I'm curious to get peoples views and opinions on how you should measure a speaker - specifically spl.
I accept that the standard distance is at 1m ..and that a lot of people aim for a flat response, but the reason I raise this issue is that I doubt that many people listen at 1m (bar those using nearfield monitors) and since the response curve will change (quit a bit in some cases) as the distance from the speakers increases, would it not make sense to be measuring at the listening position?
I guess that would give rise to determining a different standard measurement distance, which may be impossible due to the range but then why is it generally done at 1m?
I accept that the standard distance is at 1m ..and that a lot of people aim for a flat response, but the reason I raise this issue is that I doubt that many people listen at 1m (bar those using nearfield monitors) and since the response curve will change (quit a bit in some cases) as the distance from the speakers increases, would it not make sense to be measuring at the listening position?
I guess that would give rise to determining a different standard measurement distance, which may be impossible due to the range but then why is it generally done at 1m?
Hi Jeff. I was really asking if its best to measure and aim for the required response at the listening position rather than at 1m.
Mark
Mark
Not in a room, you will just measure the room reverberation. Farther only in an anechoic chamber, or outdoors.
Member
Joined 2003
You can measure SPL at any distance, and still reference to 1m for standard comparisons. SPL over distance is easily calculated for the most part.
http://www.sengpielaudio.com/calculator-distance.htm
http://www.sengpielaudio.com/calculator-distance.htm
The best way to measure frequency response is at listening distance (7 - 10 ft) with 2.83 V signal, but it must be scaled to 1 m response, for comparing purposes. SPL at 2.83V/1m is standard. It is difficult to make anechoic measurements (with windowing) over 7 ft distance because it will be impossible to get decent low-frequency resolution.
It is not a problem to measure SPL at 1 m, it will be about 6 dB higher than at 2 m, but the frequency response will not be the same (driver integration will suffer).
It is not a problem to measure SPL at 1 m, it will be about 6 dB higher than at 2 m, but the frequency response will not be the same (driver integration will suffer).
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Neither. It is best to measure at the listening distance in an anechoic chamber. Second best is to measure at 1-2m.
(edit: sorry, this was already said)
(edit: sorry, this was already said)
Anechoic chamber is not necessary - ARTA and CLIO can do anechoic measurements above 200-300 Hz in a room, and for frequency response below 200 Hz you need to go outside (ground plane method).
For comparison to others, some kind of standard must be used, or we end up comparing apples to oranges (or worse)
So "best" is 1W - 1 meter - anechoic conditions
Second best is simulating "anechoic" by some clever trickery, such as gating.
Anything further, unless you have a huge anechoic chamber, (only a dream for a Home user), or measure outside and even so .... : no significant ambient noise, elevating speaker quite a lot away from ground or the old 50´s 60´s trick: place the speaker in the ground, facing up, and suspend the microphone a few meters away, in which case you are measuring in 2 Pi space (halfspace).
Reflections and phase cancellation are the Nemesis of speaker measurements.
For own use, and for comparison between different systems in the same place, meaning your favourite listening position at home, of course you can use any standard software and setup, and for you it´s the best, at least the most realistic, just you´ll have to take measurements with a pinch of salt and not argue (much) with fellow Forum Members he he.
EDIT: a good page: https://audiojudgement.com/measure-speaker-frequency-response/
Use that to adjust speaker design?
Guess you will modify speaker for problems not its fault, I´dn use that curve to correct for room problems, if at all possible.
In a room, not that much.
So "best" is 1W - 1 meter - anechoic conditions
Second best is simulating "anechoic" by some clever trickery, such as gating.
Anything further, unless you have a huge anechoic chamber, (only a dream for a Home user), or measure outside and even so .... : no significant ambient noise, elevating speaker quite a lot away from ground or the old 50´s 60´s trick: place the speaker in the ground, facing up, and suspend the microphone a few meters away, in which case you are measuring in 2 Pi space (halfspace).
Reflections and phase cancellation are the Nemesis of speaker measurements.
For own use, and for comparison between different systems in the same place, meaning your favourite listening position at home, of course you can use any standard software and setup, and for you it´s the best, at least the most realistic, just you´ll have to take measurements with a pinch of salt and not argue (much) with fellow Forum Members he he.
EDIT: a good page: https://audiojudgement.com/measure-speaker-frequency-response/
Measure? yes,of course.
Use that to adjust speaker design?
Guess you will modify speaker for problems not its fault, I´dn use that curve to correct for room problems, if at all possible.
True, in anechoic chamber or open space.
In a room, not that much.
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