2way speakers with E120?

[Ruediger]

...
But I can't make that big box, and I wouldn't know how to raise f3.
...

You missinterpreted the following sentences:

For a given efficiency, the -3dB frequency is inversely proportional to the cube root of the box volume. Halve the -3dB frequency, and double the edge length of Your box. This means: make the box volume 8 times as large.

If You want more efficiency, raise f3 or make the box larger, or both.

I did not mean that You could or should change the parameters at will. If a speaker designer decides to make one parameter "better" then another parameter will get worse.

If You have a working Thiele alignment, and another alignment is possible for Your driver, and if that alignment has a "better" f3, then it will have a worse (larger) Vab.

ruediger

[jcomba]

Thanks for clarification. Any subjective opinion on the k110?

[jcrobso]

The specs I have state 300W here, strange... http://www.jblproservice.com/pdf/Dis...els/2202HJ.pdf

There's no such thing as RMS power, it is a misnomer.

http://www.hifi-writer.com/he/misc/rmspower.htm

http://www.google.ca/url?sa=t&source...nsdpxUNkcNm_Fw

http://en.wikipedia.org/wiki/Audio_power

http://www.google.ca/search?q=rms+po...ient=firefox-a

FYI: The term RMS applies to a pure sine way ONLY and nothing else. RMS voltage is derived by taking the positive swing of the sine wave and taking the peak voltage of the sine way and multiplying it times .707 and you have and RMS voltage.
For people in the US we have 120v RMS sine wave power. The voltage swings from 0 volts up 170V positive peak back to 0 and down to 170V negative peak. So we take the positive peak of 170V X .707=120.19V
There is an article that tries to discredit RMS by using a Square wave with a 5 second cycle. Remember RMS=pure sine wave!

[Eaulive]

FYI: The term RMS applies to a pure sine way ONLY and nothing else. RMS voltage is derived by taking the positive swing of the sine wave and taking the peak voltage of the sine way and multiplying it times .707 and you have and RMS voltage.
For people in the US we have 120v RMS sine wave power. The voltage swings from 0 volts up 170V positive peak back to 0 and down to 170V negative peak. So we take the positive peak of 170V X .707=120.19V
There is an article that tries to discredit RMS by using a Square wave with a 5 second cycle. Remember RMS=pure sine wave!

I think you didn't understand the article. It doesn't "discredit" RMS, it simply says that the RMS power, even if it could be calculated is meaningless and does not represent any useful value.
The "heating" or "working" or "usable" power created by computing the RMS voltage into a load is the "Average power", not the RMS power.

RMS power or Watts RMS is a useless measure, using "RMS power" instead of the correct "Average power" to rate amplifiers and speakers is a misnomer.

My last link didn't work, here is the right one http://www.eznec.com/Amateur/RMS_Power.pdf

[Eaulive]

Remember RMS=pure sine wave!

Yes and no.
You should say "the RMS value of a pure sine wave is always 0.707", but any waveform has an RMS value, depending on the waveform the RMS value will vary from 0 to 1

For a perfect square wave, the RMS value is 1. In the example we're talking about the square wave is not AC, it's simply a circuit DC and an on/off switch, it's an example to illustrate the average power.

RMS is a mathematical function, like average, that reduces a complex function to
a single value. And, like average, it has a precise definition. The definition is
revealed by the name – it’s the square Root of the Mean of the Square of the
function.