RSW-15!!!

[toddvj]

Just got my first RSW-15 today. This sub is no Joke!!! I hooked it up and threw on a Hip-Hop CD to test it out, of course cranked the volume up all the way, and OH MY GOD!!! It shook the whole house. I don't usually crank it up all the way, but it was nice to know that I can if I want. It is awesome for the little bit of movies I've watched so far, too. The one in the store must be bad, or be hooked up wrong, because this was more than I ever expected!!! I can't beleive I'm still getting another one, what am I going to do!!! My wife's nic-nacs hanging on the wall are in serious danger!!! Anyone considering this sub has my highest recommendation!

[boa12]

todd, congrats! those rsw have some serious spl. even the 15 i did hear at the store. another one you say? you going to stack 'em?

[prodj101]

why do you want another one? 1249 for 3 db more of output, which is on top of the output that you're already never going to use. I dunno, just seems wastefull to me. I'd rather buy a really nice turntable or cd player. Oh, and by the way, I have an RSW-15 and love it as well

[m00n]

Right on! Oh yes, I know the joy of hearing that 15" for the first time. I about poo'ed myself when I watched some Phantom Menace for the first time with that sub.

[TheEAR]

RSW15 hits quite hard,great sub for music with plenty of information around 30Hz.Now my stacked RSW15/RSW10 combo will do just fine for my PC. LOL

For RF7's and company my Sunfires bring more below 30Hz,and the RF7's are quite solid to 35Hz or so.

Yep this RSW15 packs quite a punch.Two RSW15's are better then one.

And a dozen potent subs are better then two

[Invidiosulus]

There is nothing wrong with three db more output, every three db more is double the volume.

Funny how that works

Peace, Josh

[dougdrake]

I am probably wrong, but I believe that a 10 db increase is perceived as a doubling of volume, and it takes roughly double the power to get a 3db increase in volume. That means it would take 8 times the power to double the volume with a single speaker. I guess it would take 8 subs to double the volume, eh?

[NOZ]

Dougs right..

[prodj101]

yep, drake is right. adding a second speaker doesn't just double the sound output.

[Invidiosulus]

Doug,

The decibel scale is organized exponentially.

The decibel(or tenths of a Bel) is actually the exponent.

Thus 85dB represents the number 10^8.5 and 88dB = 10^8.8

Looking at it this way 85dB becomes 316,227,766 and 88dB is 630,957,344.5

Easily seen as double the sound power.

So every 10dB increase is 10 times the power.

Peace, Josh

[m00n]

Swish.... Right over my head.

[JohnA]

Josh,

You're right, insofar as you go. However, the ear perceives 10 times the acoustic power as twice as loud. The ear's response is logarithmic, too.

[prodj101]

we're talking perceived volume level, not technical.

[justin_tx_16]

This is what BobG says

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"Increasing the decibel level of an audio system is parallel to increasing the speed of a car. Modern race cars achieve speeds more than twice as fast as modern street cars, and they need about 10 times the horsepower to do it. (Modern street cars have between 100 and 200 horsepower and modern race cars have between 700 and 1,000 horsepower.) It is similar in the acoustic sciences. Adding one powered subwoofer to a multimedia system increases the output by 3 decibels, but from there it takes two more subs to achieve a total of 6dB increase and another four more to achieve a total increase of 12 dB, and so on and so on.

It is unlikely that consumers will choose to increase their system output by 24dB with 15 additional subs, but even the novice gamer or computer audio enthusiast who likes to watch movies on his computer will be interested in adding 3-6dB"

--------- --------- --------- --------- --------- --------- --------- ---------

BTW, this was paraphrased from a press release to fit the format of my post. Read the SWS Press release if you question anything i posted hehe.

[Invidiosulus]

John,

Quite right you are indeed.

I was referring to prodj101's comment " why do you want another one? 1249 for 3 db more of output,"

The reference for the calibration of the dB being 0dB = 20 micro Pa

A Pa, called a Pascal is equal to 1 Newtons of force acting evenly over an area of 1 square meter.

So one micro Pa = 1 Newton^-6

But none of the numbers matter anything at all if your system sounds good to your ears.

And I much prefer listening to music on my stereo than doing all this math

Peace, Josh

[toddvj]

I'm getting a second one because it will sound better. I'm not trying to make it as loud as possible, just to sound good as possible. I'm going to put one on each side, to go along with my two rear subs (Infinity IL100s). I've had two front subs for about 2 years now and would never go back. ProDj--$1249 that is a good price! I'm getting them for much less than that, I won't tell you how much. And if it has 3dB more output, great!!! I still love my new sub, by the way!!!

[Mikekid]

I use a flux capacitor with my sub...10,000 times more power!

Get your hands on one of those and you will be all set!

Happy Thanksgiving all........

Mike

[Guest BobG]

If there are two uncorrelated sound sources in a room - for example a radio producing an average sound level of 62.0 dB, and a television producing a sound level of 73.0 dB - then the total decibel sound level is a logarithmic sum i.e.

Combined sound level = 10 x lg (10^(62/10) + 10^(73/10) )

= 73.3 dB

For two different sounds, the combined level cannot be more than 3 dB above the higher of the two sound levels. However, if the sounds are phase related ("correlated") there can be up to a 6dB increase in SPL.

The bass output of an audio signal sent to multiple subwoofers is an example of phase related, or correlated sound. If the multiple subs are located in the same point in space (or within ½ a wavelength of one another), theory indicates that there will be a 6 dB increase in output for every doubling of the number of subwoofers. Because many people will not put the subs all on one spot (and with enough subs, that is not even possible) we describe the increase in output as 3 dB rather than the theoretical 6 dB.

There is another valid approach to positioning subwoofers. A single sub in any room will stimulate a unique pattern of standing waves in the room. At any listening position there will be a pattern of nodes and anti-nodes that are frequency dependent. For example, at a specific listening position a given bass frequency may be as much as 12 dB above the measured level at the woofer cone (a node) or as much as 12 dB below the measured level at the cone (anti-node). This is due to individual room acoustics and occurs in every room with any reflective surfaces. Adding more subs at the same location does not help and equalization has no positive effect. Pick a different frequency and the nodal pattern is different. This is what gives rise to the suggestion to select the best location for a subwoofer by placing the sub in your listening chair while crawling around the room with your ear at subwoofer height from the floor. Where you hear smooth, balanced bass is the best spot to put the sub while you put yourself in the listening chair.

A way to minimize the impact of nodes and anti-nodes is to randomize them. Add a second subwoofer and put it in a different place in the room. That sub will make a different pattern of nodes and anti-nodes with the combined result of the two subs being a randomization of the nodes and smoother bass. This fills in the anti-nodes cutting in half the deviation from flat frequency response.

When you have enough subwoofers to raise the barometric pressure in the room (literally) you have approached a limit. Instead of propagating a wave of bass energy, you are generating DC (in air pressure). This may happen for example in a small car with the windows sealed and a system with lots of subwoofers and power. A dozen 15 inch subwoofer with massive power will pressurize the environment and bass output will have reached its limit. I have never heard of such a situation in a home installation though it is certainly possible.