Watts and Dynamic Watts?

[robmlisanti]

Can someone explain what the difference is between regular watts and "Dynamic" watts, my Velodyne has 150 Dynamic watts is that "Peak" wattage?

 

[markw]

I believe so.

the "real" number you should look at is the one rated "RMS", or "continous". This is a more true representation of what the amp can deliver on an ongoing basis, day in, day out.

As for that "peak" or "Dynamic" spec, well, amps store a bit of power in their power supply which can, for very short periods, boost that continus power but remember, this is for a very short time.

It's kinda like when you're running. You can run at a certain speed for a long time but, when you feel like it, you can "pump it up" for a bit. But, only for a bit. You can't keep it up for very long before running outta steam.

 

[j_garcia]

Yeah, what he said. One is RMS and the other is PEAK instantaneous power. The typically quoted power is the RMS.

 

[Nuglets]

If I'm not mistaken RMS can also be instantaneous so it cannot be used interchangeably with 'continuous'. I may be wrong about that but I do know that you have to be careful when shopping for anything with 'Watts' because there are many different ways to represent power output and it isn't always necessarily clear. I have seen so-called 1500Watt HTiB systems with speakers the size of Bose Cubes with a little DVD/Receiver combo powering it supposedly outputting 1500W. Then there is my Peavey amplifier that only claims 300W per channel at 8-Ohms which in reality can put out I'm guessing more than 5 times the power of the DVD/Receiver combo. It is important to research the products you wish to buy rather than deciding based on the number of Watts, whether it be RMS, Peak, Dynamic, Continuous, etc, you will not get an accurate representation of performance without further investigation.

 

[markw]

I've always been under the impression that both RMS and continuous are the same, or at so close that they can be used pretty much interchangeably.

My favorite rating was "PMPO, or "Peak Music Power Output" which used all sorta tricks to arrive at a totally meaningless number. ...disconnect all but one side of an amp, use more than the rated voltage to power it, feed it a 1kz, 10 volt input signal, measure it at 2000% distortion and get it right before it goes up in smoke, that kinda thing.

I used to love those early 80's "500 watt PMPO" boom boxes that were powered by 8 "D" cells. I worked at Rat Shak then and snotty punks would walk in with these things, think they were so, so much better than the 100 watt component stereo systems we sold, and start trying to put 'em down in front of customers. All I has to do was boost the volume a little. When they tried that, they left with their heads hanging and I sold a stereo.

...they hated it when I referred to that rating as "pimpo" which, technically, is a valid pronunciation, isn't it?

Oh, to the OP... Don't worry too much about this ratings stuff. We're not putting it down, just hopefully answering your question. That's still a pretty decent sub. I've got a Velo myself.

 

[tubesaregood]

Yes, RMS is generally the most meaningful number, usually the same sort of deal as continuous.

"Dynamic" power may not be the same thing as "peak" power. Different companies use different terms for power ratings. Dynamic may be closer to an RMS rating. It depends.

And PMPO is about the funniest concept ever. Don't forget the one ohm load and half millisecond burst of power measured.

 

[markw]

good point.

Yes, RMS is generally the most meaningful number, usually the same sort of deal as continuous.

"Dynamic" power may not be the same thing as "peak" power. Different companies use different terms for power ratings. Dynamic may be closer to an RMS rating. It depends.

And PMPO is about the funniest concept ever. Don't forget the one ohm load and half millisecond burst of power measured.

I forgot the almost-a-short-circuit load.

 

[Seth=L]

Dynamic power can give you some indication of the headroom of the amplifier. Higher headroom is very good, but most amps with high headroom have respectible RMS ratings.

One company that annoys me is Klipsch. The claim the peak power of their amplifiers is more important than the constant ratings. One sub may be rated 60 watts RMS and claim 300 watts peak (dynamic) power. I had such a sub and the thing was weak, IMO. The amplifier was tiny and had a reputation to blow fuses on transients. My little AR sub has a more stout amplifier, though it lacks the efficiency of the Klipsch woofer it outperforms it in most respects. It's frequency responce is limited due to it's size and tuning.

Basically, I wouldn't put trust in a subwoofer that claims the peak rating is most important or tries to hide the RMS rating by throwing the Peak power in your face in advertising. Sunfire is terrible about this, 1000-2000 watt subs the size of fruit baskets, please.

 

[MDS]

It's really quite simple...people are in awe of large numbers even if they are unaware of the derivation of those numbers.

Music is a time-varying signal with periods of low demand and very short periods of high demand. Dynamic Power refers to the maximum power available for very short periods of time (typically 20 ms). Dynamic power may be a good indication of how well it can handle short but demanding transients, but the majority of time the source will demand less and the RMS rating is what is most important.

 

[mtrycrafts]

Can someone explain what the difference is between regular watts and "Dynamic" watts, my Velodyne has 150 Dynamic watts is that "Peak" wattage?

Dynamic power is defined in the FTC specs for amps. 20ms signals twice a second.

Peak wattage may be based on yet a shorter time scale.

 

[ParadigmDawg]

Easy Seth,

I had a Klipsch sub for almost 2 days and it was kind-of cute...

Dynamic power can give you some indication of the headroom of the amplifier. Higher headroom is very good, but most amps with high headroom have respectible RMS ratings.

One company that annoys me is Klipsch. The claim the peak power of their amplifiers is more important than the constant ratings. One sub may be rated 60 watts RMS and claim 300 watts peak (dynamic) power. I had such a sub and the thing was weak, IMO. The amplifier was tiny and had a reputation to blow fuses on transients. My little AR sub has a more stout amplifier, though it lacks the efficiency of the Klipsch woofer it outperforms it in most respects. It's frequency responce is limited due to it's size and tuning.

Basically, I wouldn't put trust in a subwoofer that claims the peak rating is most important or tries to hide the RMS rating by throwing the Peak power in your face in advertising. Sunfire is terrible about this, 1000-2000 watt subs the size of fruit baskets, please.

 

[Seth=L]

Easy Seth,

I had a Klipsch sub for almost 2 days and it was kind-of cute...

That was an outrageously funny post Greg. "Kinda-cute", nice.

 

[robmlisanti]

Thanks to all I have a better understanding now!