awpagan said:
The first one on the page you linked to.... SPL Vs Freq.. I took 100db as my reference for +- Unless Im reading it wrong if you take the 100db line as reference, the lines above and below it are 102.5db and 97.5db and between 2Khz and 20Khz it isn't getting to either
along the back if you take it as a line is SPL vs Freq, out to the front (Z axis) is time. Basically it is showing how long it takes (at each frequency) for the sound to decay... ie the more quickly it drops off the better, at the left end the sound is taking a lot longer to decay due to the ribbon resonating. If the decay time is long it means the driver is continuing to make noise long after the signal has stopped this is not what we want.
If you are on axis it means that you are directly in front of (ie at 90 degrees to) the baffle of the speaker, and the device is at ear height... if you move to say a 30 degree angle to the baffle then you are 30 degrees off axis (this could be either horizontally or vertically, but normally these measurements are taken off axis horisontally. basically because most drivers start to become more directional at certain freqencies, at 30 deg or more off axis the SPL of higher frequencies will be lower than if you are directly on axis.
for an example see the plot below..... blue line would be the on axis the green?? (I'm colour blind) was taken at 30 deg off axis, and the red?? was taken at 60deg off axis... as you can see the resonse changes depending on the angle.
An externally hosted image should be here but it was not working when we last tested it.
if you are not sitting directly in line with the speaker then the off axis measurements become more important. eg in a typical Home theater environment you will have multiple people and not all can be directly on axis..... if it is a single person listening to music, then it becomes less (maybe) important, because that single person can sit in the "sweet spot".
Those measurements weren't done by fountek they were done by Stones sound studio, who are linked (not sure in what way) to WES Components, who are sellintg the drivers...... as to whether they are hiding something, maybe maybe not
Tony.
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