Advice re power-efficient stereo setup

[eblantz]

I take a trip every year on a houseboat. Music is a centerpiece of this trip and I'm responsible for the stereo setup. In past years, I've taken my old Marantz receiver and two sets of bookshelf speakers (Altec lansing and Bose 209). I can run this setup AC, but that requires the generator to be running, which is loud and burns lots of fuel. My solution has been to use an inverter, which works fine at low volume and when the batteries are fresh, but I get a low voltage alarm when the system gets cranked up (which is does a lot). So, I'm now considering replacing the old workhorse system with something that draws less power. music source is either an iphone/ipod or a portable CD player.

Thoughts on what system would draw the least power possible while also providing quality and volume? I'd consider a system that's just for this trip, so running something on DC is an option. Would a car stereo amp and 4ohm speakers draw less power?

Thanks in advance for your collective wisdom!

 

[dkane360]

Something like this would be pretty neat, depending on if you have the tools and technical know-how to build it. I'm sure you could build a bigger version too: http://www.instructables.com/id/DIY-Solar-Boombox/

and you could have the solar panels somewhere else, like on top of the boat.

 

[highfigh]

I take a trip every year on a houseboat. Music is a centerpiece of this trip and I'm responsible for the stereo setup. In past years, I've taken my old Marantz receiver and two sets of bookshelf speakers (Altec lansing and Bose 209). I can run this setup AC, but that requires the generator to be running, which is loud and burns lots of fuel. My solution has been to use an inverter, which works fine at low volume and when the batteries are fresh, but I get a low voltage alarm when the system gets cranked up (which is does a lot). So, I'm now considering replacing the old workhorse system with something that draws less power. music source is either an iphone/ipod or a portable CD player.

Thoughts on what system would draw the least power possible while also providing quality and volume? I'd consider a system that's just for this trip, so running something on DC is an option. Would a car stereo amp and 4ohm speakers draw less power?

Thanks in advance for your collective wisdom!

It will draw less if you look for Class D amplifiers. They're sometimes called "digital" but most of that is marketing BS. Look at the specs for current draw or call the manufacturers to get the real numbers but ask for the technical department. A head unit will draw very little if it's not using the power amp section. If you do this, get a high capacity (Amp-Hours, not Cold Cranking Amps) deep cycle battery- two if you plan to run the stereo hard or for extremely long periods. DO NOT discharge any battery and connect it to an alternator, hoping that it will recharge. That beats the crap out of the alternator and will cause it to fail when you need it to work. Since it's on a house boat, I would seriously consider a solar charging system. Also, if you use shore power, get a good battery charger and use that overnight to charge the battery when it's deeply discharged.

FYI- "deep cycle" doesn't mean you can kill it and it will come back to it's new condition- it means that you can discharge it to about 10VDC and it will return to normal.

 

[MidnightSensi]

Alpine makes some fairly efficient marine amplifiers now.

You may just need to run more house batteries.

If your connecting to shore power and charging the batteries using a battery charger, also make sure your battery charger 'charge speed' is set properly. A lot of times there are dip switches behind the face, but check your manual. Like AGM batteries have a setting, gel batteries have a setting, flood/lead acid batteries have a setting.

Since it is a house boat, and probably not super weight dependant, I'd run more house batteries. Run a bank of them. I use the Optima blue top batteries (They are AGM deep cycle) for house battery banks.

 

[eblantz]

It will draw less if you look for Class D amplifiers. They're sometimes called "digital" but most of that is marketing BS.

Thanks. This article (http://www.audioholics.com/education/amplifier-technology/the-truth-about-digital-class-d-amplifiers) seems to suggest that class D amps (or at least analog filtered ones) are very complicated to make. I assume that mean they're more expensive as well? Somewhere else I read that they are mostly for Woofers since they have a lot of distortion. True?

 

[highfigh]

It will draw less if you look for Class D amplifiers. They're sometimes called "digital" but most of that is marketing BS.

Thanks. This article (http://www.audioholics.com/education/amplifier-technology/the-truth-about-digital-class-d-amplifiers) seems to suggest that class D amps (or at least analog filtered ones) are very complicated to make. I assume that mean they're more expensive as well? Somewhere else I read that they are mostly for Woofers since they have a lot of distortion. True?

They don't necessarily produce a lot of THD but it really depends on how it's designed. If you want to build something, a site called www.41hz.com has several.

 

[BMXTRIX]

Not sure why you would want to build an amp. This is something you should buy.

http://www.alpine-usa.com/product/view/pdx-4100m

Something like that would be near the top of my list. Combine it with a decent head unit with iPod connectivity...

http://www.alpine-usa.com/product/view/cda-9886m

Then use whatever speakers you want setup for a 4ohm or 2ohm configuration and you should be good to go. You really do want to look for some high efficiency speakers, which you may not get good answers on in this thread, so you may want to check the speaker forum for high efficiency speaker threads, or start one of your own.

Make sure to be specific about your budget, size requirements, etc.

Bose, as is typically the case, does not provide any useful information about their products to help you actually choose something of quality, so they should be avoided whenever you try to make an intelligent decision. (Bose 209? 201? - no info available at all!)

 

[highfigh]

Not sure why you would want to build an amp. This is something you should buy.

http://www.alpine-usa.com/product/view/pdx-4100m

Something like that would be near the top of my list. Combine it with a decent head unit with iPod connectivity...

http://www.alpine-usa.com/product/view/cda-9886m

Then use whatever speakers you want setup for a 4ohm or 2ohm configuration and you should be good to go. You really do want to look for some high efficiency speakers, which you may not get good answers on in this thread, so you may want to check the speaker forum for high efficiency speaker threads, or start one of your own.

Make sure to be specific about your budget, size requirements, etc.

Bose, as is typically the case, does not provide any useful information about their products to help you actually choose something of quality, so they should be avoided whenever you try to make an intelligent decision. (Bose 209? 201? - no info available at all!)

I included that as another option.

That Alpine would be a good choice, for a few reasons- size, efficiency and it's not outrageously expensive.

 

[highfigh]

To the OP- do you want to put speakers inside the cabin, or outside, where most of the sound will be lost because there aren't any/many boundaries for it to reflect off of?

One option, which could be used in your yard at home, camping (if you do that), or just anywhere, is the Outcast, from Soundcast. It has a 3.5mm input jack, it's water-resistant (their video shows it being drenched in a car wash) and battery powered. The battery lasts a long time, it reaches decent SPL and actually sounds good. It can be used with the source plugged in directly or with the RF transmitter, which has outstanding range. I have seen it in action where the transmitter was inside of a warehouse office and the speaker was outside, over 100' away.

 

[Seth=L]

You could try just getting a head unit first and connecting to speakers to it. If the output reaches your satisfaction you may not need to spend more on the amplifier. If it doesn't work out you can simply add the 4 channel amplifier and connect the speakers to it instead of the head unit.

 

[JerryLove]

I'm kind-of assuming: but it seems high-efficiency speakers would be benifical as well: 10db better effeciency means 1/10th the wattage requirement for the speakers.

Also, correct me if I'm wrong, but class H amplifiers also offer pretty high effeciencies.

 

[BMXTRIX]

You could try just getting a head unit first and connecting to speakers to it. If the output reaches your satisfaction you may not need to spend more on the amplifier. If it doesn't work out you can simply add the 4 channel amplifier and connect the speakers to it instead of the head unit.

Heck, why not just flip it? Go with just an amplifier and connect the iPod directly to it? No extra electronics running beyond the iPod and the amplifier. Might draw less power and work nicely. Just use the proper RCA preout cable available for the iPod, not the headphone jack.

 

[MidnightSensi]

Heck, why not just flip it? Go with just an amplifier and connect the iPod directly to it? No extra electronics running beyond the iPod and the amplifier. Might draw less power and work nicely. Just use the proper RCA preout cable available for the iPod, not the headphone jack.

Most the headunits now you control the volume of the iPod through the unit. Kenwood's unit you just drop your iPod in. Plus the remotes and such are nice on boats. Like one keypad near the transom or something.

With a proper electrical system, having a moderately sized stereo system shouldn't be a problem. It might just need a bank of house batteries.

I'm kind-of assuming: but it seems high-efficiency speakers would be benifical as well: 10db better effeciency means 1/10th the wattage requirement for the speakers.

Also, correct me if I'm wrong, but class H amplifiers also offer pretty high effeciencies.

For sure. I've seen people put in B&C horns in boats before, but I'm not sure if they are 'marine' ...like the hardware and diapragm and so forth.

 

[eblantz]

Wow! you guys rock!

Wow. I'm just getting back here after a few days away to see all the great advice. I'm truly impressed!

Right now I'm angling toward an amp (car) with about 100w RMS @ 4ohm x 4 speakers. Sound about right?

Also, any thoughts on 4 ohm speakers that are already in cabinets so I don't have to fab these? (yes, I'll check in over on the speaker forum too).

I plan to research some of these options a bit more inthe next few days and will let you all know what I find/decide.

thanks again!