What does the term "Speed" mean in a speaker?


I often hear people say "That speaker has great speed". What do they mean? I know the music isn't playing at a different pitch. Could it possibly be related to efficiency?
koestner
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Faster than a speeding bullet! Oops, that was Superman!
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It usually refers to the ability of an attack (the first arrival) to startle you, such as with a kick drum or cymbal. It is also about the detail which can reach you at your seat.

In my mind, this is an artifact of tone, not actual driver speed, but since panel and cones couple so differently to a room, panels are often described as fast, while cones as slow. This is not really what's going on, but whatever. :)


How accurately a speaker system/driver follows a waveform. ie: Fast rise-time / square wave tracing, without ring, overshoot / etc. https://www.sweetwater.com/insync/square-wave-response/
I rarely hear the square wave definition used, but sure, some do.

The square wave has more to do with time/phase accuracy, and something that can be corrected for via DSP.

It is certainly a very rare thing to have a speaker that can replicate it with any sort of accuracy. :)
Speed is yet another quality that you may or may not want to prioritize in what you look for in a speaker.  
The Spendor D7 for example are a fast, nimble speaker.  They have a good jump factor and respond quickly to slight changes in rhythm, a lighter more airy quality to the sound.  They are attention grabbers and less relaxing for example. It isn't so obvious in all music though and for me is not a quality I necessarily prioritize.  
@eric- Certainly, much of what’s causing phase/freq anomalies, etc, in a speaker system, can be corrected with DSP. ie: https://www.audioxpress.com/article/a-loudspeaker-that-can-play-square-waves Far as individual drivers(or- identical multiples) and reproducing square waves; my thoughts on correction, would be more along the line of what Infinity and Genesis(et al) pursued, with their servo-contolled stuff: https://www.psaudio.com/pauls-posts/lightning-fast/ Personally; I’ve always trusted in a high damping factor(around 1K, out to 1kHz, usually), SS amp and long Xmax, in a TL, for bottom. Lately; I’ve added DSP, to those.
In my mind, this is an artifact of tone, not actual driver speed, but since panel and cones couple so differently to a room, panels are often described as fast, while cones as slow. This is not really what’s going on, but whatever. :)


Agreed, that makes sense to me.
(And resonances in a speaker can of course change perception of tone).
I have a pair of old Thiel 02 speakers which were cheap even circa early 80’s. It’s a good design making the best of a cheap box and cheap set of drivers at the time.
But boy does it sound "fast" in the usual audiophile sense of having transients pop out vividly, and having no bass overhang. They are rhythm-machines in that regard.
It’s just that they have a certain frequency balance, very flat in the bass region and maybe a tiny dip in the right places, to have a frequency response that creates this impression.

At least, from what I can infer.

Speed refers to transient response. 

The ability to follow musical transients (percussion, strings plucking, etc) closely. Both the attack and decay are important. 

Speakers with lighter, stiffer cone materials, and strong magnet structures are usually  have good speed.

Ribbon, electrostatic, and planar magnetic drivers tend to have good speed.
In my experience 'faster sounding' loudspeakers do tend to sound lighter in bass compared to slower designs. They simply don't bother getting involved in the arduous and problematic task of reaching down to seriously low frequencies.

Nothing gives me the impression of 'slowness' in a loudspeaker as much as bass overhang where the bass rhythms simply go to pot and hopelessly lag behind. 

Bass resonance factors also have an effect on the transient response of the cone as well as cabinet colorations. 


Can the impression of "speed" be adjusted with a multi-band parametric equalizer?
Impression being the operative word. Probably.
In reality, and measurably, no.
Fast with a speaker for me refers to low distortion resulting from minimal time lag due to inertia between signal and movement of the transducers as would be expected with a good combo of stronger magnets, precision machining and assembly of parts, and low mass driver and voice coil.

Result is the transducer/driver moves faster and more accurately than usual in response to the electric signal provided.

Efficiency is different.  That's the SPL produced in response to a standard electric signal.     Louder does not mean faster or less distortion in the time domain necessarily.







simmonmoon is correct. The correct term is transient response. Speakers with faster transient response tend to be more detailed and dynamic.
There are a bunch of rather silly terms out there in regard to audio equipment sound quality. Terms like pace and timing are frequently misapplied to speakers. The pace and timing of music is set by the musicians not the speakers. More poetic waxing.
+1  transient response is a proper technical term.

https://en.wikipedia.org/wiki/Transient_response

"fast" is slang.
Yep, transient response. I would say decay does not fall under the umbrella of speed or transient response but others may feel differently.

I just received the center channel that matches my Legacy Focus SE L/R Speakers. It mentions "speed" in their advertising also. Here’s part of their Ad


Legacy’s best center channel speaker has been updated to the Marquis XD. Featuring our 4" AMT ribbon, as found in the Legacy Dual Air Motion Tweeter system, and the 8" Italian crafted titanium encrusted midrange as utilized in the Aeris system, Marquis XD is on par with the speed of our best towers. These high precision drivers, a new crossover, and the incredible dual 12" ultra-linear bass drivers with 15 lb motors make it the best center speaker at any price. The dual 12" woofers of the Marquis XD deliver uprecedented linear output with snap and definition with rich upper bass and clean transition to the lower midrange.

Marquis XD can be placed above or below a 60” monitor, or behind a perforated projection screen in your home theater.

Thanks for all of this. Can amplifiers impact/covey speed differently? Seems they play a role as well...from peoples’ reviews. Is that right? 
Thanks!
I agree with simonmoon.  And, yes, I have noticed different amps seemingly add speed.  Again probably due to transients , attack, decay, less bass overhang.  Interestingly, speed hasn’t been something I prioritize but my favorite speakers have it! 
I was going to say the impression of Speed can only be adjusted by Keanu Reeves. But then some snowflake would have that taken down. So instead I will have to seriously explain that since the "impression" of speed nearly everyone equates to high frequencies, that yes boosting the treble a bit can indeed create the impression of speed. A false impression, to be sure. But you said impression, without reference to being true or not.

The truth is an infinitely fast speaker would actually sound LESS noticeably boosted in the treble. Why? Because true speed is not only how fast something gets moving but equally as important, how fast it stops. 

Which in retrospect probably is the best answer. Probably hardly anyone old enough to get the Speed reference anyway.
Here is a question: if both speakers have the same frequency response, why does one speaker have better speed vs the other?  

Another question: if one speaker uses a 4in. driver for the midrange, the other uses a 6.5in driver for the midrange, and both have the same frequency response, which will have more "speed"?

It's difficult to say since the 4in driver might have better speed in the midrange, but the 6.5in driver might have better speed for the bass.  

Also in general, if a speaker has a tipped up treble response, it does lend to an illusion of having better "speed" especially on the leading edge such as guitar.  Of course having too much leading edge could be a problem too.  
Yes.  The amplifiers output impedance plays a role.   It along with the speakers impedance determines the Damping  Factor which determines how well the amp can control the movements of the speaker's transducers/drivers.

https://www.sweetwater.com/insync/damping-factor/

I think our perception of speed has more to do with how fast a speaker driver stops making sound after the signal stops than how fast it reacts to a signal. That's why larger drivers often sound slower than smaller drivers. It's not too difficult to get a driver to respond quickly when its voice coil is energized. It's a lot harder to get it to stop vibrating once the signal goes away. 

Servo controlled drivers can overcome some of these limitations because they can use power to stop the driver quickly when the input signal stops. 
Another way of talking about "speed" is "lack of stored energy."

That is, the waterfall plot is very clean and very short, without ringing.
Not to brag, but...

My subwoofers are so fast, they can do a 20-cycle sine wave in a MERE fifty milliseconds.

Not only that, I’ll go out on a limb and claim NOBODY makes a subwoofer that can complete a 20-cycle sine wave in less time than mine.

;^)

Seriously, I agree with those who have noted in various ways that what happens with the trailing edge of the note - how quickly and cleanly it decays - is (in general) more important than what happens at the leading edge of the note, at least when it comes to the subjective impression of "speed".

Duke
Another way of talking about "speed" is "lack of stored energy."
I supposed that has more to do with "driver break up" or suffering from "impedance anomaly".  Paper cones may have a clean water fall plot, but an aluminum cones may have "faster speed" but may not look as clean on the water fall plot.  

Of course having "faster speed" does not always mean "better".  There word "speed" in this thread seems to have a lot of different interpretations.  Different people seem to have different impression of the word.
Now I get. The view perpendicular to the revolution is opposite except in  the downward position.  
i think speed in a speaker mostly refers to the mid and upper bass 50hz-250hz region which are the power frequencies where the music lives. vocals, drum kits, pianos, cellos, horns.....they all fall down or rise in this area.

leading edge precision and the presence or lack there of ease and refinement in these frequencies either impart flow and energy to the music and maintain the timing or muddle and restrict that flow and energy.

this is a speaker-amplifier-room issue, not just the speaker. and typically you see a crossover right here, amps struggle controlling the drivers here, and rooms have most of their worst bass nodes in this area. as you increase the dynamics and SPL’s this will be where things go to hell first as the combination of the speaker’s limitations, the amp and the room acoustics all rear their ugly heads.

but get the crossover out of this region, have sufficient driver surface to limit the need for much excursion, and appropriate amplifier for the speaker draw, solve the room issues, and you can get the ease and effortlessness and the speed and precision of the music will result in that speed that serves the music, the music breathes and soars.
Has anyone heard Martin Logan speakers? The electrostatic panel plays the mid and treble while the woofer plays the low frequencies.

I always felt like the woofer was slightly lagging behind as if the bass and the upper frequencies were playing slightly different tune.  The bass was in effect "slower" vs. the mids and high frequencies.

Also, most of the time, speaker frequency responses are measured in steady-state response which more or less erases the transient response, but the "speed" lies in the transient response.  So two speakers can have the same freq. response but one may be faster than the other.

May be a step response measurement can tell you the "speed" of different speakers because it preserves the transient information.
Mass and inertia guys. Transient response is how fast the driver starts and stops. Lets say you have 6 inch speakers with identical voice coils and magnets. In one the cone weights 1 oz and in the other the cone weights 2 Oz.  When I play a transient sound like a drum stick hitting a steel plate the 1 oz cone will start moving fractionally before the 2 oz cone because it has less inertia. It will also stop faster with fewer oscillations (ringing). Things are really more complicated as the Transient response of a driver is not only determined by the mass of its moving system but also by the power and damping capability of its motor. So an 8 inch woofer does not necessarily have better transient response than a 12" driver. Speakers with better transient response have a crispness to their sound missing in speakers that don't. This becomes quite evident when listening to ESLs, well designed horns, ribbons and to a slightly lesser extent planars. Speakers with better transient response are more revealing and can easily be made to sound crappy with bad or poorly set up equipment which I think is why some people have a jaundiced opinion of them particularly horns which are also not easy to design. 
I think a lot of what you are writing about, mijostyn is actually related to room interactions.

Your writing, while accurately portraying how dynamic drivers work makes a leap I don't feel comfortable following.

A dynamic driver can have a lot more dynamic range, smoother frequency response, better low frequency and lower distortion than a planar speaker attempting the same. What it won’t do is interact with the room the same way. Genesis got around this by making towers of 12" drivers. :)


Snell mounted the woofers as close to the floor as possible.

The final result is always a matter of speaker and room interactions, but the idea that planar speakers are measurably faster is not true.


Best,

Er

mass and inertia matter, but you missed one parameter, driver surface area, which determines the amount of excursion for a particular level of volume, which goes a long way determining the linearity of the response.

mostly in the mid bass you find one driver, maybe two. or two crossed over. my speakers each have -4- 97db, 7ohm, 11" ceramic matrix woofers. covering 40hz--250hz. with all that surface area and a very stiff light ceramic membrane, the need just a tiny bit of excursion so they stay linear. and the amplifier is not stressed by the load with 97db efficiency.

so you get planar or horn type speed, but dynamic cone impact. images have weight and authority. tonality is maintained and not washed out.
Speakers with better transient response are more revealing and can easily be made to sound crappy with bad or poorly set up equipment which I think is why some people have a jaundiced opinion of them particularly horns which are also not easy to design.
I am not quite sure this is entirely true.  A driver that has better transient does not mean it should have more detail or more revealing.  Better transient allows better micro-dynamic or macro-dynamic or both, BUT dynamic is not the same as detail or at least it's not a one to one exact.    

Now on the other hands, if a driver has more "resolution" then it will have more detail, but a more accurate characterization is to say the driver will "reveal" more details.  It shouldn't create more details that was not on the tape in the first place.

Transient and resolution are mutually exclusive that is one driver can have either or both.  Having one does not automatically also having the other.

Aluminum driver is usually perceived to have more "details" but a lot of that comes from it upper frequencies which tend to have a lot of break up and people sometimes interpret excess high frequencies as "detail".  And if the designer does not address the break-up, then aluminum will sound "crappy", but is it the driver fault or the designer fault?  I personally have used some cheap aluminum driver and expensive paper driver, and although the aluminum may appear to sound faster, the more expensive paper driver reveals more details, more natural detail.  So go figure.  

As for speakers that "sound crappy with bad or poorly set up", I think a lot of that comes from final implementation.  I've had the Thiel CS2.4 which is very revealing but it never sounds crappy even on bad recordings.  Speakers that sound crappy on bad recordings tend to have excessive energy on the high frequencies or some weird frequency response.  
I think there's a big gap between a speaker that sounds fast, and a driver that IS fast.

I mean, there's a lot of reasons for speakers having more detail or jump factor. The actual transient response of the drivers used does not really contribute to all of it.
How the speaker mates to the room, and frequency response I think are probably the first two things the casual listener associates with speed.

That's fine, nothing wrong with that since the end result is what matters.


I don't understand why manufacturers don't post 0-60 and 1/4 mile times?

It would make speaker selection much easier.
I don't understand why manufacturers don't post 0-60 and 1/4 mile times?

It would make speaker selection much easier.
You can't be serious.  
I’m pretty sure it was a joke
I think it falls into what the Brits refer to as PRaT - Paced Rhythm and Timing. Of course Prat is also British slang for:
  1. an incompetent, stupid, or foolish person; an idiot.
  2. 2. a person’s buttocks.
I think it falls into what the Brits refer to as PRaT - Paced Rhythm and Timing. Of course Prat is also British slang for:
  1. an incompetent, stupid, or foolish person; an idiot.
  2. 2. a person’s buttocks.

I supposed this is another dumb joke.  Maybe you're number 1?
"You can't be serious."
https://www.thefreedictionary.com/read+between+the+lines

Don't get out much? Sorry, couldn't resist.

"Maybe you're number 1?"
https://en.m.wikipedia.org/wiki/Snowflake_(slang)#Generation_Snowflake

Oh my, are you one of these? If not, refer back to above.


Interesting discussion. +1 on many posts. Nods to @simonmoon and similar posts and to @mikelavigne ’s points.

Adding an aspect that hasn’t been brought up...reduction in system noise.
I personally believe that the speed of bass tends to be slower than the highs because it can take longer for the waves to start energising the air due to their longer wavelengths. YMMV
"You can’t be serious."
https://www.thefreedictionary.com/read+between+the+lines

Don’t get out much? Sorry, couldn’t resist.

"Maybe you’re number 1?"
https://en.m.wikipedia.org/wiki/Snowflake_(slang)#Generation_Snowflake

Oh my, are you one of these? If not, refer back to above.
1. Stop wasting people time.
2. Stop making dumb post.
3. Maybe you should get out ... of here lols.  
Erik, yes speakers interact with the room but that has nothing to do with the transient response on the speaker.
Mike, unfortunately regular dynamic drivers are a poor impedance match to air. They have to work much harder to get the job done. ESLs and Horns do not have this problem to near the degree.
ESLs and horns are generally described as being very detailed. They also have better transient response, association or causation. I would say the later. Yes, a speaker with a lighter moving system could have better transient response assuming the motor was designed correctly. 
Andy, resolution and transient response are very closely related. By dynamic I do not mean loud. I mean snap.
Andy, all I am saying is that the more revealing a speaker is the more sensitive it is to defects up stream such as a miss tracking cartridge or distorting amplifier. ESLs, ribbons and horns are frequently blamed for problems elsewhere in the system. Not that some very good dynamic speakers might get caught up in this.  
resolution and transient response are very closely related. By dynamic I do not mean loud. I mean snap.

Yes, but they may not be one to one exact. A high end paper driver may have more resolution and a low end aluminum driver may have more transient but the aluminum driver may not have the resolution of the paper driver.

Snap could mean a lot of thing. A speaker may have a lot of snap but it does not mean it has a lot of resolution. I can fine tune my speaker to have tighter bass and extra energy in the higher frequency to give it more snap but it may not have more resolution.
Mike, unfortunately regular dynamic drivers are a poor impedance match to air. They have to work much harder to get the job done. ESLs and Horns do not have this problem to near the degree.
ESLs and horns are generally described as being very detailed. They also have better transient response, association or causation. I would say the later. Yes, a speaker with a lighter moving system could have better transient response assuming the motor was designed correctly.

there is a general rule, and then there are specific situations and execution. sure, dynamic cones have their advantages and disadvantages. so you need to execute over-the-top to overcome the disadvantages.

in my case that way they did it was high efficiency, and overkill with driver surface. you have -4- 15" powered subwoofer drivers per channel in a separate tower for under 40hz, and -4- 11" ceramic matrix woofer passive drivers for 40hz-250hz. this is considerably more driver surface for the mid-bass than any other dynamic cone speaker. and it’s an easy amp load of 97 db, 7 ohm. visitors who hear it exactly comment that it sounds like a planer or stat it’s so seamless and fast. yet it has the weight of a dynamic driver and since it’s an integrated design it is coherent with the lowest octaves from the bass tower too.

http://www.evolutionacoustics.com/loudspeakers/mm-series/mmseven/
When a speaker has "speed" it's approaching the sound of real, life like, sound. At times it can be so convincing, that it makes you forget about the other shortcomings it may have, like the actual soundstage, imaging, etc.

You'll notice it at first with a particular instrument or vocalist. Then you'll listen for other cues and with other recordings to see if it can be replicated.

It may not be done in an across the board accounting but at least you'll know what your speakers are capable of, given the right recording.

All the best,
Nonoise