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

The TS parameters for bass driver being used in a horn is very different from the same sized driver used elsewhere. For example, the surround of the driver is much stiffer (typically a cloth material), since the cone moves very little. +/- 1/16 was amount stated in the horns that I made. 

By the way, horns use conventional drivers so they are probably the same.

surroundings which hold cone and magnets(alcinico,neodium) usually is different

 As much as I have enjoyed reading through this thread, I couldn't help but remember when Velodyne made subs that used an accelerometer on the woofer cone, allowing it to be 'corrected' by the sub amp 3,500 times per second (maybe that is the way they still operate, dunno). It has been a very long time since I have owned such an animal, but I still remember the speed that I heard in the bass. To me, it came across not only in impact, but pitch definition as well. 
 Years earlier, when I owned a pair of corner horns, the bass had much of this kind of quality too, IIRC. 
 The sub that I am using presently (10" driver with a 12" passive radiator) with a velodyne SMS-1, doesn't have these effects, even though the bass is enhanced (increased).

regismc, a fast cable? Please don't make me choke on my dinner. Electricity travels at the speed of light. All wires have exactly the same speed. Resistance and capacitance are separate issues. Personally, I would rather be addicted to sex. (Big smiles from the wife)

Speed as a function...

Small floorstander, Castle Conway III, intel Nuc, Benchmark Dac pre, Mystere PA, you want ‘speed’, transient attack, dynamics with decay, openness?  Try Captains Audio Envy cables.  I’ve a pr. of the Studio Prestige rca, a usb, & a balanced cable.  Remarkable spacious detailed resolution, the fastest cable I’ve heard.  Lightweight, easy to handle, affordable, speed.   

Example... the Castles r bottom ported adjustable thru spacers to various room sizes.  With AE interconnects, ports wide open, they sound like sealed boxes, absolutely no overhang, spacious, neutral, dynamic, textured speed unleashed thru the speakers carbon fiber drivers.

Addictive.

Same thru a pr. of 1SC’s.  AE interconnects r FAST, and one can easily appreciate such thru the additional frequency range moving beyond the monitors.  Fun too.  Refined, cohesive, spacious, they convey a distinct ‘house sound’ that reminds of a good modern tube amp, or a great set of headphones, the small Castles sound like lovely dark electrostatics with better dynamics.  
Speed indeed...

Listen to the Bass Line in Glad Tidings by Van Morrison.....

Does the whole song sound in sync or can you sense some lag ...

Speed = Rise and Decay

I enjoy a fast midrange/woofer/subwoofer and cabinet design, as it sounds crisp and accurate. 

Tweeters are generally fast. I enjoyed the Focal Tc120/90 series tdxt with the vented pole piece, as you could build a rear enclosure and affect the sound/speed of the tweeter like other drivers in the system. 

I agree with most of the theories above for sure.  I also agree that the room acoustics have a lot to do with frequency dispersion and speed. To much absorption and or diffusion will have a profound effect on the fastest speaker production.
It is unfortunate fact for all of this as it really difficult to find the perfect combination without serious experimentation and or expense. I am fortunate to own full ribbon driver speakers and have had all types before them......they are easily the fastest I have experienced because of driver mass and height of the panel allowing driver radiation accuracy. In addition, I have experimented with acoustic treatments extensively (both absorption and diffusion) and feel they do pretty well with minimal treatment accept for my room's obvious modes. Nothing will be perfect so you have to choose the combination that pleases you most in the overall selection of components, speakers, and room acoustics. Everyone has different thoughts in perceived musical reproduction.

Best of luck,
gwalt

Most speakers are not time cohesive and nobody seems to care or notice.

Just because nobody seems to care does not mean it does not matter.  Just because if something has not been proven, it does not mean that it's not true.  

Time cohesion has never been proven. Most speakers are not time cohesive and nobody seems to care or notice. 

Hold on Andy. That is a mistake. Yes they are all transducers but their ability to function in air is quite different. ESLs and horns are a better impedance match to air and transmit sound waves more efficiently. Dynamic drivers have to work harder to get the same results. ESLs work entirely differently than conventional speakers. First, there are no magnets. ESLs are capacitors conventional drivers are not and represent an entirely different load to the amplifier. Designed correctly their transient response is superior to conventional drivers because the moving system has far less inertia and is a better impedance match to air.
Planar speakers are somewhere in between. IMHO in spite of the compromises you have to make ESLs rule as long as you can make them. I have personally not heard a conventional speaker sound as convincing. Some say well designed horns can do it. But I am still waiting to hear one that does.

OK, you're right.  Opposite attracts :-)

By the way, horns use conventional drivers so they are probably the same.

Obelisk, rodman is correct. The drivers have to be phase/time aligned. Sound from each individual driver has to reach your ears at exactly the same time. The Dalquist DQ-10 was the first speaker to try and deal with this. 
It is all about transient response, the ability to start and stop fast without ringing.

Boy some really odd analogies flying around here. Audiokinesis are you out there somewhere? Your help would be appreciated:)

Great discussion and lots of good info to consider. At the end of the day, it’s what one hears. I have experienced speakers that are fast but didn’t sound it because of bass overhang attributable to room acoustics. Fix the room and you’ll extract everything the speakers can offer. And also be confident when evaluating new speakers. I have a really good room acoustically and whe I compared new Raidho speakers to my existing Burmesters (both ribbon tweeters) I could really feel the impact of the transients. Not sure I would have before getting my room right. Just my opinion. 

@obelisk- "Some speaker designers used to put the tweeters physically behind the plane of the woofer to try and accomodate the slower response of the woofer." No- The physical time alignment, in multi-driver systems, has nothing to do with the relative speed of the drivers. Rather: to get the acoustic centers(actual sound source/voice coil) of the drivers, in the same plane/in phase. https://en.wikipedia.org/wiki/Loudspeaker_time_alignment

I believe it is all things that come together to have a fast set of speakers. Well designed paper drivers in a well design enclosure . With as high end crossovers as you can afford , with an amplifier with the appropriate taps , bi amplified . I think fast is what we are all trying to achieve . A speaker doing precisely what it is told . 

There are many different factors that can make a speaker sound “faster,” but in my opinion, the biggest factor is the class bias of the amp.  I’ve made this analogy before.  A class B bias amp is like a dragster sitting on the starting line with the engine at idle.  When they get the green light, they floor the throttle and are off toward the finish line.  A class A bias amp is a like a top fuel dragster.  The throttle is wide open and they pop the clutch getting off the line SOOO much quicker.  Class A bias amps are always wide open, just waiting to reproduce the musical note, hence a faster response time.

All speakers have mass and inertia, because they are mechanical devices pushing air. This means the "thing" in the speaker that moves the air will never respond instantaneously to what the amplifier throws at it (i.e. be fast).

Electrostatics is one technology that is 'faster' than most.

Large cone speakers (woofers) driven by electromagnetic coils are slow because the cones are heavy and electromagnets have electrical inertia. Electromagnets resist any signal feed to them from an amplifier and they return a signal back to the amplifier (back-EMF).

Low impedance output stages on amplifiers are important because they help 'dampen' the back-EMF, effectively stiffening the cone speaker. 

Tweeters and electrostatic panels tend to have light mass - they respond faster than woofers (bass speakers). Hence why Martin Logans can sound like the bass is slower than the panel.

Some speaker designers used to put the tweeters physically behind the plane of the woofer to try and accomodate the slower response of the woofer. Perhaps the B&W 800's do this?

Any two or three way speaker will struggle with phasing. Two way speakers often sound cleaner because of less speaker phase issues and the cross-over networks are simpler. Cross-over networks that use inductors and capacitors can potentially introduce phasing issues.

Quad electrostatics always sounded great because they were basically a single cone speaker. Bass was not great though. It was interesting playing Telarc's 1812 CD through Quad ESL 2905's.
 


 

cd318, quite a long marketing dissertation for a easily solved problem. All he says about our hearing is correct. Our ears are primarily location detection devices. They evolved to locate danger. His analysis of speakers is correct. This is the major problem for horn speakers like the K horn. The drivers are at significantly different distances from you ears.
The "easy" solution is to use one driver and no cross over. Not so easy.
The only transducer type that has been able to do this successfully is the full range ESL. Trying to do this in the analog domain with conventional drivers is difficult and only really effective at one location. At higher frequencies say the midrange to tweeter crossover it is more difficult to match things up then at much lower frequencies with longer "slower" wave lengths like a sub woofer crossover. 

Hold on Andy. That is a mistake. Yes they are all transducers but their ability to function in air is quite different. ESLs and horns are a better impedance match to air and transmit sound waves more efficiently. Dynamic drivers have to work harder to get the same results. ESLs work entirely differently than conventional speakers. First, there are no magnets. ESLs are capacitors conventional drivers are not and represent an entirely different load to the amplifier. Designed correctly their transient response is superior to conventional drivers because the moving system has far less inertia and is a better impedance match to air.
Planar speakers are somewhere in between. IMHO in spite of the compromises you have to make ESLs rule as long as you can make them. I have personally not heard a conventional speaker sound as convincing. Some say well designed horns can do it. But I am still waiting to hear one that does. 

Transient response, certainly, as has been pointed out by others, sonically perceived as a lack of smear/crispness, unforced clarity and liquidity. Usually, not least through quality all-horns, I find it linked to uninhibited dynamics as well (or: ease of "explosivity," felt as a startling experience), coupled to (at least as a partially responsible aspect) a pronounced degree of low volume level "ignition," whereby music comes alive quite easily at lower SPL's. 

The issue of loudspeaker speed (like almost everything else about loudspeakers) seems to be endlessly complex.

Here's an interesting interview with Allan Hendry of Monopulse loudspeakers.

https://www.monopulse.co.uk/quest.htm

If what he's saying is correct, and I don't have enough knowledge to know any better, then many (if not all!) two way designs could be seriously flawed when it comes to speed, phase and integration issues.

I do not put electrostatic and planer speakers in the same category as push-pull standard types of speakers

That may be true, but conventional drivers are transducers nevertheless - they convert electrical energy to mechanical energy hence by definition they are transducers. And fundamentally there’s not much difference between electrostatic panels and conventional drivers.  They might be different but not fundamentally.

When a speaker has "speed" it's approaching the sound of real, life like, sound

Designing speaker is a compromise - some are optimized for speed (dynamic), or soundstage, or musicality.  Some $80K speakers can have a huge soundstage but lack musicality.  Some are optimized for speed but soundstage may lack bloom.  And so on ...

From my time in the audio hobby and profession,  I feel speaker "speed" has much to do with the response time in moving with the very first note/electrical impulse.  The trailing edge of a note is easier for a transducer as it is already in motion.  However the leading edge begins with the speaker/transducer at "rest", and the possibility of the transducer being slower than the electrical impulse being sent to the transducer.  (sorry for the "transducer" word, but I do not put electrostatic and planer speakers in the same category as push-pull standard types of speakers).  

Interesting question and answers. 

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

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/

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.

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.  

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.

"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.  

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

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.

"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.

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?

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’m pretty sure it was a joke

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

It would make speaker selection much easier.

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.

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.  

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.

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 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. 

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.

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.

Now I get. The view perpendicular to the revolution is opposite except in  the downward position.  

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.