RMS capabilities

[sqcomp]

To clarify the most important point in RR's last post...

The one of two main culprits of dead speakers is raw Voltage. Both of RR's responses to my question say the same thing essentially. More "Wattage" (Voltage is what he means in this case) CAUSES the speaker to go past its physical limitations. A speaker can only move so much.

In my years of doing this, I have only killed one set of speakers by overpowering them and that was a pair of Diamond Audio Hex Aluminum tweeters. I fed them off of a Kicker ZR600 to the passive for the S600a set. If anyone knows that amplifier, you KNOW it is a bad a$$ piece.

I’d speculate at least 10 to 1 that most speakers are killed by UNDERPOWERING them.

When Johnny Boy Racer cranks up his badly planned system to impress Sally Mae Cameltoe…he’ll more often than not clip the signal by asking the amplifier to produce more of a signal than it can. The voice coil of a speaker moves it back and forth (hence the positive and negative points off the voice coil). Well, when junior turns that volume knob on the stereo (technically referred to as a potentiometer), he increases the signal Voltage going to that amplifier. The signal Voltage is then amplified into the positive and negative (go look for a definition of alternating current) outputs of the amplifier into the speaker’s positive and negative poles of its voice coil.

Keep tracking with me here…

An amplifier can only amplify Voltage to a certain point. When the amplifier is asked by Johnny to get louder than it can…it clips. The positive and negative Voltage signal wave wants to go beyond the amplifier’s limits. Well, the signal does, but the amplifier doesn’t put out anymore (output Voltage). It clips the wave. Unless the moron behind the volume turns the Voltage signal down, every time the CD signals the radio to play that information that clips the amplifier, it will keep clipping on that certain part. ANY part of the signal that goes past the amplifier’s ability to reproduce the output Voltage will stay at the amplifier’s maximum output. Imagine a bass line that keeps repeating on your favorite show-off CD track. The amplifier will keep trying to put out as much as it can. Well guess what people, the speaker will follow suit. The cone will move whatever way that Voltage wave is going and stay there until the Voltage wave comes back to where the amplifier can play into normal limits.

Oh, we’re not finished yet…

That speaker trying to reproduce the output Voltage signal (clipped signal) comes back to the opposite side of the wave. Basically, when you clip your amplifier, you’re heating up the voice coil. Why you ask? The voice coil isn’t moving when it’s stuck at the top and the bottom of the signal wave! You’re burning the hell out of the voice coil. Why am I burning the coil? Because genius, the cone has to move to cool itself! Why do you think speaker manufacturers have made such a selling point on the “cooling technologies” of their products? Does anybody remember the first time they smelled ferrofluid or the metallic burning smell? I certainly do. There are two main ways to work past clipping a signal. The first and smartest way is to turn down your $hit! The second way is to have enough output on the amplifier as to not need all its output Voltage. You do run the risk with the second choice of physically overpowering the speaker though. With this being said, the REAL cure to clipping is level matching your system. It’s also called gain matching. I think I put a little ditty on the board a while back about that.

In my case, my worry for my system is using the Exile Audio Xi 800.4 on a pair of VERY NICE Hybrid Audio L1 Pro tweeters. That translates to a potential output of around 400 Watts per channel bridged given 14.4 Volts. That will be watched VERY closely and mitigated with containing the speaker's signal within certain frequencies and the signal Voltage being controlled by both the processor and the gain on the amplifier itself.

There’s also the part about frequency I didn’t talk about in my rant here. I can cover that if you want but it should be obvious why you use certain speakers for certain frequencies…

If I’ve made a mistake in any of this little rant, PLEASE correct me. It’s LATE here in Baghdad. I’m a little tired from working 7 days a week.