More power needed for Tempests? (1 Viewer)

[David Giesbrecht]

no I havn't everything looks fine as far as connections are concerned, but I have been wondering if wire gauge could be the cause of the problem.

 

[David Giesbrecht]

You can add more frequencies and actually decrease the load on the amp causing it to keep from clipping. Add a 30hz tone completely out of phase with the first tone and then add any frequency you want with in the already set max power limitations and bam power in other places.

If it is out of phase yes they will cancel each other but if they are in phase they will sum together to create double the amplitude.

(To different frequencies together will cause peaks and vallies in the output) Yes I fully agree with you on this statment. But like you said you will get peaks in the amplitude when the peaks of two frequencies line up in phase. It is these peaks that will cause the amplifier to clip.

When to frequencies of the same amplitude are joined together the amplitude of the new wave will be increased.
That is all I'm saying.

 

[Shawn Solar]

Maybe, But I doubt it would have such an adverse affect. I take it that you have each sub wired for a 4 ohm load and are running each sub off one channel of the amp? have you tried a different amp. I've used 16guage and now 12guage without a difference. at least on runs less than 50ft.

 

[Pete Mazz]

I would suggest setting the gain on the amp all the way up. Turning it down only attenuates the signal, and you're probably already under what a pro amp expects to see with regard to input signal. Then set your processors sub level to 0 and calibrate with a SPL meter, leaving the subs gain up. It should get you close.

Pete

 

[Michael R Price]

"But the amplifier does, if you are already reaching the amplifiers max power @ 30 hz the amplifier cannot dedicate any more power anywhere else without clipping."

Right but that does not matter.

Did you have a chance to check the voltage output when the clip lights go on?

 

[David Giesbrecht]

I am using 14 guage wire and the runs are 15 feet so thats probably not the cause of the problem.

Did you have a chance to check the voltage output when the clip lights go on?

No I havn't my dads tester seems to be busted:frowning:
I think it needs a new battery and I can't find one but if I do I will test it.

 

[David Giesbrecht]

Conclusions, there is less required of the amp because some of the amplitude is now gone. The amp can create the other frequencies more accurately because the amp is less likely to clip.

Exactly I think this whole thing has been a misunderstanding because in this statement you are agreeing with me. LESS FREQUENCIES = LESS AMPLITUDE

And I have been stating this the entire time! You can reverse it to MORE FREQUINCIES = MORE AMPLITUDE!

 

[Patrick Sun]

And I have been stating this the entire time! You can reverse it to MORE FREQUINCIES = MORE AMPLITUDE!

This is wrong as well, see my above comment.

The amplitude of the waveforms sent to the driver is governed by the power that is capable of being sent to the load (driver) by the amplifier. Which you reach the limit of the amp's capacity to provide more current, you get the condition of clipping the amp where the waveforms get "squared off" and this creates sinewaves that weren't meant for the driver to reproduce (outside the 20KHz range for certain) being sent to the driver as the superposition (think of it as addition of a multitude of sine waves at very high frequencies to recreate the square wave condition) of these very high frequencies at high amplitude get sent to the driver with bad results.

Once you get to a clipping condition, all bets are off as to the amplitude of this frequency or that frequency being produced by the driver.

 

[David Giesbrecht]

This is wrong. It's the current demanded by the load (driver) to power both frequencies at the amplitude that has increased.

Either way the amplifier must produce more power.

 

[Patrick Sun]

And this increases the amplitude of either frequency how?

Just because you have one frequency playing, and also another frequency playing, it doesn't mean the amplitude of the aggregate waveform has increased.

Amps are designed to output enough power for its rated bandwidth (which means there's enough power for the entire 20Hz to 20KHz spectrum for audio plate amps, and it shouldn't matter it you ask the amp to amplify 2 frequencies, or 20,000 frequencies of the audio spectrum at the same time), so the aggregate waveforms at specific amplitude is totally a function of the volume control that controls the preamp output for the subwoofer output and its trim controls on the amp.

I urge you to do some reading on the fundamentals of electrical engineering before shooting from the hip.

 

[David Giesbrecht]

http://www.eatel.net/~amptech/elecdisc/caraudio.htm

If you read section 84# it shows you in plain english with little graphs what happens when you COMBINE WAVES!

If your amplifier is producing half its power producing a single 100 hz tone and you at a second 1000 hz tone the amplifier will now be producing it's full power!

Read the article.

 

[Robert A]

David, you are grossly over simplifying a very complex process. The example which you are referring to is a special case. To truly appreciate how complex it is you must have a good background in calculus, trigonometry and physics. I think a lot of the misunderstanding here arises from poor use of the two different terms, signal and frequency.

Signal: A set of information or data (in our case voltages or currents) that are functions of the independent variable time. Usually in audio this data oscillates over time.

Frequency: The number of cycles or oscillations per unit time (in our case cycles per second, Hz).

Electrical signals are defined using amplitude, phase, and frequency. If you take two sinusoidal signals with two different frequencies and the same phase and amplitude and add them together, then the peak amplitude of the resulting signal will be double that of the originals, provided that the ratios of the frequencies is a rational number. In a similar manner, if you add two signals that are exactly identical in waveform, phase, amplitude, and frequency the output will be doubled. However, the first scenario, in audio terms, is EXTREMELY rare. The second only applies to doubling amplifier power, adding a second identical speaker with the same amount of amplification or something similar. Audio signals are very complex and have vast differences in not only amplitude, frequency, and phase, but their waveforms can be completely different as well. You can’t think of a signal as an entity that varies only by frequency.

It is possible to take a signal of fixed peak amplitude and add additional frequency components to the signal with out increasing the peak amplitude. In fact, it is possible to decrease the peak amplitude by adding specific frequency components. Fourier analysis of the resulting signal will show which sinusoidal functions added together produce the signal. These sinusoids not only vary in frequency, but also usually vary by phase and amplitude. To say that you are “adding frequencies” is a vague and useless statement.

Thus, more frequency components do not equal more amplitude. And it is definitely incorrect to assume that adding any random frequency component to a signal will double the amplitude every time.

The situation becomes even more complex when dealing with signals from an amplifier to a speaker. Speaker impedance isn’t a specific value nor is it always real. The voice coil, magnetic fields, and mechanical properties all represent different inductances and capacitances adding real and imaginary components to the load. This makes the interaction of the signal with the speaker vary greatly by frequency changing phases and amplitudes in the signal. Once you have achieved a flat frequency response with your speaker your power dissipation vs. frequency is anything but uniform.

This is my feeble attempt to explain something that really is much more involved than this explanation and takes quite a while to learn. I can go into more detail if that would help. I applaud you for knowing as much as you know at your age. There is, however a lot more out there.
-Rob

 

[David Giesbrecht]

My uderstanding (or lack there of ) of this has developed overtime from the expeinces I have had while trying to record my drumkit I remember an instance when I was trying to equilize levels within my drumkit (bass,snare,toms,cymbals, etc.) and I could hit my bass drum and the level indicator showed that I was not clipping the output for the main mix and if I hit the snare drum I was not clipping the output but try to hit them together and the same time (witch does happen!) and I had problems.

It is at this point that I came to beleive what I do, and trust me I am not making this up. I have experienced these problems and I have compencated for them, thats why I beleive that at least some part of my statements in this thread hold some truth.

 

[David Giesbrecht]

I am not looking to cause any fights here or any undue stress to anyone nor do I wish to have information spoon fed to me. All I want is to be heard.

 

[Jake K]

but try to hit them together and the same time (witch does happen!) and I had problems

That would be like having two cd players playing at the same time going into a single input on a receiver. Twice the input signal, quite different from combining sound waves I think.

 

[David Giesbrecht]

but try to hit them together and the same time (witch does happen!) and I had problems

I was merely saying that if I tried to hit both bass drum and snare drum at the same time the output of the board would clip but I could play them individually without a problem.

read more carefully please :frowning:

 

[Jake K]

Actualy I understand more about what Robert said than what you have been saying.

I was merely saying that if I tried to hit both bass drum and snare drum at the same time the output of the board would clip but I could play them individually without a problem.

I won't get technical, because I can't, but that sounds like a much different situation to me than just combining sine waves.

 

[David Giesbrecht]

I won't get technical, because I can't, but that sounds like a much different situation to me than just combining sine waves.

But that is what were doing here.

The fundimental resonance of the bass drum on my drumset is centered at about 37 hz, the snare is about about 400hz plus all the overtones and undertones that come with it.
When I hit both drums together the sound the microphone hears is a combination of the two resonances and all the overtones/undertones mixed together to create a new more complex aggregate wave, when the two get mixed in the board the total amplitude of the audio signal (shown by the output readout on the soundboard) was increased.

 

[Jake K]

when the two get mixed in the board the total amplitude of the audio signal (shown by the output readout on the soundboard) was increased.

You should have said that a long time ago. That's your only example IIRC. But I am not going to keep arguing because I don't know anywhere near as much as those other guys.

BTW, I'm 17 too.

 

[David Giesbrecht]

Did you have a chance to check the voltage output when the clip lights go on?

I found a battery and the results are 36 volts