Are burst tones being used in audio measurements and if so, would it be possible to provide some examples?
By audio measurements I mean anything that is related to audio equipment (i.e audio circuits, linear or switching power supplies, etc...)
Thank you!
By audio measurements I mean anything that is related to audio equipment (i.e audio circuits, linear or switching power supplies, etc...)
Thank you!
Sure. I remember this guy Joe D'Appolito used them to test speakers.
Playing with a programmable AC source at work, I found that an ordinary driver from a plastic PC speaker could survive a couple cycles at full AC line voltage; 1500 watts or so. I'd bet a real speaker could go on to survive further - as long as the time between bursts was generous.
We used to test switching power supplies with DC transient loads all the time. I tried an AC sweep, but it failed to pinpoint where the worst case frequency response of some more rectangular shaped transient would be. (That was an attempt to make the test process more efficient...)
Playing with a programmable AC source at work, I found that an ordinary driver from a plastic PC speaker could survive a couple cycles at full AC line voltage; 1500 watts or so. I'd bet a real speaker could go on to survive further - as long as the time between bursts was generous.
We used to test switching power supplies with DC transient loads all the time. I tried an AC sweep, but it failed to pinpoint where the worst case frequency response of some more rectangular shaped transient would be. (That was an attempt to make the test process more efficient...)
Tone burst tests were commonly used for speakers in the 60s and 70s. Rather disturbing results,
since the first cycle or two were barely there. But you got a cycle or two for free at the end of the
tone burst. Seldom used for electronics though.
https://community.classicspeakerpages.net/topic/5826-ar-3a-test/
since the first cycle or two were barely there. But you got a cycle or two for free at the end of the
tone burst. Seldom used for electronics though.
https://community.classicspeakerpages.net/topic/5826-ar-3a-test/
I've build the Linkwitz cosine burst generator and am using it for measuring speaker behaviour in normal rooms.
Allthough there may be more precise methods today (the original Linkwitz schematics dates back to 1980) it is quite useful.
On my first usage I managed to pinpoint an issue with a midrange speaker that sounded "not as expected" (the reason being a stupid box design of my own 🙂
The theory behind is that to avoid room reflections to disturb a measurement with a microphone you need to use a short tone burst (to seperate the direct and the reflected sound in time).
However using a simple on/off (ususally called a rectangular window) tone burst will smear the spectrum over a wide range - by using a Hamming (or was it Hann? - can't remember) window for the tone burst the spectrum is a lot more narrow.
Cheers, Martin
Allthough there may be more precise methods today (the original Linkwitz schematics dates back to 1980) it is quite useful.
On my first usage I managed to pinpoint an issue with a midrange speaker that sounded "not as expected" (the reason being a stupid box design of my own 🙂
The theory behind is that to avoid room reflections to disturb a measurement with a microphone you need to use a short tone burst (to seperate the direct and the reflected sound in time).
However using a simple on/off (ususally called a rectangular window) tone burst will smear the spectrum over a wide range - by using a Hamming (or was it Hann? - can't remember) window for the tone burst the spectrum is a lot more narrow.
Cheers, Martin