Subwoofers - Power Handling & Output
06-11-2003, 02:55 PM
#1
500 Watt CAFz'r
Thread Starter
Join Date: Dec 2001
Posts: 550
I was thinking about the relationship between power handling of a sub and its output.
In theory, the doubling of power to the sub will increase the output by 3dB. This should occur as long as the power delivered to the driver is within the working limits of the driver. When I refer to working limits, that would include the mechanical and the thermal limits of the driver.
Here's is where things get cloudy for me... It would seem logical that at a certain point where the driver reaches its X-max that the driver will achieve maximum output (of a given frequency) and also be at its mechanical limit. If more power is given, that power will simply be dissapated as heat thus pushing the driver near its thermal limts.
Is my thinking correct?
How can one determine at what amount of power will a driver reach its X-max? Is it the MAX power rating?
I can't see the RMS rating as being so, since it is the continous amount of power and therefore it would be always near its X-max...
The floor is yours...
In theory, the doubling of power to the sub will increase the output by 3dB. This should occur as long as the power delivered to the driver is within the working limits of the driver. When I refer to working limits, that would include the mechanical and the thermal limits of the driver.
Here's is where things get cloudy for me... It would seem logical that at a certain point where the driver reaches its X-max that the driver will achieve maximum output (of a given frequency) and also be at its mechanical limit. If more power is given, that power will simply be dissapated as heat thus pushing the driver near its thermal limts.
Is my thinking correct?
How can one determine at what amount of power will a driver reach its X-max? Is it the MAX power rating?
I can't see the RMS rating as being so, since it is the continous amount of power and therefore it would be always near its X-max...
The floor is yours...
06-11-2003, 06:36 PM
#2
Originally posted by mqqball:
I was thinking about the relationship between power handling of a sub and its output.
In theory, the doubling of power to the sub will increase the output by 3dB. This should occur as long as the power delivered to the driver is within the working limits of the driver. When I refer to working limits, that would include the mechanical and the thermal limits of the driver.
Here's is where things get cloudy for me... It would seem logical that at a certain point where the driver reaches its X-max that the driver will achieve maximum output (of a given frequency) and also be at its mechanical limit. If more power is given, that power will simply be dissapated as heat thus pushing the driver near its thermal limts.
Is my thinking correct?
How can one determine at what amount of power will a driver reach its X-max? Is it the MAX power rating?
I can't see the RMS rating as being so, since it is the continous amount of power and therefore it would be always near its X-max...
The floor is yours...
I was thinking about the relationship between power handling of a sub and its output.
In theory, the doubling of power to the sub will increase the output by 3dB. This should occur as long as the power delivered to the driver is within the working limits of the driver. When I refer to working limits, that would include the mechanical and the thermal limits of the driver.
Here's is where things get cloudy for me... It would seem logical that at a certain point where the driver reaches its X-max that the driver will achieve maximum output (of a given frequency) and also be at its mechanical limit. If more power is given, that power will simply be dissapated as heat thus pushing the driver near its thermal limts.
Is my thinking correct?
How can one determine at what amount of power will a driver reach its X-max? Is it the MAX power rating?
I can't see the RMS rating as being so, since it is the continous amount of power and therefore it would be always near its X-max...
The floor is yours...
The amount of power to reach xmax is totally dependant on it's box and properties of thereof.
I can throw 1200 watts to my ED's subs and only get 6.5mm xmax but thats at 45 hz in a ported box tuned to 45 hz.
X-max is the mechanical limits of the sub to sxcourt.
Rms rating is the amount of power the sub's voice coil(s) can handle.
On the other hand my subs in a ported box tuned to 46 hz will only take 400 watts to reach xmax around 20hz. I talking 15.8mm
Get it?
X
06-12-2003, 07:59 AM
#3
50 Watt CAFz'r
Join Date: Apr 2002
Posts: 228
Some corrections:
"Once the drivers reach x-max (which is distance of excursion)"
Xmax is not the "distance of excursion"....it is the amount of LINEAR travel.
"The amount of power to reach xmax is totally dependant on it's box"
Correct
"X-max is the mechanical limits of the sub to sxcourt."
Nope...that's Xmech
"Rms rating is the amount of power the sub's voice coil(s) can handle."
You are actually describing thermal power handling.
Get it?
"Once the drivers reach x-max (which is distance of excursion)"
Xmax is not the "distance of excursion"....it is the amount of LINEAR travel.
"The amount of power to reach xmax is totally dependant on it's box"
Correct
"X-max is the mechanical limits of the sub to sxcourt."
Nope...that's Xmech
"Rms rating is the amount of power the sub's voice coil(s) can handle."
You are actually describing thermal power handling.
Get it?
06-12-2003, 12:49 PM
#4
Guest
Posts: n/a
Even after achieving Xmech you can still get more SPL out of your driver by applying more power. This is not because of the driver so much but because of the microphone.
Additional power 'might' make the cone of the driver accellerate faster and compress the air faster which in turn makes the coil of the element in the microphone move faster which generates more voltage which then shows up as a higher SPL. The old 140db mics from Audio Control were terrible for this - you could get an artificially high SPL if you played a note that would 'spike' your woofers. It is an imperfect system.
Finding the point where extra power does not correlate to more SPL takes experimentation and a lot of $$ for recones [img]graemlins/freak.gif[/img]
Additional power 'might' make the cone of the driver accellerate faster and compress the air faster which in turn makes the coil of the element in the microphone move faster which generates more voltage which then shows up as a higher SPL. The old 140db mics from Audio Control were terrible for this - you could get an artificially high SPL if you played a note that would 'spike' your woofers. It is an imperfect system.
Finding the point where extra power does not correlate to more SPL takes experimentation and a lot of $$ for recones [img]graemlins/freak.gif[/img]
06-13-2003, 03:11 PM
#5
500 Watt CAFz'r
Thread Starter
Join Date: Dec 2001
Posts: 550
Finding the point where extra power does not correlate to more SPL takes experimentation and a lot of $$ for recones.
In theory, output should be the same but if the sub reaches its maxium output potential with say 150W then I would be better off running both drivers instead of one.
06-14-2003, 07:00 AM
#6
Guest
Posts: n/a
^ You'll get more output from the pair for sure. Of course your box is then twice the size too...
I would run one and have a spare. [img]graemlins/thumb.gif[/img] 600w is still a lot for that driver.
I would run one and have a spare. [img]graemlins/thumb.gif[/img] 600w is still a lot for that driver.
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