Power Consumption: How much power does an active speaker really draw?

[wheresgrant3]

I play guitar and keys in an 80's tribute band. Our club scene is complete DIY, therefore we provide our own full range PA, lights and sound. Our backline runs 600-800 watts, our PA (two crown CE2000 FOH+ CE1000 for monitor) runs another 2000 and lights, depending on the config is 500-1500watts. For keyboard monitoring I have been using a cheap Peavey KB amp that runs at 100 watts.

 

That amp has since gone on the fritz and I was going to replace it with a comparable amp in the 100-200 watts range but have been recommended by many players instead to go with an active speaker in the 400-500watt range(JBL EON or Mackie SRM). My band already own a Samson db500a that we are currently not using, and I believe this amp will suffice fine. My concern is the amount of power this amp will draw. I will be using this amp for monitoring NOT amplification. I run every FOH through our PA, but our monitors can't take the keys and breakup upon impact. In many rooms we are at capcity for power. My concern is that an extra 500 watts will push things over the edge and we will blowing breakers.

 

 

Anyone have any advice on this?

[Craig Vecchione]

It will be extremely rare, if ever, that you actually push that Samson anywhere near its max output, especially as a monitor....much more than 50w would be peeling your ears back most of the time.

[tlbonehead]

Originally posted by wheresgrant3 I play guitar and keys in an 80's tribute band. Our club scene is complete DIY, therefore we provide our own full range PA, lights and sound. Our backline runs 600-800 watts, our PA (two crown CE2000 FOH+ CE1000 for monitor) runs another 2000 and lights, depending on the config is 500-1500watts. For keyboard monitoring I have been using a cheap Peavey KB amp that runs at 100 watts. That amp has since gone on the fritz and I was going to replace it with a comparable amp in the 100-200 watts range but have been recommended by many players instead to go with an active speaker in the 400-500watt range(JBL EON or Mackie SRM). My band already own a Samson db500a that we are currently not using, and I believe this amp will suffice fine. My concern is the amount of power this amp will draw. I will be using this amp for monitoring NOT amplification. I run every FOH through our PA, but our monitors can't take the keys and breakup upon impact. In many rooms we are at capcity for power. My concern is that an extra 500 watts will push things over the edge and we will blowing breakers. Anyone have any advice on this?

You have me confused. It sounds like you are using watts of power output and lighting wattage as being synonymous. I seriously doubt that the Samson will draw more power than the old keyboard amp,at least nothing noticeable.

[agedhorse]

 

Originally posted by tlbonehead You have me confused. It sounds like you are using watts of power output and lighting wattage as being synonymous. I seriously doubt that the Samson will draw more power than the old keyboard amp,at least nothing noticeable.

 

 

I agree!

[tomhole]

Not sure if this is helpful, but it might be relevant.

 

My last gig, I ran an RMX1450 and CE1000 on monitors and used most of their power. For mains, I had 2 EF500P's running full tilt and 2 RMX2450's on subs running just under the limiters (each bridged into 8 ohms). I ran it all on a single 20A circuit and never blew a fuse. Plus the minimal draw of the FOH (01v96 and 2 eq's).

 

I'd say your pretty safe.

 

Tom

[wheresgrant3]

My concern is that we have 2-3 rooms we play where we frequently blow a circuit if the lights are plugged into the same circuit as the PA. Rooms that were not designed for live music to begin with. I always feel that we are on borrowed time... waiting for another fuse to blow. So adding something as simple as a 500 watt active speaker causes me a little concern.

[agedhorse]

Lights are a different kind of load, and continuous loads such as lighting operate in a different portion of a breaker's inverse tim-current trip curve.

 

Amplifier AC loads are a function of size of the amp, topology, load impedance of the speakers and the duty cycle of the input signal.

 

Generally, somewhere between 1/8 and 1/4 of the maximum AC input current (steady state) for a specified load will be the average current draw with typical music program. Another way to estimate (for a class G/H amp) is to take the rated output power into the rated load and divide by approximately 3... so if the amp was rated at 1000 watts into a 4 ohm load, you could expect it to draw about 350 watts (3 amps) when operated with typical music program into 4 ohms. A class AB amp would be approx 1/2 rated power and a class D would be about 1/4 rated power.

 

This is all rough rule of thumb estimates.

[dboomer]

 

Originally posted by wheresgrant3 My concern is that we have 2-3 rooms we play where we frequently blow a circuit if the lights are plugged into the same circuit as the PA.

 

 

Turn off/down the lights ... they're the problem;) They shouldn't be in the same circuit ... you don't stand a chance.

[abzurd]

A lot of the rooms we play aren't designed for live music, BUT there's always been a second circuit available and generally there are at least 3 we can find.

[tlbonehead]

Originally posted by abzurd A lot of the rooms we play aren't designed for live music, BUT there's always been a second circuit available and generally there are at least 3 we can find.

Yep. There've been times where we had to run power cords over 50' but we've always been able to find that second and third circuit.

[Randy Focht]

WhereisGrant,

 

Slightly off subject,

but why are you not using the Samson speakers in your PA.

 

I was thinking of buying the db500's instead of Mackies.

 

What's your suggestion?