10 Audio Myths Debunked For Better Sound

S

shadyJ

Speaker of the House
Staff member
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. Read on to see what we regard as ten more audio myths that must be debunked!

READ: 10 More Audio Myths Debunked
 
D

Danzilla31

Audioholic Spartan
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. Read on to see what we regard as ten more audio myths that must be debunked!

READ: 10 More Audio Myths Debunked
That was a superb article I really enjoyed it! Especially the parts on Room EQ and Room Treatments
 
B

beaRA

Audioholic Intern
I think part of the confusion around subwoofers "pressurizing" a room comes from the fact that ratings tend to reference room volume. Both THX ratings and the Bassaholic rating do so. In fact, from the Bassaholic rating protocol:

"Room size de-ratings happen in -6dB intervals for halving of volume which requires a sub with 6dB less output accordingly (Pressure (SPL) is directly proportional to the volume in which it is confined.)"

@shadyJ can you help clarify the role of room volume vs listening distance in these ratings?
 
TLS Guy

TLS Guy

Seriously, I have no life.
Another good article Shady.

I think the issue about tweeters is well taken. Choosing a set of speakers based on the tweeter is absolutely absurd.

I have said many times you do not pull any drivers out of thin air when designing a speaker.

The questions are what is it for, and where is it going? A budget then enters into the equation.

Selection of the drivers is then crucial, and at the very heart of good design. So you look for drivers, that can be designed to work well together. At this time leave all preconceived notions on the floor.

So the only thing that matters about a tweeter, is if it right is for the job at hand, and not its mechanism and the use of materials selected.

Then we come to the matter of room correction. I agree that there is probably a place for some equalization in the bass.

However this is very much an interaction of speaker, and especially subs and the room.

Most subs I hear at not very good, and do not produce realistic bass. This was reinforced last week, when at a friends house and I heard an expensive Legacy sub. Again there was bass alright, but of very low quality.

I think the problem is that Qt of most subs is just too high. This then exaggerates room modes.

A really clean bass at the CORRECT volume really does improve the overall sound dramatically. That is why I really favor the TL if correctly executed.

All the very best speakers I have ever heard have been well designed TLs from experienced designers. My experience is that they produce a very realistic bass, and you end up with a good room curve down to the last octave.

This brings me to the next point, that unless you have a room that sounds aberant on human speech, or an instrument like a guitar or piano, then a speaker system should sound fine also. If it does not, then there is something wrong with the speaker.

You can not correct these aberrations, even if you can get a better room curve.

I totally agree with Billy Woodman of ATC about this. I would bet most members here are actually making their systems worse with Audyssey, if they listen critically.

There is no way these crude systems, feeding off a cheap $0.50 plastic mic can do anything much except harm, although you might get lucky in the bass.

If you have a really good system with excellent balance, it is just astonishing how severe the degradation is, when engaging Audyssey.

So I would encourage all members to listen critically to their systems with Audyssey off, and listen long enough to erase auditory memory.

The issue of centers is a thorny issue, that we have discussed at length before.

I believe the front three, should be designed as a unit. I think with the advent of these current incredible up mixers, that can be extended to all the speakers for the best results.

But let us return to the front three. If you walk across the front stage, then all these speakers must sound the same and the center especially not sound different. The best way to do that is make sure all the speakers have a really flat response until the bass roll off.

Now, the horizontal MTM, just has the wrong dispersion pattern.

The three way has advantages but it makes integration with the right and left speakers problematic, especially if they are two ways. This has to do with issues of phase response and cancellation nulls.

My center based on coaxial driver design, is by far my best solution to date, and is an absolutely superb center, with clear and natural speech, and also for music, both vocal and instrumental. The front three produce a seamless front soundstage and excellent imaging.

Centers need a lot more thought and research than they have been given so far. In AV I think it is true that it is the most crucial speaker of all. Making it the low boy on the totem pole is in no way acceptable.
 
Kvn_Walker

Kvn_Walker

Audioholic Field Marshall
A lot of the issues with center speakers could be resolved if furniture manufacturers begin to make stands with a central vertical space for a vertical center. Or if homeowners used two smaller stands with a space in between to position a vertical center speaker.

Form will continue to kill function until there's a serious design shift in AV furniture.
 
S

shadyJ

Speaker of the House
Staff member
I think part of the confusion around subwoofers "pressurizing" a room comes from the fact that ratings tend to reference room volume. Both THX ratings and the Bassaholic rating do so. In fact, from the Bassaholic rating protocol:

"Room size de-ratings happen in -6dB intervals for halving of volume which requires a sub with 6dB less output accordingly (Pressure (SPL) is directly proportional to the volume in which it is confined.)"

@shadyJ can you help clarify the role of room volume vs listening distance in these ratings?
I believe the bassaholics rating assumes corner placement which will get more boundary gain. The thing is most rooms get lots of boundary gain, and much of the pressure will be redirected all over the place since the space is small when considering the wavelengths of low frequencies. I don't think that placing a sub in a corner of a domestic room will yield substantially more boundary gain than anywhere else, because normal domestic rooms are pretty small compared to low frequencies. I don't think you normally get more SPL by using corner-loading but rather more SPL in deeper frequencies.

If you are placing the sub as far from the listener as possible, like what is often seen in placement diagrams, then yes, room volume matters, or more accurately room volume plus the energy losses over distance of listener from the sub. If you have freedom of placement for the subwoofer, room volume can be negated.
 
Pogre

Pogre

Audioholic Slumlord
So how do we reconcile myth number ten with those thousand dollar IsoAcoustics Gaia isolators?


10. Myth: “Acoustic isolation can very often improve the sound."

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.
 
NINaudio

NINaudio

Audioholic Samurai
So how do we reconcile myth number ten with those thousand dollar IsoAcoustics Gaia isolators?


10. Myth: “Acoustic isolation can very often improve the sound."

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.
I was thinking the exact same thing when I read that part of the article...
 
B

beaRA

Audioholic Intern
I believe the bassaholics rating assumes corner placement which will get more boundary gain. The thing is most rooms get lots of boundary gain, and much of the pressure will be redirected all over the place since the space is small when considering the wavelengths of low frequencies. I don't think that placing a sub in a corner of a domestic room will yield substantially more boundary gain than anywhere else, because normal domestic rooms are pretty small compared to low frequencies. I don't think you normally get more SPL by using corner-loading but rather more SPL in deeper frequencies.

If you are placing the sub as far from the listener as possible, like what is often seen in placement diagrams, then yes, room volume matters, or more accurately room volume plus the energy losses over distance of listener from the sub. If you have freedom of placement for the subwoofer, room volume can be negated.
Thanks for the response! Maybe I'm missing something, but I'm not seeing how corner loading is essential to the volume vs listening distance discussion. Let's assume corner loading by starting with an infinitely large Eighth space. It makes sense in this scenario that the only thing that matters in a loudness rating is the listening distance.

My confusion comes when we start to enclose the Eighth space. Does the proximity of additional boundaries matter? If a small sub can be sufficient in a small volume due to room gain, does it follow that a larger volume requires a larger sub?

I hear what you're saying about placement. If you can put your subwoofer near field, you don't necessarily need the extra headroom from room gain. Since many dictate placement based on the smoothest resulting response at the MLP, it's hard to assume the listening distance. Seems like the myth is born as a rule of thumb based on volume due to this uncertainty.
 
highfigh

highfigh

Seriously, I have no life.
Why did you use upright bass as the instrument having a simple waveform in the 3rd myth about music subs vs movie/special effects subs when there are so many other instruments that are used for bass in music?
 
L

lejack

Enthusiast
#4 Refer to Roy Allison's articles from the 1970s, about woofer placement and room boundaries.
 
VoidX

VoidX

Audioholic Intern
It's a great list, but I have to scientifically disagree with #2. The recommendation of toe-in is not for raw sound quality, but for a more uniform listening area and lower amplitude side wall reflections in the high frequency range. Wavefield synthesizers can draw what happens to the sound with and without toe-in: if you don't do this, the listening area will be a blob of nodes and antinodes, but with toe-in, you can create an arc of nodes, which eliminates changes when you move your head sideways. This completely changing soundstage is the reason I would not recommend parallelly aligned speakers, especially for movies. Whenever I worked with in-wall speakers that could not be aligned, there were always horrible balance issues. You can somewhat restore the arc with a custom DSP in these cases, but it's not common to just start coding one. Proper EQ can match the sound of aligned and misaligned speakers at one position (and there are software for sound character transitioning), so the off-axis sound can be calibrated on-axis if you'd like, but it can't fix the mentioned room issues, so toe-in is always the better way.
 
S

shadyJ

Speaker of the House
Staff member
It's a great list, but I have to scientifically disagree with #2. The recommendation of toe-in is not for raw sound quality, but for a more uniform listening area and lower amplitude side wall reflections in the high-frequency range. Wavefield synthesizers can draw what happens to the sound with and without toe-in: if you don't do this, the listening area will be a blob of nodes and antinodes, but with toe-in, you can create an arc of nodes, which eliminates changes when you move your head sideways. This completely changing soundstage is the reason I would not recommend parallelly aligned speakers, especially for movies. Whenever I worked with in-wall speakers that could not be aligned, there were always horrible balance issues. You can somewhat restore the arc with a custom DSP in these cases, but it's not common to just start coding one. Proper EQ can match the sound of aligned and misaligned speakers at one position (and there are software for sound character transitioning), so the off-axis sound can be calibrated on-axis if you'd like, but it can't fix the mentioned room issues, so toe-in is always the better way.
There is no research that I am aware of that shows a preference for toe-in. There is some research that indicates a preference for side-wall reflections in some circumstances, but nothing that indicates a distaste for them in any circumstance. Personally, I find the changes made to the sound are usually subtle, and I have experimented with toe-in using many different speakers. While there isn't any scientific research that examines the audible effects of toe-in, I am betting that if there were, it wouldn't show a major difference in typical home audio loudspeaker designs. The difference mainly comes about in controlled directivity loudspeakers.
 
TheWarrior

TheWarrior

Audioholic Ninja
There is no research that I am aware of that shows a preference for toe-in. There is some research that indicates a preference for side-wall reflections in some circumstances, but nothing that indicates a distaste for them in any circumstance. Personally, I find the changes made to the sound are usually subtle, and I have experimented with toe-in using many different speakers. While there isn't any scientific research that examines the audible effects of toe-in, I am betting that if there were, it wouldn't show a major difference in typical home audio loudspeaker designs. The difference mainly comes about in controlled directivity loudspeakers.
Sure, not everyone can be perfectly on axis across a couch. But if we're taking all these off axis measurements, and we know the SPL drops the further off your ears/mic are, isn't that a good reason to point the speakers toward the listeners?
 

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