More power needed for Tempests? (1 Viewer)

[David Giesbrecht]

I honestly hope that I am wrong about the sinewave thing, it's just that if I was, Just like Chad I would be able to make mince meat out of my subs and the amp wouldn't blink and this doesn't seem to be the case.

 

[Brian Tatnall]

About sinewaves, If all waves were seperatly amplified and amplifaction doubled for every sinewave played at the same time how would the subs cone move. would it play every wave seperatley at the same time? would it move say 20 cycles/second and then 30cycles/second at the same time. How could it? Would we here both tones or a combination of the two.

Shawn those are exactly the questions he should be asking

 

[David Giesbrecht]

I understand the fact that waves combine to make more complex ones I've always understoud that but you can't ask an amplifier to do twice the job without asking for twice the power. That just doesn't make sense, what you put in is what you get out and if you put in twice the information you get out twice the information. I you wanted a PC to perform twice as many operations per second as it does currently you would need a PC twice as powerful. The same applies to speakers and amplifiers.

Saying that it doesn't matter how complex the wave is just seems to good to be true.

 

[David Giesbrecht]

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

click on Passive XO V.S. active XO #84

Please read.

 

[Brian Tatnall]

Saying that it doesn't matter how complex the wave is just seems to good to be true.

Wave complexity really doesn't matter a whole lot unless your creating AMPLITUDE. Like a square wave. Which is as 'complex' as a wave can get.

Complexity means NOTHING without amplitude. You can have an extremely complex wave with little amplitude and it will need little amplification.

If by wave complexity you mean added amplitude then I agree that more power is required, but also remember that a wave has not only peaks, but valleys also. So in some places where there is now less amplitude less power is required.

Concerning your example:
If PC operations could combine like waves do where some operations are smaller and others become bigger then you have a point. But PC operations DON'T work like waves do. Even your examples to explain your theory work in a system that does not take into account that waves combine.

You said you "you put in is what you get out"

Exactly, but you must remember that you are putting in WAVES not just operations. Waves unlike operations combine creating less work in some places and more work in other places.

 

[Brian Tatnall]

It seems like you think lower frequencies have greater amplitude inherently and they do not.

Frequency is determined by wavelength ONLY. Nothing concerning amplitude is inherent withint any frequency.

 

[Jeff Braddock]

I have to say that I really have enjoyed this thread. There have been some excellent points brought up, especially by Dan and Brian. David, I know that you "calibrate" your subs to a level that you like. What level are the calibrated at? (i.e. could you give us a db reading) What about the rest of your speakers? I know your friends say that your level is reserved, but I'm guessing they may be comparing it to car audio.

Since there has been such a discussion about sine waves, I recomend you look back at some of Dan's posts - especially the one about the orchastra earlier on this page. I don't have much technical knowledge when it comes to this stuff, but when I look at Dan's reasoning, my common sense tells me that he has a point. I think you should sit and mull it over for a while.

 

[Michael R Price]

The next thing I can think of: Make sure the clip indicator doesn't light prematurely. Just check the output of the amplifier with a voltmeter during the scenes where you see the clip light go on. 450 watts into 4 ohms is, uh, 43 volts RMS or something. And, you can probably turn it up a little bit more and see if it distorts audibly. If it really is clipping, then bringing the level up a couple decibels would make the clipping obvious. On second thought that is kind of dangerous since you should have enough power to damage the Tempest. Just check the output voltage (and maybe the 1-meter SPL too) when the indicator lights.

 

[Brian Tatnall]

We agree on this point

What happens to ALL of those frequencies amplitudes when you turn down the volumne knob?

If your original source has huge amplitude (which would be very abnormal since sources are normalized easily now) does it matter at all if your volume know is turned to zero power?
Answer:
(The original source means nothing because it is being provide no actual amplitude without turning up the volume knob).

Now if your volume is turned to half power? Now if your volume ist turned to full power?

Now does it makes sense that your ability to change the amplitude of the wave supercedes the original recorder volume by a HUGE margin.

The actual origianl source amplitudes are ONLY correct when by RANDOM chance you have your volume know turned to the correct level.

You aren't putting in amplitude unless the volume knob is turned up. It is the gatekeeper. No wave that has three times the amplitude of other waves gets by unless IT says so.

 

[David Giesbrecht]

Look up

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

Read section 84# please

it is obvious you are not reading my posts entirely and you are making assumptions.

 

[Brian Tatnall]

That entire section is huge and I read it last night and again today. I've been through the entire site at least 20 times.

What point are you trying to make from it? What incorrect assumptions am I making?

You have not answered a most of the relevant questions I have posed. I really don't think you have answers for them either.

Your not being specific nor are you making any point. I have read all your posts entirely and the only assumptions I'm making are the ones that are grounded within the words you write.

"When both of the frequencies are mixed together, you can see that they are very close to reaching the top and bottom of the window (we will consider the vertical borders of the window to be 'clipping')."

If this is the section you are talking about you need to remember that most any source you play is normalized to keep it from doing this easily. Besides, amplitude can be changed easily with the volume knob so that clipping doesn't happen.

If a recording is already compressed or clipped before you start playing then there is nothing you can do about it anyway.

Is this the only piece of information besides common sense you are using to argue your point?

 

[David Giesbrecht]

If this is the section you are talking about you need to remember that most any source you play is normalized to keep it from doing this easily. Besides, amplitude can be changed easily with the volume knob so that clipping doesn't happen.

If you look back at my previous posts the point I was trying to make was that.

1. All frequencies within a musical peice make up only a small part of the total amplitude.

2. It is possible to drive a subwoofer much harder during a complex sinewave than a simple test tone without reaching Xmax

 

[Brian Tatnall]

Focusing on 1. This is true, but you need to remember that a sub doesn't see multiple frequencies it sees 1 amplitude at any given time. It takes your brain to divide it all up and recognize the different parts.


Focusing on 2 it is possible, but not necessary.

How hard you drive a sub is going to be more dependent on the volume knob then the wave complexity. The difference is going to be the volume knob NOT the complexity of the wave. The sub could careless how complex the wave is if the amplitude isn't greater. The way to change wave amplitude is the volume knob.

 

[David Giesbrecht]

The way to change wave amplitude is the volume knob.

I am wondering if you think I am actually stupid enough to not to relize this.

sorry but this is the way it sounds to me.

 

[Brian Tatnall]

I am wondering if you think I am actually stupid enough to not to relize this.

You really don't write as if you truly believe the way to change wave amplitude is the volume knob.

 

[Jerry Parker]

David, I don't know if you have tried this yet, but set the subwoofer output on your reciever to 0dB or higher if you can, while keeping the gain at 32 on the QSC. See if you can get any more output then, I wouldnt be surprised if you could.

 

[David Giesbrecht]

its the combination of all those different frequencies together that make the amp work hard and thus drive a loudspeaker to a high level.

Again I don't see the problem here. When adding sinewaves at any given amplitude together they total out put of the amplifier will increase. This was also proven to be correct in the link I gave you.

All of these statements are essentually saying the same thing but with different wording.

 

[David Giesbrecht]

The sub could careless how complex the wave is if the amplitude isn't greater.

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.

This again has also been proven to be true in the link I gave you and this is the point I have been arguing for the last 97 posts.

 

[Brian Tatnall]

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.

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.

 

[Shawn Solar]

I know discussion has shifted but have you figured out whats wrong yet? just wondering