# Loudspeaker Response

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DescriptionThe `Loudspeaker Response`

block evaluates the performance of a loudspeaker based on chirp measurements. The block calculates
the loudspeaker basic loudspeaker performance responses including: impulse reponse, frequency response, phase response, group delay response,
and THD response. You have the option of smoothing if desired.

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Input`Reference`

Reference is the reference chirp inputted to the loudspeaker. The recommended reference signal is a loopback
of the outputted voltage. You can input `N`

inputs with `M`

length at once.

`Signal`

signal is the measured chirp signal. You can input `N`

inputs with `M`

length at once for example if
you have repeated measurements.

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Output`Impulse Response`

is the windowed impulse response with `K`

samples according to the property `Time to nearest reflection`

.

`Frequency Response`

is the magnitude response of the windowed impulse response with desired number of `FFT bins`

and `Octave smoothing`

.

`Phase Response`

is the phase response of the windowed impulse response.

`Group delay`

is the group delay response of the windowed impulse response.

`THD`

is the Total Harmonic Distortion response of the windowed impulse response, based on `THD order`

number of harmonics.

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AttributesAttribute | Value |
---|---|

Name | LoudspeakerImpulse |

Time to nearest reflection | โ 10 ms |

FFT Bins | โ 16384 |

Octave Smoothing | 1/12 |

THD Order | โ 10 |

Chirp Time | โ 4.5 s |

Chirp Start Frequency | โ 20 Hz |

Chirp End Frequency | โ 20,000 Hz |

Inputs | 2 |

*Values with* โ *can receive external input.*

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NameName specifies the name of the block.

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Time to nearest reflectionTime to nearest reflection specifies the time delay between the direct impulse and the first reflection. If the time is higher than the delay of the first reflection then it will affect the evaluation of the loudspeaker performance.

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FFT BinsFFT Bins is the desired resolution of the frequency responses. The number of FFT Bins must be higher than the number of samples `K`

in the Impulse Response.

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Octave SmoothingOctave Smoothing is how much you want the frequency reponses smoothed. You can choose from 1/1 band octave smoothing to 1/48 band octave smoothing, or no smoothing at all.

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THD OrderTHD Order is the number of harmonics you want to calculate for the THD response. Default is up to the 10th order.

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Chirp TimeChirp time is the overall time of the reference chirp.

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Chirp Start FrequencyChirp start frequency specifies the start frequency of the reference chirp.

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Chirp End FrequencyChirp end frequency specifies the end frequency of the reference chirp.

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InputsInputs specifies the number of inputs the block requires. This cannot be changed.