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Discussion Starter · #1 ·
Curious, what amps people are using in their boats these days. I like Phoenix Gold Amps since they are digital and they have variable speed cooling fans in them to keep them cool. Instead of just aluminum fins and a thermal shut off. These work great int he Havasu heat and I have never had them shut down due to heat. Phoenix Gold amps were real quality product that I believe were made in America. The problem is, Phoenix Gold got bought out by Rodin or something another. They F'd up the PG brand and now they pump out stuff Made in China. No thermal cooling fans, just the thermal shut down. So, what else is out there that has internal cooling fans and can work in the Havasu heat? :)devil
 

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Lord of the Drinks
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It really depends on two things:

1. Ohm load. If you buy a big amp, and put a conservative load on it...any amp will stay cool. The problem is most people are cheap, and put a load on it like it's in a car.
2. Where it's mounted. Any amp will give off some heat. If you don't get air over it at some point, the heat will buildup over time- the question becomes how fast (see point #1).

I run JBL and Infinity amps. They never overheat, but I really focused on the two points above.
 

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Hey HH,

You forgot to mention the benefits of running some good caps in the system and how beneficial they are all the way around. ;)
 

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R U or U R?
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Thanks for starting the thread. I keep forgetting to buy a fan for my amp which is mounted under the rear seat.
I can run it for about an hour before it burns the crap out of my hand.
 

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We sell alot of the Exile amps, the company was started by 3 guys who left Phoenix Gold... they dont have built in fans but I have never had a customer complain that they have shut off....

check them out at exileaudio.com
 

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Class D amps are the way to go for subs. Especially on boats that are meant to be played loud. Less power/cooler/smaller. Almost a no-brainer.
 

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Discussion Starter · #11 ·
I think this is a good thread. I originally had used (this is about 6 years ago) Fosgate amps on my stereo. Mainly becasue I had installed a W7 which at the time needed a 1200w mono amp. This is when the W7 first came out. Man, that amp and speaker would kill three batteries in 3 hours or so. Or, the amp would just over heat. Not slamming Fosgate at all since they were not Class D amps. But, they would over heat.
 

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Lord of the Drinks
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I think this is a good thread. I originally had used (this is about 6 years ago) Fosgate amps on my stereo. Mainly becasue I had installed a W7 which at the time needed a 1200w mono amp. This is when the W7 first came out. Man, that amp and speaker would kill three batteries in 3 hours or so. Or, the amp would just over heat. Not slamming Fosgate at all since they were not Class D amps. But, they would over heat.
Fosgates make a Coleman stove look feel like an ice chest.

Need more caps!
 

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It really depends on two things:

1. Ohm load. If you buy a big amp, and put a conservative load on it...any amp will stay cool. The problem is most people are cheap, and put a load on it like it's in a car.
2. Where it's mounted. Any amp will give off some heat. If you don't get air over it at some point, the heat will buildup over time- the question becomes how fast (see point #1).

I run JBL and Infinity amps. They never overheat, but I really focused on the two points above.
X2....

Also I have run many amps and if all SPECS are equal then it is really a personal thing... I have had good and bad with Fosgate....I agree with you on PG being screwed with the China stuff, but I am running the PG Xenon (China assembled) series now and have had good luck with them....More important try and find a USA amp company now that is NOT having the amps assembled in China...the list is small so just pick the least poison..or try and find older USA design, engineered and assembled in the USA and get them off ebay.

I have run PDX's in a more recent boat and although I question their output you can't beat the size...my next boat will either have these small type class D amps or old school esoteric type amps....it will all depend on what will fit...
 

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class d's require less power, and dont get as hot

Class A/B sound 10x better than a class D but require more current and heat up...

As far as caps, everyone has their own opinion... I havent sold one in probably 5-6 years and that was a alumapro cap..
 

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Rubbing is Racing!!
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2 Zapco's and 2 JL's

The only thing I usually have a issue with is the batteries. I thin I am going to have Car Toyz re run my power wire as we added a cople amps and are still running 4 gauge. I think thats part of my battery issue 2 many watts not enough wire....:)bulb:)sphss

I like Nords keep it stock idea...lol:):)punch
 
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Amplifier classes defined (in case anyone cares :D)


Recently there has been a resurgence of two "ancient" technologies - vacuum tube (valve) amplifiers and Class-A systems. The big question is .... is there a difference? This discussion centres on the Class-A amplifier, and explains (or attempts to) how it is different from a conventional power amplifier.

Why would someone want to build or buy an amplifier which is sooo inefficient? A Class-A power amp will typically draw anything from 1/2 to about 1½ times the peak speaker current in its quiescent state (i.e. while it is just sitting there doing nothing).

To put this into perspective, for a measly 8 Watts into 8 Ohms, the RMS current is 1 Amp. The peak current is just over 1.4 Amps, so a typical 8 Watt Class-A amp will draw anything from 700mA to 2 Amps continuous. This equates to a quiescent (no signal) power dissipation of between 17 Watts and 48 Watts, based on a 24 Volt supply (+/- 12 Volts ). At very best, such an amplifier will have an efficiency of less than 35% at full power - at worst, this will be perhaps 15% or less.

The basic premise of a Class-A amp is that the output device(s) shall conduct all the time (through 360 degrees of the signal waveform). This means that in the simplest form, the power devices must conduct a continuous current which exceeds the maximum peak load (loudspeaker) current. If we use a power level of 20 Watts (hardly a powerhouse) for all further calculations, we can see the whole picture.

In contrast, a typical Class-AB power amplifier's output devices only conduct for about 182 degrees (at full power), which means that for much of the signal's duration, only one or the other device is conducting. The other is turned off. The "crossover distortion" so often referred to is nothing to do with the frequency divider in the speaker system, but is created as the signal "crosses over" the 0 Volt point (see Figure 3).

Figure 1 - The Sinewave Cycle

Let's have a quick look at some of the power amp "classes", so we have all the info:
  • Class-A Output device(s) conduct through 360 degrees of input cycle (never switch off) - A single output device is possible. The device conducts for the entire waveform in Figure 1
  • Class-B Output devices conduct for 180 degrees (1/2 of input cycle) - for audio, two output devices in "push-pull" must be used (see Class-AB)
  • Class-AB Halfway (or partway) between the above two examples (181 to 200 degrees typical) - also requires push-pull operation for audio. The conduction for each output device is shown in Figure 1.
  • Class-C Output device(s) conduct for less than 180 degrees (100 to 150 degrees typical) - Radio Frequencies only - cannot be used for audio! This is the sound heard when one of the output devices goes open circuit in an audio amp! See Figure 1, showing the time the output device conducts (single-ended operation is assumed, and yes this does work for RF).

    When I first wrote this article, I had completely forgotten about the Quad "Current-Dumping" amp, which uses a low power "good" amplifier, with a push-pull Class-C type amp to supply the high currents needed for high power. Although these enjoyed a brief popularity, they seem to have faded away. I was reminded of their existence by an article by Douglas Self ("Class Distinction", in the March 1999 issue of Electronics World ), in which he quite rightly points out that the current-dumper is (at least in part) Class-C.
  • Class-D Quasi-digital amplification. Uses pulse-width-modulation of a high frequency (square wave) carrier to reproduce the audio signal - although my original comments were valid when this was written, there have been some very significant advances since then. There are some very good sounding Class-D amplifiers being made now, and they are worthy of an article of their own.
 

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MEDIUM PIMPIN!!!
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I would run a high watt Kicker Class D Mono amp with the Kicker L5's. I've heard this set up and it sounds pretty good:rolleyes: Run 2 of the blue top Group 4 sized Optimas and you will be solid. As far as mids go, most of the 4 channel upper end (Pioneer, Kicker, JL, etc) amps are fine as long as you run crossovers on them (active). When you buy your mids, go with a few 6X9 3 or 4 ways for the bow (if open) and run 6.5 seperates with tweeters (not 2 ways) and you'll be good to go.
 

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If you want real audio check out

www.sundownaudio.com

www.incriminatoraudio.com

www.ddaudio.com

www.alumapro.com

The sundown stuff has been making waves in the car audio scene and there prices are frkn awesome. I own a stereo shop and I will never carry
"mainstream" audio again. These brands are still small roots, high end, not pumping out chrome plated junk like alot of the better brands have went.

Give me a call with any q's 209-383-9065

I am going to do some advertising here and blow out some equipment at my dealer cost to get the name out there and get people away from the
"mainstream" stuff
 

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I fried two Fosgate amps running little 8's. Gave up and went with an alpine and have been 100% happy. Always had good luck with Kicker stuff too.

I will say, my cheapy Autotek XS series amp has been great. For a D class amp running subs it sure is a good one. My JL amp in my Mastercraft is broke too, one channel is all messed up, and getting it warrentied was a PITA.
 
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