Hornresp

[David McBean]

Originally Posted by bubblersound

How about a window that shows the combined acoustical and electrical Impedance?

Hi bubblersound,

Not sure that I understand :-).

The acoustical impedance is automatically taken into account when calculating the electrical impedance.

To illustrate, the attached screenprints show the electrical impedance for the Hornresp default system radiating into (1) eighth space and (2) free space. As you can see, the electrical impedances for the two situations are quite different, due to the changed acoustical impedance loading conditions.

Kind regards,

David

[David_Web]

"The Multiple Speakers tool was originally restricted to single-segment horns - this constraint was relaxed in Version 23.50. The constraint has now been reimposed to avoid the generation of misleading results when large arrays are specified."

Could you explain what was wrong with it?
And how it would effect tapped horns.

[bubblersound]

Originally Posted by David McBean

The acoustical impedance is automatically taken into account when calculating the electrical impedance.

So you're saying the electrical impedance window is simulation of a measured impedance response?

[David McBean]

Originally Posted by David_Web

Could you explain what was wrong with it?
And how it would effect tapped horns.

Hi David_Web,

Unfortunately the low frequency response of a multiple speaker array made up of multiple-segment horns is understated. See the attached extreme example - the first screenprint shows the result for a large array made up of single segment exponential horns, the second screenprint shows the result for the same array and horns, with each horn now made up of two equal-length exponential segments.

The low-frequency response error progressively reduces as the number of speakers in the array becomes less. The error for an array of several tapped horns would be very small indeed, but I am not prepared to compromise the overall integrity of the Multiple Speakers tool.

Assuming Rg = 0, for all practical purposes two tapped horns connected in parallel radiating into 2 pi space will have the same SPL response as one tapped horn radiating into 1 pi space.

Assuming Rg = 0 in all cases, the following speaker array configurations will all have effectively the same response.

1S x 1P Eg = 1 Ang = 0.5 x Pi
1S x 2P Eg = 1 Ang = 1.0 x Pi
1S x 4P Eg = 1 Ang = 2.0 x Pi
1S x 8P Eg = 1 Ang = 4.0 x Pi
2S x 1P Eg = 2 Ang = 1.0 x Pi
2S x 2P Eg = 2 Ang = 2.0 x Pi
2S x 4P Eg = 2 Ang = 4.0 x Pi
4S x 1P Eg = 4 Ang = 2.0 x Pi
4S x 2P Eg = 4 Ang = 4.0 x Pi
8S x 1P Eg = 8 Ang = 4.0 x Pi

Kind regards,

David

[David McBean]

Originally Posted by bubblersound

So you're saying the electrical impedance window is simulation of a measured impedance response?

Hi bubblersound,

Yes.

Note that the amplitudes of measured resonance peaks may be a little less than the predicted values due to damping effects not taken into account by the simulation model. The frequency positions of the resonances should be reasonably accurate, though. I have seen a number of electrical impedance simulations provided by Hornresp users that have come remarkably close to actual measured values.

Kind regards,

David

[David McBean]

Originally Posted by David McBean

The frequency positions of the resonances should be reasonably accurate, though.

Hi bubblersound,

I found an old predicted versus measured electrical impedance comparison provided by a Hornresp user back in 2005. The value of Le chosen for the simulation appears to be a little low - apart from that, the comparison doesn't look too bad.

At least the resonance peaks are in the right places :-).

Kind regards,

David

[bubblersound]

Here's another comparison and it's deadly accurate.
Just want to say thanks for Horn Response, it's a great simulation software.

[David McBean]

Originally Posted by bubblersound

Here's another comparison and it's deadly accurate.
Just want to say thanks for Horn Response, it's a great simulation software.

Hi bubblersound,

Thanks for posting the comparison, and thanks for the thanks :-).

Kind regards,

David

[Telstar]

Originally Posted by David McBean

Hi Telstar,

To enter Con = 8.7 in the L34 input box, press the 'C' key to select Con and then immediately enter the number 8.7. Note that Con reverts to L34 if the length is zero.

Thank you very much, that did it.

[David McBean]

Originally Posted by Telstar

Thank you very much, that did it.

Excellent :-).