I'm using a Behringer ECM8000 and its response falls off above about 12K. Its been OK up to now but I really need to get it calibrated or buy a calibrated mic.
Sorry to hijack the thread
FE207E on Open Baffle
#61
Clive, can I ask where you got the calibrated mic from?
I'm using a Behringer ECM8000 and its response falls off above about 12K. Its been OK up to now but I really need to get it calibrated or buy a calibrated mic.
Sorry to hijack the thread
I'm using a Behringer ECM8000 and its response falls off above about 12K. Its been OK up to now but I really need to get it calibrated or buy a calibrated mic.
Sorry to hijack the thread
#62
Hi Max,
The mic I use comes with integrated soundcard and s/w:
http://www.xtz.se/produkt.php?allmant=t ... 1&eng=true
but don't assume your mic is duff. It turns out the most speakers measure flat at 1m with the mic pointed at the tweeter. Move the mic to the listening position and you get what you describe.
The mic I use comes with integrated soundcard and s/w:
http://www.xtz.se/produkt.php?allmant=t ... 1&eng=true
but don't assume your mic is duff. It turns out the most speakers measure flat at 1m with the mic pointed at the tweeter. Move the mic to the listening position and you get what you describe.
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andrew Ivimey
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#63
Hm, I know we are old chestnut territory here but to be accurate to 12kHz is not bad at all.
That's way above (the fundamental) of a violin top note and consider that the next octave is around 22kHz and an octave above that is yer good old 44.1kHz or so.
What happens abov ethis can 'spiral down' and affect what we consciously hear but getting a calibrated sound pressure level meter that can so say 100Hz to 12kHz is quite easy. Above and below this is specialized territory.
That's way above (the fundamental) of a violin top note and consider that the next octave is around 22kHz and an octave above that is yer good old 44.1kHz or so.
What happens abov ethis can 'spiral down' and affect what we consciously hear but getting a calibrated sound pressure level meter that can so say 100Hz to 12kHz is quite easy. Above and below this is specialized territory.
#64
and below 100Hz you really need to measure at least in 3 places around the room and average out the readings. Behringer even say that their measurements below 100Hz are inaccurate with the DEQ2496 and the 8000 mic, probably because they only use the mic single position. Room modes with long decay times need to be taken into account.
Above 12K? I'm not too sure how much higher I can hear anymore!
Above 12K? I'm not too sure how much higher I can hear anymore!
#65
Hi Clive/Andrew
I'm certain the mic is duff, or at least requires a calibration file above 12K. All the speakers I have measured with it (my own DIY efforts and commercial speakers) show the same roll-off.
Maybe it is all a bit academic above 12K, maybe not. I know I'm finding it a problem when I'm working in LspCAD or Speaker Workshop, designing crossovers. I'm using first order networks, and even though the crossover frequency is a long way below 12kHz, playing with the component values is still having an effect at higher frequencies. Because the mic is so far out, I don't know what slope I'm ending up with, and its disconcerting. It would make the process easier, and give me more confidence, if i knew what I was doing to the high frequency response.
Maybe I wouldn't be able to hear the difference anyway at my age, but who knows, maybe my 23 year old stepson or my 5 year old son will?
I'm certain the mic is duff, or at least requires a calibration file above 12K. All the speakers I have measured with it (my own DIY efforts and commercial speakers) show the same roll-off.
Maybe it is all a bit academic above 12K, maybe not. I know I'm finding it a problem when I'm working in LspCAD or Speaker Workshop, designing crossovers. I'm using first order networks, and even though the crossover frequency is a long way below 12kHz, playing with the component values is still having an effect at higher frequencies. Because the mic is so far out, I don't know what slope I'm ending up with, and its disconcerting. It would make the process easier, and give me more confidence, if i knew what I was doing to the high frequency response.
Maybe I wouldn't be able to hear the difference anyway at my age, but who knows, maybe my 23 year old stepson or my 5 year old son will?
#66
Hi Max,
I must admit that I've not managed to get the mic I'm using to measure totally flat at high frequencies. Moving it closer to speakers improves things. As it's intended as a room setup mic I'm not too concerned, for designing crossovers I full appreciate your needs are more stringent.
Hopefully you find a solution....
Cheers,
Clive
I must admit that I've not managed to get the mic I'm using to measure totally flat at high frequencies. Moving it closer to speakers improves things. As it's intended as a room setup mic I'm not too concerned, for designing crossovers I full appreciate your needs are more stringent.
Hopefully you find a solution....
Cheers,
Clive