What's "RMS" ??

[philwsailz]

see if this helps.

Simply put, an amplifier with higher output power can put out more VOLTAGE for a given speaker load. A smaller amplifier delivers less voltage, hence less power.

The top picture in the series below can represent the electrical output of an amplifier that is exactly delivering its rated power. Notice that the output waveform is smooth and sinusoidal.

When you turn the amp up more, it tries to make the same shape wave, only bigger / taller. The rounded peaks are progressively missing in the second and third image. The flat lines at the top and bottom are at the horizontal line which is equivalent to the maximum output voltage capablilities of the amp. The curves that shoull be at the very top and bottom are "clipped off" hence the term clipping.

Put EXTREMELY SIMPLY, clipping represents a very brief moment where the output of the amp is DC rather than AC, and DC power makes no noise, it only makes heat.

This is one small graphic representation of why too small an amplifer can be bad for a higher powered speaker...

[time2kyl]

OK, who let the engineer in???

[da.bell]

I was going to say that the last graph looks like some ppl's heart rate. Right 1lab?

[CP3]

I was going to say that the last graph looks like some ppl's heart rate. Right 1lab?

HEHEHE

[Graham Morris]

Clipping

Personally I prefer a slightly bigger / higher-powered amp, as in my first post above. Use settings, control, and sobriety to keep the stereo in check and the signal clean.

The smaller amplifer cannot drive the higher-powered speaker to its max potential, and an attempt at doing so will usually lead to clipping.

\
Can you please explain what clipping is and how clipping causes damage?

[chpthril]

I was going to say that the last graph looks like some ppl's heart rate. Right ****?

HEHEHE

Ya'll need to quit this, my PM box is full already with unwarranted nasty messages.

[dogbert]

I was going to say that the last graph looks like some ppl's heart rate. Right 1lab?

That's mean!

[philwsailz]

\
Can you please explain what clipping is and how clipping causes damage?

Hi Graham-

Clipping in the laymans terms is when the amplifier is trying to put out a larger output waveform than it can. The input waveform cannot be fully replicated at the speaker terminals, as the amp does not have the output voltge amplitute necesary to recreate it.

The result looks like the second and third pictures above.

Clipping can be a contributor to thermal failure of the speaker due to excesive heat. At any point that the output signal is flat, as in the clipped off tops and bottoms of the output, the amp is producing a DC voltage output at a constant voltage. DC voltage in a speaker does nothing more than create heat.

Loss of damping is a problem; damping is simply put the ability of the amp to smoothly control the woofer's motion. When one loses damping, the woofer can travel to extreme displacements, beyond its design intent. This can sound bad on its own, but can also cause other things. Many voice coils are aluminum, and if one hits the bottom of the motor structure, it will bend and probably rub or even get stuck. If it gets stuck, the voice coil will for sure over-heat with applied signal, as it cannot turn the electrical energy into motion, only heat.

[da.bell]

That's mean!

I have not idea what you are talking about.

[spharis]

Don't know if Phil said it or not, but clipping can be caused at numerous points throughout the signal as it passes through. Head units, eq, and the amp. Most everyone can hear clipping if they know what to listen to.

[Jason B]

Thanks for the explanations! I was kinda under that impression but wasn't really sure.

I was going to go with the MX700.5 (Kicker) for my tower speakers and sub. I'm leaning towards Pro 60's and MB8's for the tower. Is this a good amp or is there another one better suited? I don't want to go crazy, I just want good clean sound for hanging at the sand bar and boarding. Not trying to win any contests.

[chpthril]

Thanks for the explanations! I was kinda under that impression but wasn't really sure.

I was going to go with the MX700.5 (Kicker) for my tower speakers and sub. I'm leaning towards Pro 60's and MB8's for the tower. Is this a good amp or is there another one better suited? I don't want to go crazy, I just want good clean sound for hanging at the sand bar and boarding. Not trying to win any contests.

MB-8's = 150 watts RMS/ 4 ohm driver
Pro 60's = 150 watts RMS/ 4 ohm driver

MX700.5 = 85 watts x 4 @ 2ohms = about 45-50 watts x 4 @ 4ohms (correct me if i'm off Phil )

I'l say go with the ZX850.4 (215 x 4 watts RMS @ 2ohms) for 2 reasons: more power per chnl @ 4 ohm and not having the sub pounding away when the tower speakers are cranked up.

These are only the my thoughts that are based solely on street smarts Let's see what the experts say

[Lunchbox]

You guys are the best... That's why I love this board... Such a wealth of useless information...

[chpthril]

You guys are the best... That's why I love this board... Such a wealth of useless information...

with something factual thrown in every once in a while

[philwsailz]

MB-8's = 150 watts RMS/ 4 ohm driver
Pro 60's = 150 watts RMS/ 4 ohm driver

MX700.5 = 85 watts x 4 @ 2ohms = about 45-50 watts x 4 @ 4ohms (correct me if i'm off Phil )

I'l say go with the ZX850.4 (215 x 4 watts RMS @ 2ohms) for 2 reasons: more power per chnl @ 4 ohm and not having the sub pounding away when the tower speakers are cranked up.

These are only the my thoughts that are based solely on street smarts Let's see what the experts say

I agree with CHP...

I am going from memory, as I am typing from the Atlanta airport, but I seem to recall that the 850.4 is good for 150 W RMS into 4 ohm load, according to CEA-2006 specs. That will be a prefect amp for your speakres if my memory is correct.

Since you are going for the higher power on the tower, go with a KICKER ZX400.1 digital amp if you are using the KICKER marine sub(s) or I may have other recommedations if you intend to go with a different woofer. If you have no amplifier for your in-boat speakers, the MX700.5 is nice, as it has 4 channels of full range power, and 420 watts RMS of digital subwoofer power.