Freebie Stereo

[Addem 95]

Ill have to admit that reading this makes me want to go and spend stupid money on a kick ass stereo for the boat. I had an awesome car stereo once and I've never really gotten used to having an average stereo again

Oh no you don't. Some nice quiet Neil diamond is all the boat needs. You should look up the thread about noisy stereos in quiet anchorages. ????

[bazzathemammoth 37]

Haha I'll have to admit that my dream of having pork chop kitted out was somewhat squashed when I thought about trying to negotiate the nitty gritty details of what to listen to and how loud while cruising/racing with the other owners I dont think you guys share my love for angry white boy music!

[Black Panther 1,590]

Agreement on music is tough. On one boat everybody got to be DJ one day in turn. They all learned to hate my Cuban jazz.

[bazzathemammoth 37]

Oh no you don't. Some nice quiet Neil diamond is all the boat needs. You should look up the thread about noisy stereos in quiet anchorages.

 

To be fair if I am surrounded by other boats I won't use the cockpit speakers..... IMO forcing your music tastes/noisy generators on other boats is pretty much the height of inconsideration, second only to crappy anchoring.

 

One of the things I like about the new fusion unit is that the cockpit will be a separately controlled zone and it will be easier to do this.

[Battleship 100]

Sounds like it's already decided then. I am looking at the RA205 http://www.fusionentertainment.com/marine/products/head-units-200-series/ms-ra205 with the combined dock, not looking for loud but like the waterproof dock that charges the phone and the ability to browse music from the chartplotter and listen to VHF channels is pretty cool.

[Addem 95]

So, does the 4ohm with impedance of 3.24 and wattage of 3.672 mean we go faster or slower? I'm still a bit lost.

 

And does it create white noise when the boat next door has Cuban jazz?

[Black Panther 1,590]

https://www.youtube.com/watch?v=UWKQjI8VXdo

[wheels 543]

 

So, does the 4ohm with impedance of 3.24 and wattage of 3.672 mean we go faster or slower? I'm still a bit lost.

Depends on which way you point the speakers. Point them aft and you go faster, point them forward and you will go slower. Logical surely

[wheels 543]

 

Also as far as I'm aware, efficiency has nothing to do with impedance as efficiency is a measure of spl per watt @ 1m. A 91db 4 ohm speaker with a 4 watt marine amp will be as loud as a 91db 8 ohm speaker connected to a 4 watt home amp.

I will start with this comment first. Efficiency is indeed separate to impedance. You are correct with this comment...to a point. Not that you are wrong, but that SPL is not always measured as it should be. It is supposed to be 1W at 1m, but depending on what the marketing dept wants to BS us with, that rating can be stated in many different ways. What they will often not tell you is what frequency the test is carried out at. Was it White noise, Pink Noise, a Tone and at what freq was the tone, was the measurement taken at 1m and was just 1W of power actually used. The list of misinformation can be long. It is always in what they don't tell you

 

 

I will just mention that the reason car/marine speakers are 4 ohms is because of the voltage required to drive them, which is 1/2 of the voltage required for the same power output for an 8 ohm speaker. This is important because a good hunk of a car/marine amp is the DC-DC converter, which is cheaper and smaller when converting to lower voltages

I am not sure if it is your wording here or my understanding. Anyway...DC/DC converters are not common and are only found in the more expensive high powered gear, because a converter takes up a lot of realestate and employs lots of components. A converter is there to raise the voltage, not lower it.

Speakers ar Voltage devices you could say. The distance a VC (voice coil) moves is related to the voltage swing. Current is the grunt required to get the VC to move that distance against all the opposing forces trying to stop it from moving. The result of Voltage and Current equals power, which is heat in that VC. Because the nominal power of Car audio is usually 12V, with no converter, then the maximum voltage swing is only ever going to be 12V, or 13.8V. 13.8V into 8ohm equals 23.8W of total power. 13.8V into 4ohms is 47.6W. Hence why most Head units state 50W per channel.

So you can see that if you can raise the voltage, the amplifier can swing a bigger signal voltage and the power can then be increased. But to do so requires a lot of current and a converter is not a very efficient beasty and waste a fair lump of battery power as heat. So you might get a lot more power, but you need a lot of battery or a really decent Alternator to keep the thing up to voltage.

[bazzathemammoth 37]

Some good points there wheels.  I find that the cheaper the speaker and brand, the less reliable the specs sheet. High end car audio seemed to be pretty good, some of my old gear even came with calibration/testing certificates. I mainly have alpine and pioneer stuff. Funnily enough often the best sounding gear had some of the worst power ratings... 

 

You are also correct about the amps in head units not having a voltage converter, but I was more referring to the standalone power amps that put out higher voltages for driving grunty speakers. I wasnt very clear about the dc-dc converters putting out lower voltages, what I meant was:

 

8 ohm @ 80V = 10 amps and 800W

4 ohm @ 56v =14 amps and 800W

 

If a speaker is rated at 4 ohms instead of 8, then there is a 30% reduction in the voltage required for a given amount of power.

[wheels 543]

Correct. Another way of increasing Voltage swing is to bridge channels of an amplifier. And this is what stand alone amplifiers allow you to do to get the higher power ratings. Once again, the "what is not said" is important and the cheaper units say a whole heap of a lot of nothing.
 

[SloopJohnB 322]

I can hear you from here

[wheels 543]

 
 

Speakers -
Efficiency (1W/1M) - 91db
Frequency Response - 60Hz-22KHz
Impedance - 4 Ohms
Peak power (Watts) - 280

RMS Power rating (Watts) - 100

 

Driven by a amp that has this - Class-D 4 x 70W (@ 2 Ω)

 

None nerdy answer, which is more a question. Do you like the sound from them? Do they go loud enough for you??

Nerdy answer,
60Hz to 22KHz is a tricky one. Because of our hearing and how bad it is. The range they state does not say how loud the 60Hz is in relation to the loudness of the rest of that bandwidth and just how fast that low freq is dropping away through 60Hz. So you may or may nit hear 60 Hz. You may or maynot even hear 70Hz. As we get older, we lose our top end hearing. (insert wife jokes if you so wish...or Dare If you can hear 16Khz, you are either a young fellow or a medical marvel. It also does not tell how smooth that freq range is. There will be peaks and troughs for sure, but just how bad, who knows.
RMS power is your most important power rating and many manufacturers do not list that spec, because the number is so low and they want to baffle the newbs with BS. The Boy racers just look at numbers. The higher the number the better. Peak power in the real world should tell how much a very short duration sound it can handle without busting something. RMS tells you how much heating the VC can handle before it fries.
What they don't tell you and you would not normally find with Car audio anyway, is at what freq was the RMS power delivered and for how long was the duration. However, the rule of thumb is that the Speaker will handle a 100W amplifier with no problem. In fact in reality, you should always have an amplifier twice as big as what the speaker can handle. It is clipping of the audio that destroys a VC. As soon as an amplifier Clips, which means the voltage has swung as far as it can and now cannot go any further, the single is now DC and the heating value of a DC signal is 4 times the heating value of an AC RMS signal. Very quickly, the speaker VC over heats and fries.
Class D 4 x 70W into 2ohm...well that means that on your 4 ohm speaker, you can only ever get 45W of power from it. Once again, missing some figures like, is it RMS or Peak etc. We will assume RMS. So is you get 2 speaker and connect in parallel on each channel, you will in fact double the power output. the next advantage is that the speakers couple, or Add together, and add another 3dB of sound power and the Bass will extend slightly lower. Or in your case KM, you can get more loudness without turning the knob up as far and thus save some more battery power.
 

[Tim C 23]

All this stereo discussion and not yet a mention of surround sound! If you really enjoy music then 2 channel just doesn't cut it. When I change my seven speaker system on deck from stereo to 5.1 (Dolby or DTS) from DVD, it goes from good to magic. It's surprising how few marine systems get to 5.1, and in fact even very few car systems do. Yet you expect it at home, or at the movies. A concert in surround sound on the water is pretty special...

[wheels 543]

and I thought I was nerdy

[bazzathemammoth 37]

All this stereo discussion and not yet a mention of surround sound! If you really enjoy music then 2 channel just doesn't cut it. When I change my seven speaker system on deck from stereo to 5.1 (Dolby or DTS) from DVD, it goes from good to magic. It's surprising how few marine systems get to 5.1, and in fact even very few car systems do. Yet you expect it at home, or at the movies. A concert in surround sound on the water is pretty special...

The real issue with surround sound is that it is almost always a compromise. Very few people have the money and/or easy going partner that will allow a proper setup. 5 speakers are far far more difficult to setup properly than 2, and 2-3 times as expensive. Also placement and time alignment is an issue in cars/boats, especially with the real lack of time alignment adjustable headunits with decent eqs. Can many people really fit 5 speakers properly in their cockpit/cabin?

 

I agree that movies are better in surround but i have yet to hear a surround system that sounds better than 2 channel for the same money for music.

 

Simple is good imo. I disconnected the rear speakers in my car cuz I thought they made things sound worse and still blew people away with the quality.

 

Btw i used to install high end home theater, so this is my experience with a range of systems from 3k to 50k. Also into 2 channel hifi and have heard many high end 2 channel systems up to 200k. Admittedly the law of diminishing returns has well kicked in on those higher end systems.

[wheels 543]

I have the luxury with size of boat, to have 5.1. But we use it only for watching DVD. I hardly ever listen to Music in surround anywhere. It does not sound right. Music is very rarely mixed in surround to begin with and taking a studio engineered 2 ch mix and making it surround is just not right. Live recordings can sound OK, if they were genuinely recorded in surround right from the get go.
       The reason why channel distance adjustments are not built into Car audio is that a distance of 2m at the most between a listener and the speaker, is too small a delay time for the Brain to process. So no point in adding the expense.

 

Btw i used to install high end home theater,

Arrr, so you worked in the land of where Snakes produce Oil, Hens have teeth and Pigs fly

[bazzathemammoth 37]

Yea, I have this really amazing amplifier power lead than enhances its transparency. I noticed in Bach's no.3 symphony that the wooden cello sound was reverberating in a more natural way. It will transform your listening experience! $1500rrp but I can do it for you for $1299! Its all to do with its plutonium-silver core with increased flux-capacitance. This is the stuff of the future!

 

On a more serious note my car stereo has full 6 channel time alignment and it makes all the difference imo. Its all about the ratios as much as the distance.

[Battleship 100]

Dude you need to go sailing more. Turn the stereo off and listen to the water rushing past. Bliss

[too_tall 15]

Yea, I have this really amazing amplifier power lead than enhances its transparency. I noticed in Bach's no.3 symphony that the wooden cello sound was reverberating in a more natural way. It will transform your listening experience! $1500rrp but I can do it for you for $1299! Its all to do with its plutonium-silver core with increased flux-capacitance. 

I most certainly hope that you use cable elevators made of unobtainium when using such cheap cables. Otherwise the hand placed cotton snake oil impregnated dielectric will compress on one side and you will totally loose your entire 3d sound stage. Also, I will be most disappointed if your not using cryogenicaly treated interconnect and speaker leads which are specifically burnt in for the latitude you reside at, and that you have observed the magnetic anomalies in your residence when choosing the appropriate routing of the cables.

 

 

I actually have some pretty high end audio gear here - right up to 6' tall Focal speakers. But, for some reason, I find that home made power leads costing about $8 per meter ( VSD cable ) work very nicely and my speaker cable is simply 4.2mm2 cable which cost me $5 per meter. I tried a $20K nordost cable setup and also a $10K kimber cable setup and found that I woulr rather spend the money on something which actually made an improvement....