Hi there,
I’m really confused about this.
I’ve attached a photo of a Hornresp power window. This is a simple sealed box using a woofer
According to the manufacturers specification, the driver responds approximately how I’ve marked over the photo.
Yet what Hornresp displays is as if a low pass filter is a applied. I’ve checked filter wizard and nothing is engaged.
what am I missing??
Thanks.
I’m really confused about this.
I’ve attached a photo of a Hornresp power window. This is a simple sealed box using a woofer
According to the manufacturers specification, the driver responds approximately how I’ve marked over the photo.
Yet what Hornresp displays is as if a low pass filter is a applied. I’ve checked filter wizard and nothing is engaged.
what am I missing??
Thanks.
T/s theory peters out at the driver's upper mass corner and HR rolls off its HF based on its mass, inductance, so to see its HF above this point, then in 'acoustic power' need to go to tools/directivity/response/'0' for on axis or input degree angle offset.
Make inductance/Le = 0 and it should be flat all the way up like simple programs do.
[Qes'/Qts']: [Qes/Qts] + any added series resistance [Rs]: http://www.mh-audio.nl/Calculators/newqts.html
Make inductance/Le = 0 and it should be flat all the way up like simple programs do.
[Qes'/Qts']: [Qes/Qts] + any added series resistance [Rs]: http://www.mh-audio.nl/Calculators/newqts.html
The Hornresp "Acoustical Power" is the average of the sound radiated 360 degrees from a flat, rigid piston.
The response Peterjohnswindly marked in yellow in post #2 would be the on-axis response, including cone breakup and "beaming".
The larger the piston (Sd, cone area), the more difference will be seen between on-axis response and the "Acoustical Power" response.
In the example below of an 18" (460mm) driver on axis response peaks in the 1500 Hz range, at 45 degrees drops off from 500Hz. At 1200 Hz, the 45 degree off axis response is around -10dB.
If the measurement was continued to 180 degrees off axis, the HF would be much further down.
Since the on axis response peak beamwidth is narrow, it amounts to only a small portion of the radiated power, the acoustical power response average would be much lower in the high frequency range.
Art
The response Peterjohnswindly marked in yellow in post #2 would be the on-axis response, including cone breakup and "beaming".
The larger the piston (Sd, cone area), the more difference will be seen between on-axis response and the "Acoustical Power" response.
In the example below of an 18" (460mm) driver on axis response peaks in the 1500 Hz range, at 45 degrees drops off from 500Hz. At 1200 Hz, the 45 degree off axis response is around -10dB.
If the measurement was continued to 180 degrees off axis, the HF would be much further down.
Since the on axis response peak beamwidth is narrow, it amounts to only a small portion of the radiated power, the acoustical power response average would be much lower in the high frequency range.
Art
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Excellent!
I’ll digest this tomorrow.
I thought it was something to do with the greater relevance of TS parameters in the the bass, but these contributions will help me understand in better detail.
thanks!
I’ll digest this tomorrow.
I thought it was something to do with the greater relevance of TS parameters in the the bass, but these contributions will help me understand in better detail.
thanks!
Hornresp is showing "power" and your hand drawn graph is the speaker axial "pressure" (SPL).
To switch from "power" to "pressure" hit [CTRL][X} and set the directivity response to axial (0 deg). The response is idealized for a piston so you will not get secondary effects like the cone breakup or motor shorting rings.
[edit] The program's author (David McBean) has a dedicated thread in this sub forum Subwoofers
To switch from "power" to "pressure" hit [CTRL][X} and set the directivity response to axial (0 deg). The response is idealized for a piston so you will not get secondary effects like the cone breakup or motor shorting rings.
[edit] The program's author (David McBean) has a dedicated thread in this sub forum Subwoofers
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