Power draw of high powered sub in "real world" conditions

[NMG]

Hey folks,

So I was thinking about upgrading my Paradigm PW-2200 to a Paradigm Sub 12 and I got looking at the amp in that Sub 12. It's rated at 1700 watts "RMS sustained" and 3400 watts "dynamic peak". My initial thought was "good grief, I'd be tripping breakers if I plugged that thing in along with my other gear", so I decided to actually measure what my current system drew at what I would consider a loud level. The highest peak we noted when we tested was 5.7 Amps. This was watching Kung Fu Panda on Blu-Ray through my PS3 in 5.1. I think the volume was at 65 on the 1056. Other equipment that was going:

- Rotel RB-1080 for the front left and right
- Rotel RSX-1056 for the center and surrounds
- Paradigm PW-2200
- Panasonic 50 inch plasma (this had the single biggest impact on draw)
- Monster Power Conditioner
- Rotel RCD-1072 was on but not playing
- Satellite receiver was on

When I looked at the power consumption ratings for all of this gear, I expected the draw to be considerably more than what it was. When I just listened to music in 2.1 (without the tv and PS3 on), the draw was like 2.4 Amps, not much at all.

The room is on a 15 Amp circut and nothing else is really in there or will be. Do you think adding the Sub 12 would put me over the limit? If you look at the rated specs, it would look like it would but based on my test and the fact that the actual draw was so much less than what I thought it would be based on the rated power consumption of all my current gear, I can't imagine that going with the Sub 12 would pose any problems. I would be swapping out the PW-2200 for it if I go that route.

Any thoughts? Would you say that my results are typical in that the power draw in the "real world" is only a fraction of what the paper specs may suggest?

Thanks in advance for any feedback!

[Glen B]

IMO swapping out a sub with a higher maximum rating is not likely to make a difference. As you've discovered, actual system current draw under normal listening conditions is less than the maximum. Your current draw is similar to what I have measured with my 2-channel and HT systems.

[NMG]

Thanks for the feedback Glen B!

[whoaru99]

Would you say that my results are typical in that the power draw in the "real world" is only a fraction of what the paper specs may suggest?

Thanks in advance for any feedback!

Yes, typical.

It helps to understand that for an amp of say 1,000 watts (use what ever number suits), you almost never produce sustained output of 1,000W with music/movie because of the dynamic nature. A commonly used factor is 1/8 power on average. Meaning, even if you crank up your 1,000W amp to produce full output right to the verge of clipping, your average power output will be only around 125 watts.

Besides that, a 15A circuit breaker does not trip immediately at 15A of current. It will allow much greater current to pass for short times which provides for some peak demand to be satisfied without tripping. If you look at a Square D trip curve for a 15A breaker, you'd see it could pass 2x rated current (so 30A) for somewhere from ~8 to ~30 seconds before it would trip. Going even further out to 5x rated current, trip times could be expected in the ~1 to ~3 second range. Clearly enough to handle some very serious peaks without tripping. That said, lack of breaker tripping doesn't make up for some likely significant voltage drop on peaks that large. Only short and or large gauge wire can fix that part though. Well, higher voltage helps too, but often that's not a choice.

[NMG]

Just a quick update as well to confirm that the Sub 12 is now in my system and I've had no issues at all with breakers or power related concerns :T

[htsteve]

Excellent. I'm glad it's working out.