Does Size Matter?

[WVEAS]

I got in a discussion with a self-proclaimed audioholic the other day and he was trying to tell me that when it came to straight-up SPL's, the size and quantity of drivers had little to do with the volume you could get out of a speaker. Basically saying a well-made 3.5" driver could produce the same SPL's in the same room as a moderately built 7" driver.

Is it just me, or is this guy smoking something?

 

[gmichael]

I got in a discussion with a self-proclaimed audioholic the other day and he was trying to tell me that when it came to straight-up SPL's, the size and quantity of drivers had little to do with the volume you could get out of a speaker. Basically saying a well-made 3.5" driver could produce the same SPL's in the same room as a moderately built 7" driver.

Is it just me, or is this guy smoking something?

It's possible, but usually not the case.

 

[BoredSysAdmin]

Or even if it could do so, the response will be far from flat.

Possible exception to this rule - B&W XT4 - they do sound amazing for tiny drivers they have... but then again - it took 4 years for B&W to perfect them...
But then they probably have some issue human ears typically can't pick-up

 

[MidnightSensi]

There are lots of factors that go into how much SPL a driver can create. Is he talking about at a given frequency? A smaller driver is generally more efficient at higher frequencies than a larger one, but a larger one is generally more efficient at lower frequencies. For example, a compression tweeter might keep up at 10kHz with a 12" subwoofer at 50Hz.

Larger drivers have an advantage with heat disapation and excursion, their larger magnets have more volume to cool themselves, and their larger surround size can allow for more suspension travel.

Now when you factor in cabinet design, materials, crossover design (frequencies they need to cover), it really requires you to evaluate it on a case-by-case basis.

In my experience, drivers that stretch the limits of physics are generally not cost effective and/or don't sound as good. If you have to make big sound in a small package, then more esoteric drivers may be needed, but otherwise I'd spend money elsewhere.

 

[WVEAS]

The argument was honestly started by someone wanting a new home theater set-up and this guy recommended a HTiB from Klipsch. It was a 5.1 with an 8" powered sub, then 4 satelites with 3/4" dome tweeters and a single 3.5" driver and the center has 2 of thes 3.5" drivers and one tweeter. I mentioned that depending on the size of the room, that system probably isn't going to be enough to match his brand-new 55" TV.

I was then corrected by the guy saying "size doesn't matter"... but, like it's been said, why work 3.5" to death when a nice satelite with a 6.5" and a 1" done tweeter can be had?

 

[j_garcia]

The argument was honestly started by someone wanting a new home theater set-up and this guy recommended a HTiB from Klipsch. It was a 5.1 with an 8" powered sub, then 4 satelites with 3/4" dome tweeters and a single 3.5" driver and the center has 2 of thes 3.5" drivers and one tweeter. I mentioned that depending on the size of the room, that system probably isn't going to be enough to match his brand-new 55" TV.

I was then corrected by the guy saying "size doesn't matter"... but, like it's been said, why work 3.5" to death when a nice satelite with a 6.5" and a 1" done tweeter can be had?

What his comment doesn't take into account is where do you want your midbass to come from? Even with multiple drivers in a small enclosure, you are going to have to cross them high as these types of speakers typically don't extend much below about 70Hz and run the risk of creating a gap or dip between them and the sub. The mains need to cover low enough to properly blend with the sub. So in a way he is sort of right, but it really depends on the speakers in question. I have heard some speakers with drivers of this size that sound good, but it isn't the norm and they also tend to not be the best with music as they lack the lower midbass performance.

 

[JerryLove]

Another way to add SPL is *more* drivers.

 

[j_garcia]

Another way to add SPL is *more* drivers.

I sort of touched on that, but more drivers playing the same thing add SPL over the same frequency. They will not add extension.

 

[JerryLove]

I sort of touched on that, but more drivers playing the same thing add SPL over the same frequency. They will not add extension.

Very true, and bigger won't do HF well.

 

[GirgleMirt]

I got in a discussion with a self-proclaimed audioholic the other day and he was trying to tell me that when it came to straight-up SPL's, the size and quantity of drivers had little to do with the volume you could get out of a speaker. Basically saying a well-made 3.5" driver could produce the same SPL's in the same room as a moderately built 7" driver.

Is it just me, or is this guy smoking something?

Your 'friend' is an idiot, or simply ignorant, or both. You're basically moving air. Bigger drivers need to move much less than a small driver to move the same amount of air. There's a limit to how much a woofer can move back and forth, it's called excursion. So that said, a larger driver with same excursion will move more air. More drivers will, again, move more air.

Proof: Go to a car show where they've riced up their cars. Notice the lack 3.5 inch subwoofers.

Is it impossible that a 3.5 inch would outperform a pitiful 7 inch? Not impossible, but show me a 3.5 inch driver which can reproduce better bass than an average 7 inch woofer... And multiple 7 inch woofers? He's on crack...

Check here:

http://www.baudline.com/erik/bass/xmaxer.html

a 3.5 inch, needs to move 55mm for 40hz @ 100dB... FIVE cm... What about 110dB? 17.8 cm. LOL

Now what about a 7inch?
17mm for 40hz @ 100dB, 44mm at 110.

Now what about four 7 inch woofers?
each needs to move 3.5mm for 40hz @ 100dB, and 11mm for 110dB.

Now what about four 15 inch woofers?
Only 2.4 mm for 110dB.

Which would you think would sound better? Seriously... :\ What about 130dB?

Four 15 inch: 24 mm.
One 3.5 inch: 1782mm. Or, almost 2 meters. Yes. Many 3.5 inches have an excursion of 2 meters. He's right. You're wrong... (sarcasm obviously).

That said, reproducing higher frequencies does not require very big movements but actually very fast movements. If you replace 100hz by 5000hz, then you'll notice it really doesn't require much excursion. What is taxing when increasing the volume is the bass. So if that was his point, that the 3.5 inch woofer is actually a mid and doesn't need to reproduce low frequencies, then he'd not be wrong. A 3.5 inch mid could play ridiculously loud, just not bass.

The argument was honestly started by someone wanting a new home theater set-up and this guy recommended a HTiB from Klipsch. It was a 5.1 with an 8" powered sub, then 4 satelites with 3/4" dome tweeters and a single 3.5" driver and the center has 2 of thes 3.5" drivers and one tweeter. I mentioned that depending on the size of the room, that system probably isn't going to be enough to match his brand-new 55" TV.

I was then corrected by the guy saying "size doesn't matter"... but, like it's been said, why work 3.5" to death when a nice satelite with a 6.5" and a 1" done tweeter can be had?
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Which is basically what he said here. But then again, it depends on the crossover point, you'll want your mains to cross to the sub fairly low, say 120hz minimum, and 120hz for a 3.5 inch is still quite too low. So again, he's wrong. If he had dozens of 3.5 inchs he could do it, with one, I seriously doubt it. Again, the premise is false, quantity and size for woofers are key for high SPL.

 

[highfigh]

I got in a discussion with a self-proclaimed audioholic the other day and he was trying to tell me that when it came to straight-up SPL's, the size and quantity of drivers had little to do with the volume you could get out of a speaker. Basically saying a well-made 3.5" driver could produce the same SPL's in the same room as a moderately built 7" driver.

Is it just me, or is this guy smoking something?

At close range, they may have the same output and frequency response but once you mpve away, the frequency response falls off at the low end and it definitely won't sound the same. While a 7" will beam at high frequencies, I can't think of anyone who has ever tried to use that size for full-range. SPL is frequency-dependent. Did he say it would have the same response, too? That's highly unlikely, if not impossible.

Tell me he doesn't have Bose speakers. Self-proclaimed 'audioholic', or audiophile?

If his opinion was true, I'm not sure large speakers would still be made for consumer use. People, usually wife-type people, don't want big speakers and the market for little speakers that roar would be very brisk, to say the least.

 

[just-some-guy]

that guy doesn't know what he is talking about. look at it this way. if smaller speakers put out the same spl and sound quality as large speakers. then why would rock bands use large speakers at their concerts.

 

[TLS Guy]

I got in a discussion with a self-proclaimed audioholic the other day and he was trying to tell me that when it came to straight-up SPL's, the size and quantity of drivers had little to do with the volume you could get out of a speaker. Basically saying a well-made 3.5" driver could produce the same SPL's in the same room as a moderately built 7" driver.

Is it just me, or is this guy smoking something?

There is a grain of truth in what he says, but that is as far as it goes.

If you want to get high spl out of a small driver and you can, you need one of two things or both.

1) Efficient horn loading. This means the driver may be small, but the enclosure huge.

2). A very long throw driver. This is a very expensive proposition and not usually done. To develop bass the driver must have a very flexible suspension, because of you add mass to get F3 down then you have a small sub driver, and that is not useful. A very flexible suspension caries huge problems of reliability and risk of damage.

So for the above reasons drivers are made larger to get expense down and reliability up.

The most famous high spl small drivers are the Lowthers. They I think must handily qualify as the worlds most long lived Hi-Fi speaker company going back to before WW II. The company was founded by the great Paul Voight. Those little drivers cost a small fortune by the way.

Back in the fifties and sixties Donald Chave was at the helm until his far too early death.

I remember in the pre solid state era, they needed accurate reinforcement for a concert in St Paul's Cathedral.

The professional sound reinforcement boys just gave up. Somehow Donald was contacted. He filled the space with four six inch drivers and four tube amps. The next day the daily papers in their reports were gushing about the quality of the sound reinforcement! So it can be done.

Donald was a really nice guy. Lowther were then in Bromley, Kent not far from where I grew up. I feel privileged to have know and been guided by so many of those great pioneers from that era.

 

[Johnny2Bad]

It's possible in a smaller room. In a large room, you need to be able to move some serious volumes of air, and smaller speakers are going to be working pretty hard at it. A smaller speaker working at the limits isn't going to have that effortless quality that a bigger set will have under those conditions.

There are ways around that, such as horn loading, or a seriously efficient acoustically treated and purpose-built room, but I'm going to assume we're talking conventional dynamic drivers in a conventional home setting here.

If you limit the listening levels to moderate or lower, they have a chance. You could also have your listening position fairly close to the smaller set, and get away with it, but if you get up and walk around, you'll notice a difference.

You might also run up against issues with a system and a sub; to move big air you are going to need a fairly hefty sub, or a pair of fairly hefty subs, even, big or little speakers. That's an issue you will always run into with big rooms and subwoofers.

The problem will show when you try to integrate a relatively huge sub with smaller speakers; there will often be a discontinuity with the transition from sub to low bass and perhaps mid-bass that won't seem quite right, at least not in comparison with what bigger speakers will be able to do in that situation.

There can be a related issue when the speakers are huge and the room is small as well; in that case it's going to be hard to find a good placement. Smaller speakers will usually not have a problem in that situation.

You've got to keep in mind that it's not particularly easy or even a good idea to generalize too much, but broadly speaking, it's the room that you have to excite that is going to determine what will work speaker-size wise with dynamic type speakers in the home setting, at least.

There are situations where a small speaker set in a large room is what is preferred; not everyone wants to break a lease every night. If you have a gathering, and some guests are in the nearfield watching a movie, you might be OK with people in the back still being able to carry a conversation without being driven to the kitchen. It's not a hard-and-fast rule you need big speakers making big sound in a big room if that's incompatible with your intended use.

 

[26oz]

This may be ignorant as Im not by anymeans an "audiophile" I just love good sounding systems and want to jab my ears out at bad sound. etc Im a fan of large drivers and always thought how does a small driver accurately reproduce the sound of a large instrument. when i listen to smaller driver I am always really aware that its coming from a speaker, you know what i mean?

 

[TLS Guy]

This may be ignorant as Im not by anymeans an "audiophile" I just love good sounding systems and want to jab my ears out at bad sound. etc Im a fan of large drivers and always thought how does a small driver accurately reproduce the sound of a large instrument. when i listen to smaller driver I am always really aware that its coming from a speaker, you know what i mean?

Only in a sealed design does the driver produce all the sound output. In a bass horn the driver produces practically none of the bass output, it all comes from the large horn mouth. In a horn low frequency extension is pretty much determined by the size of the horn mouth.

In TLs a great deal of the low frequency output is from the open end of the pipe.

In reflex enclosures at tuning frequency the driver pretty much stops still and the output is from the port.

The low frequency extension of a driver is determined solely by the free air resonance (Fs) and the stiffness of the suspension, not driver size. However a small driver unless the cone can move a vast distance needs a lot of help from the enclosure.

 

[JerryLove]

This may be ignorant as Im not by anymeans an "audiophile" I just love good sounding systems and want to jab my ears out at bad sound. etc Im a fan of large drivers and always thought how does a small driver accurately reproduce the sound of a large instrument.

What is a "large insturment"? A tuba is a folder horn for a mouth. The low registers on a piano are (admittely rather long) peices of string.

Some drums are large, though I'm not sure where in the mix of mallet and drum-skin size we would size it.

But the fact that the need-glasses-to-see speaker in a good pair of ear-buds can produce anything at all says that speaker size doesn't *need* to match insturment size. Of course, if you want SPL...

 

[TLS Guy]

What is a "large insturment"? A tuba is a folder horn for a mouth. The low registers on a piano are (admittely rather long) peices of string.

Some drums are large, though I'm not sure where in the mix of mallet and drum-skin size we would size it.

But the fact that the need-glasses-to-see speaker in a good pair of ear-buds can produce anything at all says that speaker size doesn't *need* to match insturment size. Of course, if you want SPL...

I'm going to extend those remarks. If you take a tuba, and the player just plays the mouth piece (substitute speaker) you get practically no sound and certainly not any bass. Now put the mouth piece (substitute horn enclosure) on the tuba and you get a huge sound and lots of bass. Same for trumpets, trombones, French horns etc.

Now have a player just play a clarinet or oboe reed, same thing. Now put it on the instrument (pipe) and it fills a hall.

Now try playing a stringed instrument without a body, and you get the idea. Now a stringed instrument is somewhat like a ported reflex enclosure (Helmholtz resonator) but the analogy breaks down here as there are complex radiation modes of the bodies of the instruments.

The best examples are the horns and pipes as these are such good acoustic transformers with such good coupling to the space and encirclement especially from pipes. A loudspeaker cone can do none of that which is why they have such trouble filling rooms, especially large ones. That is why I regard sealed enclosures as less than elegant. I admit that reflex loading is which is so common is significantly less than ideal.

Horns and pipes are better, but you have to give them a lot of real estate.

To hell with WAF and give them their real estate!

 

[Ed Seedhouse]

Speaker size definitely makes a difference, because of something we call "the laws of physics". Whether that difference matters is another question, whose answer largely depends on what matters to you.

 

[CNguyen777]

bigger speakers = better sounds period. Bose did the opposite though with their ads in the 80s . Bigger sounds coming from their tiny speakers they claimed.