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Marine Speakers


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I've seen Wheels home stereo. Its very much in the :shock: proportions. Just one enclosure made a 42" flat screen look like a 7" portable DVD player.

 

But Booboos is floating so he has an edge. If Wheels gets his floating and a stereo war erupts everyone north of Hamilton will know it :) :)

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A soundoff! I like that idea, I got 2 new subwoofers (that's 4) and another amp to try out! Although I don't have the battery power to run 4 at once!

And I'm about to sign up for the 'stupidly loud stereoholics annoymous' Meetings.

 

I got an idea, why doesn't squid bring some mt gay (and whoever else) and come for a rum race, then after that we can find wheels boat (when he gets up here!) and have a party/soundoff. The winner gets a bottle to be drunk on the spot. Sounds like an idea to me. It can also incorporate the welcome north party for wheels!

Something like that anyway.

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I hear Booboos asked Japan if he can have one of their 2nd hand nuclear reactors just to power his system :lol: :lol:

 

I do like his idea though :thumbup:

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Well to be fair, it was a past life of mine. But I retained two boxes from the rig I had. The rig I had was pretty special and we were the first to get one down here in the Southern Hemisphere. I sold it all to a friend several years back now and they are still going strong and nothing has been made yet that can out perform them. The Bass Bins were also really special and each bin was powered by a 5Kw amp. A mate in the US is using a 10Kw amp for each Bin. One bin alone had the same output as four traditional bins. They kick arse.

Anyway, the two boxes I have, can produce 127dB of sound power. So two boxes will produce 130dB. Which means, the speaker box that Booboo has would need an amplifier of 40Kw to equal that :wink:

But hey, I am waaay to old to be bothered compeating in that stuff now. Besides, the music I would be playing would have all you young guys wondering what the?????

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Hmmmm, Val Doonican at 130dB ...... that'd be sure to clear a bay in record time (even quicker than a bunch of Piedy's turning up). Maybe Wheels is onto a surefire way to enjoy the Hauraki Gulf with few other boats around :thumbup: Nana Mouskouri's Greatest Hits would certainly clear out the bay.

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With all due respect, there is quite a difference between a car audio speaker that has been "marinized" and a genuinely marine designed speaker. A Marine speaker has a fully enclosed motor unit, meaning moisture cant get near the voice coil, nor near parts which can corrode. The baskets are almost always made of some form of plastic ( stronger than cheap pressed steel ) or are cast, and then generally are powder coated or even hot dipped. The cones are made of water impermeable materials and the surround likewise. The spider will also be made of a different material.

 

However, they come at a marine price. Often they will sound quite a bit better than a cheap car audio speaker which has a plastic cover over it to marinize it.

 

Speaker location, and more importantly, the enclosure they are in, will make more of a difference to the overall sound than the brand or quality however, within reason.

 

Regarding amplification, yes, separate power amps make anything from a large to a massive difference. One poster mentioned the "digital" amplifiers. While they are called "digital" often, this is an incorrect term. What they are, is basically a PWM amplifier. So far, far more efficient, as they lose very little power as heat. Running on a battery, this is good. Do they sound as good? Thats subjective, and I object to the sound quality, however, in a boat?..... Why power amplifiers tend to make a difference is not only that they deliver more current, but they also are not sharing a pretty limited power supply with the source electronics, in other words, they are not hogging all the power from the head unit. Put in reasonable speakers, and a reasonable power amp, and you may well be satisfied with the level of bass from the full range speakers, and not feel the need for a subwoofer.

 

Most head units ( in spite of the claims of 4*50w or whatever they are claiming now ) are lucky to put out more than about 10w rms power. In an open cockpit, with a lot of environmental noise, you need to have very efficient speakers to get much volume with a max of 10w. Indeed, cockpit speakers have to work pretty hard, as most of you probably know, putting your home stereo outside results in it not feeling anywhere near as loud as it does inside. This also applies to cockpit speakers, except cheapish ones are designed to fill with sound the 2 or 3 cubic meters inside a car, not an open area.

 

I typed this yesterday but must have only previewed it.... :oops: :D

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Well to be fair, it was a past life of mine. But I retained two boxes from the rig I had. The rig I had was pretty special and we were the first to get one down here in the Southern Hemisphere. I sold it all to a friend several years back now and they are still going strong and nothing has been made yet that can out perform them. The Bass Bins were also really special and each bin was powered by a 5Kw amp. A mate in the US is using a 10Kw amp for each Bin. One bin alone had the same output as four traditional bins. They kick arse.

Anyway, the two boxes I have, can produce 127dB of sound power. So two boxes will produce 130dB. Which means, the speaker box that Booboo has would need an amplifier of 40Kw to equal that :wink:

But hey, I am waaay to old to be bothered compeating in that stuff now. Besides, the music I would be playing would have all you young guys wondering what the?????

 

 

Ok wheels you win, that all sounds pretty loud!

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Nah well actually you win really, cause in the end, you have yours on the water and I am not sure I could be bothered hauling that weight out there. Besides, I want peace and quite and have been warned to stay clear of bays with Piedies in any numbers more than 1. :wink:

 

What they are, is basically a PWM amplifier.
No that's not quite right either. There are classes of amplifier design. Like A class, A/B class and so on. But that is how the output transisters are driven. As for signal, that is simply AC. A small AC signal in is made into a very large AC signal out. Anything that is not a Sinewave is heard as distortion. The height of the sine wave, which is Volts, determins how far the Speaker motor(coil) drives the cone in or out. The greater the voltage swing, the louder the sound. The frequency is how many time the cone is pulled in and out in one second. PWM varies the width of a waveform and thus, if it was the output of an amplifier, it would alter the frequency and not the amplitude of the sinewave. Where the term digital came from was from the use of output devices in some amplifiers being a complete solid state device and this is often seen in car radio and car amplifiers. But when it crept into Home HiFi, it was incorrectly used as a selling point that others did not have.

PWM is used in power supplies and is how 12V is often coverted to higher Voltages. The only way to create power is to have Current(which the car battery hgas plenty of, Voltage(which a Car battery is not so hot at providing) and drive those two into a Load. 8ohm is a common home HiFi load, but Car audio is 4ohm so as to present to the amplifier a greater load. But it the Car amplifeirs power is limited by the Voltage of 12V. So a PWM power supply is used to increase the Voltage and by sucking even more current from the battery, the Voltage is increased and the output of the amp along with it.

Power output in the Car audio world has the truth stretch beyond belief and figures stated are usually totaly impossible to reach in reality.

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What they are, is basically a PWM amplifier.
No that's not quite right either.

 

Well if we want to be pedants ( :thumbdown: to those of us who do, including myself! :D ), its PW/FM ( width/frequency), but I was more putting it in the modified transistor created waveform basket, of which PWM is probably the best known, and, in reality, it is very similar - indeed, its still relying on the width of the pulse ( at several mhz ) being fed through a low pass filter ( namely the output inductors ) to smooth the waveform and make it produce a pretty similar looking ( on a scope ) output to that of a class A A/B etc amp.

 

More to the point - for anyone wanting an amplifier in a power restricted environment, class D has a lot more going for it than class A/Ab. My quad 250w class A monoblocks and my twin 350w class A stereo power amps would make even a 1000ah battery bank turn sad very, very quickly. That being said, my speakers would also probably not fit in anything less than about 80', and at 400Kg each, alongside another 200Kg of amplifiers, would seriously unbalance the vessel!. Fortunately, most are far more sane than myself, and are generally fairly happy with some 6" speakers running off a head unit :D

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Oh, just a note, dont be considering Wakeboarding speaker systems - they are definitely not made for a marine environment, they do not respond well to salt or even 24/7 outdoor exposure. They do go loud ( last set I heard could easily be heard over a 510ci Chevy V8 while I was 60' behind the boat!

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its PW/FM ( width/frequency), but I was more putting it in the modified transistor created waveform basket, of which PWM is probably the best known, and, in reality, it is very similar - indeed, its still relying on the width of the pulse ( at several mhz ) being fed through a low pass filter ( namely the output inductors )

 

Huh?

Mate, don't believe half the hype written in the glossy Brochures or from the Glossy Sales dudes in the HiFi shops. There is so much crap created in that industry, it's a wonder they don't have to get a Suction truck in once a week to clean the shop out.

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Low quality is a relative term. In comparison to dedicated Class-A amps in a dedicated (or at least well-set-up) listening room, then yes; they won't sound as good. However, this difference will not be noticeable in a marine environment, and the gain in efficiency is more than worth it. The headroom provided will give the speakers a much better chance to do what speakers are supposed to for a given amount of power required.

 

When we were living in our house in Orakei we had two class A amps that negated the need for the heater in winter...and this wasn't a small room in the least. The power bills were commensurate with the amount of current being consumed. The sound was incredible, but like most things of quality, it comes with a cost!

 

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).

 

As a tip; look at the damping; this is the ability of the amplifier to control the speaker cone. The better it is, generally the better the sound. Also, match the speaker rated power handling capacity and amplifier output. Just because a speaker has a higher wattage rating it doesn't mean it'll be louder, or sound better for a given amplifier. In fact, often it will sound worse, as the amplifier won't have enough control over the speaker cone, and clipping will occur, which will have a very detrimental effect on sound and can cause damage to equipment.

 

Also; if you give any consideration at all to sound quality and a nice tight bass, sealed enclosures.

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Mothership, I am impressed. Many vary important and often left out points in your post.

 

Yes I am familair with Class D Fineline. I used big amplifiers made by companies such as Lab Grupen, Crown, EV and Crest. They all produce a Class D amplifier for the Pro audio world and they are good amps and very powerful with very high Sonic performance. But they and any Class D circuit is not digital and should not be considered as such.

The low pass filter gets rid of switching transients that would otherwise be heard as very loud noise and destroy high frequency drivers. There are a couple of points in the Wiki description I have to say are not quite right. 100% efficiency for instance, is not correct. They are efficient, but not 100%. 90% is more realistic.

 

As Mothership said above, Damping factor is one of the most important aspects of any amplifier design. The better the DF, the better control of the Cone. Don't go getting all caught up in the world of speaker cable BS. Copper is copper. But size is important, because size is what connects that DF of the amplifier to the Speaker.

 

Speaker efficiency(SPL) is more important than it's power rating. Most car audio speakers are around 80dB efficient. Home Hifi would be around the 90dB mark. Concert speakers are above 100dB. Car audio power ratings are often given in Peak or even peak to peak ratings, not RMS. Or if given in RMS, it is often at a peak frequency, or a very shgort tone burst. Home HiFi usually is given in RMS, but most usually in Tone burst also. Good Concert gear is usually at RMS over the entire audio spectrum (Pink noise) for a specified number of hrs.

Closely related is efficiency at what frequency. Saying a speaker can work from 20Hz to 20Khz maybe correct on paper, but in reality, you most likely will not be able to hear anything upto say 80Hz and then lose everything again at say 10Khz. So linearity is important. A speaker will naturally have a "loud spot" and that can often be exploited by giving the SPL test at that spot, producing a figure that is not possible over the rest of it's range.

 

Enclosed cabinets for subs have a 3-6dB roll off per octave response and keep falling away in that manner. So they will go down very low, but the very low end may not be audible. A Ported enclosure has a flatter response to a low point at which it then dives away. They are basicaly a Low pass filter and any filter changes phase. So hence why they often don't sound as nice as an enclosed box. But they have a more usable low end for most applications.

 

And Finally, you can detry a 100W speaker with a 10W amp driven into distortion, but a 10W speaker will work OK on a 100W amp. It is better to have more power and we recommend at least twice the RMS rating of the speaker, but if you really want the best ratio, 10X is good. So a 100W amp driving a 10W speaker is actually a good match. The reason is peak information present in the music. It is called Dynamic range. You don't "hear" it as loud, but the reproduction is quite something. It is as important as Damping Factor.

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Huh?

Mate, don't believe half the hype written in the glossy Brochures or from the Glossy Sales dudes in the HiFi shops. There is so much crap created in that industry, it's a wonder they don't have to get a Suction truck in once a week to clean the shop out.

 

I take absolutely no notice whatsoever of what they would say in a hifi shop. They tend to want to sell stuff. I have built my own class A, SET, Output transformer less valve, class A A/B and D amps. I have lots of soldering iron burns, and a hunched back, coke bottle glasses and get quite excited when I smell solder.I feel that I do have a general understanding of what they are all about. I am wondering if we are defining things differently here, as a class D amp is a PWM unit, or, if you prefer, a switch mode ( on and off, very rapidly ) - or at least, it is what I would describe as that. Its not simple PWM, but, it is a form of PWM with the Fq component thrown in also.

 

Actually, this is not overly dissimilar to how an inverter works.

 

However - this is getting more than way off topic, and I don't wish to lead the conversation there. If you want to debate the finer points of class D amplification, we can carry it on via PM. Otherwise, lets agree to disagree :). What we do agree on is that while class D amps may sound a little less hifi than some of us would like ( although I did try some Jeff Rowland amps once which were stunningly good ) it is the best option for in a boat, due to the efficiency with which they convert DC power into a speaker level audio signal. Class A and Valves are not suited in a boat. Specially not valves. That would get expensive, even if it did suffice for saloon lighting.

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Anyone who cares enough could read this white paper type of PDF from International Rectifier if they care to do so. Explains all the different classes of amplification fairly accurately.

 

http://www.irf.com/technical-info/appnotes/an-1071.pdf

 

 

A note re damping factor - I used to be a firm believer in having a high DF. Indeed, most PA gear has DF's in the thousands. Most home audio gear is in the hundreds ( and thats good gear, not crap ). Yet I have heard amps with a DF in the low hundreds ( in this case, a Pass Labs amp ) deliver tighter, punchier bass than a lot of PA amplifiers ( and I am talking the likes of Crown, QSC, LabGruppen etc ). I still think that all other things being equal, its beneficial. Be aware that DF changes with different load speakers - its the "sink" impedance / "source" impedance.

 

As for frequency response - I would suggest that all but particularly fussy listeners, or bass heads, would be happy with a response range that is fairly flat between 45Hz and 16Khz ( most of us will be pretty deaf above 16K, specially those of us who have toyed around with live sound gear much, used power tools without hearing protection, worked in noisy environments etx ) Unfortunately I am fussy. Very fussy. I have 16Hz to 40Khz with near flat response ( although the room will effect that a lot ). There is not a hell of a lot of music that has much information below 40hz however.

 

This probably makes a good argument to steer clear of 4" or 5" cockpit ( or anywhere else, for that matter ) speakers . 6" or 8" should produce better bass response, as long as they are well mounted on a rigid surface, and have a reasonable "enclosure" behind them. Car audio and Marine speakers excluding subs are generally designed to run as "infinite baffle" speakers - which means they do not require an enclosure they are able to work "against" but they still require to have the air space behind them well separated from the airspace in front of them. An ideal way to describe this would be to imagine a wall 10M by 10M. That is a very large baffle. Putting them into a board 50cm by 50cm will result in a lot less bass response.

 

As has been said by Wheels and maybe others, don't use undersized speaker wire - 2mm should be fine for anything other than a very high power system as long as the runs are not stupidly long. Which they wont be on a boat. Rexel sell a pretty decent speaker wire for about $.90/meter. The reason for not using light wire is voltage drop. There is not much voltage to lose to start with, and once your current demands start to create voltage drop, bass response in particular will become very compromised.

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Now back to the marine speaker.

So does anyone make a "proper" marine speaker?? I know of no one that make a true waterpoof driver. Only a box speaker, but no driver on it's own.

I also see another on trademe called Lanzar. No idea if it's anygood. I imagine them no different to the rest. I have tried GME, Pioneer, Blaupunkt, Panansonis, Sony and none have done any better then the other.

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In addition to the grills to protect my speakers they now have covers made that protect them from sun & rain. I figure they may last twice as long that way.

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Now back to the marine speaker.

So does anyone make a "proper" marine speaker?? I know of no one that make a true waterpoof driver. Only a box speaker, but no driver on it's own.

I also see another on trademe called Lanzar. No idea if it's anygood. I imagine them no different to the rest. I have tried GME, Pioneer, Blaupunkt, Panansonis, Sony and none have done any better then the other.

 

JL audio make a speaker range specifically designed for marine use, not a car audio type with a plastic cone and grill. Fully sealed motor assembly and a poly something basket. They also have quite robust grills ( although not a heavy stainless grill as I would like to see ). Expensive.

 

JBL at leased used to make "harsh environment" speakers - which were ip68 rated. These were rated for marine use, and again, expensive. I am not sure if they still make them, but they boasted that they could be submerged and still work fine. They are not on the Harman website anymore however. They do still do a range of marine speakers.

 

MTX also make marine speakers, and they definitely appear to be a marine design from the ground up also.

 

Much to my disgust, Focal do not make genuine marine speakers.

 

There will be others, but I suggest that sticking to a company who's main game is speaker manufacturing as opposed to general electronics. They will cost more, but they will last far far longer. Things to look for include a sealed motor assembly, polymer or other non corrosive basket, a grill mounted or separate tweeter ( mounting it in the "traditional" way car speakers mount them, on a pole in the center of the motor assembly just means the motor assembly is not sealed )

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