Speaker Size Question

[Russell L]

Ok, forget the cab. Now, with some speakers sitting on a bench by themselves, no cabs, what is the inherent sound that each size will have? Is this even an intelligent question? It's just that with so much talk of how speaker size doesn't matter, and with my own lack of understanding, I'm curious if there is anything that is noticeable, or rather, "characteristic," about speaker size.

Don't worry, I won't be offended if ya wanna kick me for a stupid question, lol. I guess this goes backto the question, "If speaker size doesn't matter, then, why do they make different size speakers?" Beats me, so I'm asking, that's all.

Thanks.

[runmikeyrun]

without a cab they're all going to sound like crap.

[holcombj1]

Secrets of Amplifier and Speaker Power Requirements Revealed - eCoustics.com

this article is pretty detailed with the mathematical properties of sound. hope it helps your understanding of how sound works!

[scottfeldstein]

I'm pretty ignorant as well. But I think really big or really small speakers have different "most efficient" frequencies than others. But to actually realize that kind of optimization, you'd have to have the signal crossed over. Like an 18" speaker may be more efficient in the 50hz range, but you'd probably need to have it only receiving only the low sounds to begin with (and reverse mounted in a big W cabinet).

Speaker size probably doesn't matter much when they're expected to receive the full range of frequencies. Except... I am under the impression that smaller speakers are more "responsive." Which I take to mean that a 10" cone can move and respond a lot quicker than an 18" one. This can lead to a nimbler reproduction of the original signal.

Now the knowledgeable people can come and tell me why i'm wrong about all this. I need the education as much as you!

[Mr. Foxen]

Originally Posted by runmikeyrun

without a cab they're all going to sound like crap.

That is wrong. Plenty of drivers are happy not in cabs, just not generally bass ones. Anything happy in an open backed cab.

Weight and stiffness and motor power are more important, which are kind of affected by size, because you can't make massive cones light and stiff, and you have more scope for suspension flex, but those are all specs that can vary between speakers of the same size.

[Smokin' Toaster]

Remember also that it takes more time to get a larger mass moving and more time to get a larger mass stopped. That's why a larger cone and move more air and produce low frequencies well, but it may not be the tightest, most defined sounding speaker. Some folks like 18s and some folks like 10s, or even 8s

[dhomer]

I think the question posted is a bit too generic to get a definitive answer.. Simply put, not all speakers are created equal. Can't lump 10"s, 12"s and 15"s in groups, just as well as you just can't throw any speaker in any cab.. I mean CB15s and 3015LFs are both 15" speakers, the comparison ends there..

I can make a couple of generalizations, though. In our application, displacement is king. Given 3 drivers (10", 12", and 15") w/similar motors and xmax measurements, the 15 is going to have a larger displacement. Simply means better LF response. Take the Eminence neo LF's as an example. A single 3015 LF has more displacement than a single 3012LF. However, use two 3012's you have more LF capability than the single 3015..

Does not mean that 10's aren't usable.. these newer designs simply allow a bit more power to be used without distortion/fartout. A properly designed cab will do the trick..

Don't know what you have on the bench, but thats a starting point.. What's actually usable??

[RickenBoogie]

...all speakers move at the same rate.

[craig.p]

Originally Posted by Russell L

Ok, forget the cab. [...] I'm curious if there is anything that is noticeable, or rather, "characteristic," about speaker size.

The problem is that if you "forget the cab," it all de-evolves into an academic, context-free exercise, because it's the system, i.e. the enclosed drivers, that has the real-world significance.

Traynor makes an 8x8 bass cab that kicks serious butt. Pedal steel players love stiff-coned fifteens. So, out the window go 98% of the generalizations. The remaining two percent need to have all else being equal tied pretty tight to them -- and even then things can get dangerous in a hurry.

[Russell L]

Well, ya'll, I pretty much thought this would be a mess. Like I said, I didn't even think this would be a reasonable question. I can see that it is hard to answer when there is no context. And no, I don't have any speakers on a bench right now. It's just that I have been reading a lot of threads about a lot of different things on here, and, I must say learned a lot that I never knew before. But, as I am still just learning some aspects of the technical stuff, I am at the point to wanting to know more. So...this crazy question.

Thanks to all who have offered info here (and those who wish to continue the discussion). I'll keep checking in. Meantime, I'll be reading some more (thanks, "holcombj1 for the link). If nothing else, maybe some myths will get dispelled here.

[gnjpowell]

Impossible to consider the "sound" of a typical frame & cone type driver without a cab, they are components of a SYSTEM. You would need to devise a "reference standard" cab and as each size driver needs a different size [read volume] cab you even then could not directly compare the relative sound of each driver. In general, a larger driver will go lower but will also roll-off the highs at a lower freq as well and that means less natural harmonics. Like everything in life - it's a compromise....

[billfitzmaurice]

Originally Posted by Russell L

Ok, forget the cab. Now, with some speakers sitting on a bench by themselves, no cabs, what is the inherent sound that each size will have?

Drivers must be mounted in an enclosure. There is no 'inherent sound' based on driver size alone.

[JimmyM]

If driver size created an "inherent sound," then all same size drivers would sound the same. They obviously don't.

[Smokin' Toaster]

Originally Posted by RickenBoogie

...all speakers move at the same rate.

But they do NOT start and stop in the same time span.

[JimmyM]

Originally Posted by Smokin' Toaster

But they do NOT start and stop in the same time span.

Yes they do.

[Sartori]

This should be an amusing thread.

[Russell L]

Originally Posted by Sartori

This should be an amusing thread.

Hope I haven't opened a can o' worms.

I am hoping that this discussion will help me, and others, understand how our equipment works, as well as how to intelligently choose future equipment. I was talking to an audio engineer yesterday at work. Interestingly, some of his comments contained some of the things that I have been reading to be myths. That was disturbing to me. Even in this thread there is controversy. Everywhere I go there is controversy. Eventually, I get to believing that there is no way to find the right answers, and that the only way to know how anything sounds is to play it myself, and to forget the technical stuff. But, when shopping for something, such as a cab or amp, one cannot always play it before purchasing. As much as I love the stuff I have now, I must say that I bought it without knowing very much technically. Just a little, but very basic. Now, the more I learn, I wonder if I made the right decisions.

It is unfortunate that manufacturers don't list specs that are more useful. Am I right in saying that?

[billfitzmaurice]

Originally Posted by JimmyM

Yes they do.

He's got you there, sort of. A driver with a heavier cone will damp out the high frequencies more quickly than one with a lighter cone after the signal is removed. But there's no correlation between cone size and cone mass, so it remains that cone size alone has no effect on anything other than dispersion angle.

It is unfortunate that manufacturers don't list specs that are more useful. Am I right in saying that?

Spot on.

[Russell L]

Speaking of dispersion, how much difference is there, really, between a 10", 12", and 15"? Now that I've gone and bought a 15" I am concerned.

[billfitzmaurice]

Originally Posted by Russell L

Speaking of dispersion, how much difference is there, really, between a 10", 12", and 15"? Now that I've gone and bought a 15" I am concerned.

Dispersion and driver size are inversely proportional. I wouldn't use a fifteen on its own above 1kHz. Tens are good to 2kHz. But only when vertically aligned. Two tens side by side have the same dispersion as an eighteen, give or take.

The bigger question is: Why did you buy a fifteen? If you're building your own cab first you choose a cabinet design based on your frequency response, output and pack space needs, then you load it with the driver(s) recommended for it. Unless you're an expert loudspeaker designer, of course, but if you were you wouldn't be asking these questions.