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How to Choose a Loudspeaker -- What the Science Shows

550K views 6K replies 267 participants last post by  Rex Anderson 
#1 ·
Choosing a loudspeaker may be the biggest challenge for music and home theater lovers. There are countless brands from which to choose, and even more claims and counter-claims. Since the room has such a profound impact on the sound of a loudspeaker at lower frequencies, and it is impossible to listen in a blind test at an audio store, if they can find one, there is little that an audiophile can do to make a rational decision. Fortunately, science has come to the rescue with a set of measurements that have been proven to demonstrate an extremely close correlation with sound quality, as based on carefully controlled double-blind listening tests. This group of measurements have been adopted as the industry standard for measuring loudspeakers, as ANSI/CEA-2034-A. https://standards.cta.tech/apps/group_public/project/details.php?project_id=165

Contradicting the oft-repeated claim that choosing a loudspeaker is a very personal choice, research has proven that regardless of age, culture, or listening experience, all people with nominally normal hearing generally agree on which speakers sound better than others. Indeed, there is a universal definition of what sounds good. http://www.aes.org/e-lib/browse.cfm?elib=12794 and https://secure.aes.org/forum/pubs/conventions/?elib=12847

In this thread, we will publish the results of these measurements. In addition, we will discuss their correlation to double-blind listening tests, http://seanolive.blogspot.com/2008/12/part-3-relationship-between-loudspeaker.html as well as publishing the results of formal listening tests, when available. We will add measurement results as they become available. The intention of this thread is for it to be reality-based, and to inform and discuss loudspeaker measurements and listening tests. The papers that really started it all are now available for free from the Audio Engineering Society here: http://www.aes.org/e-lib/browse.cfm?elib=5276 and here: http://www.aes.org/e-lib/browse.cfm?elib=5270
 
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#4,628 ·
Small jazz or other acoustic groups, choral groups, handbells, orchestral performances, piano/organ recitals... I believe this thread is about meeting the challenge of reproducing music of any genre.
 
#4,640 ·
This thread is gold. My sincerest thanks to all of the scientists who have improved the state of the art.
I am 57 and can really appreciate how much speakers have improved over my life.

I was at a venue and was under a hanging line array...the engineer was playing music through it at
a low background level before the show. I was struck by the sound...it was amazing and so much better
than sound stage stuff in the 70's. I made it a point to note the brand of the array. JBL.
 
#4,646 ·
Oddly in video no production or editing would ever take place on anything less than fully calibrated equipment. Not so much on a 32" 720p 99$ out-of-the-box screen bought from *random store*. Yet in audio a small square with a 5" paper full-range is regularly used to "check on translation". It's a stupid practice that has been in place for far too long. Same goes for placing otherwise excellent speaker sideways on consoles (no they don't feature white cones or tissued tweeters)
 
#4,670 ·
I have a question regarding speaker tilt.
I want to place my front (well, it's stereo, so it's front and only front) speakers higher than usual. Obviously tweeter level will get higher than my ear level, so I want to tilt them. How much tilt is acceptable before it starts altering the sound?
I can listen probably, but organising blind test is hard due to different placement (higher/lower) that will affect bass.
 
#4,675 ·
"I've heard the idea that recording engineers optimize for different speakers/environments, e.g. cars, TVs, laptops, movie theaters, etc." You can't "optimize" for all of those playback possibilities.

Most recording engineers I have known monitor on a wide variety of speakers and try to get the mix to sound good on as many systems as possible. It's a series of compromises. Great mix engineers can monitor on NS-10's and Auratones and get pretty good results because they know the speakers and the flaws intimately. That said, what I found is many of those mixes are all over the place re: the amount of low end. It sure helps to have smooth flat extended LF response in the mix facility. Mastering engineers generally work on big full range monitors to be able to tell what is there and make it as good as possible, "hopefully" using neutral monitors tuned in the room. Look at Bob Katz, Bob Ludwig, etc. Pretty impressive facilities.

IMO, the best way to approach playback is to use neutral speakers, with multiple subs, tuned in the room. If it doesn't sound like you want it to, use EQ, essentially "re-mastering" to your taste, on your system, in your room. This approach works if you are listening to an entire album (CD etc) from one artist. If you are streaming and playing songs from different albums by different artists from different years, there is not much you can do.
 
#4,681 ·
"I've heard the idea that recording engineers optimize for different speakers/environments, e.g. cars, TVs, laptops, movie theaters, etc." You can't "optimize" for all of those playback possibilities.

Most recording engineers I have known monitor on a wide variety of speakers and try to get the mix to sound good on as many systems as possible. It's a series of compromises. Great mix engineers can monitor on NS-10's and Auratones and get pretty good results because they know the speakers and the flaws intimately. That said, what I found is many of those mixes are all over the place re: the amount of low end. It sure helps to have smooth flat extended LF response in the mix facility. Mastering engineers generally work on big full range monitors to be able to tell what is there and make it as good as possible, "hopefully" using neutral monitors tuned in the room. Look at Bob Katz, Bob Ludwig, etc. Pretty impressive facilities.

IMO, the best way to approach playback is to use neutral speakers, with multiple subs, tuned in the room. If it doesn't sound like you want it to, use EQ, essentially "re-mastering" to your taste, on your system, in your room. This approach works if you are listening to an entire album (CD etc) from one artist. If you are streaming and playing songs from different albums by different artists from different years, there is not much you can do.

That certainly sounds like a logical approach, at least for those who want to go to that much trouble - e.g. multiple subs, using EQ per whatever they are listening to.


Another approach some take is to find a speaker that, even if not exactly neutral, sounds great to that person with most or all the music he/she listens to. Then it's sort of set and forget, no other complications, no fiddling with EQ etc.


I personally like the sounds of different speakers, 'cause I think speakers are cool! I have some neutral sounding speakers, and some less-than-neutral sounding speakers, and they give me a thrill in their own way. But in either case, I never, ever feel the need or desire to fiddle with an eq. I seem to enjoy pretty much everything I hear through the speakers. (In fact, I had a nice digital EQ in my system that I never bothered using for so many years, I finally recently sold it).
 
#4,676 ·
ex 10 year recording and mixing engineer here. Also taught recording engineering for a couple of years, based on curriculum derived from several of the excellent textbooks out there on the subject area. I worked in over a dozen different control rooms back in the day, each acoustically designed, using a variety of approaches, all of which had pros and cons.

However, the one overriding factor is we wanted a neutral sounding room and neutral sounding speakers. Why? So when we recorded and mixed sound, we could make judgements based on the sound we were recording or mixing, and not have the room and/or loudspeakers colour or mask the sound. From the audio engineers I talked to, we were all interested in this, some more than others and some had their favourite rooms and/or speakers, but the main point, neutral, neutral, neutral.

But getting neutral became quite the issue. Most studio controls rooms I worked in had large soffit mount speakers, like Urei 813 time aligns or Westlakes or JBL 43xx series, etc. Every one of them was eq'd to one of the many so called standards like EBU Tech 3276 or ITU-R BS.1116-3 or the so called B&K curve or Dolby's 5.1 mixing guidelines, etc. Lot of good solid information in those guidelines, except for the target frequency response. In the Cinema world it is the dreaded X-curve.

For a (whole) variety of reasons, most of the soffit mount, large format monitors did not sound good, but mainly because the speakers were not neutral to begin with. Eq'ing the speakers based on the guidelines more often than not made it worse, due to very poor off axis response, poor crossover designs and simply not understanding what a neutral speaker sounds like or should sound like. We would take our mixes and recordings to our home systems and/or artists systems and there was always a balance problem between bass, mids and treble (i.e. not enough or too much in each of the ranges). Some control room monitors and rooms were just downright awful. All of which led to most people using near field monitors on the mixing desk bridge and the trend still continues today (figuratively speaking as most mixing desks are now computers).

Sure, I used NS10's (as others have pointed out the farce of why they became popular in control rooms and I did not use them long because they aren't anything relative to being neutral) Auratones to simulate what one's mix may sound like over car radio loudspeakers and a vast array of other bridge monitors, occasionally using the large format monitors to gauge bass extension. On the West Coast we ended up using JBL monitors as they were easy to get and most often had real published specifications and relatively speaking sounded the most neutral to a group of us when we did a shootout. I think they were 4410's or 4408's at that time.

A balanced mix on the JBL 4410's sounded good and sounded good when played back on most other speakers. Our goal was to provide the best sounding mix we could, that highlighted the bands own "sound". Of course, everyone knows it is all fake right ;) We used all sorts of mechanical and digital devices, reverb, delays, distortion, etc., to paint a sonic picture of the band on a blank audio canvas. I am talking typical mono-mic'd, multi-track recordings. For a really good insight on how mixing engineers paint their mix, have a look at: If you don't want to know how the sausage is made, don't look :cool:

Of course nowadays, we know what makes for a neutral sounding speaker and what we prefer. Dr. Toole and Dr. Olive have done a great job in my opinion in making that happen. Now it is embodied as a free standard. I would love to see the existing control room and critical listening standards, like referenced above, updated to include what makes for a neutral sounding speaker.

Nowadays big recording studio budgets have mainly disappeared and with the advent of a studio in a box (DAW’s), everyone is now a recording/mixing engineer with little to know education (and/or skill!) in the art of recording and mixing sound. With so many presets, one can simply click one button in the DAW to engage soul crushing dynamic range compression.

Back to neutral speakers… :) More education about what makes for a neutral sounding speaker in the pro sound industry, aside from the consumer market, will assist in making better sounding recordings. I am hopeful with the ANSI/CEA-2034-A Standard Method of Measurement for In-Home Loudspeakers available for free, more consumer and pro speaker manufactures will use it to design and develop more neutral sounding speakers.

Sorry for the wall of text, I hope folks are enjoying the music!
 
#4,677 · (Edited)
ex 10 year recording and mixing engineer here. Also taught recording engineering for a couple of years, based on curriculum derived from several of the excellent textbooks out there on the subject area. I worked in over a dozen different control rooms back in the day, each acoustically designed, using a variety of approaches, all of which had pros and cons.

However, the one overriding factor is we wanted a neutral sounding room and neutral sounding speakers. Why? So when we recorded and mixed sound, we could make judgements based on the sound we were recording or mixing, and not have the room and/or loudspeakers colour or mask the sound. From the audio engineers I talked to, we were all interested in this, some more than others and some had their favourite rooms and/or speakers, but the main point, neutral, neutral, neutral.

But getting neutral became quite the issue. Most studio controls rooms I worked in had large soffit mount speakers, like Urei 813 time aligns or Westlakes or JBL 43xx series, etc. Every one of them was eq'd to one of the many so called standards like EBU Tech 3276 or ITU-R BS.1116-3 or the so called B&K curve or Dolby's 5.1 mixing guidelines, etc. Lot of good solid information in those guidelines, except for the target frequency response. In the Cinema world it is the dreaded X-curve.

For a (whole) variety of reasons, most of the soffit mount, large format monitors did not sound good, but mainly because the speakers were not neutral to begin with. Eq'ing the speakers based on the guidelines more often than not made it worse, due to very poor off axis response, poor crossover designs and simply not understanding what a neutral speaker sounds like or should sound like. We would take our mixes and recordings to our home systems and/or artists systems and there was always a balance problem between bass, mids and treble (i.e. not enough or too much in each of the ranges). Some control room monitors and rooms were just downright awful. All of which led to most people using near field monitors on the mixing desk bridge and the trend still continues today (figuratively speaking as most mixing desks are now computers).

Sure, I used NS10's (as others have pointed out the farce of why they became popular in control rooms and I did not use them long because they aren't anything relative to being neutral) Auratones to simulate what one's mix may sound like over car radio loudspeakers and a vast array of other bridge monitors, occasionally using the large format monitors to gauge bass extension. On the West Coast we ended up using JBL monitors as they were easy to get and most often had real published specifications and relatively speaking sounded the most neutral to a group of us when we did a shootout. I think they were 4410's or 4408's at that time.

A balanced mix on the JBL 4410's sounded good and sounded good when played back on most other speakers. Our goal was to provide the best sounding mix we could, that highlighted the bands own "sound". Of course, everyone knows it is all fake right ;) We used all sorts of mechanical and digital devices, reverb, delays, distortion, etc., to paint a sonic picture of the band on a blank audio canvas. I am talking typical mono-mic'd, multi-track recordings. For a really good insight on how mixing engineers paint their mix, have a look at: https://www.youtube.com/watch?v=TEjOdqZFvhY If you don't want to know how the sausage is made, don't look :cool:

Of course nowadays, we know what makes for a neutral sounding speaker and what we prefer. Dr. Toole and Dr. Olive have done a great job in my opinion in making that happen. Now it is embodied as a free standard. I would love to see the existing control room and critical listening standards, like referenced above, updated to include what makes for a neutral sounding speaker.

Nowadays big recording studio budgets have mainly disappeared and with the advent of a studio in a box (DAW’s), everyone is now a recording/mixing engineer with little to know education (and/or skill!) in the art of recording and mixing sound. With so many presets, one can simply click one button in the DAW to engage soul crushing dynamic range compression.

Back to neutral speakers… :) More education about what makes for a neutral sounding speaker in the pro sound industry, aside from the consumer market, will assist in making better sounding recordings. I am hopeful with the ANSI/CEA-2034-A Standard Method of Measurement for In-Home Loudspeakers available for free, more consumer and pro speaker manufactures will use it to design and develop more neutral sounding speakers.

Sorry for the wall of text, I hope folks are enjoying the music!
"Of course, everyone knows it is all fake right"

Not always and not all that often with what I listen too. I don't know when that vid was produced, but it appears to be 70s. I watched until min 20:57 and maybe a couple of min or so beyond, but that was enough, i.e., "the image never appear above the top of the speakers" "image doesn't extend beyond the boundaries of the left and right speaker" etc. If that vid is more current than the 70s, dude needs to get out more. Even a JBL can do it if anyone has taken a listen to the revised L100s.

Give me my one stereo mic recordings

 
#4,678 ·
As mentioned in my wall of text scotth3886, I am talking main stream pop, rock, alt, country, R&B, etc., where 99.9% is mono mic'd multitrack recordings, which is prevalent everywhere. I am not talking about speciality recordings. I have done my fair share of binaural, xy coincident, mid-side (my personal fav), and my preference are for these simple and best sounding stereo mic techniques. But that's the exception. And btw, it is still fake man, as stereo is just an illusion :D
 
#4,679 · (Edited)
As mentioned in my wall of text scotth3886, I am talking main stream pop, rock, alt, country, R&B, etc., where 99.9% is mono mic'd multitrack recordings, which is prevalent everywhere. I am not talking about speciality recordings. I have done my fair share of binaural, xy coincident, mid-side (my personal fav), and my preference are for these simple and best sounding stereo mic techniques. But that's the exception. And btw, it is still fake man, as stereo is just an illusion :D
Well, man, just as much of an illusion as us being here posting on AVS, but an illusion that most closely matched what I sit there live and hear and have been doing since 1947.

Yeah, and "Mid side" true, Alan Blumlein was with you on that one.
 
#4,700 ·
Resonances are the most detrimental because they are independent of program material. As for spectral balance.. in an ideal world recording engineers use spectrally neutral loudspeakers, which means those of us at home that use similarly neutral loudspeakers will get an equally good (or bad) presentation.
 
#4,705 ·
I think that, by definition, all resonances affect neutrality. A neutral system would react the same regardless of input. A resonance is when the system reacts differently to a particular frequency. So you can't have a resonance that doesn't impact speaker neutrality.

I think noise is a completely different concept than resonances. A resonance has to do with how a system reacts to an input. Noise is an attribute of the input or the output itself.
 
#4,734 ·
I think that's the 1st time I've seen a posted deleted post!
 
#4,743 ·
People who know my posts over the years know I've questioned other speakers as well, including my own, I really am just trying to apply the science we've been talking about to what I hear in real speakers. If anyone thinks I'm misinterpreting the Spins please correct me but the BMR measurements from Audioholics show a similar response in the tweeter region. And yes I know the Sierra 2 uses a "custom" 64-10 but surely they are very close in response. Still no evidence of a resonance in the tweeter range of the 64-10?

 

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#4,745 ·
People who know my posts over the years know I've questioned other speakers as well, including my own, I really am just trying to apply the science we've been talking about to what I hear in real speakers. If anyone thinks I'm misinterpreting the Spins please correct me
It seems like several people have been trying to correct you, no?

but the BMR measurements from Audioholics show a similar response in the tweeter region. And yes I know the Sierra 2 uses a "custom" 64-10 but surely they are very close in response. Still no evidence of a resonance in the tweeter range of the 64-10?
Is your point that a particular tweeter results in a particular bump?

Sure, in the new spin you posted for the BMR, I see a slight bump in all the top traces centered around 9 kHz.

Your Sierra bump centers around 7 kHz and only in the early-reflections and sound-power traces... if you look at the top two traces at 7 kHz, they're absolutely average, if not actually a little bit low, compared to the rest of the spectrum.

If you're trying to say these bumps are in any way similar, I'm not seeing it.
 
#4,748 · (Edited)
I don't have the time or energy to offer a full reply to all of the "bumps" and grinds of this thread. But as a general matter, I think a lot of people are missing the forest for some pretty insignificant trees. The forest is the very small frequency deviations shown by the various spinorama plots, even though they may appear more significant on these very detailed displays. For example, if you examine the listening window plot for the BMR, it fits within a 2.1 dB window, or about +1, -1 dB. That in and of itself rules out any significant resonance in the RAAL response or overall system response. The slight lift in the treble response might not even show up in if a different mic were used. There is no elevation in the NRC plots for the BMR, and my measurements only show about a .5 dB rise. I'm not sure whose mic is "right," but the point is were's talking about deviations that are well within the range of normal microphone calibrations. Finally, I think there's fundamental confusion between a true resonance and a gentle rise in output that may simply reflect the ultra-low mass of a ribbon element, and the associated tendency to increase in sensitivity at higher frequencies where the ribbon excursions are smaller than at lower frequencies. This response profile is easily equalized with the crossover, or, in the case of the RAAL 70-10, with foam diffusion pads. If any true resonances were involved, they would show up in a waterfall plot. Every waterfall plot I've seen for a RAAL speaker has been extremely clean. A real mechanical resonance would be much higher in Q, reflecting a ringing of the driver within a narrow range of frequencies.
 
#4,749 ·
I don't have the time or energy to offer a full reply to all of the "bumps" and grinds of this thread. But as a general matter, I think a lot of people are missing the forest for some pretty insignificant trees. The forest is the very small frequency deviations shown by the various spinorama plots, ...
Sorry, didn't mean to imply anything negative about the speaker, although I realized that that would be an unfortunate side-effect of what I wrote as I was writing it. I've been trying to argue that it's not useful to discuss these +/- 1 dB variations too.
 
#4,758 ·
I can criticize my own speakers right? Back to the Spins I posted, the 1st was the LS50 that I have. What seems to be lost is the power of the early reflections curve and how closely it resembles the in-room response, it's actually a big part of the formula used in predicting subjective preference from the Spins. I was able to match this PIR curve very closely with my own in-room measurements and after EQ'ing that 2k resonance, excess energy, wide dispersion, whatever you want to call it, they sound more neutral and any brightness is gone. I know many speakers have their flaws, especially 2-ways and I'm not saying it makes them bad, sometimes all you need is a bit of EQ.



 

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#4,782 ·
Multiple readings with my measurement mic (Earthworks M30) when fixed in position and with nothing else changing overlie within the noise floor of the system (
 
#4,802 ·
To Resonate or not to Resonate, That is the Question?

Apologies to Shakespeare . . .

This discussion has drifted into an area of literal interpretations of classical definitions with some semantics thrown in. If there is a shallow hump in a frequency response, in literal terms it is a very low-Q resonance, implying a mechanical, electrical or acoustical system with a "favored" frequency range. In a physical system as complex as a loudspeaker it may sometimes be difficult to decide what is happening. Crossovers are equalizers, by any other name, that interact with transducers having inherently non-flat tendencies - the result is a combination of both electrical and mechanical elements. Equalizers can be resonators just as surely as acoustical cavities, enclosure panels and cone breakup. So a frequency response feature may be partly mechanical and partly electrical , but the end result can be that of a resonance having Q. Achieving a desirable flat on-axis sound using passive or active networks can result in non-flat off-axis behavior because transducers have frequency-dependent directivity. In a room the result is that even with flat direct sound, the early reflected and later reflected sounds may exhibit emphasis over a range of frequencies that could forgivably be interpreted as a low-Q resonance.

As discussed many times in this thread, transducers are inherently minimum-phase devices, so electrical EQ can modify the performance of mechanical resonances - a huge advantage for active loudspeakers or those for which accurate anechoic data are available.

In the crossover between a 6- to 8-inch woofer and a 1-inch tweeter, a directivity mismatch at crossover is unavoidable. Above crossover, the tweeter has much wider dispersion than the woofer, so there is an energy rise over a wide frequency range. Is this a resonance? Technically not, in the dictionary definition sense. However, there is a broad hump in radiated energy, so perceptually it may appear to be so. Figure 4.13 shows such an example where even crude room curves were adequate to recognize the energy excess in an above-crossover energy excess and attenuate it. Because wide bandwidth (low-Q) phenomena are detected at very small deviations there was a clear improvement in perceived sound quality even though medium and higher-Q "real" resonances were essentially unchanged. Addressing all of the "resonances" was not surprisingly the best.

So, don't get hung up on semantics. Deviations from a linear frequency response are all describable as "resonances" if one chooses to. Broadband trends are very low-Q, narrower trends, medium Q, and so on. Even a bass tone control is an opportunity to manipulate a "resonance" - in this case the hump that develops above the low cutoff frequency which, depending on the system design will have a Q.

Narrow dips are usually the result of destructive acoustical interference and are usually audibly innocuous because they change with direction/position. Broader dips can be interpreted as anti-resonances if one chooses to, whether there is an associated frequency selective absorption process or not. Mostly not.

All fodder for more discussion :)
 
#4,804 ·
...
In the crossover between a 6- to 8-inch woofer and a 1-inch tweeter, a directivity mismatch at crossover is unavoidable. Above crossover, the tweeter has much wider dispersion than the woofer, so there is an energy rise over a wide frequency range. Is this a resonance? Technically not, in the dictionary definition sense. ...
If we're being pedantic, how is this not a resonance? An increase of output over a frequency range (wide or not) seems like it would be the dictionary definition of a resonance?
 
#4,817 · (Edited)
Das Orgelwerks! My favourite topic. I'll only recommend a few that should still be available if the Archive site is up to date.

To test the lungs of any stereo system (low D that will give a sub a work out at 19 Hz): Mendelssohn played by Peter Hurford on Decca. Good tunes too.

Also played by Hurford, a Decca 2-fer of Bach giving a range of his output.

Another Romantic piece played by Simon Preston of Reubke's Sonata on the 94th Psalm on DGG.

And modern music by Oliver Messiaen played by Louis Thiry, and inexpensive 3-fer on Caliope.

These would be my musical picks of some 150 organ CDs and another 150 LPs. I would love to add others, but for availability and not knowing others' musical tastes.

Message me if you'd like other suggestions.
 
#4,819 ·
I'm still not understanding concept of resonance being applied to every frequency response aberration in a speaker:
Resonance

In sound applications, a resonant frequency is a natural frequency of vibration determined by the physical parameters of the vibrating object. This same basic idea of physically determined natural frequencies applies throughout physics in mechanics, electricity and magnetism, and even throughout the realm of modern physics. Some of the implications of resonant frequencies are:

1. It is easy to get an object to vibrate at its resonant frequencies, hard to get it to vibrate at other frequencies.Example
2. A vibrating object will pick out its resonant frequencies from a complex excitation and vibrate at those frequencies, essentially "filtering out" other frequencies present in the excitation.Example
3. Most vibrating objects have multiple resonant frequencies.
http://hyperphysics.phy-astr.gsu.edu/hbase/Sound/reson.html

As I understand that definition, a "natural resonant frequency" is tied to the physical parameters of the speaker, (size, mass, volume, internal bracing, etc.) It doesn't say that external influences that cause the speaker to oscillate at frequencies other than its natural frequencies are considered resonances.
@sdurani likes to use the example of blowing across the top of a bottle as example of resonance. When you blow across the top of the bottle, the air inside the bottle will resonate at its natural frequency. If you add some water to the bottle, you change the volume of the chamber and therefore the natural resonant frequency:





Adding water to the bottle is a change to a physical property of the system, and that changes the natural oscillating frequency or the resonant frequency.

I guess what I'm still having trouble understanding is, if the natural resonant frequency is tied to mass or volume, how does externally/electronically adding a rise in the response in a certain bandwidth change the natural oscillating frequency? How does an external electrical adjustment, (i.e., something done in a crossover), change any physical parameter of the speaker, or change it's *natural* frequency of oscillation? It can certainly change the levels at which the driver oscillates in a certain frequency band, but it doesn't change any of the inherent physical attributes of the speaker. Moreover, the frequency band of the external adjustment does not even consider any natural oscillating frequency of anything in the system. It's simply a choice made by a design engineer. Since frequencies other than the natural oscillating frequency are harder to make oscillate, it seems counter-intuitive to call an externally induced oscillation a resonance.

The definition of resonance being used here excludes the concept of the "natural resonant frequency" and replaces it with any oscillating frequency. If this is the way the term resonance is used, and that usage is what is used to define neutrality of a speaker, I will readjust my thinking, even if it doesn't match the definitions I've always used.

Having said that, I think it would be more clear to use the definitions as they've generally been used, because I think many/most forum members were and are using those terms in that way. The only time I've ever encountered someone calling a designer induced mid-bass hump, (or any other external FR change), a "resonance" has been in this thread.

Craig
 
#4,820 · (Edited)
I'm still not understanding concept of resonance being applied to every frequency response aberration in a speaker:
http://hyperphysics.phy-astr.gsu.edu/hbase/Sound/reson.html

As I understand that definition, a "natural resonant frequency" is tied to the physical parameters of the speaker, (size, mass, volume, internal bracing, etc.) It doesn't say that external influences that cause the speaker to oscillate at frequencies other than its natural frequencies are considered resonances.
@sdurani likes to use the example of blowing across the top of a bottle as example of resonance. When you blow across the top of the bottle, the air inside the bottle will resonate at its natural frequency. If you add some water to the bottle, you change the volume of the chamber and therefore the natural resonant frequency:


https://youtu.be/PZVeJ2rh6ts


Adding water to the bottle is a change to a physical property of the system, and that changes the natural oscillating frequency or the resonant frequency.

I guess what I'm still having trouble understanding is, if the natural resonant frequency is tied to mass or volume, how does externally/electronically adding a rise in the response in a certain bandwidth change the natural oscillating frequency? How does an external electrical adjustment, (i.e., something done in a crossover), change any physical parameter of the speaker, or change it's *natural* frequency of oscillation? It can certainly change the levels at which the driver oscillates in a certain frequency band, but it doesn't change any of the inherent physical attributes of the speaker. Moreover, the frequency band of the external adjustment does not even consider any natural oscillating frequency of anything in the system. It's simply a choice made by a design engineer. Since frequencies other than the natural oscillating frequency are harder to make oscillate, it seems counter-intuitive to call an externally induced oscillation a resonance.

The definition of resonance being used here excludes the concept of the "natural resonant frequency" and replaces it with any oscillating frequency. If this is the way the term resonance is used, and that usage is what is used to define neutrality of a speaker, I will readjust my thinking, even if it doesn't match the definitions I've always used.

Having said that, I think it would be more clear to use the definitions as they've generally been used, because I think many/most forum members were and are using those terms in that way. The only time I've ever encountered someone calling a designer induced mid-bass hump, (or any other external FR change), a "resonance" has been in this thread.

Craig
Look at it this way:

Once connected to the other equipment "speaker", by itself, stops existing - it is now a single system where "natural resonant frequencies" of both electrical and mechanical parts (and parametric EQs are creating resonances or notches) become somewhat equal.
 
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