How important is impulse response? - AVS Forum
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post #1 of 7 Old 06-23-2013, 11:52 AM - Thread Starter
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Looking at the impulse response measurements on data-bass, there's quite a variety of results among the different sub models.

How important is this and how does impulse response manifest itself in what we hear?

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post #2 of 7 Old 06-24-2013, 04:58 AM
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Originally Posted by Saturn94 View Post

Looking at the impulse response measurements on data-bass, there's quite a variety of results among the different sub models.

How important is this and how does impulse response manifest itself in what we hear?

Impulse response in this context is just another way of saying frequency response.

Frequency response is one of the most important properties of reproduced sound.

Of course I am speaking of reproduced sound in the perceptible frequency range. Sound is perceptible (either heard or felt) down into almost impossibly low frequency ranges. It is not very perceptible at all above about 16 KHz.
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post #3 of 7 Old 06-25-2013, 06:43 AM - Thread Starter
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On the Data Bass site their measurements include a graph for "impulse response". For example, here's the graph for an SVS sub;



I thought maybe what it's showing is how quickly the driver settles down when the signal stops, but I don't know. It seems if they are taking these measurements and posting them they must be important to sub performance.

So I'm trying to get a handle on what this measurement is showing us and what it means in terms of what we hear.

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post #4 of 7 Old 06-25-2013, 07:30 AM
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Quote:
Originally Posted by Saturn94 View Post

On the Data Bass site their measurements include a graph for "impulse response"...
I thought maybe what it's showing is how quickly the driver settles down when the signal stops.
Correct.
Quote:
It seems if they are taking these measurements and posting them they must be important to sub performance.
Not terribly so. What the impulse mainly shows is how quickly inertia is overcome and the cone returns to rest after a single cycle pulse is applied. We don't listen to single cycle impulses, we listen to a continuous stream of impulses, and the inertial force is totally dwarfed by the electro-magnetic force provided by the motor. If the impulse response was really bad you'd hear it, but the frequency response would also point out the speaker deficiencies, and it would do so far more obviously. The main use of impulse response is to help identify what might be causing a really poor frequency response.

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post #5 of 7 Old 06-25-2013, 07:37 AM
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Quote:
Originally Posted by Saturn94 View Post

On the Data Bass site their measurements include a graph for "impulse response". For example, here's the graph for an SVS sub;



I thought maybe what it's showing is how quickly the driver settles down when the signal stops, but I don't know. It seems if they are taking these measurements and posting them they must be important to sub performance.

So I'm trying to get a handle on what this measurement is showing us and what it means in terms of what we hear.

One rule of thumb is that an impulse response that settles down right quick represents more extended frequency response, so you're right.

Ideal impulse response is a nearly zero width impulse. Ideal band limited response is still very narrow, but looks more like a highly damped sine wave.

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post #6 of 7 Old 06-25-2013, 12:13 PM - Thread Starter
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Quote:
Originally Posted by Bill Fitzmaurice View Post

Correct.
Not terribly so. What the impulse mainly shows is how quickly inertia is overcome and the cone returns to rest after a single cycle pulse is applied. We don't listen to single cycle impulses, we listen to a continuous stream of impulses, and the inertial force is totally dwarfed by the electro-magnetic force provided by the motor. If the impulse response was really bad you'd hear it, but the frequency response would also point out the speaker deficiencies, and it would do so far more obviously. The main use of impulse response is to help identify what might be causing a really poor frequency response.

So impulse performance bad enough to be audible will show up as an issue in frequency response? What would I look for in the frequency response to determine if there is an issue? Is there a particular part of the fequency band that would be affected?

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post #7 of 7 Old 06-25-2013, 01:42 PM
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Would the impulse response give any indication of transient response?

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