Audio Asylum Thread Printer
Get a view of an entire thread on one page
|For Sale Ads|
In Reply to: RE: 105db/meter NON horn loaded speakers posted by used-hifi on April 21, 2017 at 18:37:54
For a source with no directivity, the 106dB 1w 1m sensitivity would imply about a 25% efficiency which is quite high.
An array of sources where the radiators are all less than ¼ wavelength from each other does benefit from mutual coupling however the limit is somewhere around 25%.
I don't know of a way to do this with direct radiators above low frequencies, above that arrays of driver are individual sources and while one can form a beam, the energy time envelope also shows individual arrivals in time a "time distortion" of the input impulse.
Even with a horn this is not an easy task
The Fostex FW305 is 1.4% efficient and 12" diameter, and could give 30Hz with a ported box, if you use an SET with a damping factor of 2-3.
To get 20% efficiency would need 14 of them. With close packing, you might make an array as small as 4 feet diameter, which is 1/4 wave at 70Hz - a reasonable maximum for the crossover. A hair more than an octave bandwidth. The box would be somewhere around 100-200 cubic feet.
A similar array of 6" 96dB drivers (there are some) could cover 70Hz to 160Hz.
I don't know any direct radiators with 96dB sensitivity and 3"diameter, so I think you would be in trouble without horns.
Yes this is a tough challenge and why i said "I don't know of a way to do this with direct radiators above low frequencies, above that arrays of driver are individual sources and while one can form a beam, the energy time envelope also shows individual arrivals in time a "time distortion" of the input impulse."
The problem is seen most clearly at the other end where say at 10Khz, even a great compression driver on a horn has very low efficiency and 105dB 1w 1m only achieved by a very narrow pattern up high.
If I'm reading this spec sheet right, it is > 105dB from 9-30kHz.
That seems so high that I suspect I'm misinterpreting something.
I see "recommended frequency range is 3kHz to 50kHz with an sensitivity of 96dB. " Or do you mean from their weird response curve?
And it's weird how they say it's a dead short to the amp (which is why some ribbons have transformers, or used to)
Post a Message!
This post is made possible by the generous support of people like you and our sponsors: