DevilDriver

<-- currently reading Dracula For fun? Not a bad book...must read for those of us who love vampires.

Very interesting results....thanks for sharing. The symmetry on the BL curve is excellent, although a little more extended plateau might be preferable. Le(x) reflects the lack of a shorting ring, while the compliance symmetry could definitely use some work. Still a great value driver at that price.

So there were no improvements or changes made then? Well thats a relief This is not the case and all box programs are wrong. Any insight on what Thiele and Small's models are doing incorrectly?

Question everything.

How were you recording this? With a microphone and mic pre-amp? What soundcard was this with? More info would help.

The WT3 is a fine option. The real advantage to it is the quickness with which you can take Thiele/Small measurements. http://audiojunkies.com/blog/1016/wt3-woof...ew-dayton-audio

It's Shay Laren. Here's something nsfw.

It's like science for rockets....

Really quite tired this evening. Funny, don't have a job at the moment but am working harder now than I had to before. Definitely looking forward to school again in the Fall.....

What on earth does any of that mean? How do you hear accuracy with your ears?

The BTL is the most efficient driver and at any power level, it will be the most efficient driver. Efficiency, in the simplest sense, is the ratio of input vs output, ie. in a highly efficient system, there will be more output for a given input. So what affects efficiency? In a very general sense, we are looking at two primary factors: mass and BL (or for comparison's sake, BL^2/Re). We know mass will not change at 1 W or 10,000 W. We know the B (flux density in the gap) will not change (within reason). And the L (length of coil that cuts the flux) will only significantly change once we approach Xmax. The BTL's coil also happens to be capable of handling more power before the resistance increases, so we know the BTL will be most efficient at any power level. Now....does this necessarily transfer to loudness? First, we need to look at the bandwidth (range of frequencies) that the subwoofer will be covering. Yes, the BTL is more efficient than the Q, but will it be louder at 20 Hz for a given input? There are many factors and, at the risk of oversimplifying, the answer is no. This is the tradeoff that is Hoffman's Iron Law (look in the Tech Area on this site). However, through most of the bandwidth that is typical of a subwoofer, the BTL will, in fact, be louder than any other Fi driver. No speaker "needs" a certain amount of power.....the only time you need more power is if you're not satisfied with the output you already have. So why not just buy the BTL? Well, there are different applications for each driver. Some drivers are more linear than others (generate less distortion), some drivers have better low frequency extension, and some drivers will meet your needs at a much lower cost than buying the big boy BTL.

This is nothing short of horse shit. Plain and simple. I hope no Canadian honestly believes any of this (I don't know of many who would), especially since we tend to take pride in our multiculturalism. Up here, it is seen as an asset rather than a detriment. Explains a lot about the current state of the US, mind you.

All enclosures are just filters.

To answer the question about what specifically causes subwoofers to sound sloppy, people look for a lot of reasons but it really comes down to what happens in the frequency domain (ie. frequency response). Flat response in the subwoofer range, especially transitioning into the midbass, is really what is key to good, even performance from your subwoofer. A common mistake people make is to allow the low frequency performance of a driver to practically swamp the response above 50-60 Hz (particularly when we consider the transfer function/cabin gain of your vehicle). The primary negative detractors will be the inductance of the voice coil, the enclosure, the vehicle's transfer function, the power on tap, and the midrange/midbass driver's own performance. All of these things need to be managed appropriately to achieve the response you're looking for. There are secondary detractors (like mass, BL, and others) but these can easily be accounted for or even avoided if the primary detractors are taken care of.

For linear displacement, look at the Thiele/Small parameters.... Vd = Sd * 2(Xmax) The radius would be one half of the diameter of the cone plus 1/3 the width of the surround (not 1/2 as is often claimed). Then you can use this radius to calculate the effective surface area using the methods described above.

Double LOL.

Congress was really giving it to them. One congress woman would not even listen to what the Exxon VP had to say. Their argument is that the company is making 40+ billion dollars and should lower their gas prices. Exxon countered that the amount they are making hasn't changed, but that the reason the price is going up is because crude oil has been going up (which is true). Still, the congress was convinced that Exxon should be willing to take a cut in their profits in order to help consumers out. I understand congress' argument, but I think it is Exxon's right to free enterprise and capitalism...if the consumers are tired of paying for gas at that price, they need to stop buying it.

www.noisedead.com/vbp Thanks. I give you credit for full disclosure. Why this type of stuff isn't first and foremost for companies like Anthony's is beyond me. Actually, I know why they do it....I just can't stand it.

It is coming down to semantics, really, but in any room, the limitation in low frequency response will almost always be linear displacement.

What site is this?

I would love some here. We haven't had enough this year and it will make it hard on the crops locally. Plus, I just really love precipitation.

Also, my ~1 year journey with agnosticism is over. I have officially lost all patience for religion, particularly those of the monotheistic nature.

Have you guys seen any of the coverage where congress was arguing with Exxon today?

What do you mean by "power options"? You'll probably get your choice of coil configurations (d2 or d2) and that will be it, much like most subwoofers.

Good match between Man U and Chelsea in the Champions League final today. Lampard has pushed one off the woodwork twice. Shootout imminent....