What size battery and inverter would I need?

[Telecruiser]

I have thought about doing some busking in the future. Part of this is being places where you do not have readily available power. I am considering using my 2 PRX 512's or 612's plus a Yamaha MG124CX mixer. Any ideas how much battery and what size inverter I would need to run at moderate volume for 2-4 hrs.?

[Bobby1Note]

I run an NX55p (or two), a Soundcraft EFX-8, and a few LEDRain light fixtures, for 7-8 hours, on a single 12v/115amp-hour Deep Cycle battery. I run it through a 1500w Xantrex MSW inverter. I've been doing this for over 3 years now, and not a single issue. This year however, I also added a Costco surge/protecter audio/video power bar, so I could increase the number of outlets. Works great for me.

[Shaster]

I have thought about doing some busking in the future. Part of this is being places where you do not have readily available power. I am considering using my 2 PRX 512's or 612's plus a Yamaha MG124CX mixer. Any ideas how much battery and what size inverter I would need to run at moderate volume for 2-4 hrs.?

 

That's not busking, that's an outdoor concert. In parts of the city where I live, you might get mugged with gear that nice

 

Now I'm curious. Where would your busking take place? And couldn't you use anything smaller, maybe like those self contained busker specials, like the peavey and pignose stuff? Or maybe an all in one acoustic or keyboard amp and just use a small inverter.....

[Bobby1Note]

Most of those little battery-powered combo-amps that I've heard, are basically useless. More of a gimmick than anything else. AER has one that's really good, but $$$$$. ($1700-$1800)

[Tomm Williams]

What is Busking?

[Bobby1Note]

What is Busking?

Usually refers to playing on a street corner, subway entrance, that kind of thing. You play, and folks throw monry in the "hat" (guitar case).

[Tomm Williams]

Bobby

 

At the risk of starting something controversial--------------Isn't a modified sine wave inverter problematic with audio equipment? I seem to recall this coming up in past threads.

[Bobby1Note]

 

Bobby At the risk of starting something controversial--------------Isn't a modified sine wave inverter problematic with audio equipment? I seem to recall this coming up in past threads.

 

 

Tomm, there are MILLIONS of these things (inverters), in use in trailers/campers, mobile homes, trucks, boats,,, you name it. Do a search, and put into perspective how many "issues" you can have. I've had ZERO issues,,, not a hum,,, not a buzz,,,, nothing. Clean as a whistle. It probably depends on how crappy the power-supplies are, on the items you're plugging in,,,,,rather than the fact that it's a "modified sine-wave" inverter.

 

Give one a listen some time, and tell me what YOU think.

[Bobby1Note]

Tomm,

 

There are MILLIONS of these things in service, in cottages, trailers, mobile-homes, cars, trucks, boats. Do a search, to put in proper perspective, how many "issues" you might encounter. I've had ZERO issues; not a hum,,,, not a buzz,,,, not a click,,,, nothing but pure clean sound. A lot probably depends on how crappy the power-supplies are, in the items that you're plugging in. Sizing the unit properly, is important however. You need to consider the dynamic-range of musical instruments. Just check the amp-draw of your components, and you'll be fine.

 

Mind you Tomm, I didn't run out and buy the cheapest inverter I could find. The Xantrex is a quality unit. That said, I bought minr in a 1/2 price sale, at Canadian Tire. I probably payed around $90-$100. (reg was $189. I believe)

[Shaster]

 

Most of those little battery-powered combo-amps that I've heard, are basically useless. More of a gimmick than anything else. AER has one that's really good, but $$$$$. ($1700-$1800)

 

 

What, you don't like that "I'm a ten watt amp trying to fill a city block" sound?

 

Actually I've heard a few okay ones - well for that purpose anyway.

 

Sometimes the cops.... will come by and move you along. It sure would be hard to pack up a couple of PRX's and a board, load the stuff into the car and then find another site. That's why I'm thinking this ins't busking in the usual sense of the word.

[BillESC]

Busking actually refers to unscripted lighting cues.

 

A deep cycle marine battery is what you want, it will serve you well.

[agedhorse]

 

Bobby At the risk of starting something controversial--------------Isn't a modified sine wave inverter problematic with audio equipment? I seem to recall this coming up in past threads.

 

 

Yes, it can end with disasterous results depending on the inverter, the number of steps, the type of power supply that the loads have, PFC issues, etc.

 

I would really recommend a PWM sine wave inverter rather than a modified sine wave inverter for anything that you value not failing.

 

Yes there are millions out there running devices and there are plenty of problems too. Some devices are tolerant, some are not. I hesitate to recommend something like this that I can not test and analyze for possible negative reliability issues. I do not recommend any of our products to be used with MSW type inverteres either.

[Greg Adams]

 

Yes, it can end with disasterous results depending on the inverter, the number of steps, the type of power supply that the loads have, PFC issues, etc. I would really recommend a PWM sine wave inverter rather than a modified sine wave inverter for anything that you value not failing. Yes there are millions out there running devices and there are plenty of problems too. Some devices are tolerant, some are not. I hesitate to recommend something like this that I can not test and analyze for possible negative reliability issues. I do not recommend any of our products to be used with MSW type inverteres either.

 

 

What does the "p" stand for Aged,Pure or pulse?

[Bobby1Note]

PSW is Pure Sine Wave,,, and MSW is Modified sine wave

 

FWIW, my Xantrex inverters (I have two of them, a 1500w MSW, and a 300w MSW) are CSA approved.

 

I've used the 300w to power my AER Compact 60/2 60w RMS combo-amp, with exactly the same results .Runs clean as a whistle.I've also had plenty of emails from guys around the world, who do exactly the same thing as I do, and have the same results. Judge for yourself.

[Greg Adams]

 

PSW is Pure Sine Wave,,, and MSW is Modified sine wave

 

 

Thanks Bobby,just found a link with some good reading about it,"bookmarked,read later"

[Tomm Williams]

Reason I'm still beating this not-quite-dead horse is I purchased a Xantrex MSW and while using it heard a noticeable "buzzing" sound coming from my amp. Having never used an inverter/deep cycle battery set up before, wasn't sure what the problem was but I knew it didn't seem right. Not saying Bobby isn't having good luck but I'm a little gun shy about mine. Gonna look for a different one.

[agedhorse]

 

What does the "p" stand for Aged,Pure or pulse?

 

 

P stands for PULSE Width Modulation, the modern way sine waves are generated at high efficiency with good representation in inverters.

[agedhorse]

 

Reason I'm still beating this not-quite-dead horse is I purchased a Xantrex MSW and while using it heard a noticeable "buzzing" sound coming from my amp. Having never used an inverter/deep cycle battery set up before, wasn't sure what the problem was but I knew it didn't seem right. Not saying Bobby isn't having good luck but I'm a little gun shy about mine. Gonna look for a different one.

 

 

Absolutely possible and even likely.

 

Power supplies and power supply magnetics are designed for a sine wave input. There are a lot of variables involved depending on the type of power supply involved and the linearity ofthe load that it's driving.

 

The problem with a modified sine wave is that there are discontinuities in the waveform that occur and these cause dV/dT problems with the magnetics as well as possibly filter capacitors and commutated swiitches in PFC's.

 

I would strongly discourage using MSW type inverters unless the load device has been approved for use with such sources.

[Miko Man]

 

Reason I'm still beating this not-quite-dead horse is I purchased a Xantrex MSW and while using it heard a noticeable "buzzing" sound coming from my amp. Having never used an inverter/deep cycle battery set up before, wasn't sure what the problem was but I knew it didn't seem right. Not saying Bobby isn't having good luck but I'm a little gun shy about mine. Gonna look for a different one.

 

 

Tomm, have you tried another sample of that model inverter? I recognize that there is a difference between what an EE or an OEM would "recommend" and the "it works OK for me" experience, but you might just have gotten a bad/less clean model as part of the manufacturing tolerance. Is there a solar/wind power dealer in your area to talk to? He/she might have something you could try. Mark C.

[Bobby1Note]

Then, I'd buy a PSW inverter Tomm. They're double and triple the price though, for the same wattage rating. Most "buskers" I know, won't spend the dough, to power what is usually/often a cheap combo-amp. As I said, I've had zero issues, and neither have the guys on the acoustic-guitar forums who've tried it, That may not guarantee that "your" buzzing issue will go away. Depends what the actual cause was.

[agedhorse]

 

PSW is Pure Sine Wave,,, and MSW is Modified sine wave FWIW, my Xantrex inverters (I have two of them, a 1500w MSW, and a 300w MSW) are CSA approved. I've used the 300w to power my AER Compact 60/2 60w RMS combo-amp, with exactly the same results .Runs clean as a whistle.I've also had plenty of emails from guys around the world, who do exactly the same thing as I do, and have the same results. Judge for yourself.

 

 

CSA approval doesn't mean sh*t regarding this subject. Has absolutely nothing to do with it other than that under normal use it (essentially) won't catch fire or electrocute you.

 

Your experience is on a couple of devices, and you do not know what the long term effects are on it's internal components. In fact, the power supply on your amp is probably fairly tolerant to crappy power (ie. MSW inverter), but the OP's load is a totally different topology AND with a PWM load in addition to a SMPS. I would really discourage testing the PRX and similar products behind the woodshed using MSW inverters.

 

IMO, your advice, suggestion, recommendation, whatever, is not good for others who may be interested.

[agedhorse]

 

Then, I'd buy a PSW inverter Tomm. They're double and triple the price though, for the same wattage rating. Most "buskers" I know, won't spend the dough, to power what is usually/often a cheap combo-amp. As I said, I've had zero issues, and neither have the guys on the acoustic-guitar forums who've tried it, That may not guarantee that "your" buzzing issue will go away. Depends what the actual cause was.

 

 

What you are missing Bobby is that the specific questions from both Tomm and the OP regarded a totally different application with different types of equipment, different topologies, etc. Yeah, it might work just fine on a $100 plain vanilla cheapo amp but that's NOT what others are asking.

[Bobby1Note]

Yeah, I realize I'm just a lowly "idiot" consumer Andy, and you're a "smart" ENGINEER". Lord knows, you've told us enough times.

 

Fact is though, there ARE millions of these things in service. If they were as "dangerous" as you describe, they'd be taken off the market immediately, and there would be a hue and cry that stretches around the globe.

 

Somehow, I've made it through 63 years of life, without ever hearing of an issue with these devices. I must live a sheltered life.

[Speedhead]

Quote From this page : http://www.donrowe.com/inverters/inverter_faq.html#appliancecautions

 

 

 

 

Do I need Modified Sine Wave, or Pure Sine Wave? Advantages of Pure Sine Wave inverters over modified sine wave inverters: a) Output voltage wave form is pure sine wave with very low harmonic distortion and clean power like utility-supplied electricity. b) Inductive loads like microwave ovens and motors run faster, quieter and cooler. c) Reduces audible and electrical noise in fans, fluorescent lights, audio amplifiers, TV, Game consoles, Fax, and answering machines. d) Prevents crashes in computers, weird print out, and glitches and noise in monitors. e) Reliably powers the following devices that will normally not work with modified sine wave inverters: Laser printers, photocopiers, magneto-optical hard drives Certain laptop computers (you should check with your manufacturer) Some fluorescent lights with electronic ballasts Power tools employing "solid state" power or variable speed control Some battery chargers for cordless tools Some new furnaces and pellet stoves with microprocessor control Digital clocks with radios Sewing machines with speed/microprocessor control X-10 home automation system Medical equipment such as oxygen concentrators We carry a full line of Pure Sine Wave Inverters here at DonRowe.com, though most of the inverters we carry are Modified Sine Wave inverters. Modified Sine Wave works well for most uses, and is the most common type of inverter on the market, as well as the most economical. Pure Sine Wave inverters (also called True Sine Wave) are more suited for sensitive electrical or electronic items such as laptop computers, stereos, laser printers, certain specialized applications such as medical equipment, a pellet stove with an internal computer, digital clocks, bread makers with multi-stage timers, and variable speed or rechargeable tools (see "Appliance Cautions" below). If you wish to use those items with an inverter, then choose a Pure Sine Wave inverter. If you mostly want to run lights, TV, microwave oven, tools, etc, a Modified Sine Wave inverter is fine for your needs. We often are asked if computers will work with Modified Sine Wave. It's been our experience that most (with the exception of some laptops) will work (though some monitors will have interference such as lines or a hum). However, if you have any doubt about any appliance, tool or device, particularly laptop computers and medical equipment such as oxygen concentrators, we recommend that you check with its manufacturer to be sure it is compatible with a Modified Sine Wave inverter. If it is not, choose one of our Pure Sine Inverters instead. The difference between them is the Pure Sine Wave inverter produces a better and cleaner current. They are also considerably more expensive. You might find it practical to get a small Pure Sine Wave inverter for any "special need" you may have, and also a larger Modified Sine Wave inverter for the rest of your applications.

 

 

Probably worth spending extra money and get a PSW inverter I would say if you are planning on running some nice equipment this way. As with anything else you usually get what you pay for IMO.

[agedhorse]

Yeah Bobby, right. That's how it is.

 

You seem to have no problem giving bad advice and then offering a sarcastic edge when called on it.

 

Maybe you ought to give it another thought when giving advice to somebody else when you do not know the real facts about a device or process. You are, of course, welcome to do anything you like to your own gear. Are you willing to pay to replace or repair something that gets damaged by your poor advice?

 

I used to design inverters and solar charging controllers in a "past life" and I am intimately familiar with inverters... especially PSW inverters which are nothing more than a class D power amp with a low frequency clock and a 60Hz sine wave reference.

 

Yeah, I realize I'm just a lowly "idiot" consumer Andy, and you're a "smart" ENGINEER". Lord knows, you've told us enough times. Fact is though, there ARE millions of these things in service. If they were as "dangerous" as you describe, they'd be taken off the market immediately, and there would be a hue and cry that stretches around the globe. Somehow, I've made it through 63 years of life, without ever hearing of an issue with these devices. I must live a sheltered life.