modifry,

Alumapro makes the C.A.P in three "sizes": 5, 15, and 50 farad capacitance. They range from 4 to 16 lbs and are rather small in their physical dimensions. Their technology was originally used in the military to supply power to the starting motor of tanks. These models are specifically meant for automotive uses...

 

[QUOTE]Originally posted by modifry
[B]Yea, what MacGyver said.

 

Thanks for the input, but these are not the guys I saw. The ones I saw were from an industrial only company, and they were small, I mean really small, for the rated capacitance. No joke, I'm talking about 10 farads in a 1" X 3" package. I don't remember the exact dimensions or capacity, but it was significantly better that anything I had ever heard of.

A friend of mine had a magazine with an adveretisment or tech update that talked about them, and we were so intrigued we went searching on the internet till we found them. They did not list prices, which probably means we can't afford it.

A note on Alumapro - I thought it was interesting that they make a customer demo kit for Alumapro dealers to use to show how their caps improve the sound system. But do they compare the actual bass level (sound) with and without the cap? No. Do they compare amplifier output peak voltage with and without the cap? No. Instead they compare the DC input voltage to the amp with and without the cap. This is a perfectly good comparison, since a cap will make a voltage difference at that point in the circuit, but, it doesn't necessarily prove it affects the sound output of the amplifier, which is what we're all after.

I'm not saying it won't make an improvement, I'm just saying I haven't seen any tests showing an improvement. I would think if AlumaPro had a test where an amp put out 500W peaks without the cap, and 600W with it, they would show those test results. Why don't they? Is it the same reason they don't show the ouput power increase or distortion decrease when you use "gold-plated connectors" ?

 

[QUOTE]Originally posted by MacGyver
[B]Sorry modifry, I honestly thought your question was to find out the mathematics behind the calculation as well.

 

Ask, and ye shall receive

Forgetting about all of the integrals for a moment, the equation comes down to this:

v(t) - v(o) = (i/C) * t

where:

v(0) = Cap voltage at time 0 (i.e., our charged voltage, or 14.4V)
v(t) = Cap voltage at some time down the road
since we're looking at 90% of the roginal voltage, v(t) = 0.9 * v(0)
i = Current (100A, or 10A, depending on what you're calculating)
C = Capacitance (1 Farad)
t = Time, the values we were calculating for

I'm sure you can handle this math, so rearrange as necessary to calculate whatever values you might need.

 

[QUOTE]Originally posted by MacGyver
[B]If it wasn't for the theory behind things, those rules of thumb you hold so dear wouldn't have a basis to stand upon...remember your own words, "I don't need to understand it!" the next time you tell people CD-Rs don't work in the stock player, or that 1000W of power into a 50W speaker is OK.

 

MacGyver -

Thanks, I needed the expanation of terms. Now I feel literate again. If I get around to doing any testing this weekend I'll let you know what I "discover".

 

Pinky,

I don't believe we were trying to calculate an exact size cap...I think we can all agree that oversizing the cap by .5F to 1F isn't going to hurt anything. Modifry asked a very specific question, one that can only be answered with the use of mathematics...rules of thumb would have absolutely no bearing, usefulness, or even the ability to answer it. Now that I've provided him with the basic equations behind his question and expanded his theoretical experience, he can fiddle with the numbers to his heart's content, trying new things and hopefully extending his practical experience as well.

I admit, I did take your quote out of context, and shame on me for doing so. But my reason for doing so was to prove a point. You claim the CD-Rs wear on the motor faster, but your reason for saying so is a thicker CD...this proves the point quite eloquently. As I said in the other thread, CD-Rs are no different (none, zip, nada) from other CDs in terms of weight...they differ only in the reflective layer material (being an organic dye, in the case of CD-Rs, and aluminum in CDs). Weights may differ from manufacturer to manufacturer and lot to lot, but not from type to type. Hence, your argument is completely invalid. And the only reason no side won in the wattage debate is that you refused to run the original test proposed, instead changing parameters (using a high-pass filter to get rid of damaging low frequencies)...quite convenient, that.

Yes, it does sometimes come down to differences between mathematics and real-world experience, and sometimes it comes down to plain common sense. This is one of those times where a question could only be answered by mathematics. Using that as a basis, we now know what "range" we should be looking at. We take that "range" and look at what happens in the real world...if it wasn't for that "range" we'd be shooting blind.

For a long time, you were the only one posting, so of course they appreciated your input...and still do. Where I believe you run into problems is failing to accept that sometimes real-world experience has to be tempered with mathematics and theory, just as the reverse is true. You stand on top of the mountain screaming your ideas, but if someone doubts what you have to say, you scream AT them and say how they don't have your experience....they call those people zealots. People who understand the process of making a CD/CD-R can tell you that your information on differing weights is false, yet you've heard/read it once and you tout is as gospel. Being confident about your knowledge is commendable, but failing to recognize when your facts may be skewed or incorrect is not.

For all of our disagreements, I AM willing to trust you, but only if your argument makes logical sense. Sometimes they have, and I've agreed with you wholeheartedly. When I don't agree, I say so and provide my reasons for why I disagree. Unfortunately, you take it as a personal attack and complain that I'm muddling the issue with heavy mathematics and theory...sometimes you can't simplfy things with real-world experience, you just have to theorize.

 

Can somebody with a very accurate scale please take a off the shelf CD / CD-R / CD-RW and post the weights. Please! I would like a answer on this one because I have no empirical data to support it just what I have been told from my Boss who has been in the business for 30 years, reps, and brochures only recently saying CD-R compatible and then not for all models! Though I guess that's just theory hu?

As for the wattage debate..........it was a pointless issue to take to such an extent! It was said to make a point not to be used as a proven fact. Though hell if you want to still do it. I will go get the cheapest piece of Kraco crap out there amp and my surfboard of an amp that shoots out 450 watts RMS and we can toast a speaker or 2 of mine. If your going to fall colors we could surely set that up

Definitely at times there needs to be some # crunching. Though its not the answer to everything. Sometimes things that don't seem logical is just something that you have not yet comprehended full yet and that is why they seem illogical.

This thread is turning to doo doo so I will refrain from fighting any longer. Its so not worth it.

 

I hadn't heard about the CD/CD-R disscussion before. I do agree that some CD-R discs appear thicker than pre-recorded CD's. I would believe there would be a weight difference if the CD was thicker. If the weight difference is enough to cause premature motor wear, there must be some really crappy crappy crappy CD player manufacturers out there.

Just suppose a thick CD-R weighs 20% more than a pre-recorded CD. The only time the extra weight will affect the motor is when it's having to accelereate the CD (speeding up), which I would think would be a relatively small percentage of the time a CD is in use, unless you're one of those people who constantly changes tracks, fast-forwards, changes CD's etc.

And wouldn't the motor encounter just as much (or more)additional wear if I played twice as many CD's a day as you do? I've never seen where a CD manufacturer puts a limit on the number of CD's per hour the player is designed for, like you see with some other electronic machines (copiers and printers come to mind).

If I brought my broken CD player into a dealer, and he told me it broke because I played CD-R's in it, thus pre-maturely wearing out the motor, after laughing in his face, I'd have to pre-maturely wear out his butt,

Now for my measurements:

While I don't have a scale of sufficient accuracy to weigh CD's, I do have a micrometer, so I measured the thickness. Every CD I can find in my considerable collection measures in the range of .047 to .049 inches. Which for any practical purpose is an insignificant difference.

There seems to be no discernable pattern as to which ones will be thicker or thinner. I tried pre-recorded CD's from several recording compainies, and CD-R's from Memrex, Hi-Val, Nashua, and CompUSA generic, they all measure in the same range.

Even the CD-RW's that I would almost swear were thicker by looking at them, measure the same.