# 10s Verses 15s Again - But A Slightly Different Question This Time (I Hope)

Discussion in 'Amps and Cabs [BG]' started by SurferJoe46, Jan 17, 2012.

1. ### SurferJoe46

Specifically if we are to compare a 410 and a vaporware 415 cab - I wonder if anyone can answer this question::::

Is/are the size of the coils and the cones and moving parts in a 15" driver going to need more power to move than a 410?

Assume the Ohms are the same and we have a perfectly calibrated amplifier that puts out X Watts in either situation.

My gut feeling is that the 415s require more energy to make them move as well as the 410s.

Let's leave out the cabinet variables and dampening/acoustics of the wood and the grill cloth here - OK?

2. ### Downunderwonder

Aug 26, 2009
New Zealand
Watts have no meaning by themselves, it's all the other variables that you left out that determine output. Sure 15's use more power but they move more air at the same time. If your question is about the intrinsic efficiency of vaporware, ask a different question.

3. ### T-Bird

Hi.

IMLE, it depends on three factors really.
The strenght of the motor, the mass of the moving parts and the resistance these moving parts see.

None of those factors are directly related to cone diameter AFAIK.

I'm sure BFM will be here shortly to give more elaborate answer.

Regards
Sam

4. ### JdoubleHCold, Daring. No flies on me.Supporting Member

Jul 10, 2008
Ellerslie, Georgia
By "move" do you mean from a dead stop, or do you mean move the same amount of air (in other words, produce the same sound pressure level)?

Jul 6, 2007
Phoenix, AZ

6. ### Arjank

Oct 9, 2007
Above Amsterdam
If you mean " amplifier" energy and the sound pressure level the speaker will generate, then your above statement is not true (when everything stays in " proportion" ).

E.g. when I have two drivers with identical Fs(resonance frequency), identical Qes and they only differ in cone area (and moving mass increases proportionally)then the driver with the larger cone area will have a higher efficiency, thus, requiring less energy to get the same SPL as the smaller driver.
But, when the mass of the cone increases dramatically and the Fs should stay the same, the efficiency drops (and so does the Vas). This is what happens with most of the car-subwoofers, these guys are real watt-hungry.

The 4x15 might require more energy... but it moves more air than the 4x10. Given similar specs in other areas, it's going to be louder.

8. ### billfitzmauriceCommercial User

Sep 15, 2004
New Hampshire
Owner, Bill Fitzmaurice Loudspeaker Design
No.

9. ### NKUSigEp

Jun 6, 2006
Bright, IN
It sounds like the OP only wants to address the issue of inertia and getting the woofers to woof. It doesn't sound like he's asking about volume and air displacement.

So yeah, 15's would require more work (and thusly power) since they are larger and have more mass...assuming they are made of the same materials as the 10's.

10. ### Arjank

Oct 9, 2007
Above Amsterdam
If you mean amp power the answer is no

11. ### SurferJoe46

Well, I can see there are some considerations of which I never thought. NKUSigEp makes my point for me in that I was really interested in just the power consumption/requirements of the drivers and not much of anything else.

The MASS of the 15s verses the 10s is where I was going and trying to leave a lot of the other variables out - but I see a lot of other very interesting things are going on at the same time.

In a vacuum, I guess then it takes more energy going INTO the 15s to actually accelerate and reverse the direction of travel since the cones and other parts are just plain larger or more massive.

Then I also feel by extension, that if a single frequency - a CLEAN frequency if you will - was the baseline testing input, I can see that the 10s would use less power to move then than the 15s. That was my supposition in the first place.

I can also see that there is no formulaic corollary that can be used here to imply speaker efficiency in the area in which I was thinking.

This appears to not be a Rosetta Stone for drivers in the 10s v 15s arena.

Thanks for all the pointers and information.

12. ### NKUSigEp

Jun 6, 2006
Bright, IN
I was making a statement, not asking a question.

13. ### Arjank

Oct 9, 2007
Above Amsterdam
I know.
My point was to show that if you mean amplifier power, that your statement " 15's would require more work (and thusly power)" is false.

14. ### B-string

In a practical sense, no. There may be a measurable difference IF you could use sensitive enough equipment, but the point would be???

Jun 6, 2006
Bright, IN

16. ### mbelue

Dec 11, 2010
A question such as this could only be answerable in a world with a standardized coil size/cone area ratio. Nearly every manufacturer's ratio is different. Not to mention each different model of each manufacturer. Ergo, each analogy( regardless of its psuedo-science references ) is just as true or valid as every other explanation.

17. ### rpsands

Jul 6, 2007
Phoenix, AZ
The question is "Take more power to do What?"

To achieve the same SPL? No. The 15s will be more sensitive all things being equal.

And that's really the only valid question I can think of here

Apr 17, 2006
Lombard, IL
+1

19. ### Arjank

Oct 9, 2007
Above Amsterdam
See post #6

20. ### NKUSigEp

Jun 6, 2006
Bright, IN
Well, I know we like to get all technically gaga over speaker size and volume and power and all that fun stuff here on Talkbass. But my translation of the OP is that he was simply asking: "In order to move an object of larger mass, will more power be required?" And the answer to that, here on Earth, is yes. End of story.