Marine Speakers

[wal 27]

"When we toyed with the idea of a wee bit more sound for Demonstrator, the basic premise was sealed enclosure for subs and component woofers, driven by digital amps which could be easily removed (along with the speakers). "

 

.... and I'm ready to do more about it if ya want to get involved

 

 

The fleet'll know I've upgraded when you hear The Cult - She Sells Sanctuary being given some wick

[tmouse 3]

So where do I get covers/guards for Fusion 6.5 speakers?

[Guest]

So where do I get covers/guards for Fusion 6.5 speakers?

Sailors corner had em on Sat...

[Guest]

I have just tried a Pioneers so I can just for the brand I have tried. And though they have a steeper price compared to what the Fusions are offering, you get better quality and a better guarantee that it would last. I know that the brand is just a label but sometimes, it can speak more about how you would assume a product would work.

[Tim C 23]

On Pulse I've been through a few sets of speakers, Pioneer, Majestic, Blaupunkt (crap) and now on to Fusion. Larger ones aft and the smaller ones with the separate tweeter forward. Luckily the latter are well protected, but not immune to rust from the tweeter, which is pity as they sound great. The secret on my boat seems to be that the speaker boxes are effectively triangles, so there is no internal reflection.

But my latest trick is the full audio visual experience, with a small LED projector beaming onto a screen just behind the mast, so we can get the full music video party going. It has taken a few goes getting all the systems to talk to each other. Projector resolution isn't high, but good enough for yachties after a few beers...

Hard to photograph this at night, but an idea of the round cockpit below.

[wheels 543]

Don't be afraid to spray copiuos quantities of silicon over speakers. We did it all the time for stage monitors when it rained. Never harmned anything and protected the conbes well.

[Guest]

[sow1ld 2]

Hey ya we've had a few crazy parties on Bullfinch it's got to the stage where we are now dubbed "club Bullfich" and the marnier gave us out very own mooring outside the habour with which to enjoy our music and the potato cannon.

Cockpit speakers are all just ok. The best way to maximise them is location. Mine are set aft in to the lazerette this amplifies the base set up. Down satirs I run a nice set of 6s" set in a locker.

Amplifying does wonders but its dear on battries. To get around this problem I brought a good good 10"sub dual voice coil. The trick is to match the sub and the amp up so you are getting the most out of them. Monoblocks are dear to buy and only slightly better on power. I run with a phenoix gold 2channel and that can be brigded down to 2ohms as can my sub. This way you are getting soo much more out of your amp and sub without burnning up power.

The amp is a true 280rms @20amps or 15amps in normal operation. On the remote wire I run a led 30amp switch so I can shut the sub off at any time but still run the speakers of the head unit. If it's a weekend and the weathers good chance's are there will be music playing all welcome to join...bring potatoes!

[too_tall 15]

Amplifying does wonders but its dear on battries.

 

Yes, it is, however a class D amplifier will help significantly with this. Class D amps tend to lose a lot less power as heat - turning much more of the consumed power into music with the help of the speakers.

 

To get around this problem I brought a good good 10"sub dual voice coil. The trick is to match the sub and the amp up so you are getting the most out of them. Monoblocks are dear to buy and only slightly better on power. I run with a phenoix gold 2channel and that can be bridged down to 2ohms as can my sub. This way you are getting soo much more out of your amp and sub without burnning up power.

 

Im afraid that this is actually not helping your power consumption at all - indeed, it may be hurting it. If your getting 280w rms out of your amp, your going to be putting ( considerably ) more than that into it - so, at least 20 amps IF your running it at max unclipped power output sustained. There is simply no way you can get 100% out for what you put in. No amplifier is capable of doing this.

 

Lowering the impedance will actually tend to make your amplifier less efficient, as well as losing more heat in all the cabling due to running far higher currents. In a perfect world, an amplifier should double the power output if you halve the impedance it is working into. So, a 100w @8 ohm amp, in a perfect world, will produce 200w @4ohm. Very few amplifiers actually are capable of doing this. My $10K home audio ones will. A lot of PA ones will. 12V ones claim to but if you test them... well.... the results are not pretty.

 

Halving the impedance is not changing the voltage at all, all the additional "power" comes about by doubling the current. This will double the current draw on the battery too. Batteries prefer to deliver smaller amounts of current over a longer period if possible.

 

Bridging an amplifier effectively doubles the output voltage - which into the same load, will mean that it also doubles the current draw. Remember Ohm's law. So if your amp normally outputs 50V rms, and your speaker draws say 3 amps, bridging it will mean the amp is delivering 100V rms, and the speaker will then be able to draw 6 amps. Ohm's law again. Whats this going to do to the current draw on the battery? Well. Remember that a very efficient class A/AB amp is

 

Of course, very, very few people would want this much power if they have reasonably efficient speakers.

 

In conclusion, if your wanting your audio to have the least effect on your batteries, then buy all class D amplifiers. And buy highly efficient speakers. a 90dB/w speaker will use 1/2 the power to deliver the same volume as an 87dB/w speaker will.

 

You will maximize bass if you specify the correct speakers for your chosen mounting location and method. If you can do so, have a well built, rigid enclosure that the speaker is mounted in. There is a reason that very expensive hifi speakers may well weigh 100Kg.

[wheels 543]

This way you are getting soo much more out of your amp and sub without burnning up power.

Haha, sorry not aiming anything personally at you S, but for us nerds with technical backgrounds, these kind of comments are quite funny.

If I explain, the term "Power" is used because it is the best way of explaining "work done". Power is power and is the sum of what energy is required to do that work. In this case of driving a magnetic motor, Power is the sum of Current and Voltage. The easiest way to expalin it is if you draw a circle and divide it into a pie with three sectors. One being power, one being Voltage and the last being Current. Now simply put, if you change one sector, you also change at least one other sector. Unfortunately the accuracy of the pie graph stops right there, as in if you are increasing power, you actually decrease one of the others, which is incorrect. But it is still something to ruffly keep in mind, that if you alter one sector of the pie, you have to alter at least one other in doing so.

As TT has also stated, you get more loss in both heat and across cables. But one very important point is that you blow your damping factor right out the door. In high performance audio, that is one of the most important points in low frequency reproduction. In a boat or even in the average home, probably not of that great an importance.

Another point to understand is that amplifiers are actually Voltage amplifiers, not current amplifiers. Magnetic motors, or transducers require Voltage swing. They follow the sine wave. The Current is the "backbone". Remember, you have to have both current and Voltage to get the power. Car audio has one major draw back. It only has 12V or 13.8V if the Alt is running, to play with. It does not have a great voltage swing for the driver to follow. Increasing current will not do anything, apart from pouring excessive heat into the voice coil, but because the volatge swing is not great, the voice coil will not move any great distance. So tricks are done in car audio to help with that. Firstly, the speakers designed in such a way that they do not have a great deal of natural travel. Also not that they are often have a very poor sensitivity rating, which is partly due to that. They also have very low impedances to provide the greatest load practicable to the amplifier.

One way to get around the low voltage is to increase that. So expensive high powered amps have inverters that increase that voltage to a much higher swing. But back to that pie graph, you can't get more Voltage, without affecting one of the others. Adn seeing as we want to get more power, then the only thing we can do is increase that current. So hence why some of the expensive amps draw so much current. they are inverters as well as amplifiers, doing two very different jobs and both jobs have a loss. That is fine in a car that you can run the engine whenever you want, but in a boat it gets hard on batteries.

[sow1ld 2]

No point in having a amp that can run at 2ohm and a sub that cant. Best bet which i was trying to say is that matching the amp and sub up correctly is a better package than having a 2ohm stable amp but only having a 4ohm sub.

I researched the ass out of D class amps and found that for any given rms value the D calss was only arginally better on power. Now when your drawing say15 amp vs 18amp big woop either way u split your hairs its still sh*t loads of amps going out the door. This is a economical system that works well. By all means drop ten k on a sound system but keep in mind it wil have to be really really loud for anyone to hear it cos we would all have spent the ten k on sails and wil be too far in front to hear it

[wheels 543]

No point in having a amp that can run at 2ohm and a sub that cant. Best bet which i was trying to say is that matching the amp and sub up correctly is a better package than having a 2ohm stable amp but only having a 4ohm sub.

It doesn't work that way. What load an amplifier can drive into does not mean that amplifier can only drive into that load. How it works is that each amplifying section will be able to normally operater into a nominal load of say 8ohm. " Nominal" because the load is constantly changing due to impedance. The vioce coil in the driver is a coil that has a constantly changing resistance to the voltage due to the frequency changing. Thus the reason it is called impedance and not resistance. Impedance can vary from almost dead short to almost open circuit. If the impedance of the voice coil is increased from 8ohm to 4ohm then the closer to short circuit at certain frequencies the load will become. The amplifier must be able to cope with this. Righty then, to cheaply and easily increase the power output of the amplifier (because remember we are talking 12V here) they take two 8ohm amplifiers and place them in parrellel with outputs opposing one another. This results in twice the voltage swing and thus if the load remains the same, then twice the power. You will often find this ability on many car audio amplifiers, called "bridging". So now manufacturers can take it all to the next step again and they produce a "power module" or Block. Which ios effectively that above bilt into a package and by now bridging those two blocks together, you can now double the power output once again. But the current drawn is enormous. This also now means loads dow to 2ohms can be used, because the individual ammplifier is actually seeing 8ohm, but the combined can work into 4ohm or 2ohm for the quad blocks. But there are many other issues that arise from that. One being the impedance droping to close to dead shorts, but another is the power losed in the cables to the Driver. Lets just say for ease of numbers, you have a loss of 1ohm in the cable to the Driver and the Driver is presenting a load of 2ohm. So there for, half the power output disapears into that cable and does not make it to the VoiceCoil to be turned into accoustic energy. And the cable also changes it's impedance with frequency and plus the VC sometimes heading toward a short circuit load also means even more power being dissapated into the cable. Plus, the Damping factor is now shared across 4 blocks of 8ohm amplifiers and thus is decreased by the factor of four. So driver control is greatly reduced. So finally, having an amplifier "stable" at 2ohm, does not mean you have to have a 2ohm driver to match. It just means it is stable, or capable of driving into that kind of load. But you have to have some big arse cables supplying the amolifer and a big arse cable supplying the driver/s.

[too_tall 15]

Wheels, I think that you may have gotten a couple of things crossed there in your explanation.

 

Doubling voltage ( bridging, internally bridging, etc ) will actually quadruple the power, as it will also double the current drawn ( if the amplifier can deliver that current )

 

Also, bridging an amplifier that is "2 ohm stable" unbridged, will make it only stable into a 4 ohm load, as you still have the maximum current draw capability, no matter if its bridged or unbridged. Ohms law - Voltage = Current / Resistance ( impedance in this case, but to keep things simple, impedance is an AC resistance ). Double the voltage, and you therefore also double the current.

 

I agree with you however that just because an amplifier is "2 ohm stable" does not mean it _should_ be driving that load.

[wheels 543]

Purely semantics in what is a far more complicated world and probably completely boring to eveyone else bar us three. Unless we are in a dedicated Audio forum, I find it far better to be a little lighter on explanation and allow people to understand, rather than technically nerdy and have everyone roll eyes and switch off. Although I imagne we have lost a fair few now anyway

For instance, in the real world, pretty much all amplifiers are derated in power output when you bridge them, because components simply can not handle the heat. By an equation you may get quadruple the power. But it the real world, it will be unlikely that an 8ohm amp bridged could now work into a 4ohm load and have the output increase from for say, 100W to 400W. Infact, in the real world, it would be more likely 100W to 190W.

However, all the above and much more than we have delved into here, is really a smoke screen to the more important points.

Firstly, the most important points in sound is as follows.

1: Sensitivity of the Drivers.

2: closely related to 1...Maximum SPL of Drivers, at what frequency and what is the freq response over all.

3: Dynamic headroom. How much power is available from your amplifier, over and above the rating of your drivers. Does not mean you have to crank it to 11 because it can. Digital recordings have a dynamic range of 10dB. This is the peaks that are of very short duration that you do not hear as "loud". They are miniscle periods of energy, and we tend to sense them rather than hear them. This is what gives great clarity and "air" to the upper range of music. So in essence, a 100W driver, should have a 1000W amplifier driving it if you want that quality or reproduction. You do not turn the sound up to max or you will blow the driver. But the sound will be clear and crisp.

4: and Finally, Dampning Factor. This results in the ability of the amplifier to move driver, stop driver from moving, move driver in opposite direction. Most important in the low frequency reproduction. this is what controlls and gives base definition.

And finally, we are presumably supposed to be discussing audio on boats. So really, the important aspects will be greatest noise for least power consumption, which means best speaker efficiency. And actually really, nothing else. Because a speaker assembly that has an efficiency of 90dB will sound only half as loud as a speaker with an efficiency of 96dB. To get 90dB speaker to sound the same loudness as 96dB speaker is, you have to have 4x the power. So you would need to change your 100W amplifier to a 400W amplifier to get the sound twice as loud. So in most of our situations, choosing the right speaker(as in how efficient it is) is far more important that any other point. And simply, you don't get car audio speakers that are very efficient.

[too_tall 15]

Wheels,

 

I think that if you look about 5 posts ago, you will see that I pretty much said what you just did..

 

96dB efficiency speakers - have you ever found any "12 volt" speakers which are so sensitive? I generally have found that 90dB is not easily come by in car audio gear - and by default, this is going to be the same for the marine world also. 96dB efficiency is also really pushing it for most domestic gear ( although my speakers are slightly over that in room ). That efficiency is getting to the door of professional PA gear. Not quite the 100dB+ that the more efficient gear is, but nearly there.

 

P.S. I dont entirely agree with you re damping factor, as I have heard 10w valve amps which have stunningly tight and accurate bass. High damping factors and valves are not complementary. Indeed, I cant recall the exact formula used, but the damping factor of an amplifier is the relationship between the the amplifiers output resistance and the circuit resistance. In other words, how easily the amplifier will dump current into the circuit. That being said, all my domestic amplifiers are big arse Perreaux amps, and they do have very high DF values.

[Guest]

Enuff with the techno babble, most of us here aren't that smart

 

These following Specs are from a very well known brand name and their 'marine' range.

 

10" Sub

Maximum input power 800W Peak Power

Rated output power 200W Rated Power

Frequency response 18Hz - 2.5kHz

Sensitivity 88db

Cone material Injected Polypropylene Diaphragm + Rubber Edge + Single Voice Coil + 25cm Woofer

Magnet Ferrite

Weight 4kg

Dimensions (WxHxD) 273mm diameter top mount with 232mm diameter x 126mm deep below mount

Box recommendations 26.6 Litres / 0.93 Cu.ft

$149.95

 

And 6'5" 2-way 'marine' speakers

Size: 6.5" speakers

2-way design

Colour: White or Black

Built in woofer for mids + bass tones

Built in tweeter for highs

160 watts peak each or 320 watts total per pair

45 watts RMS each

Polypropylene cone (makes speakers last a long time and sound excellent)

Polly cone tweeter

Marine ready + Water-Resistant Marine Design

Sensitivity 90 dB

Frequency response: 40Hz-20kHz

90 watts RMS Per Pair

Maximum input power 160W

Rated output power 45W

Frequency response 35Hz - 26kHz

Sensitivity 91dB

Impedence 4ohm

Woofer 25mm HOP Cone + Ferrite Magnet

Mid range 40mm Aluminium Cone + Neodymium Magnet

Dimensions (WxHxD) 16cm diameter top mount

Cut-out Dimensions

Mounting depth- 64mm( 2 1/2")

Diameter - 127mm (5")

$149.95

 

Now the questions for dumbarses -

What should we look for in those specs? i.e. what is actually useful and what's marketing dribble.

Are those Specs the sort you would want if you were say installing a new stereo on your power generating challenged boat? I say power challenged as most of us poorer peoples have boats that are.

What in those Specs isn't crash hot and you would suggest to look further to find better options?

How sort of 'the norm' would you expect those Specs to be? i.e are they pretty std or low end or higher end

Are those a 'matching set' if such a thing actually exists?

What sort of headunit/Amp/Whatever would you suggest is the best to run those to get max noise with minimum power consumption?

 

 

Discuss and disassemble those Specs for us please............ turn 7/8ths of your brains off when you do please, that'll just even up the playing field with most of the rest of us

[SloopJohnB 323]

Crickey I saw something in KM's post that I could recognize.

 

$149.95.

[wheels 543]

The spec that is the most important is as SJB just pointed out, the $149.94. For most people, it's all about cost.

Pretty much all the rest of the specs listed tell you nothing.

The 800W is a rating produced in a test that means nothing in the real world. It is there to fool those unknowing by having a big number. It's like saying a Red car goes faster because it's red.

The 200W is not an RMS rating. simply, that is the maximum heating the voice coil can take before it is damaged. So once again, it is probably a "music Power" or "average" rating, which tends to be terms used losely today.

Note what they did with the specs on the other speakers. 90W RMS per pair. So they have taken the 45W RMS and combined it so as the big number catches the attention of those unknowing. Not lying, just baffling with big numbers.

Frequency response of 18Hz to 2.5Khz is also meaningless. It's like saying a Car is fast because the speedo goes to 260Km/hr. You have to use those figures in combination with how loud the speaker is at those frequencies. Just saying a speaker goes down to 18Hz, but you have to have a Hearing aid to hear it is rather pointless, when the frequency at 100Hz is going to blow your hearing aid into next week. Frequency response is also dependant on the enclosure the speaker is fitted into.

Sensitivity without a frequency is also rather useless. All speakers have a natural resonance. So what they do is find that resonance and then put a tone into the speaker at that frequency and see how loud it is. It also has to be backed up with how it is measured. Normal industry standard is 1W/1m (1W of audio power measured from 1m away from the speaker. For a sub, that sensitivity could well be at the 2.5Khz, which would not be used for sub duty anyway. A correct measurment would look like this

Sensitivity...18Hz to 2.5Khz, +/- 3dB @1W/1M. Or in what that driver may actually produce, it may look more like, 45Hz to 150Hz +/- 3dB @1W/1M.

3dB by the way, is the amount of change in sound energy that we can hear as an increase or decrease. And while we are on that subject, 1dB is the smallest amount of sound energy someone with perfect hearing can detect. 10dB is the amount of energy that we percieve something as being Twice as loud/quite

What the cone is made from is telling you that at least the cone can stand a splash of water, but apart from that, it is a cheap means of making a cone. Or....The red car has a plastic Dashboard.

All normal speakers use Ferrite Magnets. The red car has black rubber tyres. The tweeter is using a Neodynium magnet. Strong little fella's for their size and often used in expensive speakers. Used in this case due to keeping the tweeter really small. Aluminium cones are used because they have a natural resonance at a very extreme upper end and make the sound unnaturally sound topendy. Good for getting over the noise in a Car along the road.

the size of the box is the most important point next to the price. It will allow the speaker to produce the loudest sound it can with that specific size box. It may not be the best sound, but will be the loudest. So yes, Size does count on this case. Any change in size will alter both frequency reproduction and the SPL(sound pressure output).

 

And I agree, it's too much technical mumbo jumbo for most all normal people. We aren't trying to get sound across a Stadium for a U2 concert after all.

 

TT, Valve Amps sound the way they do, because they are full of harmonic distortion. Some people like that and say a Valve amp sounds "warmer" or in the low end, grunty. But it is the Harmonic distortion that is tricking you into that. A guitar Valve amp for instance, gives a particular "tone" to the guitar because of those Harmonics.

Leaving power consumption and size aside, it is the main reason why we do not use Valve amplification in Live audio today. But we do use it alot in the Studio for adding a particular "tone" to a voice or instrument.

As an aside, at the very original Woodstock, the biggest amplifier available then, was an 80W Valve amp and they used lots of them on huge Horn loaded speakers. Horn loaded means they have a construction in front of the speaker driver that is shaped like a Horn and it makes the driver extremely sensitive, producing very high SPL figures with very little power input. Some of the very old movie theatres used to have enormous long Horn speakers behind the screen and the power rating was usually only 10W.

[Guest]

mostly I'm just that happy from where I'm at aided with a coldey to not actually give a flying f*ck to the difference a million or 2 giilybobs makes as I sing along quite untunefully on the water

[wheels 543]

Sounds like you got the best balance there L4