onboard entertainment system

[Jerry]

I am in the research stage of installing an entertainment system on board that would include surround sound (the amp should be able to accommodate cockpit speakers also), flat screen tv, dvd, cd, cassette, sattelite radio, & am/fm receiver. Is there anyone out there that has suggestions with quality, size & power in mind. I would prefer 12 volt systems but I do have a 1500 watt inverter on board. Thanks for your advice. If I posted this in the wrong forum please let me know.

[cyclepro]

Earlier this week I installed a Toshiba flat panel LCD TV on my 35ft boat. It runs on 12V and I connected it direct to the boat's wiring system with a 7.5 Amp fuse in between.

http://www.bestbuy.com/site/olspage....=1099395091923

This little TV also runs the various other recording media.

It is small but sufficient for the size boat I have. It has all the necessary outlets to hook up additional devices and sound systems.

The only drawback is having the large cable-box on board but that one will be gone once I cast off.

I have not tried the DVD player yet though.

Good luck

[Jerry]

Thanks for the information...what modeldid you get?

[Jerry]

Sorry Cyclepro,
I replied before I tried the hyperlink

[ssullivan]

Jerry once whispered in the wind:
I am in the research stage of installing an entertainment system on board that would include surround sound (the amp should be able to accommodate cockpit speakers also), flat screen tv, dvd, cd, cassette, sattelite radio, & am/fm receiver. Is there anyone out there that has suggestions with quality, size & power in mind. I would prefer 12 volt systems but I do have a 1500 watt inverter on board. Thanks for your advice. If I posted this in the wrong forum please let me know.

Hi Jerry,

Having just gone through this, I will add a few things:

AMPS: There are several ways to go. The amp is basically bringing any line level audio up power for your speakers. These days, they add in surround sound and many other features I personally don't even want in a house, nevermind a boat. When shopping for the amp, if you desire surround sound AND another set of speaker outputs to go to the cockpit, you might find yourself with limited choices, or having to spend big $$. I would not go anything less than a 100 watt per channel amp if you would like to power speakers in the cockpit. You need a lot of power to drive outdoor speakers and have the sound come out ok. Even 100 watts per channel is on the light side. I chose a simple 120V Sony amp, since the car/boat stereo market is so limited. It's hard to find what you're looking for in that market, if not impossible. When looking at matching amps and speakers, think about the intended use. If kids will be cranking it, get an amp that is matched to the speakers and can't do too much damage. If someone responsible and who understands the stero will be cranking it, go for a more powerful amp than the speakers (stereo store guys will help). You can get better sound quality this way, as the distortion from the amp doesn't rattle the speakers at higher volumes. Lastly, if you are looking for quality in an amp, there is an old trick that actualy still works in this day and age. Pick up the amp. If it's light, it's junk. If you can barely pick it up... it's good! Amps rely on many components that can't be put onto an integrated circuit, so while computers and such are lighter all the time, good amps tend to stay heavy.

LCD/Plasma TV: Take your pick. Many run on 12V. I just run mine through the same inverter the amp is running on, for convenience. Not as efficient as it should be, but hey... it's easy.

Cassette/CD/DVD/Sattelite Radio,AM/FM: Seems like a lot of stuff. Why would you want a cassette player if you have CD capability? Better question... why not get an iPod? Seems like you are looking to have too many formats. You could simplify your setup (and save valuable space on your boat) by going digital. Replace the CD/Cassette with an iPod. Maybe adding in Sattelite radio would be ok, at least if you are staying in the coverage area. The AM/FM is in the amp if you buy a standard "home" type amp.

DVD: Go cheap. Buy the cheapest junker you can find. They're mostly all the same inside. Plus, if the lens gets mucked up from moisture, you can always get a new one.

Speakers: Be absolutely certain to get a polyurethane cone! Do not get paper cones for a marine installation... the water and moisture can destroy these speakers. Make sure they can withstand some water. Incidentally, many of the speakers made for flush mounting in walls at home are designed to take a splash or two. They have the poly cones. I got a pair of 100 watters for my salon, and they are working well.

Brand: Don't worry about the brand. Any reputable brand will do. Worry about power, ability to do everything you listed, quality connectors, multiple types of inputs (both audio and video - s video, etc...). And look for something you can add components to. Don't get locked in. Make sure you have enough inputs to add whatever you want as time goes on. And do be sure to look for HEAVY items when it comes to amps and speakers if you are looking for quality.

Final Comments: I chose not to go for a "marine" audio system because they just don't have the capabilities that a standard home audio system does at any price. It's nice to know that if something goes wrong, you can just replace a component and be back up in running in no time. Plus the sound can't be touched by any car/marine system.

[Rick]

You've got the inverter and , therefore, you have the broadest choices available in 120V source products. One reason for having the inverter is so that you are NOT tied in to specialty 12V source products.

Virtually all of the good quality and good priced procucts are 120V sourced ones....just shop them and verify that even the best "automotive" sound systems are not as good (dollar for dollar) as those which are for other (like "bookshelf") applications which lend themselves very well to your boat.

Especially price sensitive are amplifiers which exceed about 25 Watts (total both channels or more) when confined to 12V sourcing. It is less expensive to manufacture high power multiple channel amps with higher voltage sources.

If you have a "good" installation of your inverter (short battery cables twisted together, etc. according to recommended practices) you can have a very good quality sound system including sub-woofer with overall decent efficiency with some judicious choices.

[CaptainK]

I used to work for MTX. They make car stereo amplifiers. And they also manufacturer, surround sound systems.''

Like what Sean said earlier about the weight. He's right about that. The more heavier the amp. The better. Also about 65% of the weight, is the heatsink. That helps dissapate the heat from the electronic circuits. So you're higher end amps are like this.

Rockford Fosgate. Another car stereo amplifier manufacturer. They also make great amplifiers.

The reason I posted this. Is that these two manufacturers' make the best audio equipment for autos and home applications. It wouldn't hurrt anyone to research it for yourself.

[Alan Wheeler]

Audio! This subject is my life. I used to eat a breath it. I was at the top of the feild in sound design.

OK, first rule of life. The HiFi audio world is full of snake oil, hens teeth and flying pigs, all sprinkled with a fairydust and served with a gravey of BS.
Your responsability?=don't be easily suckered by the sales guy.

OK, on to the task. I will try and keep this concise, but it will still be long.
First question is, just what do you want to spend. You can go mad. I can sell you speakers that will cost you around US$60K. Quite frankly I think they are crap when compared to the price. But you can also go bargan basment as well. It is also false economy.
Several here have already suggested not to go 12V. This is true if you are looking at power. To get Power from 12V, you have to have internal inverters in the circuit. You pay for that. So reputable brand name high end car audio is usually expensive. That then brings us to the point of power. How do you measure power. You will see many of the following.
RMS @ 10% distortion
RMS @ 1% Dist.
RMS @ 0.05%
Peak music power
Peak to peak music power
What does all the above mean? Well actually, absolutely nothing. Although the RMS ratings are more realistic, none of the above actually tell you how they were measured.
Most HiFi amplifiers will give you figures that look impressive but mean absolutely nothing.
Oh and sorry guy's, Weight means totally nothing. The weight comes from the mains AC transformer. The heatsink weighs nothing and I'll come back to that. The conventional mains transformer Power supply is cheap. It is also highly inefficient. If you want the best, a solid state switching supply can't be beat. But unfortunately, the industry has dished out a pile of crap about weight equaling quality.
Back to the heatsink. The heatsink gets rid of heat. The heat is produced by the output circuit design. Some designs are more efficient than others. A big heatsink can also mean a cheap design.
I have a commercial high end audio amplifier that can produce a total of 2KWRMS at 0.001% total harmonic distortion measured from 20Hz to 26Khz and it has no heatsink and no fan. It is in a totally enclosed case.Expensive, but I used them in clubs and such were there was a lot of dust dirt and grime from tobaco smoke that would cause a fan type amp to packup in a month.

Matching amplifier to speakers. The correct way is to go double the amplifier power to a speaker. Once again, you need to know how the manufacturer has rated there speaker. The same issues as the amplifier power further above, apply. So lets say we have a speaker that is 100WRMS rated. In theory the amplifier should be 200WRMS. You will never turn the amplifier up that loud. It allows a thing called dynamic headroom. Let me go back a step. You know how some of the purests rave on about the old records sounding better than a CD. Well this is all about compression of dynamic music peaks. This is a form of distortion and is why you also complain about TV adds sounding louder than the normal broadcast. Actually it isn't. The add is highly compressed and gives us the impression that it is louder. This problem when listening to music equats to listening fatique and "noise". Being able to reproduce dynamic peaks allows the music to "breath". sorry, I just can't find anyother word to describe it. But you hear detail that you don't in a compressed source. OK, this is the scary part. Dynamic peaks can be as high as 10dB above the main level. Even on a CD, especially todays stuff as Digital has come along way. To reproduce a peak of 10dB, you need an amplifier that has a peak ability of 10 x the main RMS programme material. So you actually need 1000WRMS amplifier to run those 100W speakers. Of course, that ain't going to happen, but it is why a more powerful amplifier sounds better.
The next point is cliping. This is when the amplifier can no longer reproduce enough of the peak content. It has run out of what is called "headroom". It cuts of the tops of the waveforms.This is death to any speaker. A 50WRMSamplifier run into clipping will fry a 2000W speaker in minutes or even less. Clipping is the distortion you hear when it is truned up to loud. C-rap seems to love distorted bass.
How loud will it all go. Well actually, this has little to do with the power output. Our human hearing works like this. The smallest sound for someone with perfect hearing can discern is called 1dB. Decibel after Mr A Bell, the telephone dude.
3dB is considered the amount a sound has to increase for us to percieve an increase in level. 10dB is the amount of sound pressure we persieve as twice as loud. An increase of 3dB, requires twice the power. So to turn up a 10W amplifier and "hear" an increase, requires 20W of power. To "hear" it as twice as loud would require 100W. So what makes a speaker loud. It's called it's Effieciency and is measured as the following.
"x" dB@1W/1m. A good Hifi speaker may be as efficient as 80dB@1W/1m. This means that if you measure the sound level from a distance of 1metre, place 1watt of sound energy into the speaker, the measurment will equall 80dB. Indoors, a rule of thumb is that for every doubling of distance, that sound level will reduce by 3dB. Outdoors it is -6dB. Most people listen to music around the 90 through to 100dB. A loud rock concert can be about 110dB upto the earbleeding levels of 130dB. The loudest concert I have mixed for peaked at 121.8dB. That was damn loud.
I have a pair of top end commercial speakers here that have a sensitivity of 106dB@1w/1m
The sensitivity rating is probably the most iportant measurment that can be made. When it is measured along with the frequency plot, it tells you everything you ever need to know about the speaker. No wonder vertually no one in the HiFi world ever produce or publish that figure for there speakers. Or if they do, they publish it such a way, that it makes no sense.

Interconnects. These are the cables that connect your equipment together and the power cables and the speakers leads. Thsi is where I have found the biggest pile of crap in the industry. You can if you are easily parted with you money, payUS$300ft for speaker cable and audio signal cable. I even know if a 4ft power cable that sold for US$4500. I have close freind that produces audio cable for the commercial industry. When he started out, he wanted to be the best in the world. So they decided to look at who they wereup against. So they went and bought all sorts of cables from everywhere you could imagine and all the prices you could imagine. They had very sophistcated measuring equipment. After all the test were made. the conclusion was, some of the best cables measured were el'chepo's from your Radioshack. Don't get fooled by cables that have arows printed on them because the electrones flow better that way. Yes it's sold. It's called directionalised copper cable. OFC (oxygen free)copper is another one. Now we all know what happens when metals, especially copper gets oxygen in it. Metals oxidise and copper becomes useless at conducting. Yes it's true it is OFC, but all copper wire is unless it is stuffed.

OK, that does it for now. I can goon and on and on and on an.....
But I can just imagine all your eyes glazing over.

Oh, poly cones can be water resistant. But you have to ensure ll the speaker is. Corrosion is it's worst enemy. But poly cones sound plain awefull to me. Paper cones still sound the betterand can be made water resistant. Just spray the silicon sail slide lightly over the face of the cone. It works reall good.

[CaptainK]

Wheels.

I'm impressed!!

At the place I used to work at. Some of the amps we made were light. Up to heavy.

Starting price US $150.00 up to over US$1,800.00 , for the high end models!!

MTX, Xtant, owned by MTX. DCM. And a whole bunch more owned by MTX.

Rockford Fosgate. MTX's rival. Makes alot of different types of amps. I am not too familiar with their product line though. Except that I do know they make amplifiers.

I agree Wheels. That these companies hype the so-called proformance levels and such. And people out there in this industry will debate that theirs is better. Til they are blue in the face?

You're right about alot of the stuff you mentioned in your last post.

[NoTies]

I've always been confused by the term RMS (root mean squared?) Surely the root and the square cancel each other out. why is not called "mean" power?

[GordMay]

The root-mean-square (sometimes called the quadratic mean) is the square root of the average of the squares, of a set of numbers. To find the root mean square of a set of numbers, square each of the numbers in the set , and then find the arithmetic mean of the squares (add up the individual squares, anbd divide by the number of squares). Take the square root of the result. This is the root mean square.
TO CALCULATE RMS:
1. SQUARE all the values
2. Take the average (arithmetic mean) of the squares
3. Take the square root of the average

eg: For the numbers: 2, 4 , 6
4 + 16 + 36 = 56
56 / 3 = 18.66
Sq Rt 18.66 = 4.32
Hence, RMS of 2, 4, 6 = 4.32

Not 12, as you might have miscalculated

[NoTies]

Thanks Gord. I've been puzzling over this for about 30 years (not full time ) Amazing to come to a sailing website and have it answerred.

[CaptainK]

Don't feel bad pwederell.

That root-squared stuff, gives me a headache. Everytime!!

[ssullivan]

Um... "what Wheels said!"

Ha ha ha. Very nice description Wheels. A great primer on audio equipment. I think I was pulling out the "heavier is better" just as a beginner's comment. I know at the level you are talking about, things change somewhat. So I agree.

You also did a great job explaining the headroom and clipping aspects.

Now how about all these choices for amps? Have you noticed that unless you are buying a Harmon Kardon or some kind of high end amp, they are always set up to do surround sound (at lower power per channel), rather than set up for good performance for music?

When I went shopping for our system, it was hell trying to find an amp that output a stereo signal in the "bottom of the barrel" price range. They were all "surround sound" systems.

[CaptainK]

Sean.

Harmon Kardon is a good brand name. But, I'd continue to shop around before making any final decisions.

It can be a tough, to sort out what model & make that you'd want to buy.

For example. Whenever somene comes up tp me about what car stereo amplifier to buy. I basically tell them this.

If you don't give a damn about quality. Buy any name brand. But if you're into sound quality. And something that doesn't fall apart quickly. I tell them to buy MTX or Rockford Fosgate amplifiers. And from there, I'd tell them to get the best car stereo speakers on the market.

That's my two cents!!