# low usage stereo advice please



## Sparticle (Nov 1, 2004)

Hello all. On the way to our move to off grid living we must find a good sounding stereo that won't drain us dry. Should we look for a small boom box type deal? Any and all advice welcome. Thanks.


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## damoc (Jul 14, 2007)

dont know what battery voltage you intend to use but if it is 12v shop around
for a small portable stero which uses a 12v battery supply so it will easily
run directly of your batteries.

if you need to run through an inverter there is a good chance of severe interferance unless its one of those spendy true sine wave inverters.

also if you can run directly from battery power it will be much more efficient


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## Harry Chickpea (Dec 19, 2008)

Bass = power. If you are comfortable listening to music, then yes, some of the boom boxes are QUITE good. If you need to have your kishkas shaken, then look into an auto add-on system and amp up the power.


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## 12vman (Feb 17, 2004)

A car stereo and a nice set of home stereo speakers works well. The louder ya crank it, the more power ya use.. 

I have all kinds of micro stereo ideas that I use around here..


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## Sparticle (Nov 1, 2004)

I would never have imagined that a car stereo would work. Can I connect it straight to the batteries? Don't have the batteries yet but we have almost 800 watts in the solar array. I reckon I could box in the stereo to make it look nice. So, it will connect to the batteries okay? Thanks folks.


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## Windy in Kansas (Jun 16, 2002)

I guess my answer would be---define stereo? I think of bookshelf units that have AM/FM tuner, CD player, and perhaps duplicating tape deck and maybe even a turntable too.

For just a tuner and CD player I'd look to one of the Bose units as they have magnificent sound for their size and energy consumption. 

As to other options---a stereo receiver is also a great way to go but can eat some wattage. My 200 watt unit provides all of the surround sound I could ask for. Through it I route TV, DVD player, VHS tape player, and when I was still subscribing to satellite Dish Network that too. 

I have upgraded the quality of speakers twice from the originals as I found better and better ones at Goodwill or elsewhere. 

While my 200 watt unit doesn't sound like much power compared to most systems I like a lower volume of overall sound and it renders at that level quite well.

I could put a Kill-O-Watt meter on it and find the consumption if you'd like. Just ask.


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## 12vman (Feb 17, 2004)

Sparticle said:


> I would never have imagined that a car stereo would work. Can I connect it straight to the batteries? Don't have the batteries yet but we have almost 800 watts in the solar array. I reckon I could box in the stereo to make it look nice. So, it will connect to the batteries okay? Thanks folks.


If you plan to do a 12 volt system, just about any kind of car stereo will work.

I was jammin' for a while. I had 2-12" subs on a 200 watt amp with a Pioneer double din indash stereo. (Mounted in a fancy wooden box) It would play CD's, Cassette tapes, Tuner, (AM/FM) Aux. input for a MP3 or anything else you wanted to connect to it. (Couldn't do vinyl.. Dangit!) Used 2-Pioneer home stereo speakers rated at 100 watts. (3-way) Remote control.. Sure sounded good BUT it was a power hog!

Appalachian Surround Sound..

I also use a small set of amplified computer speakers on my "Big Screen" (9") TV. I use a universal DC regulated power supply to operate the speakers..

http://store.sundancesolar.com/undcadpoco.html

The original wall wart for the speakers puts out 9 VDC. I select 9 volts, make sure the polarity is correct with the right adaptor and they work fine. I use the earphone output from the TV..

*CAUTION* Before anyone attempts this! There will be a serious ground loop issue if both units are powered from the same battery! They need isolation! I have a cure if you need one.. (Don't ask how I discovered this..)

I have all kinds of low level stereo ideas that work. I luvs my music!


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## SolarGary (Sep 8, 2005)

Hi,
I've been trying to find a new TV for us that does not use a lot of power and performs well. I found that the reviews on CNET to be the most helpful -- they include all the usual performance stuff along with careful power measurements. You might see what they have for stereos.

http://reviews.cnet.com/

Gary


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## idahodave (Jan 20, 2005)

I just walked through the big box stores and read the power consumption off the back of the sets. 

Wound up buying a 22" Vizio with LED backlight that uses less power than the 13" LCD and HD converter box it replaces. Uses a little over 30 watts.

Found my car radio for off grid by convincing a stereo store to let me measure static current consumption with my meter. Lowest power use was a simple Panasonic with lcd.


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## Sparticle (Nov 1, 2004)

Hey 12vman. Got any wiring diagrams for the car stereo and battery set up?


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## SolarGary (Sep 8, 2005)

idahodave said:


> I just walked through the big box stores and read the power consumption off the back of the sets.
> 
> Wound up buying a 22" Vizio with LED backlight that uses less power than the 13" LCD and HD converter box it replaces. Uses a little over 30 watts.
> 
> Found my car radio for off grid by convincing a stereo store to let me measure static current consumption with my meter. Lowest power use was a simple Panasonic with lcd.



Hi,
The only problem with reading power consumption off the set label is that its the maximum consumption and can be well over the actual average use.

I have taken my KillAWatt meter into Costco, and they were fine with letting me plug a set into it and seeing what it actually uses. But, even this does not work that well with some of the new TVs in that they have energy saving modes that you can activate, and you would have to read through the manual to find them. Some of the sets even have a mode for use in the store that produces a brighter picture (so they look good next to the other sets), but uses even more power.

I ended up buying a Sharp LCD TV with LED backlight. It has a screen about 30% larger than our 10 year old Toshiba and only uses half as much power. CNET says its the lowest power per sq inch of screen area of any TV they have tested.

The thing that gets me is why we can't just have labels on the front of anything that uses electricity that gives the power use when operating, power use when "off", and the KWH per year with average use. I find the Energy Star labels nearly useless -- a 50 inch TV set that uses 180 watts gets the same Energy Star label as a 15 inch set that uses 30 watts.

Gary


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## roachhill (Jul 8, 2009)

I was looking at putting in a stereo and decided a car stereo was the way to go. If you pick one set up for mp3 you gain a USB charger port and a plug that you can plug your laptop or small TV into to get better sound. Unfortunately most car stereo boxes don't list power consumption just sound output so your guessing at power use. If somebody knows of a brand of car stereo that lists power consumption on the box let us know.


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## 12vman (Feb 17, 2004)

"Hey 12vman. Got any wiring diagrams for the car stereo and battery set up?"

If you purchase a new unit, you'll get an installation manual and the wiring will be marked pretty well as for where each wire goes. Don't worry about grounding the chassis of the unit. It will get its connection through the ground wire in the wiring harness.

The power connections are fairly easy. One goes to ground (-), one goes to the battery (+) and another goes to the ignition so the unit turns on/off with the key switch. I just connect the ignition and the battery wires together and use the on/off switch in the unit. This leaves the display on all of the time but it doesn't draw much current.(milliamps) You can set the clock and have another clock that you can read after dark..

Speakers are easy. There will be a pos. (+) and a neg. (-) wire for each speaker output from the unit. If you use home stereo speakers, the polarity is clearly marked. If you only use 2 speakers, just use the front left/right output wires from the unit. Keep the front/rear fader (if it has one) faded to the front. Terminate any and all unused wires with wirenuts or tape so there is no way they can come into contact with anything.

Don't be intimidated. Most of the wiring harnesses already have the fuse holders already installed. All you need to do is get the power and ground to the unit. Just add a fuse holder and fuse in the pos. lead where you make your connection to your battery, a little larger than the one in the original harness to protect the wiring. (Fuse at the source!) 

I figure 12 gauge wire should run most standard units within a 12-15 ft. radius from the battery. If it's a hi-power unit, You may need to use larger wire if ya wanna jam.. LOL 

Antenna connection.. Just cut a length of insulated wire about 30-35" and strip the insulation from one end around an inch. Find the antenna connector on the unit and stick the bare wire in the center hole or get a Motorola connector at Radio Shack and solder the wire to the center pin only. Just string the wire up a wall near the unit and Vala! (Appalachian Antenna) Or, purchase a replacement antenna and hang it somewhere..

"If somebody knows of a brand of car stereo that lists power consumption on the box let us know."

All of them do. They tell you the wattage output BUT it's called "Peak" power. Divide the stated wattage rating in half and do the math..

Example..

If a unit says it puts out 45 watts/channel, assume it has 4 channels. (180 total) Divide in half. (90) Divide 90 by 12.. 7.5 amps.. at full volume. Add about another 500 milliamps for the CD drive motor and the display and stuff and you should have a good idea of what it uses..

Roachhill.. Beware of ground loops! If you connect something to something else that's connected to a common battery, you could have issues. If the volume is low or distorted, disconnect it fast! Install some type of isolation to lift the grounds from each unit. You WILL/CAN damage something! (Don't ask me how I learnt this..)


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## roachhill (Jul 8, 2009)

I appreciate the info but I'm not sure I understand the ground loop issue. If I plug my laptop into the mp3 input on a car stereo to use it as an amplified speaker that will somehow cause problems if they are running on the same battery bank? That's really confusing. The MP3 shouldn't have a problem because it's not plugged into the battery just the stereo connections, right?


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## 12vman (Feb 17, 2004)

roachhill said:


> I appreciate the info but I'm not sure I understand the ground loop issue. If I plug my laptop into the mp3 input on a car stereo to use it as an amplified speaker that will somehow cause problems if they are running on the same battery bank? That's really confusing. The MP3 shouldn't have a problem because it's not plugged into the battery just the stereo connections, right?


I have a TV connected direct to my battery. I also have a set of amplified computer speakers connected to the earphone output of the TV. I power the computer speakers with a voltage converter like the one in the link I provided earlier. Both units are connected to a common battery for their power. I plugged the speakers into the TV and I knew something wasn't right. The sound was very low and distorted. 

From experience, I knew to disconnect quickly! I used my VOM to see if there was any voltage between the ground of the amplified speaker plug and the ground of the TV earphone jack. I measured around 3 volts. That told me that one or the other has a floating ground circuit and if I left things connected, something was gonna fry!

I ended up getting two of these to solve the problem..

http://www.radioshack.com/product/index.jsp?productId=2103994

These allow the audio signals to pass (L&R) but isolates the grounds from each other. 

If you use an MP3 player that is operating on its own power supply, (internal battery) you will not have any issues. If you are using your computer from your battery with a voltage converter and using the MP3 output into a car stereo connected to the same battery, you could have issues. I've never connected this way myself. I just use the headphone output through an isolator that I build with 2 of the transformers just to be sure.

I know it sounds crazy and you could assume that ground is ground but that's not always true. Many audio circuits have a floating ground and the audio ground isn't at the same potential as the battery ground. So Beware..

"If I plug my laptop into the mp3 input on a car stereo to use it as an amplified speaker that will somehow cause problems if they are running on the same battery bank?"

If you are running your computer on the internal battery only.. No Problem..
If you use a power converter to power the computer from a battery and the car stereo is connected to the same battery.. I would say it's most likely you will have a ground loop issue.

If you connect anything (CD player, cassette player, MP3 player, computer, ect..) to the Aux. input of a car stereo that is operating on it's own internal battery, there will be no issues at all. The problems start when you use a common battery to power both units. In most cases, ground isolation will be needed..


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## cmcon=7 (Mar 7, 2010)

I have done the car stereo, also the boom box, my favorite is a boom box and a high power car amp, when power is plentiful you can rock out with the amp (3.5mm plug into phone jack), when power is tight the boom box is good on power.

I just hook wires to the bat terminals, I've even hooked a half dozen 9v units to 12v without smoke.


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## artificer (Feb 26, 2007)

Just a data point: While I was out at the shed installing insulation, I put the kill-a-watt on the stereo. Pioneer component/tuner system driving old style (large) speakers and a XMradio reciever. 32watts baseline. 40watts when I cranked it a bit. 50watts when I didn't want to stand in front of the speakers, or when I worked downstairs and still wanted tunes. This is 120V, so powered by either the inverter or the generator. 

Michael


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## Sparticle (Nov 1, 2004)

With the help of the brilliant 12vman we are now rocking out! Got the car CD/receiver going and it sounds great. Rock on 12vman!!!!!!!!!!!!


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## 12vman (Feb 17, 2004)

Rock on, my friend. Praise yourself for looking outside of the box and learning something new!


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## texican (Oct 4, 2003)

I've used both boom boxes that used 8D cells, and hot wired through the battery compartment, directly to my 12vdc battery bank.

Like others said, a regular car stereo will work great... I've heard quite a few car stereos that sounded better than my home setup. What's really nice about a lot of car stereo's now is they have usb connections, so a usb thumb drive or portable hd can be hooked up. Quite a few have remotes, woohoo!!!


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## WisJim (Jan 14, 2004)

If I were starting out over again with an off grid system, I would use my laptop to play CDs or music stored on the hard drive or on a flash drive, connected to a efficient car stereo amplifier.


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## wy_white_wolf (Oct 14, 2004)

I was thinking a portable MP3 player hooked into a car amp. All modern car stereos have phatom loads when turned off to keep time on the clock and stations stored in memory.


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## 12vman (Feb 17, 2004)

Quote..
"All modern car stereos have phatom loads when turned off to keep time on the clock and stations stored in memory."

I've tested this load and it's no more than operating a standard L.E.D. (20-30 milliamps) Not enough to really worry about. At 30 mills, it would take 33.3 hrs. to consume 1 amp hr. from the battery and you have a clock that you can see at night! Well worth it, IMO..


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## 12vman (Feb 17, 2004)

I got really cheap and disgusting with my home made boom box.. 










The speaker enclosures are from Wally World. The 6"x9" speakers are from an old Chevy Cavalier. The Super Tweets are a set that I've had laying around. (Think from a garage sale somewhere) The amp is a battery operated amplified speaker system to be used with a MP3 player or other portable device with the speakers removed and wiring added to connect to the speakers I built. The amp has an extended 1/8" male stereo jack so I can plug it into almost any portable battery operated music source. (MP3, CD, Cassette, ect..)










All of my "toys" run on "AA" rechargable batteries. (3 in the amp and 2 in my other audio sources) I recharge the batteries from my house system..

The amp and speakers are just that. An amp and speakers. I can connect any source I want..










The amp puts out a whopping 1 watt per channel but it sounds great! I subscribe to Live 365 for a music source and use a FM modulator to broadcast the music from my laptop to anywhere outside around the house to an FM reciever connected to my boom box..


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