a product line as well as the left/right pair, so our reviews can be a good guide as to whether the center is a good match for the fronts.
2. Myth: "Toe-in makes speakers sound better." The reasoning for this myth is that it can often be true. Many speakers are engineered to have the fullest sound projected out at the on-axis angle, i.e., dead ahead.
Truth: it depends on the speaker and the preferences of the listener. Don't blithely assume that the on-axis response is the best. There are many instances where it is not, and the speaker is intended to be listened to at an angle. As many loudspeaker manufacturers know, most people don’t set their speakers up to be facing them directly, and the manufacturers can design their speakers accordingly. Here at Audioholics, we have reviewed many speakers where the most neutral response didn’t occur on-axis but rather at an angle maybe fifteen to thirty degrees off-axis. This is about the angle where a listener would be in the ‘sweet spot’ between the speakers if they facing straight ahead in a parallel direction - much like how many people set up their systems. If you want to be sure about the best angle to toe in the speaker, examine the off-axis measurements taken in third-party reviews such as Audioholics. Our reviews often make a note of what angle holds the most neutral response, so you can use that information to position the speakers accordingly if you are after the most accurate sound.
In speaker positioning, there is also the matter of personal preference in sound signature. Loudspeakers normally have the highest treble response in the on-axis angle. That means if you like a more detailed or more forward, aggressive sound, you will probably want to position the speaker to face you directly. However, if you are after a more relaxed, warmer sound, you might position the speakers to face outward more thereby placing the listening position at an off-axis angle. There are also cases where the speaker is meant to have a very aggressive toe-in such that the intersecting angle of the tweeters occurs in front of the listener; some narrower dispersion speakers were designed with this in mind (for those who want details about that, Audioholics has an in-depth Livestream discussion of that in: Finding the Loudspeaker Sweet Spot). Simply changing the angle of the speaker can have a major effect on the tonality and soundstage, but you can’t really know for sure what the best angle is for you until you have experimented with the speakers to find it.
3. Myth: "Music bass requires a good subwoofer since it is complex and demanding but not so much for movie bass which is just effects noise." The reasoning behind this is that somehow music is more finely recorded or mixed sound than film or television. Advocates of this myth say that audio enthusiasts need a “hi-fi” sub for music and that the performance standards for film/television content for subwoofers is lower.
Truth: Music bass is usually very clean and simple compared to the sound effects bass from film and television soundtracks. This is true in both the spectral composition of the sound as well as temporal behavior. You are far more likely to discern the difference between subwoofers in movie content rather than music content. The plucks of an upright bass is a relatively simple waveform compared to the sound of a space shuttle launch or an earthquake. A recorded musical note is comprised of the fundamental frequency and its various harmonics. It is a relatively tidy sound compared to the far more complex noises of everyday life - and that is why we like it. It is a clean sound that is easy to comprehend. It is not a challenge for any halfway decent subwoofer to reproduce accurately.
On the occasions where I have run A/B comparisons of some of the subwoofers I have reviewed, music content was never where differences were clear. However, switching back and forth in a demanding movie scene really separated the sound and ability of one subwoofer from the other. It might be argued that it doesn’t matter so much that movie sound effects are reproduced accurately since the sound of robot battles or supervolcano eruptions aren’t noises anyone is familiar with. However, if you want a high-fidelity sound system, that implies the system must accurately reproduce content, regardless of what that content is. A subwoofer that can reproduce film sound mixes accurately will have no problem with the vast majority of recorded music.
4. Myth: "Subwoofers have to pressurize an entire room in order to get a good bass response at the listening position." The reasoning behind this is something like in order to get an even low-frequency response and adequate headroom at the listening positions in a typical room, the entire room has to be pressurized as though it were a balloon. So a large room needs an enormous amount of low-frequency displacement for bass to be good at the listening position.
Truth: Aside from the misuse of the word “pressurize,” it is very possible to get a good response as well as good headroom at the listening position without worrying about the volumetric space of the entire room. First of all, the word pressurize is being misused here, and we see it a lot in social media discussions of subwoofers. Sound pressure waves are not like atmospheric pressure, and we think that the mistake many people make is conflating the two. Sound pressure waves are compression waves that radiate or from an object interacting with some medium (usually that is air for us, but if you were diving in the ocean, it would be water). Atmospheric pressure is the uniform, ambient force on everything in a space due to the motion of the atoms that compose the air. These are very different physical forces. Sound waves can reflect, absorb, scatter, diffract, and refract, and are far more dynamic in behavior than atmospheric pressure (for the purposes of this discussion). Atmospheric pressure is constant everywhere (again, for the purpose of this discussion), whereas sound pressure waves diminish in energy with distance.
There is one slightly similar behavior between the two that may have caused this misunderstanding, and that is how sound pressure waves can build up when confined in a small space. Atmospheric pressure also increases in energy when you force a lot of gas or fluid into a small space. However, an important difference is that compression waves that interact within a confined space can have a relatively uneven behavior, where atmospheric pressure is very predictable and ordered (when looked at in a statistical sense). This key difference is why we at Audioholics advocate for a multi-sub system. We want the sound pressure waves’ unevenness to be randomized out so that it is more uniform like that of atmospheric pressure. However, it is still operating in a fundamentally different physical principle.
Having dealt with the misuse of the word “pressurize,” do you need to have the entire room energized with low-frequency sound pressure levels just to get a good bass sound at the listening position? The answer is no. Another reason that this myth persists is that many people are often forced to place the subs against a wall or in a corner that may be as far from the listening position as possible. If that is the standard practice in placement, then yes, you do need output sufficient to charge the entire room with as much SPL capability as you would have in the listening position. However, it doesn’t have to be this way. The further you place the sub away from you, the more powerful it needs to be to hit you with loud bass, but it doesn’t need to be as powerful to achieve the same loudness as you move closer to it.
So as far as dynamic range goes, all you need to have is sufficient proximity from the subwoofer. You might not need multiple 18” subwoofers each with multi-kilowatt amplifiers to give you chest-slamming bass in a large room. It may be that all you need is one 12” sub with a near-field placement to achieve the same effect. You can experience the same SPL while using a lot less energy. What is more is that it is far less likely to be a nuisance to other household occupants or neighbors, since the total level of low-frequency energy being produced by the system is a lot less. The idea that you need a monster subwoofer system to charge the entire room with loud bass just to have a good sound at the listening position should come to an end.
5. Myth: “Home theaters should be capable of THX Reference Levels in order to be good." The reasoning for this myth is that since many commercial theaters target THX Reference levels for loudness, this is what should be used for a quality home system. If your system cannot reproduce THX Reference levels, then it cannot deliver a true movie-going experience.
Truth: THX Reference Level capability is much louder than most people would want to listen to for the duration of a movie. We often see home theater enthusiasts advising that home audio systems should be capable of THX Reference Level loudness, which is 85dB average with 105dB maximum for main speakers and 105dB nominal with 115dB peaks for low-frequency effects. For a home theater, this is overkill and is too loud to be enjoyable for many people. The reason for this is that when those reference levels were established, commercial theaters didn’t have as much sound control over their environments. The sound system had to be loud enough so that HVAC, talkative audiences, and other environmental noises would not mask dialogue or other important elements of the soundtrack. These levels were set for very large rooms too, so the loudness and acoustics of the entire space had to be considered. The factors that determined these average and maximum loudness levels are not as relevant for home audio as they are for commercial cinemas.
It should also be noted that THX Reference Level is what the sound engineers intended for the film to sound like at that loudness level as a reference point, not as a regular listening level. They are trying to maximize the dynamic range of the sound mix for systems that have that capability so that the presentation is experienced the same no matter where the content is reproduced so long as the sound system is THX certified. It is not like playing the movie at a lower loudness level will miss something. It is merely a way of ensuring qualitative consistency for a certain loudness level. That loudness level happens to be well over what most people are comfortable with for a home audio setup.
The ATSC recommends that the reference level be 85dB but in rooms of over 20,000 cubic feet, a much larger room than we see in an average home. However, for more typical domestic spaces, the recommended reference level goes down (see table 10.2 in this ATSC guide). For rooms of 10,000 to 20,000 cubic feet, the reference level is 82dB. For rooms of 5,000 cubic feet to 10,000 cubic feet, the recommended reference level is 80dB, and that is probably the size of most home theaters. From 1,500 cubic feet to 5,000 cubic feet, the reference level is 78dB, and below 1,500 cubic feet, it’s 76dB. My guess is that for everyday listening, most people set their audio system so that the average loudness level is 70 to 75dB. Keep in mind that 75dB is about how loud a normal vacuum cleaner is, but part of what makes it annoying is that it is a constant sound. Nonetheless, it is very easy to hear.
The equipment demands of THX Reference Level capability is pretty stout. It takes a lot of money and also some large loudspeakers with serious energy demands. It is not a performance goal that should be advised lightly, especially since few people would ever watch a full-length feature film at that level. If you are setting up a sound system, it probably isn’t worth trying to replicate the sound levels of your local THX-certified IMAX cinema unless you are sure you want an extremely loud sound system. On the other hand, it doesn’t hurt to have a system like that if you have the resources and space for it, even if you never use it. There is a saying in firearms that is true in the audio hobby as well: “it’s better to have it and not need it than to need it and not have it.”
6. Myth: “Any acoustic treatments necessarily improve the sound." The reasoning for this is that acoustic treatments often do improve the sound (when deployed intelligently).
Truth: You can’t throw up acoustic treatments just anywhere and expect an improvement in sound. Acoustic treatments are made to address specific problems. If you want to use acoustic treatments to improve the sound, you have to know what elements of sound that could actually be improved through treatments. Otherwise, you may be throwing money away on nothing, and in some cases, you could be making the sound worse. An example of making the sound worse is over-treating side-wall reflections in cases where they can be beneficial. For two-channel systems, certain types of recordings benefit from early reflections, especially recordings that are naturally heard in large spaces like concert halls. You do not want the acoustic space of your room to be too dry for the reproduction of that kind of content. On the other hand, dedicated home theater environments benefit from a less lively room, but you should be looking at reducing the RT60 decay times in a uniform manner (RT60 is defined as the measure of the time after the sound source ends that it takes for the sound pressure level to reduce by 60 dB). That means placing acoustic absorbers in specific locations that should be determined by in-room measurements. Simply throwing up absorbers at convenient locations is not necessarily going to help. However, the nature of the treatment you should use should depend on your goals, room particulars, and personal preferences.
If you are looking into using acoustic treatments to improve your system sound, you need to do your homework since it is not a simple subject (or you can just hire an acoustician). Audioholics contains some great starting points for research into this subjects, and a few good articles toward this and is “Room Reflections and Human Adaptation for Small Room Acoustics,” “Early Reflections and Bass for Small Room Acoustics,” and “Early Reflections in Home Theater Rooms: Beneficial or Detrimental?” Our YouTube channel also has a handful of good videos that cover this subject such as “The Acoustics of Studio Versus Domestic Listening Spaces,” “Optimizing Small Room Acoustics,” and “Room Acoustics for Home Theater: How to Treat?” Acoustically treating your room can pay dividends in sound reproduction. However, those dividends will not come to those who don’t implement those treatments thoughtfully.
7. Myth: "Sealed subs are faster/tighter/more accurate than ported subs." The reasoning behind this is that low-end ported subwoofers really can have audible artifacts that make them sound muddy or sloppy.
Truth: The idea that sealed subs somehow have better time-domain behavior was born from over-generalizing from poorly-performing ported subwoofers. Many people’s first subwoofers were entry-level models. They were built to be extremely low-cost and so their performance was greatly compromised. They had to wring as much performance from a small and cheap enclosure as possible, and that means using a ported design. That also necessitated the port-tuning frequency to be at a relatively high frequency since tuning it to a low frequency would leave the sub with very little output considering the size and parts limitations they had to deal with. The problem with that is that port output does have a cycle of delay with respect to the woofer. For a ported sub with an extremely low tuning frequency like a high-end home theater subwoofer, that isn’t a problem since that delayed sound occurs in a frequency region that is barely audible to begin with and where human hearing is very insensitive. However, human hearing is much more sensitive in lower mid-bass which is where many cheap ported subs will be tuned at, and so the time-domain problems of porting at such a high frequency are audible.
The fact is that in real-world use, a well-engineered ported sub has no significant time-domain disadvantage against a sealed subwoofer with respect to human hearing. In fact, for those who tout the accuracy of a sealed sub versus ported designs, all things being equal, a sealed sub can have audible problems that are alleviated by ports. A port can offer two to four times as much output at port-tuned frequencies, all while keeping the driver in a comfortable zone of operation and therefore low nonlinear distortion. However, for a sealed sub, the driver has to quadruple excursion to maintain the same SPL for every octave lower it is asked to play. That means that not only is the ported subwoofer able to play much more loudly in port-generated frequencies, it is also playing much more cleanly for the same SPL. The audibility of nonlinear distortion is going to be much greater than group delay from ports at low frequencies. What’s more, many sealed subs will have equalized response that hikes up the group delay to similar levels seen in ported subwoofers.
If you want to know how accurate a subwoofer really is, you have to ignore the design type and look at measurements. You can’t just look at one measurement either; you have to look at a multitude to get an overall picture of the subwoofer’s performance. You need to look at the frequency response to see tonality. You need to look at how the response changes with output level to see the dynamic range. You need to look at group delay to see time-domain behavior. You need to look at how nonlinear distortion scales with output to see how clean the subwoofer can stay under pressure. Rarely will you get all that information from a manufacturer, but you can get it from in-depth third-party reviews such as the ones we publish at Audioholics.
8. Myth: “Room correction auto-EQ necessarily makes the sound better." The reasoning behind this is something like the auto-EQ algorithm can compensate for problems in room acoustics, and since few people can afford to acoustically treat their room properly, auto-EQ correction can seemingly make a "big" improvement. It has also been argued that auto-EQ correction can compensate for problems in loudspeakers, so don’t worry if your speakers are flawed because auto-EQ will "fix it".
Truth: Auto-EQ systems are far from perfect and can easily make a system sound worse. One of the major mistakes that many audio enthusiasts make today is thinking that auto-EQ systems can fully compensate for room acoustics. The reality is that they can only partially compensate for room acoustics but almost entirely in low frequencies. However, the people who believe that these auto-EQ systems can do more can be forgiven for thinking this because many of these EQ systems have the phrase “room correction” attached to them. Auto-EQ systems such as Audyssey, Dirac, and Anthem’s ARC, can’t compensate for poor acoustic conditions outside of low frequencies, and they have fairly significant limitations even in low frequencies. If poor acoustics are adversely affecting the sound, the only way to address that is to physically alter the room, at least for the frequency range above the modal region of the room which is usually between 300Hz and 500Hz. Auto-EQ systems can NOT add or remove acoustic reflections or change reverberation time.
As for auto-EQ being able to fix subpar loudspeakers, that is not usually the case. The only errors in a loudspeaker that auto-EQ can fix are resonances that affect output at all angles. However, many loudspeakers have problematic sound that occurs at some angles from the speaker but not all; these are called directivity errors. Not only are auto-EQ systems incapable of correcting these, but they can also actually make the sound worse. This is because most auto-EQ systems cannot discriminate between direct sound from loudspeaker from its reflected sound.
What is more is that the target response that auto-EQ systems aim for can be inappropriate for your room or your speakers, so even if it yields a response close to its target curve, that still may have degraded the sound since it wasn’t right for that room and/or system. Human hearing adjusts to many acoustical properties of its environment so that it can discern a natural sound source within it, and the room response of a sound source will change depending on the room size and level of absorption. Auto-EQ ignores all of that. It assumes that your room and your speakers should behave one way and adjusts the response accordingly. This can make the sound too bright in a large room or too dull in a small room.
Furthermore, auto-EQ systems depend on a chain of processes to work correctly in order to function well at all, but there are a lot of things that can go wrong that most people don’t realize. First of all, some EQ systems are better than others, meaning that some EQ systems are so flawed that they should probably be avoided even in the best of circumstances. Secondly, the components have to work correctly, specifically the microphone. How well does that cheap microphone work that came with your entry-level AVR? What do you think the manufacturing error tolerances are in something like that? Third, the user has to take care in running the calibration routine correctly. That means carefully following the instructions to achieve optimal results. It takes time to do and is tedious, and a lot of people probably don’t have the patience to run it correctly. Audioholics has an excellent two-part livestream discussion of the problems that auto-EQ systems can create which can be seen here: Does Room Correction EQ Improve Home Theater Quality and Room Correction EQ: How it Affects Loudspeaker Performance.
9. Myth: "Tweeter type X is superior to tweeter type Y." The reasoning behind this varies widely since so many people have their own tweeter preferences with their own reasons for choosing those tweeters. However, one common advantage claimed by proponents of some tweeter types is that tweeter type X has less mass and so must somehow be ‘faster’ than traditional tweeters by which they mean dome tweeters.
Truth: The strengths of any driver type depend on how well it serves the application of the overall speaker design. There is no one superior tweeter type, even for high-fidelity home audio. If you truly prioritize sound quality in loudspeakers, you should consider a loudspeaker to be a “black box,” that is, something that accepts an input for a given output, and the way it accomplishes this task is totally irrelevant. In a loudspeaker, the input would be a modulated electrical signal, and the output would be compression waves of air. The fidelity of the system should be gauged as to how well the frequency of the air pressure waves follows the waveform of the electrical signal. Nothing else matters. It doesn’t matter how light the diaphragm of the tweeter is. It doesn’t matter how inert the loudspeaker enclosure is. It doesn’t matter how complex the crossover circuit is or what types of components it uses. It doesn’t matter how expensive the loudspeaker is. If you only really care about sound quality from a sound system, the only thing that matters is how well the system translates an electrical signal to an acoustic signal.
It turns out that the accuracy by which a loudspeaker can transduce electricity to acoustic energy can be measured quite precisely, and that is what we do in our loudspeaker reviews at Audioholics. What we have seen is that loudspeakers can achieve high fidelity with a plethora of different tweeter types: fabric domes, aluminum domes, titanium domes, beryllium domes, compression drivers, ring radiators, AMTs, planar tweeters, ribbon tweeters, etc. Some speakers have different design goals and use the correct tweeter accordingly. You wouldn’t expect a speaker to use a compression driver for wide dispersion, nor would you expect to see a ribbon tweeter to be used for an extremely wide dynamic range.
As for the idea of a “fast” tweeter, the speed at which a tweeter responds is easy to see in any frequency response chart. Simply look at the upper end of the speaker’s response. The moving mass of the tweeter has to literally be able to move faster to achieve higher amplitudes in higher frequencies. Let’s take a look at the upper end of healthy human hearing for example, which is 20kHz. Most tweeters can reproduce 20kHz to some degree, some more efficiently than others, but if a tweeter plays 20kHz louder for the same input energy, it is a faster tweeter. It has to move back and forth twenty-thousand times per second, but at a greater distance for more air displacement and thus sound pressure level, so it has to cover that area more quickly. A “fast” tweeter is fine in the sense that it can cover the spectrum of human hearing, but the catch is that it ceases to matter outside of audible frequencies. And a lot of tweeters can reach up to the upper bounds of human hearing very easily, so that isn’t exactly a special feat. This is why anytime anyone talks about a “fast” tweeter, that should be a cause for skepticism. A lot of tweeters are fast, but that doesn’t mean they are good. Phrases such a “speed”, “fast”, and “tight” are often marketing buzzwords that have little to do with reality.
10. Myth: “Acoustic isolation can very often improve the sound." The reasoning for this is that vibrating things make sound, and your loudspeaker cabinet isn’t totally inert, so it must be vibrating, and this enclosure vibration is mechanically transferring through contact with other things. This vibrational transfer must be causing unintended sound which is polluting the pure sound of the speaker.
Truth: Competently designed loudspeakers don't transmit much mechanical energy through their enclosures and are not usually enough to audibly vibrate other objects through mechanical transmission. Loudspeakers are transmitting most of their energy into the air, and pressure waves of air is a good medium to exert force on things. So if you are worried about loudspeakers vibrating things, I have some bad news for you: that is what they are supposed to do. You are likely getting more vibrations from pressure waves of air causing vibrations than direct surface contact. All but the cheapest speaker cabinets use at least ½” thick material, usually MDF, for paneling, and many of them have internal bracing as well as acoustic stuffing far damping inside. They tend to be fairly solid enclosures. The moving mass of the drivers, which is necessarily very light, doesn’t push them around very much, so whatever they are in contact with will be less affected still.
If the speaker is resting on a flimsy desk or shelf surface, some resonances might be audible, but you don't need a whole lot of damping to shut that noise down. A soft rubber matte or polyurethane pad will damp those vibrations easily, and they don’t cost much money. Don't spend a lot of money on isolation pads or isolation stands or risers. If you are getting vibration noise from mechanical transmission from a loudspeaker, there are very inexpensive and easy solutions to deal with that. All you need is something soft between the speaker and resting surface that is soft enough to damp the vibrations, and there are a lot of common materials that can do that well.
Regarding speaker spikes and cone feet, Audioholics did publish an article some years ago that did address this (Speaker Spikes and Cones - What’s the Point?). In it, a study was cited where it was found that cones ended up transmitting over a hundred times the level of vibration as rubber feet. Spikes and cones would not seem to be a good way to reduce vibration transmission, in fact, quite the opposite. Loudspeaker feet do not need to be fancy. In my opinion, hard rubber is a good material because it is good for its damping qualities but not so soft as to make the speaker “bouncy.”
There are plenty more bad ideas about audio floating around, and this list is just a sampling of a few that seem to persist even with folks who should know better. These are some which we felt seem to fly under the radar of obvious fallacies like “audiophile-grade” power cables, acoustic paint, gemstones that absorb “bad” harmonics, or demagnetizing vinyl records before playback for a better aural experience. It’s time these get some pushback, and we hope that we have purged these ideas in at least some of our readers so they become more widely disputed in the future.
Do you have any audio pet peeves that you see which fly in the face of science? If so, let us know in the comments section. We are always on the lookout for more misleading theories and beliefs to cleanse from the audio world in an effort to make a better-sounding tomorrow.
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Audioholics is famous for deflating audio myths whether they be sham acoustic ideas, snake-oil audio cable, illogical loudspeaker design, or pseudoscience in the electronics realm. It is one of the reasons why I came to be such a big fan of the site and its community, and Id like to think Audioholics agenda of injecting more objectivity in audio has had an effect on the business at large, although its difficult to assess how much exactly. Bad ideas in audio are still a force to be reckoned with, and at times, Audioholics seems like merely a lonely island of rationality in a vast ocean of nonsense. The battle against balderdash is an eternal struggle. Here are ten audio ideas that seem to persist without any solid grounding, and so we will attempt to set the record straight to help thwart their persistence. Read on to see what we regard as ten more audio myths that must be debunked!
READ: 10 More Audio Myths Debunked