Lumify
I just did the math and realized 2400W is 20A at 120V. I don't know the max current draw on my circuits, but a quick google reveals most home circuits support between 15A and 20A. It seems that if your power capabilities are on the higher end, you'll barely be able to support a Submersive HP running on its own circuit.

Slave masters make no sense at 4000W. Wouldn't it be better to get two non-slaves and run extension cords to different rooms for each one of them? That way the rest of your equipment doesn't limit the output. I'm at around 10A already for the closest circuit with the rest of my stuff, so that's what I'll be doing.

I don't mean to sound pessimistic; I'd bet half of the rave reviewers for the amp weren't even paying attention to other hardware on the circuit and accounting for their power usage. Is power output a significant factor in Submersive HP performance? Should I be dedicating a circuit for each sub?
Quote 0 0
Mark_Seaton

Lumify wrote:
I just did the math and realized 2400W is 20A at 120V. I don't know the max current draw on my circuits, but a quick google reveals most home circuits support between 15A and 20A. It seems that if your power capabilities are on the higher end, you'll barely be able to support a Submersive HP running on its own circuit.

Slave masters make no sense at 4000W. Wouldn't it be better to get two non-slaves and run extension cords to different rooms for each one of them? That way the rest of your equipment doesn't limit the output. I'm at around 10A already for the closest circuit with the rest of my stuff, so that's what I'll be doing.

I don't mean to sound pessimistic; I'd bet half of the rave reviewers for the amp weren't even paying attention to other hardware on the circuit and accounting for their power usage. Is power output a significant factor in Submersive HP performance? Should I be dedicating a circuit for each sub?


Fortunately for our wall outlets and circuit breakers, any audio signal we will want to listen to is dynamic in nature.  Speakers are also not pure resistors, so over much of the operating range what we call "audio power" requires a lot less V*A than the simple level might suggest.  Our circuit breakers also don't really care about bursts of power, their primary purpose is to insure wires don't overheat and the hardware supplying power to our homes don't get overloaded.  Such overheating and overloading happens on a time scale of minutes and seconds, where audio power draw is more often measured in small fractions of a second to a few seconds.

A typical home breaker can pass 2-10 times its rated current for a brief moment.  The longer the duration, the lower the multiplier.  If you looked at power level vs time, you're basically looking at area under the curve.  This means a long duration signal just above the threshold will pop the signal, but a brief burst has to be very high to cover the same area.

When power systems are designed devices are considered in terms of either a demand factor.  This relates to how often something is used and what the peaks vs average power draw is at those times.  In audio this is often referred to as crest factor of a signal.  For most full range speaker uses, we can plan on 1/6th of maximum power draw for an amplifier, with 1/3rd being a more conservative, "CYA" rating.  For production subwoofers with maximum output protection, 1/4 rated power is what is typically planned for with a CYA figure up to 1/2 maximum power draw.  Accordingly, most customers have no issue running two 4000W, HP+ & HP-Slave units on a single 20A circuit.

Finally, we also need to consider the efficiency of various electronics.  You probably noticed I noted figuring a fraction of the maximum power draw, not rated audio power.  Class AB, G or H amplifiers rarely will be more than 40-60% efficiency.  This means that nearly 1/2 the power coming from the wall turns into heat in the amplifier and never makes it to the speaker or subwoofer.  By comparison, the proprietary class D design we use from SpeakerPower operates at more than 90% efficiency for most all cases above 200W.  This means that more of the power from the wall is delivered to the subwoofer, and you get more power to your subwoofer from the same breaker; up to double the power in fact.

Hope that helps...  Again we recommend a 20A circuit per pair of 4000W amplifiers when each amp is loaded with a slave.   In the case of the F18 and driving 3-4 18s, the same power allocation will work for most, but those who really like to push it might want a single 20A circuit per amplifier.

A minor detail most overlook is that adding slaves and more subwoofers to a system increases overall efficiency such that you actually use less power to produce the same playback level (SPL).  You only use more power when you actually push the system louder.  Every time you double your number of identical subwoofers you get 3dB more output for the same power usage, and it takes 1/2 the power to produce the same level.

Mark Seaton
Seaton Sound, Inc.
sales@seatonsound.net
773-290-8436
Quote 0 0
Lumify
That clears things up a lot. I'm getting a secondhand Submersive HP, the older version without slave, and I'm wondering if it would work on a somewhat cluttered circuit. Adding up all the devices' current ratings, I'm at 10A. I assume it's a 15A circuit, so I guess that's 5A steady. Except I read about a rule where you can't run above 80% for more than 3 minutes, or the breaker will go off. That puts me at a safe 2A constant draw, assuming my other stuff is running at fully power (2 small monitors, gaming laptop, lava lamp, wifi router, modem, printer, DAC, Wii, big TV). Of course, the power ratings probably aren't super precise, and I won't have all these devices running constantly.

When circuits are overloaded, does speaker performance suffer, or does the breaker just go off? I prefer the latter since I'd rather have no sound (that I can quickly identify) than bad sound.
Quote 0 0