JimmyL-DJ
Proverb: The more you know... the more you know you don't know !
I'm currently in subwoofer HELL. I had ordered a pair of EV Eliminator KW subs last week to beef up my system. One got destroyed by a forklift, and both were sent back to the warehouse.
What a lesson I learned about subwoofers this week. I cancelled ordering anything else till I figure out how to proceed. Perhaps you can help me please.
I'm not into the active subwoofers because I hate laying and wrapping cords. I'm sticking with an amp and passive subs. The problem is the same with either system.
If I get a pair of subs rated for 400 W cont. / 800 W prog. / 1600 W peak, and I run 2 of them off my QSC 2450... non bridged at 8 ohms would give me 500 watts into each sub. I don't think this is enough power to give them a decent "kick".
Bridging the 2450 will get me 2400 watts at 4 ohms. Parallel the cabinets to 4 ohms, and each will have 1200 watts to kick some ass.
The problem is 2400 watts at 120 volts is 20 amps. Then plus the midrange amp, a monitor amp, the mixer, and all processing stuff... a problem will arise. You get 'em dancing then poof goes the breaker.
One answer is to reduce the sound system size and be happy with a 15 amp outlet. I can do this for a smaller gig. The system is very modular and can be re-arranged accordingly. But I want a club sound with a good punch.
For the bigger gigs in a large room like a gymnasium, or ballroom, I would have to find 3 independent power circuits... 1: subwoofer breaker 2: everything else breaker 3: lights breaker. I'd have to bring my "beep" tool along and tone out the outlets to the breaker panel. Or build a power snake that can clamp on the electrical panel rails with 40 or 60 amp breakers like bands do.
This doesn't seem too practical. I run a Furman power strip that displays voltage and current. I see my sound system now stabbing at 18 amps when I'm kickin' it to a good crowd. If I replace my inefficient EV Force subs and add 2 dual 18's and bridge the amp I will no doubt have to run 2 power cords to my amp rack.
I'm curious how you DJ's that set up double 18's handle the power issue. You can't assume that the outlet on "that" wall is on a different circuit than the one on the opposite wall. And to split to 3 different circuits would be very time consuming doing it right and not guessing.
What is your power strategy???
Thanks,
Jim
I'm currently in subwoofer HELL. I had ordered a pair of EV Eliminator KW subs last week to beef up my system. One got destroyed by a forklift, and both were sent back to the warehouse.
What a lesson I learned about subwoofers this week. I cancelled ordering anything else till I figure out how to proceed. Perhaps you can help me please.
I'm not into the active subwoofers because I hate laying and wrapping cords. I'm sticking with an amp and passive subs. The problem is the same with either system.
If I get a pair of subs rated for 400 W cont. / 800 W prog. / 1600 W peak, and I run 2 of them off my QSC 2450... non bridged at 8 ohms would give me 500 watts into each sub. I don't think this is enough power to give them a decent "kick".
Bridging the 2450 will get me 2400 watts at 4 ohms. Parallel the cabinets to 4 ohms, and each will have 1200 watts to kick some ass.
The problem is 2400 watts at 120 volts is 20 amps. Then plus the midrange amp, a monitor amp, the mixer, and all processing stuff... a problem will arise. You get 'em dancing then poof goes the breaker.
One answer is to reduce the sound system size and be happy with a 15 amp outlet. I can do this for a smaller gig. The system is very modular and can be re-arranged accordingly. But I want a club sound with a good punch.
For the bigger gigs in a large room like a gymnasium, or ballroom, I would have to find 3 independent power circuits... 1: subwoofer breaker 2: everything else breaker 3: lights breaker. I'd have to bring my "beep" tool along and tone out the outlets to the breaker panel. Or build a power snake that can clamp on the electrical panel rails with 40 or 60 amp breakers like bands do.
This doesn't seem too practical. I run a Furman power strip that displays voltage and current. I see my sound system now stabbing at 18 amps when I'm kickin' it to a good crowd. If I replace my inefficient EV Force subs and add 2 dual 18's and bridge the amp I will no doubt have to run 2 power cords to my amp rack.
I'm curious how you DJ's that set up double 18's handle the power issue. You can't assume that the outlet on "that" wall is on a different circuit than the one on the opposite wall. And to split to 3 different circuits would be very time consuming doing it right and not guessing.
What is your power strategy???
Thanks,
Jim
Mensajes Wed 06 Apr 11 @ 3:34 am
DJ Marcel_1
Most DJ's and live bands that I know of that do larger Events that require lots of electricity, such as lots of P.A., and lots of Lighting have a 220v socket and cable that is usually run to a plywood backed break out panel.
220v in, to a 110v breaker box, and then to about 3 or 4 receptacles hooked up to a separate panel
I don't have a pic because I don't use that type of power distribution, but it's very common.
220v in, to a 110v breaker box, and then to about 3 or 4 receptacles hooked up to a separate panel
I don't have a pic because I don't use that type of power distribution, but it's very common.
Mensajes Wed 06 Apr 11 @ 8:26 am
SBDJ
One point - you've calculated your current figure using the output power but the input voltage.
Have a look at how much voltage is actually put out - it isn't mains.
According to your amp spec sheet, typical draw at 120VAC is 6.3 amps. 15.6 is what they label severe draw. obviously you can half that for those of us on higher voltages around 240.
Have a look at how much voltage is actually put out - it isn't mains.
According to your amp spec sheet, typical draw at 120VAC is 6.3 amps. 15.6 is what they label severe draw. obviously you can half that for those of us on higher voltages around 240.
Mensajes Wed 06 Apr 11 @ 8:46 am
hippydog
JimmyL-DJ wrote :
What is your power strategy???
Get to know your equipment.. Get to know the venues you will be playing at.. Then charge your clients accordingly..
Most of the bigger rooms already have the power requirements you need.. but you have to talk to the manager or facility cordinator and get the power drop set up.. (this sometimes costs money.. know ahead of time so you can charge accordingly)
For the rooms with no possibilty of an in-house power drop you will need to do your own.. for legal and safety reasons you will need to find a local electrician who will do this for you.. (again.. costs money.. charge accordingly)
Mensajes Wed 06 Apr 11 @ 11:15 am
Charlie Wilson
Get some 4ohm subs or get a bigger amp, you should have 1200w per channel for subs really.
Mensajes Wed 06 Apr 11 @ 11:26 am
Rob Kalmar
You said you won't use powered subs because you hate laying & wrapping cords? Are your existing subs 'wireless'? ;-)
Mensajes Wed 06 Apr 11 @ 12:09 pm
Rob Kalmar
Actually your problem would not be the same with powered subs as you say, because then you would then have the ability to run the subs power cords to various outlets to alleviate the breaker issue. That might actually solve your dilemma in most instances.
Mensajes Wed 06 Apr 11 @ 12:56 pm
JimmyL-DJ
djrobinhamilton wrote :
Actually your problem would not be the same with powered subs as you say, because then you would then have the ability to run the subs power cords to various outlets to alleviate the breaker issue. That might actually solve your dilemma in most instances.
No my speakers are not wireless silly. Each passive cabinet takes 1 wire instead of 2. That would be 6 extra wires counting monitors.
I'm starting to build up DMX lighting and there are lots of wires involved in additon to sound wires. I need to be efficient with time. Someone always have to wait till you're done loading so they can go home. Minutes count.
I've done gigs where I plug in one side of the room for sound, and the other side for lights. That was just to be sure that I was on different circuits. Guess what happened. Turn it UP then Click/Silence/Boos
You can't count on the electrician or electrical code that require outlets on different walls to be on different breakers. Unless you seek out the breaker panel and look... you won't know if the outlet is 15 or 20 amps.
LED lighting helps a lot. Way less power draw.
Then there is the issue of ground loops. If you plug into two outlets and they are on different phases will you get noise problems?
I've had experience connecting in a video projector powered on different outlet and distortion lines would go up through the picture. Plugging all into one outlet helped. Ground loop?.
I guess I can buy a bigger amp and make it optional. I really want double 18's. Tough to get more money for the extra equipment, but I have more fun when the system kicks good.
Thanks for the help.
Jim
Mensajes Wed 06 Apr 11 @ 1:31 pm
Dazmax
Hi Jimmy
As you are finding out, once you get up to the higher power systems you end up with supply quality problems. This is where the info for people in the US departs from the UK. In the UK we use a Ring Main power supply wireing system and the max load on any outlet is 3KW. Multiple outlets on the same ring main up to a load of 30 Amps is no problem. In the US point to point wireing is used and the max load on a 110V Duplex/twin outlet is usualy 15 or max 20Amps.
You do, as you have said need to take care with using multiple outlets to supply your rig due to the possibility of having different outlets on alternate phases. This is not just a noise problem though. There is a safety issue here. On a 110V 3 phase supply you will have 220V between the live conductors on each phase. In the US all it takes is a badly wired Duplex/twin socket with a broken Neutral connection and you are in trouble. It is still leagle in some States to supply a Duplex/twin socket from 2 phases (1 for each outlet) On a 240V 3 phase system you will find 415V between phases. Not a good situation at all as under fault conditions you can end up with voltages flying arround your rig which are way above what you expect.
DMX lighting gear also has a tendency to go bang if not correctly switched and it MUST all be connected to the same phase (unless it is designed for 3 Phase use).
I would suggest that you ensure that you have 220/240V outlets available to you at the venues where you work. 110V will always give you problems with multiple high power amplifiers. You also have to consider the power cables that you use have to be very heavy duty to run with 110V (Idealy twice the conductor diameter of what you would use for 240V).
If your system power demands it you will need to go for a proper 3 Phase power distibution unit with all the cost that this involves.
To get the most out of your amps. Use the heaviest shortest speaker cables and good quality 2mm or thicker mains power cables. Throw the molded plastic power cords in the bin and make your own using good quality cable and connectors.
Daz
As you are finding out, once you get up to the higher power systems you end up with supply quality problems. This is where the info for people in the US departs from the UK. In the UK we use a Ring Main power supply wireing system and the max load on any outlet is 3KW. Multiple outlets on the same ring main up to a load of 30 Amps is no problem. In the US point to point wireing is used and the max load on a 110V Duplex/twin outlet is usualy 15 or max 20Amps.
You do, as you have said need to take care with using multiple outlets to supply your rig due to the possibility of having different outlets on alternate phases. This is not just a noise problem though. There is a safety issue here. On a 110V 3 phase supply you will have 220V between the live conductors on each phase. In the US all it takes is a badly wired Duplex/twin socket with a broken Neutral connection and you are in trouble. It is still leagle in some States to supply a Duplex/twin socket from 2 phases (1 for each outlet) On a 240V 3 phase system you will find 415V between phases. Not a good situation at all as under fault conditions you can end up with voltages flying arround your rig which are way above what you expect.
DMX lighting gear also has a tendency to go bang if not correctly switched and it MUST all be connected to the same phase (unless it is designed for 3 Phase use).
I would suggest that you ensure that you have 220/240V outlets available to you at the venues where you work. 110V will always give you problems with multiple high power amplifiers. You also have to consider the power cables that you use have to be very heavy duty to run with 110V (Idealy twice the conductor diameter of what you would use for 240V).
If your system power demands it you will need to go for a proper 3 Phase power distibution unit with all the cost that this involves.
To get the most out of your amps. Use the heaviest shortest speaker cables and good quality 2mm or thicker mains power cables. Throw the molded plastic power cords in the bin and make your own using good quality cable and connectors.
Daz
Mensajes Wed 06 Apr 11 @ 2:31 pm
JimmyL-DJ
Thanks guys for the information. Looks like I'll have to upgrade to a bigger amp. Perhaps a QSC RMX 4040 or PLX 3602.
I'll just have to test to find outlets on different breakers at gigs where I provide the subs for extra punch. I have a "beep" tool that you plug in an outlet... then go to the breaker box with a probe that ampifies sound, so I can find the right breaker. It works. I used it around the house to identify outlet/breakers.
Even you powered-sub DJs could use this tool. It's not expensive.
http://www.sears.com/shc/s/p_10153_12605_SPM258598564P?sid=IDx20101019x00001a&ci_src=14110944&ci_sku=SPM161871056
It will probably take another 30 minutes setup time to figure out the AC. And hopefully code law will prevent any outlet in any one room to be on a different phase. That would be very dangerous as Daz mentioned above.
I had a picnic gig a couple of years ago where we were having video that night. While connecting the projector I blew up my laptop, a VGA port on a monitor, an S-Video port on the projector, and it exploded my video splitter
The laptop and monitor were working fine till I hooked up the projector to AC from a trailer on the other side of the campground. An owner said "here tap into my trailer power". He even ran some of his wire to meet mine.
It took just a minute till my buddy is saying "hey something is smoking". Then the splitter snap crackled and popped.
I'm sure I had a power spike that came back to the splitter, and laptop, and monitor, through the S-Video wire.
I wanted a power feed for the projector to take the load off the sound system power feed. And never thought I would have a problem. Lesson learned big time.
I'm glad no one was hurt. Be careful out there.
And keep on jammin'
JimL
I'll just have to test to find outlets on different breakers at gigs where I provide the subs for extra punch. I have a "beep" tool that you plug in an outlet... then go to the breaker box with a probe that ampifies sound, so I can find the right breaker. It works. I used it around the house to identify outlet/breakers.
Even you powered-sub DJs could use this tool. It's not expensive.
http://www.sears.com/shc/s/p_10153_12605_SPM258598564P?sid=IDx20101019x00001a&ci_src=14110944&ci_sku=SPM161871056
It will probably take another 30 minutes setup time to figure out the AC. And hopefully code law will prevent any outlet in any one room to be on a different phase. That would be very dangerous as Daz mentioned above.
I had a picnic gig a couple of years ago where we were having video that night. While connecting the projector I blew up my laptop, a VGA port on a monitor, an S-Video port on the projector, and it exploded my video splitter
The laptop and monitor were working fine till I hooked up the projector to AC from a trailer on the other side of the campground. An owner said "here tap into my trailer power". He even ran some of his wire to meet mine.
It took just a minute till my buddy is saying "hey something is smoking". Then the splitter snap crackled and popped.
I'm sure I had a power spike that came back to the splitter, and laptop, and monitor, through the S-Video wire.
I wanted a power feed for the projector to take the load off the sound system power feed. And never thought I would have a problem. Lesson learned big time.
I'm glad no one was hurt. Be careful out there.
And keep on jammin'
JimL
Mensajes Thu 07 Apr 11 @ 1:40 am
Dazmax
Hi Jimmy
Some usefull checks for our friends across the pond.
Get yourelf a basic test multimeter.
On US 110V Duplex/twin outlets make the following check's before plugging anything in:-
1. With the meter set to mesure AC Volts on a 250V or 500V range. Insert the test probes into the live and Neutral connections on the top outlet (Taking care NOT to touch the metal probes at any point). A voltage reading of 110-120V indicates the Normal Voltage.
2. Repeat the above for the lower outlet.
3. Insert the probes beween the Live of the upper outlet and the Live of the lower outlet. A normal reading is 0Volts. If a reading of 220-240Volts is found, this outlet is connected to TWO PHASES. USE GREAT CARE here. If you must, use only use one of the outlets! If you intend to use multiple outlet points use the same (Top or Bottom) outlet on each. Better still if the outlets are close enough, find two which give a reading of 0Volts between the live connectors on each. you are then certain of having two outlets running on the same Phase.
4. Repeat the above between the two neutral connections. A normal reading is 0Volts. Anything above 0Volts indicates a fault. DO NOT USE THE OUTLET!
5. Repeat the above for the two Ground/earth connections. And then between each Ground/Earth connection and the metal facia of the outlet. All readings here should be 0Volts. Any reading above 0Volts indicates a fault DO NOT USE THE OUTLET!
6. Insert the probes between the live connection on the top or bottom outlet and the Ground/Earth connection. 110-120V indicates a good ground connection. ANY OTHER READING shows a Ground/earthing fault. DO NOT USE THE OUTLET!
7. Finaly insert the probes between the Neutral and ground connections on each outlet. The reading here should be 0Volts (or very low 3-5Volts) Again any reading that is higher indicates a fault.DO NOT USE THE OUTLET!
Again take great care NOT to touch the metal part of the test meter probes at any point.
Have fun but STAY SAFE!!!!!!!
Daz
Some usefull checks for our friends across the pond.
Get yourelf a basic test multimeter.
On US 110V Duplex/twin outlets make the following check's before plugging anything in:-
1. With the meter set to mesure AC Volts on a 250V or 500V range. Insert the test probes into the live and Neutral connections on the top outlet (Taking care NOT to touch the metal probes at any point). A voltage reading of 110-120V indicates the Normal Voltage.
2. Repeat the above for the lower outlet.
3. Insert the probes beween the Live of the upper outlet and the Live of the lower outlet. A normal reading is 0Volts. If a reading of 220-240Volts is found, this outlet is connected to TWO PHASES. USE GREAT CARE here. If you must, use only use one of the outlets! If you intend to use multiple outlet points use the same (Top or Bottom) outlet on each. Better still if the outlets are close enough, find two which give a reading of 0Volts between the live connectors on each. you are then certain of having two outlets running on the same Phase.
4. Repeat the above between the two neutral connections. A normal reading is 0Volts. Anything above 0Volts indicates a fault. DO NOT USE THE OUTLET!
5. Repeat the above for the two Ground/earth connections. And then between each Ground/Earth connection and the metal facia of the outlet. All readings here should be 0Volts. Any reading above 0Volts indicates a fault DO NOT USE THE OUTLET!
6. Insert the probes between the live connection on the top or bottom outlet and the Ground/Earth connection. 110-120V indicates a good ground connection. ANY OTHER READING shows a Ground/earthing fault. DO NOT USE THE OUTLET!
7. Finaly insert the probes between the Neutral and ground connections on each outlet. The reading here should be 0Volts (or very low 3-5Volts) Again any reading that is higher indicates a fault.DO NOT USE THE OUTLET!
Again take great care NOT to touch the metal part of the test meter probes at any point.
Have fun but STAY SAFE!!!!!!!
Daz
Mensajes Thu 07 Apr 11 @ 6:15 am