compression driver peak music power testing

[Sanon]

Hi ,

I need to test my compression driver (100W RMS ) for peak music power handeling capablities. I need to check if it could support 10-20db crest factor mucic waveforms without failure or not. I need help on how to , or from where I could get a test signal wave files for this .

Thanks in Advance.

[whgeiger]

Originally Posted by Sanon

Hi ,

I need to test my compression driver (100W RMS ) for peak music power handeling capablities. I need to check if it could support 10-20db crest factor mucic waveforms without failure or not. I need help on how to , or from where I could get a test signal wave files for this .

Thanks in Advance.

Do not test compression drivers in this manner. Doing so would most likely destroy the driver. Read and calculate driver performance from the information provided here.

Due to the close proximity of a phase plug, diaphragm excursion is the principal limiting factor in compression driver output at lower frequencies. For a constant power output, diaphragm excursion quadruples when signal frequency is halved. Horn loading, and high pass filtering of the input signal are also important determinates of driver peak output capacity.

Frank Massa of RCA, published in the mid 1930s, the following formula from which a chart of power output at various excursions and different frequencies can be built:

Given:

Sd - diaphragm area in square inches
St - throat (phase plug aperture) area in square inches
Sd/St - driver compression ratio (typical value = 10)
f - frequency in Hz.
d - peak diaphragm amplitude in inches

P - power output in acoustical watts

= 0.0034 * (f^2) * (d^2) * (Sd^2) / St

Notice:

For this information to be valid, the compression driver must be attached to a horn that provides adequate low frequency loading to the lowest frequency of interest. Note that the small trapped air volume behind the diaphragm also limits low frequency output as well. Typical power conversion efficiencies range between 25-30%

See the following JBL Technical Note for additional information.

Regards,

WHG

Characteristics of High Frequency Compression Drivers
http://www.jblpro.com/catalog/suppor...=295&doctype=3