Can A Sound System Be Powered By A Power Inverter?

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Rich@RPM Music

New Member
I see that automotive stores sell 12 volt to 110 power inverters - 400 watts - 800 watts - 1200 watts!

Could I use one of these to power a CD player and 2 Mackie 450's to have sound in a parade? Which size?
 

MusicSantaCruz

New Member
I would reccomend more like 1800watts, but you could get by with 1200 if you HAD to, just use the hp filter on the 450's. These will have to be wired directly to your battery.

-Chris
 

brian@btm

New Member
I've done it several times, here is what I use:

http://www.provantage.com/buy-7TRPI00V-tripp-lite-power-inverters-powerverter-1000w-plus-inverter-12vdc-120vac-2-0utlet-freq-control-pv1000fc-shopping.htm

Wired with two Marine Deep cycle batteries in parallel I can get about 4-6 hours of 50% system output with a PLX 3402 and (4) 15"/1" speakers (Ramsa Ws-AT300). I do not run it off the vehicle’s battery, the wire runs are fused 8 guage about 2' long each. I would like to mount this in my van with a RV type isolated feed from the alternator, but I pull it out occasionaly for remote ceremony use.
 

Scott McKinney

Active Member
Do it all the time. The Deep-Cycle batteries work too. Go 1200 or higher, but with that much draw, you have to run dirrect from battery....NOT the lighter socket.
 

Rich@RPM Music

New Member
It's 1200 Watts w/2400 watt peak. Mosfet technology,
Specifications:
Maximum Continuous Power: 1200 Watts
Surge Capacity (Peak Power): 2400 Watts
Maximum Efficiency: Approximately 90%
No Load Current Draw: .6 Amperes
Input Voltage: 10 - 14.7 VDC
Output Voltage: 110 VAC 60 Hz
Low Voltage Shutdown: 10.0 Volts auto-reset
Low Voltage Alarm Activation: 10.6 Volts
Wave Form: Modified Sine Wave
Weight: 9.26 lbs.
Length: 15"
Width: 9.5"
Height: 3.125"
Receptacle: 3 North American Standard Three Conductor
 

fist

New Member
Rich that should work pretty well.


Don't play with the wires though! Make sure to get BIG wire for like high powered stereo amplifiers.
 

JSMain

Active Member
I had a single outlet 800 watt unit from Radio Shack some time ago that would power a 5 disc changer, and a 100 watt per channel amp. You couldn't crank it to far, as it would want to shut down, but it worked plenty well for a parade. It has since died, and I need to replace it with a little heftier unit to power a couple of mackies, and a laptop.


Not sure what your Pep boys are charging, but I'm looking at this one...
http://www.powersystemsdirect.com/Cobra/1500_Watt_12V_Power_Inverter_CPI-1550_140.php
 

Partyco

New Member
Rich,

Let me know how that works, because we are going to be in a parade on July 4th.


Thanks.

Charlie
 

JSMain

Active Member
That's about what I paid for the 800 watt RS unit several years ago.

Still reasonable for what it does. I used mine for long trips also to entertain the kids with PS2 games and movies.
 

DJ Dr. Drax

Active Member
Rich,

I owuld NOT buy one from Pep boys. They are not very good quality. YES the produce the power, but it is VERY dirty power. It has a lot of hash & noise. This will shorten the life of gear connected to it that is not extremely well filtered.

There are units designed for what you want to do. They include the battery & every thing. Those are quite a bit better than the unit you showed.
 

Curt

New Member
We've used an inverter to power our parade rig for years. It works fine. All you need is a pair of powered JBL or Mackie speakers, and a MP3 player or Discman. Be sure to record your parade music in monaural mode, because stereo separation sounds bad with speakers pointing in opposite directions while outdoors. Make sure you have some heavy gauge cables feeding 12v to your inverter. Buy a pair of 4 or 6 gauge jumper cables, and cannibalize them. If the 12v cables are too small, you'll have a meltdown. Sam's club has deep cycle batteries for boats or golf carts that have a lot of capacity. Two or three of their "Tournament" batteries hooked up in parallel will run max volume for hours (maybe days!).

Curt
 

Rich@RPM Music

New Member
Curt:

What you are describing are seperate batteries to hook up to your converter instead of running it off of your vehicle's battery - right? If that's the case, this is going to cost a few hundred $$s to buy all of that. Maybe I'll look at a rental store for something.

Dr Drax:

I can believe that the unit shown might not be the best for the job, and although you said there are better one out there, you didn't offer any brand names.
 

Partyco

New Member
Rich,

I to have been researching this and the I think the separate 'marine' batteries would work better than hooking to your truck battery while moving. Unless we do an actual generator with gas, smoke, & noise.

Drax,

Here is another question for you, or anybody with any suggestions:

Once we get the sound going, how could we do video during the parade? I have thought about opening the back doors and stretching a 'fabric screen' with the projector inside (rear projection), or opening the back doors and just 'strapping' down a big TV in the back.

Ideally, it would be cool to attach a plasma to each side of trailer or van, but aside from sun light, you wouldn't want them to bounce too much.

Any ideas on audio or video?

Thanks.

Charlie
 

Curt

New Member
Yes, the startup cost was a little high. Inverters used to be a lot more expen$ive than they are today. We paid $600 for our 550w inverter in 1988. The marine batteries were about $225 for a set of 3, and 4 gauge cables were another $80. The good news is that the inverter should last for many years (our is 17 yrs old!), and the batteries should last for several years (3-6?). It's an investment, just like any equipment purchase.

Curt
 

wavesound

Member
If you're going to be hooking your precious speakers up to the Vector Inverter you found at Pep-Boys I would think again. Not because Pep-Boys sells cheap gaer or that Vector has made a poor product but that the design leaves much to be desired for sensitive electical equipment.

Let's take a step back to what makes up to high quality 120V AC power.

A good AC signal is composed by an undistorted *sine* wave oscillating at 60 Hz with peaks at +/- 170V (120V RMS).

An inverter works by taking in the 12V from your car's electrical system and then ramps it up to 120V using a simple op-amp or similar circuit. It then takes this DC signal into a signal generator that produces a true 60 Hz sinewave with peaks at +/- 120V (RMS) and adds a few unity gain power amps to deliver the current.

The most expensive component in that system is the signal generator and to cut production costs, manufacturers like Vector have replaced the signal generator with a simple switching MOSFET circuit that just slams the rails at +/- 120V (RMS) at a rate of 60 cycles per second. So in essence what you get is a sharp *square* wave instead of nice smooth *sine* wave.

When you connect your amps and speakers up, you will probably hear some "buzzing" from the power supplies of your gear and that buzz may very well travel through to the output of the speaker if the power supplies on all of your gear are not properly filtered (which in most cases they are not).

For most small appliances, this is usually not an issue and may not even be an issue for your system. Even though the wave is square and not rounded like the sine wave you would get from an outlet, this *should* not affect your equipment. However, I think we are all familiar with difference between what should happen and what does (sometimes unpredictably) happen.

So, you will be much better off spending about 3-5 times as much for an inverter that produces an AC signal with a *true sine wave*. Your equipment will sound better and people won't wonder what bugs you are trying to attract with your buzzing speakers. :)
 
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