I must respectfully disagree with the last post.
Pyle makes 100 watt marine speakers and a 400 watt waterproof marine amplifier... you can find them on Amazon.com with stereos having outputs at 40-50watt peak 20-25w RMS (this is where you want a 25w speaker)
Speaker wattage ratings are for the most part irrelevant and also very often bold faced lies. With clean power most any speaker out there, unless walkie talkie grade can handle the "deck power".. When buying speakers focus on sound quality not what the package says in "W"...
I can guarantee I could blow up those speakers at FAR LESS than 100W of REAL POWER not bogus massaged & misleading marketing claims. My home stereo amp, only a two channel amp no volume buttons, puts out 100 WPC and it weighs over 80 pounds to do so. It has eaten 400W "rated" speakers for lunch. Done it to prove a point to a friend.. The speaker cones were popping at max extension at just 1/4 volume on my pre-amp. That was probably about 30 real watts against a 400W "rated" speaker.
The Boss Audio MR1420S is 240w peak and likely only 100w rms and likely only 50w rms per channel. That's a decent sounding system with 2 50watt speakers well under the point where the clipping and distortion begin. Therefore you could expect more than 8 amps continuous if operating at the units true maximum output.
Those claims by Boss are EXACTLY what I am talking about, complete lies, but, quite typical. As I mentioned above that unit is at best a 4-8 watt unit if you use any sort of "legitimate" wattage rating system.
This is what a 150 watt per channel amplifier would really look like. It weighs 90 pounds and requires its own dedicated 20A outlet on AC!!!!!!:
This is what a "chip amp" looks like. They are found in most car in-dash stereos. it is about the size of a quarter and weighs about the same as a dime.
240 WPC from a car deck ?
Only if they're egregiously lying about it... Those are most often heavily "massaged" numbers taking one specific easy to drive frequency at a horrible THD distortion level and rating a split second peak to trough. They have other sneaky ways of rating them too, like the "W" does not even mean watts but 400 "wow" factor and some other bogus shenanigans....... More like 4-8 listenable WPC at best at 12.3 - 12.7V and perhaps up to 9-11 at 14.6V... Car audio companies are among the most misleading of any consumer brands when it comes to marketing claims, but they get away with it because the industry is rather lax and few want to self regulate. The ones who are honest, lose sales to the liars so they all choose to mislead....
To be fair here is a 100 WPC car amplifier (at car audio "quality") with only somewhat misleading specs and decent sound quality. It will set you back about $2200.00... it is 3" Tall x 12.5" Wide x 18.4" Long and will draw upwards of 50A DC and 2.5A DC sitting there at idle doing NOTHING.......
If you want a unit that is more fairly rated, still not a fool proof standard, buy one that says: "Amplifier Power Standard CEA-2006 Compliant." Keep in mind though that this power rating is at 1.0% THD and 14.4V. A 1.0% THD is HORRIBLE and in the ear bleeding range especially when you consider that it is not rated at 20 Hz to 20 kHz and they've picked a "favorable" frequency to rate it at. They are usually way worse than 1% THD if they were accurately rated from 20 Hz to 20 kHz.. My old amp was rated at 0.04% @ 20 Hz to 20 kHz.. This is in the range of not even audible across the entire frequency range but it took 90 pounds of weight and a dedicated 20A outlet to get there..
On a sailboat you're rarely at 14.4V, and 1% THD is a pretty poor level of distortion as far as sound "quality"... I would bet it is pretty hard finding ANY CAR OR MARINE DECK (not an external amplifier) that has a CEA-2006 "amplifier" rating. Manufacturers only tend to rate EXTERNAL AMPS not in-dash decks. They don't rate decks so they can lie to you in the aisles of Wal*Mart and Best Buy.
I found this a while ago and it makes for some interesting reading..
Outrageous Audio Claims]http://www.outrageousaudio.com/page_files/amp_wattage.pdf] I know all about the stereo salesman's lies.
However you CAN find, and have 50 watts per channel. But you can't say it doesn't exist. You are correct that most really cheap marine radios can only pump about 10 watts to a speaker and putting 100 watt speakers on a 10 watt radio is for people who know nothing about electronics or sound.
You're not going to find in-dash "deck power" in any car or marine stereo with a real 50WPC that meets CEA standards or any "reputable" method of testing output, but, you can find PLENTY of liars...Yes, you CAN find an external AMPLIFIER that puts out 50WPC but it will suck your bank like a Vampire sucks blood. A quick glance a the McIntosh amp above and its 50A DC current capability should solidify what it takes to produce a real 100WPC in a 12V amplifier. It really puts the "bogus" 240WPC in-dash stereo in perspective..
100 dB is not 100 watts, not sure about that comparison.
Not a comparison at all that deck pumps about about 4-8 watts at 12.5v and you can still hit 100dB with it though not very "cleanly".
If an ordinary factory sound system in an 07 Silverado renders a 60amp/hr battery incapable of starting the vehicle after only 3 hours, then it is drawing some worry-some current for some unknown reason.
Many car systems these days use large external amplifiers, and with the key on with most cars these days you're powering more than just the stereo.
Is your 1.4 amp with you inside and the doors closed? If you're on your boat with 4 or more people with the music on and all the loud talking and so on, will your stereo be set to a nice easy listening volume? what if it's windy, well it will be, and you need to pump harder to get the sound through all that moving air.
I already tossed my normal type boombox running on D cells, cuz you can't hear it unless you're on top of it.
Yes 1.4A renders a very "listenable" level with our Kenwood Excelon deck but we have efficient speakers and two in the cockpit and two in the salon.
This is two channels driven, 4 Ohm nominal speakers w/92 SPL "rated" efficiency, white noise CD @ 1.62A and 103dB.
Anyway, there is basis for my comment about doing the math on a substantial entertainment system. Only thing is... I don't care!!! Mine will be on it's own battery, if it goes flat, the only thing I will have to contend with is SILENCE.
No in-dash car deck is a "substantial" system and you'll be at .3A to 4.8A +/- ....
