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[John Lackner]

You are mistaken.

I am not mistaken. go back to electrician school.

[g'bye, Dick Rees]

I am not mistaken. go back to electrician school.

It's a narrow margin on this, but the 6500 is not the most of the problem.  You've probably read every post in the thread, so you know that the operative factors here are too long a cable run (and in desert temperatures), too small wiring gauge, funky home-mafe "distro"  and driving the speakers into thermal compression.

While it is true that class D amps are nice and efficient, their lack of "heavy iron" in the power supplies does make them get a bir funky when power is close to minimum specs.  The power loss between the generator and the speakers is enough to cause problems given the deployment and use, but the 6500 @ 54 amps should handle the 6 Mackies @ a rated draw of 8 amps each.

Yes, it's close to the bone.  But addressing the setup and cabling issues are first priority for the OP as he's seeking a way to get the most out of what he has.  You can recommend a larger generator and be correct in a sense, but so are those who recommend more powerful speakers.

Neither recommendation addresses the OP's desires to work with what he has even though such recommendations are correct in essence.

[Ray Aberle]

I am not mistaken. go back to electrician school.

Comments like that are not helpful, John. If you disagree with Dick (who is, I might add, one of the more highly respected members of the forum) then please explain where you're coming from.

The active Mackie gear is quite energy efficient, but with them being plugged in at the end of a 200' run of 6/4 wired to the L14-30 output on the generator -- well, the 6/4 is helping to negate the voltage drop a bit, but it's probably still present, and probably what's contributing to these sags.

What might help is if the OP were to check the generator while it is running, which helpfully has an output reading to show how much it's actually using. See what that does during those bass hits, and see if that helps narrow down the problem. And use a shorter main feeder cable. And fix the distro setup!

-Ray

[John Lackner]

Comments like that are not helpful, John. If you disagree with Dick (who is, I might add, one of the more highly respected members of the forum) then please explain where you're coming from.

The active Mackie gear is quite energy efficient, but with them being plugged in at the end of a 200' run of 6/4 wired to the L14-30 output on the generator -- well, the 6/4 is helping to negate the voltage drop a bit, but it's probably still present, and probably what's contributing to these sags.

What might help is if the OP were to check the generator while it is running, which helpfully has an output reading to show how much it's actually using. See what that does during those bass hits, and see if that helps narrow down the problem. And use a shorter main feeder cable. And fix the distro setup!

-Ray

You an also connect a voltmeter at the load (amp) end. If there a lot of voltage fluctuations the genny could be overtaxed.
If the average load is 3500 watts the peak load could be much more than that. Some of these smaller generators might work fine on an average loads but come up short during peaks. Of course the easy fix would be to turn the bass down a bit. But try telling that to EDM DJ's. Go ahead. Try it.

[Ray Aberle]

Of course the easy fix would be to turn the bass down a bit. But try telling that to EDM DJ's. Go ahead. Try it.

Depends on your relationship with the DJs. The anecdote I gave above, I knew the guy and had worked with him before, so I was able to tell him to go a bit easier on the bass. Of course, dropping the sub amp 10dB helped as well.

Most DJs, though, will prefer a sound systems that is actually ON and will stop juuuuust short of destruction of the generator. One would hope, at least.

Anyways, we're in agreement that the bass is probably taxing the generator, and that plus the voltage drop over 200' of feeder is the cause(s) of the complaints from the OP. But, since this is all that they have to work with, the key here is to help them make the most of it!

-Ray

[g'bye, Dick Rees]

You an also connect a voltmeter at the load (amp) end. If there a lot of voltage fluctuations the genny could be overtaxed.
If the average load is 3500 watts the peak load could be much more than that. Some of these smaller generators might work fine on an average loads but come up short during peaks. Of course the easy fix would be to turn the bass down a bit. But try telling that to EDM DJ's. Go ahead. Try it.

John..

I believe you should be calculating the power draw in amps, not watts.  One watt is defined as one joule (amount of energy) per second (time) and as such defines the RATE of energy conversion.  Are you saying that rate is more applicable than amperage available or do the two measurements combine to predict the probable outcome...based on program content in this case.

[John Lackner]

Depends on your relationship with the DJs. The anecdote I gave above, I knew the guy and had worked with him before, so I was able to tell him to go a bit easier on the bass. Of course, dropping the sub amp 10dB helped as well.

Most DJs, though, will prefer a sound systems that is actually ON and will stop juuuuust short of destruction of the generator. One would hope, at least.

Anyways, we're in agreement that the bass is probably taxing the generator, and that plus the voltage drop over 200' of feeder is the cause(s) of the complaints from the OP. But, since this is all that they have to work with, the key here is to help them make the most of it!

-Ray

Last but not least, that 30 amp connector on the genny could be getting a bit old and flimsy, limiting current flow. Also, check for any dirt or corrosion or loose screws on all the power cords and connectors . Actually, the cables and connections should be inspected FIRST. This could save a lot of time and money on bigger gennies and more gear.

[Rob Spence]

Depends on your relationship with the DJs. The anecdote I gave above, I knew the guy and had worked with him before, so I was able to tell him to go a bit easier on the bass. Of course, dropping the sub amp 10dB helped as well.

Most DJs, though, will prefer a sound systems that is actually ON and will stop juuuuust short of destruction of the generator. One would hope, at least.

Anyways, we're in agreement that the bass is probably taxing the generator, and that plus the voltage drop over 200' of feeder is the cause(s) of the complaints from the OP. But, since this is all that they have to work with, the key here is to help them make the most of it!

-Ray

Actually, don't forget the 100' extension cords to the speakers and that one stack is getting its power from the other stack so that is 300' to the first stack then what ever to the second.

I agree that I would make the 6-4 feeder shorter. With the rig blasting no one is going to hear the generator. Putting a sheet of ply between it and the stage should let you shorten things up a lot. I would try to get it well below 100' if I could.

Next, I would make up a pair of quad boxes with 10-3 from the distro to the base of each stack then plug in the speakers with shorter iec cords.

That should stiffen up the power and perhaps remove some of the sagging.



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[Ray Aberle]

Actually, don't forget the 100' extension cords to the speakers and that one stack is getting its power from the other stack so that is 300' to the first stack then what ever to the second.

I agree that I would make the 6-4 feeder shorter. With the rig blasting no one is going to hear the generator. Putting a sheet of ply between it and the stage should let you shorten things up a lot. I would try to get it well below 100' if I could.

Next, I would make up a pair of quad boxes with 10-3 from the distro to the base of each stack then plug in the speakers with shorter iec cords.

That should stiffen up the power and perhaps remove some of the sagging.

Absolutely, this has always had a pretty simple solution...
- Position the gennie 30-40' behind the stage
- Get a 25' L14-30 cord
- Get a breakout box/rackpack to split the L14-30 into 4-20A circuits
- Run short cables to each speaker stack-- sheesh, life is good!

-Ray

[TJ (Tom) Cornish]

I am not mistaken. go back to electrician school.

I would suggest waiting until you have a few more than 22 posts before being obnoxious.

Mackie's web site lists the "recommended amperage service" of the SR1530 as 8 amps.  This almost certainly has peak draw already factored in; the "500w" amp rating already represents peak power, as all music - even EDM - has a crest factor - a ratio of the peak to the average, meaning that probably more like 50w continuous are put to the drivers. 

The amplifiers have some energy storage built-in, which softens the peak draw, and the generator has rotational inertia that also effectively is some amount of reserve capacity.

If it were me and I had to decide between using the very adequate EU6500 that I already owned or ponying up $20K for a real 20KW entertainment generator (and all the permitting and logistics that entails), I would invest the money in some more efficient gear in order to get more output on existing power.  That is not difficult - reducing the audio level 3dB cuts the power draw roughly in half.  It wouldn't be very hard to find speakers 3dB more efficient than the Mackies in question, meaning that the same or more output is available for considerably less electrical power.

[ProSoundWeb Community]