What difference does wattage really make?

[djwdfw]

Newbie here, first time post, just trying to start figuring out what really matters when it comes to subs. If your sub can put out 100 decibels at 30 HZ in your room, does it matter whether it is driven by an amplifier of 100 watts or 500 watts? In other words, if it takes 80 watts to accomplish this and you have an amp that peaks at 100, is there any advantage to having a 500 watt amp doing it in terms of the listener's experience of the sound (I realize the 500 watt amp is working less hard, might run cooler etc., but are there any sound benefits inherent)? Thanks for any thoughts.

[Sorny]

Newbie here, first time post, just trying to start figuring out what really matters when it comes to subs. If your sub can put out 100 decibels at 30 HZ in your room, does it matter whether it is driven by an amplifier of 100 watts or 500 watts? In other words, if it takes 80 watts to accomplish this and you have an amp that peaks at 100, is there any advantage to having a 500 watt amp doing it in terms of the listener's experience of the sound (I realize the 500 watt amp is working less hard, might run cooler etc., but are there any sound benefits inherent)? Thanks for any thoughts.

If both amps are of good design, then yes, there will be a difference. The difference is that the larger amp has more headroom for dynamic peaks, and will also likely be well within the linear range of operation and should have lower distortion. Whether or not this is audible is a subject of much debate.

Did this help?

Sorny

[djwdfw]

Sorny, thanks for the reply. Does this follow as an implication then: if you knew the most you'd want out of your amp (say because you don't want to damage your hearing or wake the neighbors, etc.) is a peak of 95 db at 25HZ, and your current sub can deliver that without any audible distortion, then there would probably not be a clear reason to get a sub with greater amplification power (ruling out for the moment the rate at which either sub might drop off below 25 HZ)? Thanks for any more thoughts.

[spyboy]

If your current sub can deliver the volume you desire at the lowest frequency you consider important without any audible distortion there is little, if any, reason to be considering more power.

[djwdfw]

Thanks spyboy. A follow-up question -- if two subs are putting out 95dbs at 25 hz in the same room from the same position, is it going to feel the same in terms of the impact of the sound (how much it shakes the couch or hits you in the chest? In other words what other factors in the subs besides wattage and decibels delivered and frequency affect how the bass feels?

[mrtristan]

If both subs are delivering a pure 25Hz signal at the same level, they should feel and sound identical. In the real world, if both subs of different designs were fed the same signal, chances are they will sound different. One would produce more harmonic distortion than the other, making it feel and sound different. In other words the subs will play the fundemental frequency of 25Hz plus multiples of that frequency (50Hz, 75Hz, 100HZ, etc..) in varying degree.


Let's not forget that power rating alone is no indication of how loud a subwoofer is going to play. It's maximum output will be a function of the maximum rating of the amplifier and the sensitivity of the driver within it's enlcosure design....You can put a 500 horse power engine in a honda civic or you can put it in a huge bus. To say that both vehicles will accelerate identically and reach the same speed is like saying all subwoofers powered with a 100W amp will sound the same.

Tristan
Home Digital (http://www.homedigitalav.com)

[djwdfw]

Well, I was wondering, for example, whether the amount of air displacement might have an effect (moving a bigger speaker, having greater excursion, or something). Or is that all represented by the decibel reading?

[Lwang]

A dipole sub would definitely sound very different from a ported sub at your stated freq and level. They load up the room very differently.