Speaker question

[caseydog]

CD

[Justin & Katy]

Nice! Well played!

[Jason and Amanda]

I've been contemplating a movie watching solution for my tear. So far the best solution is just a laptop, but there are times where you need better sound quality than what is offered by laptop speakers. I'm probably going to just place some unpowered speakers that have a standard mini headphone jack, that way I can plug in an FM radio, laptop, MP3 player, whatever.

If you feel the need for a head unit, consider one with a remote!

I would NEVER bridge the speaker outputs of a head unit, you are effectively cutting the Ohm's in half and you will most likely blow the amp in the head unit over time. If you are considering an amplifier, I say you should do it. Buy the smallest good quality one with a signal/noise ration of at least 110 and you will really like the sound clarity. It's NOT always about power. I'm serious, just buy like a 30 watt RMS 2 channel amp, it will be small, have low current draw, and will clean up your signal nicely.

[dh]

I have a plan for defense against loud music and bright lights invading my campsite. Drew this up a few years ago........

I wonder that would do to your gas milage

[MceeD]

You can always use a motorcycle amp. 2 or 4 channel...Like these.

http://cgi.ebay.com/ebaymotors/CLASS-D-350W-MOSFET-MOTORCYCLE-SMALL-CAR-AMPLIFIER-AMP_W0QQcmdZViewItemQQhashZitem414e6f31e6QQitemZ280488784358QQptZMotorcyclesQ5fPartsQ5fAccessories#ht_3885wt_939

or:

http://www.amazon.com/MOTORCYCLE-SPORTS-COMPACT-AMPLIFIER-POWERFUL/dp/B002X1IE52

You should find that deck power will be fine for a small area such as the cab in a teardrop, You really wouldn't need amps unless your very concerned about sound quality or your planning on a sub.

remember if you are going to put speakers near a Monitor or PC you should get shielded speakers.

Using a sealed enclosure for your speaker will help a lot in their efficiency and their ability to reach lower frequencies.

I will have a lot of electronics in my trailer including two touchscreen LCD's a 17" in the cab and a 7" in the galley. A computer for video and audio. 4.1 speakers for the cab and 2 galley. and two amp to power them all. Of course without saying some serious batteries and a solar panel :0

[Engineer Guy]

5 Watt output HUs have gone the way of black, rotary dial Telephones ;-). The way to get >12 watts audio out of a Head Unit [HU] running off a +12 Volt Battery is to use IC Audio Output 'Chips' that are 'push - pull'. That is, neither side is connected to, or can be connected to, electrical or chassis ground as we all know it. See the Speaker connections 'Out +' and 'Out -' designations on the IC .pdf linked below. Audio ICs have gotten more powerful and less expensive since that 02/2000 article. Ohm's Law: P [wattage] = I [amperes] x E [voltage].

One very standard Audio IC [read: inexpensive] used in the biz, especially for Euro HUs, outputs 20 watts/channel x 4 [L & R - front & back]. Given that +12 Volt vehicle systems are more like 14 Volts, the Audio amp IC has more like 28 'raw' Volts input to work with in push - pull mode. That voltage excursion, via these push - pull IC Amps, means each HU channel can reasonably output 20 Watts [20 Volts @ 1 Amp] since amplifier efficiency is never 100%. Higher HU and subwoofer amp wattages can be realized by outputting either more amperes, or by using internal voltage doublers, etc.. Maximum audio IC output is derated as voltage input drops from the 14.4 volts supplied by a running Alternator to voltages less than that off a battery per Ohm's Law above.

DO NOT connect HU front - back Fader outputs together into 1 speaker. Built-in dead short and overcurrent protection in most all Audio ICs means your HU would likely survive, but may not output any sound at all. Protection varies by HU Manufacturer, but most design in only a handful of Audio amplifier ICs standard in the marketplace. A lot of HUs now output 50+ Watts x 4 channels as standard, so use just one set of Fader channels [front OR back] for plenty of sound. 80 Watts [~40 x 2] in a TD will be seriously loud. 40 Watts at 4' equals the decibel [sound] level of 80 Watts at 8', and so on. Get an HU w/an iPod input jack and that TD will be rockin'! If you want, add a powered Sub that accepts speaker level inputs and run the HU rear outputs to that outboard amp and woofer. Depending on how the Bass control on your HU cranks up, you may not want/need a sub. Subs typically have 2 voice coils: 1 for HU left channel; a 2nd for right channel.

Not connecting a pair of outputs [front or back] won't hurt anything. Connect the rear channels to some outdoor speakers via foolproof connectors [with neither speaker wire being grounded] and use the front - back HU Fader to control TD internal speaker sound vs. external 'party speaker' sound when camping while isolated. 'Zach' had some good ideas posted above.

I've got an aging, self-installed Sony HU in my SUV, and it's 50 Watts x 4 channels. It also has a Remote; a great idea mentioned above. For reference, see some Kenwood HUs here:

http://www.kenwoodusa.com/Car_Entertain ... _Receiver/

Note on the specs the max current draw of any HU you're considering. Then, do the math on how quickly an HU cranked up [w/o a sub amp] can draw down to 50% a deep cycle battery in <1 day. 6 Amps power draw x 10 hours = 50% draw down of a 120 AH Battery. A smart pal killed his good-condition Bronco battery above treeline listening to music while SUV camping. He was with someone, and they jump started his Bronco.

Long wavelength Bass frequencies, especially, carry very LONG distances outside, and even longer distances over calm water. Note how far away you can hear thunder. A Band at a pal's Wedding Reception on Long Island got a noise complaint years ago from 10 miles away in another State because sound traveled that far over the water adjacent to the Reception location.

http://www.reber.si/TDA/TDA1562Q/e002044.pdf