There is no substitute for cubic inch or in this case surface area

Just curious, what were the speakers with the two 12in. drivers?

I agree that a large enveloping sound and impact is abetted by physically large systems.  My own system has twin 12” woofers and a midrange horn thst is two feet wide by six inches tall.  My local dealer’s current custom builds often utilize twin 18” woofers and Much larger horns—up to 4.5 feet wide by 4 feet tall.  

Don't confuse "cubic inches" with "surface area" (i.e., "square inches") of cone movement.

While four 6" diameter woofers have the same "surface area" as a single 12" diameter woofer, it is extremely doubtful that each of these 6" woofers could "xmax" as far as the 12" woofer so they would not be able to move the same volume (i.e., "cubic inches") of air or attain the same maximum volume level.

HOGWASH!
 Big speakers with large drivers are more directional than small speakers with minimal drivers...

What has dispersion have to do with sense of scale?  I like many small speakers, but they don’t do scale, sense of authority and impact of the big boys.

There has been a really large difference in woofer technology over the last forty or fifty years. Once the standard 12" woofer was used in substantial speakers. The bass was large, fat and sloppy. It would depend on the speakers. Some were very inefficient and were not as fat and slow, but still so in comparison to today’s.

What has changed is the throw and speed. So, large, slow woofers have been replaced with smaller, fast, longer throw. They are far more articulate and directional... meaning the images of the instruments in the lower registers are more focused and nuanced. This is a huge improvement in realism. My Sonus Faber have two 8.7" woofers. They do not sound fat... like bigger speakers of the past, but they are incredibly fast, and accurate. The soundstage goes deep into the wall and on both sides of the speakers. 

Today's muscle speakers like the B&W 801 D4 use 10" woofers and develop amazing bass sound pressure levels, but are still very articulate.

Some folks may like the old sound of the old big woofers. 

Just curious, what were the speakers with the two 12in. drivers?

It's a DIY speakers that I made.  It has two 12in. driver on the back of the cabinet and the tweeter is horn loaded with a 8in mid range drivers.

It does not have the speed of the smaller drivers, but it does "big" really well.

I have had infinity woofer towers with 6 - 10 inch drivers. Not for home theater but they play all music as good as it gets.

Most newer speakers have multiple smaller drivers so you could have speed and low bass.  But which one would you rather have: two 8in drivers moving violently or one 12in driver moving gently?

Speaking of soundstage, one 8" woofer can do it very well. It very much depends on electronics, including tubes. I had some vintage GE 12AX7 tubes in the preamp of VAC integrated when I bought it. Then I replaced them with vintage Mullard long plates. The difference was big in every element, and it wasn't really bad even with those GE. Tubes matter, a lot.

As for scale, dynamics and impact, well, that's different subject.

Good question.  At face value 12 inch drivers will put out a bigger soundstage than 3 inch drivers.  I find it depends on the listening room.  Large tower speakers with multiple 8+ inch drivers will put out a large soundstage if properly designed and built but can over power a smaller room.  By the same token a pair of bookshelves with 6 inch drivers that are a great match for a smaller room can be limited in a larger room.  I have both types of speakers in two different rooms and matched well they each sound excellent with a soundstage that fits the room.  

There are a lot of variables in play, very few absolutes, and pros and cons with every choice.  Freedriver touched on the fact that larger drivers become directional at frequencies that are larger than the surface diameter.  

Implementation, setup, the listening space, phase coherency all play a large role in the outcome.

I prefer the sound of low excursion woofers--I like their ability to reproduce tonal nuances instead of just delivering deep, punchy bass; they sound more natural to me.  This does come at the cost of not being able to go very deep in frequency response.  This is admittedly a big price to pay but it is a personal preference.  Among the better modern woofers I've heard are custom woofers that are 18" in diameter and have pleated fabric surrounds that limit excursion and the thiele-small parameters require use of a very large enclosure.  A local builder who got a manufacturer to build drivers to his specifications uses twin 18" drivers in some of his bigger speaker and is proud that they go down to 35 hz.  I really don't miss the lower frequencies when I hear these systems.  Another modern driver supplier who sells 18" field coil woofers also makes them with low excursion and they are even more limited in deep bass response but sound very agile and clean; this builder uses these drivers too for customers looking for its signature, but, these drivers cost more than $20k per pair.

In my experience there is only moderate correlation between speaker or driver size and the size of the soundstage the speaker throws. There are small bookshelf speakers with two drivers that when placed on stands and positioned properly produce a huge soundstage.

However, I must admit that the largest soundstages I have heard are from giant speakers with multiple drivers. Von Schweikert Ultra 11's, big Wilsons, and a couple other huge speakers. Another speaker that generates a huge soundstage is the MBL 101 E.

I'm running Thiel CS6 speakers and they throw a respectably large soundstage with a small number of drivers.

With smaller driver it has to move a lot to produce the same sound pressure vs. bigger drivers.  

When the small drivers move violently, it creates distortion.  

@andy2 

My Rockport Avior ii speakers can go to 25 hz. I play all types of music and even on the lowest electronic music the drivers don’t move much. I have seen smaller woofers move like you say and it’s not desirable. 

Rockport Avior ii

I wish I have your speakers.

Advancements in woofer and cabinet technology no longer require large diaphragm elements to produce accurate bass response capable of properly loading a room and producing the benefit of enhancing soundstage you seek.  The effect on soundstage is related to the accuracy of the low and mid bass, and the woofer’s ability to move enough air in correlation to room size to create  the effect.   For example, my speakers are known for the fast, articulate, and dynamic bass response with two vent loaded 5.5” woofers.  These woofers are a rigid, long throw diaphragm design that move large volumes of air even though they are small diameter drivers.  25Hz test tones are audible (a little over 3db down); however, there is a steep roll off after that and 20Hz test tones are not audible to my old ears.  This level of response is amazing from such small drivers.  In fact, multiple smaller woofer speaker designs have the advantage of wider dispersion and less beaming than older large diaphragm woofers, enhancing the soundstage better. Therefore, it is not necessary to have a large diaphragm woofer to get deep, accurate response that enhances soundstage.  

The technological advances include, but are not limited to:

1. New magnetic materials with higher field strength (higher Tesla rating). 
2. New magnetic designs (for example, my speakers use a ring magnet structure) that are more accurate and more efficient transducers of electrical to mechanical energy.
3. Long throw armature designs moving as much air as a larger diaphragm, short throw design. 
4. More rigid diagram materials and computer assisted design with less break-up effects resulting in lower distortion. 

These advances permit the design of small size woofers that have the advantages of lower distortion, speed, dispersion and accuracy while moving significant quantities of air compared to older large diaphragm designs.  Within a given brand, woofer size increases with larger, more expensive models that are usually designed for more voluminous rooms in order to correlate the volume of air moved by the speaker with room volume.  

I just experienced exactly that. My speakers are 12" 3 way. I've been looking for a smaller speaker that can best them, and have come up empty. 

Most recently, I auditioned a pair of ATC SCM20P. Having heard the 50s and being told that all ATC speakers share the same sound, I had great expectations. And they are great sounding speakers but just don't have the scale of sound I'm used to.

Since my existing speakers are JBL, I also auditioned a pair of 4309s, the 6.5 inch version of the 4349 which is a great speaker. And they too, are great sounding speakers overall but just sound small. 

The ATC SCM50s only have 9 inch woofers but sound as large as mine so maybe there's just a threshold of size for that big sound. The wavefront a larger woofer puts out is recognized by our hearing as representing a bigger scale of sound. 

@andy2 ​​​​@ronboco 

Modern, long throw woofer designed have significantly advanced so there is very little measurable distortion. The technology has advanced to produce drivers with accurate pistonic diaphragm movement reducing breakup effects.  Rigid diaphragm materials also prevent breakup effects.  I recommend reading reviews on Vivid and Vandersteen  speakers  and peer reviewed literature on the benefits of their IP on this subject.  What you state was correct 20 years ago, may be correct today for improperly designed speakers today, but is incorrect for well designed speakers form audiophile companies on the market now.  I see the woofer excursion on my Vivids vividly and the distortion rating is <0.5% second and third harmonic over frequency range.  

That's the great thing about extolling the virtues of home-built; nobody else has a means for comparison to confirm or refute the claims.

The term for the combined cone area and how far they move is called SD.

Also in consideration if how long the voice coil is compared to how far they can move and being under control properly.

Multiple small drivers can do what any big driver can do as well, if used correctly can even be used to cancel out issues many particular drivers tend to have.

I like the sound of big drivers but also the sound of small ones designed and used correctly, both can be very satisfying.

I have had horn systems that would blow away most all big driver systems in dynamics and incredible overall live sounding output and they used very small drivers.

I was also designing a very high end and complex system for a car project with massive horns built into the vehicle and dual 21" infinite baffle subs before I decided to go full time RVing so I sold that project off.

There is simply no one solution for what can be archeived for any particular size of drivers. Then of course first and foremost the space it will occupy and room treatments being top priority, always.

My next DIY speakers are going to be Frugel-horn Joan with Mark Audio MA200 eight inch full range drivers just because I have not done this before and it should work really well in our full time RV where my Egarhorns are the wrong design and far to big, line arrays I have might work, wanted to go with OB but not a good place for it....I could end up building something else but I like the idea of no crossovers and my little Baby Sophia 10w PP amp, fully upgraded of course.

Rick

My Martin Logan classic 9’s with their 9”x44” panel provide for an incredible sense of “there” in the room….im suspecting that large radiating area has a lot to do with that. 

Not totally necessary if you have good design vented speakers with dual woofers 

you can get very good deep bass $$ is the limiting factor.

great stand mounts ,with a pair of good subs click all the boxes 

your $$ budget makes or breaks the speakers design,build quality 

from my experiences.

I've often thought of woofer speed not as acceleration but deceleration. The ability to stop fast is also speed and it affects the following tones since if it hasn't stopped it partly obscures the next tones and it reduces the dynamics since the next tones start from a higher noise floor. Basically it's the Q of the bass design that describes woofer control with 0.5 Q being maximal damping and 0.707 Q being flattest response. Above 0,707 the bass becomes more and more bloated. I might add that below 0.5 the bass becomes thinner and rolls off too quickly. There's more to balancing Q and bass cut off but that's a longer tale.

I'm always going to bat for large, stiff woofers with high excursion capabilities over small woofers no matter how many.  The distortion specifications are pretty clear.

The good reasons for small woofers are usually more related to having limited bass not waking the room modes that are deeper.  So much of what is attributed to using small speakers because they are faster ends up being caused by room mode issues, not speed. 

As for soundstage, not sure but maybe it has more to do with wide baffle speakers?

Interesting. I would have thought soundstage was more related to the mid and higher frequencies, since our localization of low frequencies is very poor. If the 12" drivers were operating up into the midrange, their higher directivity at those frequencies could result in less room interaction, and a higher direct to reverberant ratio, which could be more effective at preserving directional information. Just a thought.

Interesting. I would have thought soundstage was more related to the mid and higher frequencies

I know a lot of people have reported back that by adding the a good sub, the soundstage also was improved so I think low frequencies are related to soundstage.

@andy2 Have you considered pairing a sub with your Thiels? That might solve your problem.

This has been a solved problem for many years.  My 20+ year old Velodyne 18 inch sub is -3 at 14hz and distortion is <1%.  People who think big subs are slow should turn off their mains and listen to just the subs.  There is nothing fast sounding <60hz.  

I experimented with a bunch of smaller subs to see how it worked and I wouldn't recommend it.  I had 2 10", 2 8", and 2 little PSB sub-series 100s.  The surface area was equivalent to a 20" sub but it didn't come close to the big Velodyne. The excursion wasn't anywhere near comparable.  I understand having multiple subs to help with room interaction but the bigger the better. 

My experience with bass speed and impact is that it has more to do with mid and upper bass energy coming from woofers rather than subs.  I've got a pair of ATC 110s and those have that in spades.  They sound so powerful and dynamic, way more than any other speaker I've heard.  But they're not flat to 20hz or anything even close.  They each have 2 9" woofers with 275 watts to each driver in active configuration.  

I consider an 8" woofer to be the minimum for satisfying bass.  I've tried speakers with 6.5" woofers and subs.  It works fine for some music but if you want to crank beethoven or AC/DC it never satisfies.  

Well I obviously agree :-)

https://www.youtube.com/shorts/VsWzdS8Fa0A

Happy Listening Everyone

Peter

Peter, I was there.  Was impressive, but I get better imaging in my living room and this would be unnecessary overkill.

But I don't need to fill that much volume and only use two JBL 18"ers, not 12.

@jon_5912 

I also have an 18" Velodyne subwoofer.  The cone excursion is servo controlled in a real feedback loop, right where it matters.  The Velodyne blends in superbly so I only become aware of it when particularly low notes play!

@jsalemo277

Speakers like the KEF Reference series produce huge volumes for their size, in part because they use aluminium for the voice coils.  Aluminium is 4 times more conductive than copper, weight for weight.

I am convinced that to get a great soundstage, you cannot go past apparent single point speakers, like KEF, Fyne, later Quad electrostatics, Tannoy ...

While this discussion has focused on woofers, the midrange driver(s) are key to the attributes we are discussing.  I particularly like compression drivers and horns, and I have found that the bigger the horn and the lower one can set the crossover point, the better the sound.  Truly large horns, with the right drivers deliver scale, impact, and authority at lower volume levels than any other kind of driver.

Most modern box speakers use reflex loading to handle the bass region.  The most obvious "violent" cone movement occurs at the port tuning frequency, where the box acoustically vanishes and the woofer is completely unloaded.

My Yamaha NS-5000's have one 12 inch woofer each. You have to look carefully to see them move. It's a 6 ohm driver with a 3.5 pound woofer coil, which I think is key to its incredible bass texture and detail down to 26hz. I rarely hear my subwoofer. 

Midrange and tweeter (4 ohms both) are the identical (to the woofer) carbon fiber coated in Monel (copper nickel alloy). Hence it is virtually impossible to isolate a driver with your ears. 

The rub is this design is in its relative energy inefficiency. The user guide says 200 watts "nominal." I ran them on 250/500 8/4 ohm Ice Modules for a while. Now they are connected to 500/1000 watt Ice Modules which I think is about right. My wife noticed the difference immediately. We have a 13 foot listening distance in an open plan tract house. So no nearfield listening and no flea watt amplification. 

@larryi Wrote:

Truly large horns, with the right drivers deliver scale, impact, and authority at lower volume levels than any other kind of driver.

I agree!

Mike!

Check out a pair of Legacy Focus SEs. They feature 2@ 12 inch woofers. They are incredible. 

The Focus SE’s woofers have a 15 lb motor structure. 

Discounting surround widths, cone depths, voice coil dust cover diameters, and any additional surface available from any ribbing in the cone itself:

6" dia. = 28.27 sq. in.

8"  "     = 50.27  "   "

10"  "    = 78.5   "   "

12"  "    = 113.1  "  "

18"  "    = 254.5  "  "

pi x radius squared for anything else....

I play with truncated cone surface areas.....

Mine work out to be about equal to about a 9" dia. in the diameter of a 6"... ;)

Voice coil suspension and travel is whatever I want to play with, keeping in mind the surround pistonic travel will require.  And not a lot of concern over tariff ruckus for the immediate future....

Mix 'n match to your pleasure, J

@dynamiclinearity Thank you for pointing out Q = 0.707 (1/√2) resulting in flattest freq. response. Do you happen to know how is it derived? 

@asvjerry 

24" =  452.4 sq in.

nah nah nah nah nah!

Hartleys kickin' butt.......

And BTW you can't see them move and will play subsonic.

"Just doin' a little Hartley hammerin'....." *L*
Keeps the skin supple....try that excuse on the sig other... ;)) 

Let me know if it works at all....😎

We had a 32" Clarion sub in our possession for quite a while.  In a 6 cu ft sealed enclosure it would rattle the rafters in our (and adjacent) building -- while moving about 1/4". 

Thoughts on the OPs observations:

What might be happening here an aggregate of amplitude, detail, and dispersion. While smaller drivers are very good at projecting an image from wall to wall, they may be a couple of dbs short of a glorious presentation.  And, have to work pretty hard when dynamic passages demand that the drivers to move large distances. When you have large bass drivers of dipping well into the subsonic region and producing massive amounts of bass, the speaker designer can "open up" the other drivers (or choose higher efficiency drivers) and let them play, thus increasing the dynamic range of the entire musical bandwidth, and lower overall distortion.

At lower levels, the system is just humming along with low distortion and plenty of dynamic headroom on reserve.  This lower distortion also keeps spacial cues intact, thus providing a coherent soundstage, while maintaining detail and focus.  In this way, the speaker with more "cubic inches" may, in fact, provide a more realistic presentation than a smaller example.

Bigger can be, and in my case is better.  Just scored a pair of Pure Audio Project Trio 15 coaxials at AXPONA25.  Two 15 in woofers per channel.

I haven't been this immersed in the music since I got my Thiel CS3.5's. I also have a pair of Ohm Walsh 4.5000's.  Each of these speakers do some things better than the other and I'd often switch between them.

But the Pure Audio Project Trio 15 coaxials do it all better.

There is no replacement for displacement. 

My listening room is 20'x15' with wooden floors (with an 8x12 carpet) and windows. What I don't want are woofers that are so powerful they rattle my windows and shake my floors, adding bass distortions.

I have a pair of Sonus Faber Olympica Nova 5s with three 7" woofers that go down to 32 Hz. They are perfect for my room. I can feel the vibration on really low sounds and various percussion like tympani, sticks, and snare drums sound accurate. I can also hear placement and depth.

Prior to these I owned a pair of Golden Ear 2+ speakers. They had two 5" by 9" subwoofers and two 8"by 12" planar bass radiators. The bass was not nearly as accurate as my Sonus Fabers. I could turn the bass up and down, but if I turned it up too high my windows rattled and floor shaked. So, accurate with sound waves that are felt by my body is about as much bass as I want.

My main towers are 15” Altec 604C coaxial. 

My sub is the floor firing 15” Velodyne. 

Imho in order to project authority, you need to move a lot of air. 

...And then some.

https://youtu.be/iGa9259pz-I