Thiele/Small Parameters: The Language a Driver Speaks to Its Designer

T/S isn’t a spec sheet — it’s a model, and that model lets you hear the bass of a box that doesn’t exist yet, before cutting a single panel.

There’s a misconception that shows up constantly in loudspeaker work: treating Thiele/Small parameters as just a “spec table.” You open a datasheet, see numbers in a row — what’s Fs, what’s Qts, how many litres is Vas, what’s Bl, what’s Re, how many millihenries is Le — and stop there.

But to a loudspeaker designer these numbers aren’t there to decorate a datasheet. They’re there to predict.

Thiele/Small parameters are a mathematical language that compresses an entire driver into a handful of basic systems: mass, spring, damping, and motor. Once you know how much mass the system has, how soft its spring is, how much it’s damped, and how well the motor makes force, you can predict how that driver will behave in a box that hasn’t been built yet.

That is the heart of this article.

The way of reading T/S this article teaches rests on three simple principles: speaker design is a system problem, not a chase to make each value look pretty; no single parameter should be judged alone; and the goal of reading a value is to predict behaviour, not to memorise a number.

In this article we use a single example driver throughout — the same 6.5-inch woofer that runs through Driver and Cabinet Resonance and Load, Amplifier and Enclosure. The headline values we’ll mention often:

• Fs = 37.5 Hz
• Qts = 0.378
• Vas = 30.1 L
• Bl = 7.0 T·m

And the underlying values that produce the numbers above, which we’ll substitute into the equations throughout:

• Mms = 15 g (moving mass)
• Cms = 1.2 mm/N (suspension compliance)
• Rms = 1.18 N·s/m (mechanical damping)
• Re = 6 Ω, Le = 0.5 mH (the electrical side of the motor)
• Sd = 133 cm² (cone area)
• Qms = 3.0, Qes = 0.433 (mechanical and electrical Q)

These numbers aren’t here to memorise. They’re the main characters — used to show what the driver is telling the designer, and so every equation in this article substitutes real numbers you can cross-check.

T/S is not a spec table

Picture a bench in a speaker workshop.

A 6.5-inch driver sits on the bench. No box yet, no port, no passive radiator, not a single panel of MDF or birch plywood cut. All that’s there is the bare driver, measurement gear, and a datasheet — or the values measured from the real driver.

An ordinary person might look at it and say only: it’s a 6.5-inch driver, this size voice coil, a fairly big magnet. But a loudspeaker designer who knows this driver’s T/S values starts to see what isn’t there yet. They begin to know that too small a sealed box will push the bass up and make it tight; a bigger box relaxes the system; for a bass reflex, which way the box volume and tuning frequency need to go; for a passive radiator, where to watch excursion.

All of this happens before any box is built.

That’s why T/S matters. It doesn’t just tell you “what this driver is” — it tells you “what this driver tends to do.” The gap between those two sentences is large.

If you read T/S like a spec table, you ask: is Fs low, is Qts nice, is Vas big, is Bl high. If you read T/S like a model, you ask differently — does this Fs come from heavy mass or a soft spring; is this Qts set by mechanical damping or by the motor; what is this Vas saying about how soft the suspension is; how well does this Bl control the cone’s mass. This is where a designer begins to actually read a driver.

For our example driver, Fs = 37.5 Hz doesn’t simply mean the driver “plays down to 37.5 Hz.” It means the driver’s mass-and-spring system has a natural resonance around 37.5 Hz. Qts = 0.378 isn’t “good” or “bad” on its own; it says the system is damped to a certain degree — not so loose it rings, not so tight it sounds dry. Vas = 30.1 L isn’t the box size you must use; it says the suspension’s softness is equivalent to about 30.1 litres of air. Bl = 7.0 T·m isn’t a marketing strength score; it says that with 1 amp of current the motor makes about 7 newtons of force.

Read together, what emerges isn’t a table of numbers — it’s a conversation. The driver is telling the designer: I have this much mass, my spring is about this soft, I’m damped about this much, my motor makes about this much force; if you’re going to build me a home, you should know these traits first.

That’s why this article is titled the language a driver speaks to its designer. T/S isn’t just data — it’s a language. Read it fluently and you stop seeing isolated numbers; you start seeing the whole driver describe itself. Reading those numbers off a real datasheet — what they look like, how they were measured, how far to trust them — is the subject of another article. Here we focus on what the numbers mean first.

The mechanism beneath every parameter

Before we get to Fs, Qts, Vas or Bl, we have to step back and look at what sits beneath all the numbers.

A single driver looks complicated — a cone, a spider, a surround, a voice coil, a magnet, a frame, a magnetic gap, a venting system. But through the T/S lens, the whole thing reduces to just four basic mechanisms:

1. Mass
2. Spring
3. Damping
4. Motor

Every time a bass note arrives from the amplifier, current flows through the voice coil, the motor makes force, that force pushes the mass, the mass moves, the spring pulls it back, and damping eats some of the energy away. That’s the core skeleton of the system.

T/S doesn’t invent a new world; it just names the behaviour of the real one — Mms is the language of mass, Cms the language of the spring, Rms the language of damping, Bl the language of the motor, Fs the result of mass and spring together, Qms/Qes/Qts the result of damping seen from different angles, and Vas the translation of suspension softness into units of air.

Here’s the thing to watch. Learn T/S as vocabulary and you’ll know what each term means; learn T/S as mechanism and you’ll know where those numbers come from and how they pull on each other. Fs comes from Mms and Cms; Qts comes from mechanical and electrical damping combined; Vas is tied to Cms and cone area; Bl bridges the electrical motor to the mechanical world.

Seen this way, a datasheet changes its face. It stops being a spec table and becomes a map of a mass-spring-damping-motor system. That’s the foundation you need before walking the pillars one at a time, starting with the most straightforward: mass.

Mms is the mass the system must move

The first question in speaker work isn’t “how low does it go.” It’s: how much mass does the system have to move?

Mms stands for moving mass — the moving mass of the loudspeaker system, usually given in grams, or converted to kilograms in equations. Our example driver has Mms = 15 g, or 0.015 kg. It isn’t the cone weight alone; it includes the cone, voice coil, dust cap, glue, and a portion of air dragged along with the cone. To the motor, all of this is a load it must accelerate, stop, and reverse constantly.

Picture two carts — one empty, one full of cement bags. Push with the same force and the empty cart starts more easily, stops more easily, changes direction more easily; the heavier one is more stubborn, slower, and needs more force. A loudspeaker cone is no different. As Mms rises the system has more inertia and the driver doesn’t want to change velocity quickly. Conversely, more mass usually lowers Fs, because the mass-spring system swings more slowly.

What it means for a designer

More mass, Fs usually drops, but agility falls, efficiency usually falls, and the motor has to work harder. Less mass, Fs usually rises, response is quicker, but reaching low naturally gets harder. This is why subwoofer drivers often have higher Mms than midrange drivers — they’re designed to move a lot of air down low — while a midrange works with faster transients and doesn’t want to carry more mass than necessary. Mass is also one of the things that sets a driver’s loudness-per-watt, but we’ll save efficiency for the Sensitivity article.

Mms alone never tells the whole story. A driver with high Mms but very high Bl may be well controlled; a driver with low Mms but a weak Bl may be less lively than you’d think. If you see Mms and ask “is it heavy,” that’s the first question — but the more important one is: how well does the motor attached to this mass control it, and how soft or stiff is the spring carrying it.

And of the mass’s companions, the one paired most tightly with it is the spring — because mass and spring together create resonance. So we go meet that spring next.

Cms is the softness of the suspension

If Mms is the mass that must move, Cms is the spring trying to pull that mass back home.

Cms stands for mechanical compliance — the flexibility of the suspension, in metres per newton (m/N). It says how far the cone moves per newton of force. Our example has Cms = 1.2 mm/N, meaning 1 newton moves the cone 1.2 millimetres. High Cms means a soft system: a little force moves the cone a lot. Low Cms means a stiff system: you need more force for the same motion.

In a driver the spider and surround are the main parts that set this softness. But “soft” here isn’t soft as in sweet or smooth sound — it’s mechanical softness: how easily the system lets the cone move.

Cms affects Fs directly, because resonance comes from mass and spring working together. The basic equation is:

The 37.5 Hz we see on the datasheet didn’t come from nowhere — it’s exactly the result of a 15-gram mass hung on a 1.2 mm/N soft spring. Same Mms, higher Cms, softer system, Fs falls. Lower Cms, stiffer system, Fs rises.

What it means for a designer

Cms is one of the parameters that links the bare-driver world directly to the box world. High Cms, soft suspension, the driver responds to the box’s air spring one way; low Cms, stiff suspension, it responds differently. For a box designer, Cms is the first signal of whether this driver will “talk to the air in the box” easily or not.

And if Cms rises, it isn’t only Fs that changes — Vas changes too, because Vas is the translation of suspension softness into an equivalent air volume. This is why Vas shouldn’t be read apart from Cms, and Cms shouldn’t be read apart from Fs. They’re different words for the same system.

If Mms is “how heavy the thing is,” Cms is “how easily the spring lets that thing move.” When the two meet, we get Fs. But left alone these two would ring forever. What calms them is the system’s third pillar — damping.

Rms is the damping in the mechanical system

If a driver had only mass and spring it would be a very ringy system. Pull the cone out, let go, and it bounces back and forth like a weight on a spring. But a real driver doesn’t ring forever. When the signal stops, the cone settles; the energy that was in the system fades away. It doesn’t vanish — it’s turned into heat and losses inside the mechanical system.

The parameter that describes this loss is Rms — mechanical resistance, in N·s/m (newton-seconds per metre). Our example has Rms = 1.18 N·s/m. In workshop terms, Rms is the mechanical viscosity of the system. It isn’t electrical resistance, but it acts like it in the mechanical world: it eats energy and makes the oscillation die down. Its sources add up — the spider, the surround, glue and materials all lose energy; parts that flex and unflex don’t return 100% of it.

Too little Rms and the system stores energy for a long time, so resonance can be sharp and ringy. More Rms and it dissipates energy faster, so resonance is more controlled. But very high Rms isn’t automatically good, because the energy eaten away is energy that never becomes sound. Damping isn’t good or bad in itself — it’s a balance.

What it means for a designer

What a designer cares about isn’t Rms as a raw number, but how this lump of mechanical damping shows up as Qms. Qms translates mass, spring, and mechanical damping into a single number that says how sharp the mechanical resonance is. High Qms means low mechanical damping; low Qms means high mechanical damping. Our example has Qms = 3.0, which says the mechanical system itself is fairly loose and doesn’t waste much energy.

But there’s another, more important layer. A driver isn’t damped mechanically alone — the electrical motor damps the system too, through back-EMF. That leads us to Bl and Qes.

So Rms is the system’s third pillar: Mms the mass, Cms the spring, Rms the damping. And it still isn’t enough, because a loudspeaker must have a motor — and that motor turns out to be another damping source, often more important than the mechanical one.

Bl is the bridge between electrical and mechanical

So far we’ve talked about the mechanical world: mass, spring, and damping. But a loudspeaker doesn’t start from mechanical force — it starts from electricity. The amplifier sends voltage, voltage drives current through the voice coil, and that current must be turned into a force that pushes the cone. The parameter that describes this conversion is Bl.

Bl, or B·l, is called the force factor, in T·m (tesla-metres), where B is magnetic flux density and l is the length of voice-coil wire in the magnetic field. When current flows through wire in a magnetic field, force appears. The basic relationship:

That’s the tangible picture of Bl. It isn’t a mysterious number — it’s the exchange rate between electrical current and mechanical force. Higher Bl means the same current makes more force.

What it means for a designer

Bl doesn’t just say “force” — it says “control,” because Bl is tied closely to Qes. When the cone moves, the voice coil cuts the magnetic field and generates a back-voltage called back-EMF, which lets the motor “control” the cone’s motion. A stronger motor usually gives more electrical damping, so Qes falls, and as Qes falls Qts is pulled down too. Our example has Qes = 0.433, several times lower than Qms = 3.0 — a sign this driver is controlled mainly by its motor, not by mechanical losses.

Besides Bl there are Re and Le in the motor group. Re is the voice coil’s DC resistance, in ohms (6 Ω here), setting how much current flows in DC or very-low-frequency terms. Le is the voice coil’s inductance, in millihenries (0.5 mH here), playing a bigger role as frequency rises because the coil resists changes in current more.

In this article we treat Bl as a single constant. We won’t go into how Bl changes with the cone’s displacement (BL(x)), flux modulation, or motor nonlinearity. Those “the motor isn’t linear” topics have their own article — BL Product. What matters here is to see clearly that Bl, Re and Le aren’t three separate things — together they’re the language of the motor, and that motor is the bridge connecting the amplifier’s electricity to the mechanical world of the cone.

Now we have all four pillars — mass, spring, damping, motor. Time to go back to the first number everyone looks for and prove it’s only a result of these four: Fs.

Fs isn’t set by a single value

If there’s one number speaker enthusiasts look at first, it’s Fs, because it seems to say how low the driver goes. Low Fs = deep, high Fs = not deep. That’s not entirely wrong, but it isn’t enough for a designer.

ωM_ms (mass)1/ωC_ms (compliance)|difference|

The key thing in the equation is the square root. Double Mms and Fs doesn’t halve — it drops by the square root. Double Cms (a spring twice as soft) and Fs drops by the square root too. Our example has Fs = 37.5 Hz; double the mass (15 g → 30 g) without changing the spring:

If instead you make Cms twice as soft, Fs lands around 26.5 Hz the same way. Same destination, completely different route.

On the bench, the most direct way to lower an existing driver’s Fs is to add mass to the cone. Add a few grams and Fs shifts down by the square root, just as the equation says — but the meter shows at the same time that sensitivity drops and the impedance peak at Fs rises. Mass loading is never a single-variable edit; it drags the whole system along.

What it means for a designer

Don’t just ask what Fs is — ask what this Fs comes from: heavy mass, a soft spring, or both. Because the different mechanical roots are exactly what decide how many watts the driver eats, how easily it’s controlled, and what box it likes.

For our example, Fs = 37.5 Hz says the mass-spring system tends to resonate naturally around 37.5 Hz. But it doesn’t say whether the bass is good, how big the box must be, or how safe excursion is. Fs is one door, not the whole answer. Looking through Fs to the damping, the next question is: how tightly is this resonance controlled, and from which side — the job of the group of numbers called Q.

Qms, Qes and Qts are one thing seen from different sides

Q confuses newcomers a lot, because a datasheet usually lists Qms, Qes and Qts together, looking like three separate variables. But they’re really one thing seen from different sides.

Q describes how heavily a resonance is damped. High Q means the system loses little energy — the resonance is sharp and lasts long. Low Q means it’s more damped — the resonance is more controlled.

high Q (light damping)low Q (heavy damping)

Qms is the mechanical Q, looking at losses from Rms, the spider, the surround and other mechanical losses. Qes is the electrical Q, looking at damping from the motor, voice coil, and back-EMF. Qts is the combined Q of both systems. The key relationship:

The equation says Qts isn’t Qms plus Qes the ordinary way — it’s a reciprocal combination. So Qts is always lower than both Qms and Qes, and it matches the datasheet’s Qts = 0.378 for our example exactly.

|Z| free-air

This shows immediately that this driver’s Qts is dominated by Qes more than Qms, because Qes (0.433) is several times lower than Qms (3.0). In a reciprocal sum, the smaller term speaks louder. So electrical damping from the motor plays the leading role in setting this driver’s total Q.

What it means for a designer

This is what a shallow datasheet reader misses. They see only Qts = 0.378 and say “middling, usable.” A designer asks further: is this Qts low because the mechanical system is heavily damped, or because the motor controls hard.

You see this clearly on the bench. Two models whose datasheets list a similar Qts often turn out, when you open Qms and Qes separately, to arrive there by different routes — one with high Qms and low Qes, the other with a lower Qms because its mechanical system loses more. Put them in the same box, drive them from the same amplifier, and the damping behaviour around the box’s tuning frequency isn’t the same, even though the Qts on paper looks identical.

So Qms, Qes and Qts shouldn’t be read separately. Qts gives the overview, Qms the mechanical world, Qes the electrical world, and together they say from which side the mass-spring system is being controlled. By the car analogy: Mms is the car’s mass, Cms the suspension spring, Rms the shock-absorber viscosity, Bl and the motor the controlling force from the drivetrain, and Qts the overall picture of whether the car bounces, is controlled, or is stiff.

Up to here we’ve talked about the driver’s internal world. But one number acts as an interpreter, translating that internal world out to the box: Vas.

Vas is the size of the equivalent air spring

Vas is one of the most misunderstood values, because it’s in litres, and when people see litres they immediately think of box size.

In workshop terms, Vas is the translation of the spider and surround’s softness into units of “litres of air.” Why air? Because the air in a sealed box acts like a spring. A small box, the air inside is harder to compress, a stiffer air spring; a big box, the air has more room to flex, a softer air spring.

system fc in a closed box of volume Vb

So when you put a driver in a box, you aren’t placing it in an empty box. You’re putting two spring systems to work together: the first spring is the driver’s suspension, the second is the air in the box. Vas tells you how soft the first spring is in litres of air.

For our example, Vas = 30.1 L means the suspension’s softness is equivalent to about 30.1 litres of air. Put this driver in a box much smaller than Vas and the box’s air spring is stiff compared to the suspension, so the box affects the system strongly. In a box much larger than Vas the air spring is softer and the box’s effect on the system is smaller. This doesn’t mean you should use a box equal to Vas — it helps you see the proportion between driver and box.

The basic relationship for Vas:

Again, 30.1 litres didn’t appear from nowhere — it’s the cone area squared times the suspension softness, directly.

What it means for a designer

The key point of the equation: Vas scales with Cms and with Sd². A softer suspension raises Vas, and more cone area raises Vas strongly because area is squared. This is why many large drivers have high Vas — not because they “need a big box” directly, but because the cone area and suspension softness make their equivalent spring large.

This matters in real production. Changing the surround on the same driver changes Cms and can shift Vas by several litres, even though the cone and motor are the same parts. The box volume that fit a previous batch may not fit a batch with a changed surround material — which is why you measure the Vas of the actual batch, not quote a value from an old spec.

For a designer, Vas is the language connecting driver to box. Mms and Cms describe the driver’s inner world; Vas translates that world into the language of the air in the box. It isn’t an order to “use this box size” — it’s a hint about how the driver’s spring relates to the air spring. Taking Vas, Fs and Qts to actually compute closed-box volume and vented-box tuning is the job of the box articles to come — Sealed Box, Bass Reflex and Passive Radiator.

Now we know every number, and we’ve seen along the way that they’re quietly holding hands the whole time. Time to gather every thread together and see how the whole system moves at once.

Every parameter is woven into one web

By now we’ve met Mms, Cms, Rms, Bl, Fs, Q and Vas. If you were learning them as definitions one by one, the article could end here. But to really understand T/S, the important part is just beginning — because the heart of T/S isn’t knowing what each one means. The heart is seeing that none of them stands alone.

FsQtsrelative efficiency

Let’s trace one thread at a time, starting with mass.

In real numbers for our example, raise mass from 15 g to 30 g (double) and touch nothing else:

• Fs: 37.5 Hz → about 26.5 Hz (drops by the square root)
• Qts: 0.378 → about 0.535 (both Qms and Qes rise by about √2, since both scale with mass and resonance frequency)
• efficiency: down about 4× or roughly −6 dB (reference efficiency scales inversely with mass squared)

Moving “one value” makes the driver go lower, get less damped, and get quieter all at once. It isn’t tuning a single knob — it’s shaking the whole system. And this is why speaker design is a system problem, not a one-value-at-a-time chase.

Next, the spring.

Soften the suspension and Fs drops, but Vas rises, because the suspension spring is equivalent to a larger air volume. The moment Vas changes, how the driver responds to the box air changes too. This isn’t only about the bare driver — it reaches all the way to the box the driver wants to live in.

Next, the motor.

Raise Bl and the motor makes more force from the same current, but the other key effect is more electrical damping — Qes falls, Qts falls, the system is more controlled. But if Bl is very high relative to mass and spring, the system can be over-controlled for some uses. Too low a Bl and it can be loose.

And mechanical damping.

Add mechanical damping and the system dissipates energy faster, so resonance doesn’t ring on. But the energy lost is energy that never becomes sound, so it affects efficiency too.

Seeing this map, you understand the article’s key sentence — T/S isn’t many numbers, T/S is one system seen from many angles. Fs is the result of Mms and Cms; Qts is the combination of Qms and Qes; Qms ties to Rms; Qes ties to Bl, Re and the motor; Vas ties to Cms and Sd; Bl bridges electrical and mechanical. Everything is woven into one web.

In practice, two drivers that measure exactly the same Fs often give different bass in the same box — because one got its low Fs from mass, the other from a soft spring, which take Vas and Qts to different values. Matching driver to box has to look at the whole parameter set, not Fs alone. The route to the number is what gives each driver its own behaviour.

T/S describes the basic grammar of that behaviour. It doesn’t describe everything, but without that grammar you’ll never read the sentence the loudspeaker is speaking. And every powerful grammar has its limits. Knowing what T/S can explain matters; knowing what it can’t matters just as much.

What T/S can and can’t predict

Once you start to understand T/S many people get excited, because instead of having to try real boxes you can simulate before building. But careful here: T/S is a very powerful model, but not a model of everything.

What T/S does well is predict low-frequency behaviour in the small-signal regime. It helps forecast Fs, Q, sealed-box behaviour, bass-reflex behaviour, the effect of box volume, the effect of the air spring, low-frequency impedance, and the trend of bass response. This is why T/S became the common language of loudspeaker design for decades.

But its limits are sharp, and the most important boundary is the words small signal.

In the large-signal regime, things start to move: Bl isn’t constant over excursion because the voice coil slides out of the region of strongest field; Cms isn’t constant over the stroke because the suspension stiffens near its limits; Le changes with position and frequency; Re rises as the voice coil heats. This is the world of nonlinearity, which basic T/S doesn’t fully tell, and it’s why a value like BL(x) needs its own article — BL Product.

Beyond the small/large-signal line, several other things sit outside T/S’s view.

First, T/S doesn’t tell you Xmax. Two drivers may have similar Fs, Qts and Vas, but one moves much farther than the other. Without Xmax you don’t know how hard a bass the driver takes before distortion or bottoming out — Xmax.

Second, T/S doesn’t tell you thermal compression. As the voice coil heats, Re rises, current falls, force falls, loudness drops, behaviour changes. This matters a lot in PA, subwoofer, and continuously-loud systems — Thermal Compression.

Third, T/S doesn’t tell you cone breakup. A driver may have beautiful low-frequency T/S but violent breakup in the midrange, or off-axis behaviour to watch. That needs frequency response, distortion and directivity too, because T/S treats the cone as a single rigid piston — true only at low frequencies.

Fourth, T/S doesn’t tell you whether the sound is “good” or “bad.” It tells you what the driver tends to do, but not the driver’s whole identity.

T/S is the grammar — essential; without it you can’t read the language. But knowing the grammar doesn’t mean understanding everything. In the loudspeaker world there’s still cone material, motor topology, linearity, directivity, distortion, crossover design, the box, the room, and real listening, that T/S alone doesn’t cover.

So this article doesn’t claim you see everything from T/S. It claims that without understanding T/S you haven’t begun to hear the driver’s basic language. That’s the correct boundary. T/S isn’t the final answer, but it’s a very important first door.

A driver is speaking all the time

Back to the article’s first question: why can measuring a driver just once predict how it behaves in a box that hasn’t been built?

The answer is clearer now. Because that measurement doesn’t measure just numbers — it measures the system’s basic structure: mass through Mms, spring through Cms, damping through Rms, Qms, Qes and Qts, the motor through Bl, Re and Le, and the relationship between driver and air spring through Vas.

When this information is combined, you don’t merely have a datasheet — you have a model. The model reduces the whole driver to a mass-spring-damping-motor system, and because that system is computable, you can simulate a box that doesn’t exist yet.

And a good designer isn’t good because they memorise the most numbers — they’re good because they read these relationships. Seeing Fs, they don’t see Hz, they ask what mass and spring are doing; seeing Qts, they ask from which side the system is controlled; seeing Vas, they ask how the suspension relates to the box air; seeing Bl, they ask whether the motor makes enough force to control its mass.

Different drivers can make the same frequencies, but from different sets of mass, spring, damping and motor — that’s the “accent” that differs, and T/S is what lets us pin down which parameter that accent comes from. Without it, we only hear that speakers differ but not why. With it, we begin to hear the reasons behind the difference.

This is what the article aims for: not to make you recite Fs, Qts, Vas, Bl, but to start reading a driver’s behaviour — because the goal of reading T/S is to predict, not to memorise. The next time you open a datasheet, you may not see the numbers the same way. You’ll see mass, spring, damping, motor — a system telling its own story.

A designer’s job is to learn the language the driver speaks. That language is called Thiele/Small parameters, and the next step is to open a real datasheet and try reading it with these new ears — which is what the next article, How to Read a Loudspeaker Datasheet, will do.

References

• aesThiele, A. N. “Loudspeakers in Vented Boxes, Part I & II,” JAES 19(5):382–392 (1971); 19(6):471–483 (1971).
• aesSmall, R. H. “Direct-Radiator Loudspeaker System Analysis,” JAES 20(5):383–395 (1972).
• aesSmall, R. H. “Closed-Box Loudspeaker Systems — Part I & II,” JAES 20(10):798–808 (1972); 21(1):11–18 (1973).
• stdIEC 60268-5, Sound system equipment — Part 5: Loudspeakers.
• bookBeranek, L. L. & Mellow, T. J. Acoustics: Sound Fields and Transducers, Academic Press 2012.
• bookDickason, V. The Loudspeaker Design Cookbook, 7th ed., Audio Amateur Press 2006.