Has anybody actually characterized the X5 for
use as an audio spectrum analyzer???
I tried HASA and Handee analyzer demos.
They both seem to work, but they have such a
short time limit that I can't even get all the
setup done before the thing times out.
No chance to setup for a real measurement to
characterize the X5 microphone and audio system.
Anybody got a frequency response graph of the
Axim audio system?
Is there a freeware analyzer program for PPC2002?
Thanks, mike
I don't know of any freeware, but Pocket RTA ($29.95 @ PocketGear.com) has a free Demo version with no expiration date limit which runs for 60 seconds.
That should be long enough for you to analyze what you're after, so long as you have everything ready to roll when you start Pocket RTA.
I've actually used Pocket RTA extensively to do stuff similar to what you're after. However, using a low impedance audio source instead of the X5 microphone (the line out or headphone output of a stereo or PC sound card), the X5 has a flat frequency response over the entire audio band (I've measured it myself). Without a calibrated and high quality speaker, it's next to impossible to obtain an accurate frequency response for the X5 audio recording system when using the X5's built-in microphone.
Check out my "View MyPDA" to see what I've done with my X5 Advanced for audio recordings using external audio sources other than the built-in X5 microphone!
I don't know of any freeware, but Pocket RTA ($29.95 @ PocketGear.com) has a free Demo version with no expiration date limit which runs for 60 seconds.
That should be long enough for you to analyze what you're after, so long as you have everything ready to roll when you start Pocket RTA.
I've actually used Pocket RTA extensively to do stuff similar to what you're after. However, using a low impedance audio source instead of the X5 microphone (the line out or headphone output of a stereo or PC sound card), the X5 has a flat frequency response over the entire audio band (I've measured it myself). Without a calibrated and high quality speaker, it's next to impossible to obtain an accurate frequency response for the X5 audio recording system when using the X5's built-in microphone.
Check out my "View MyPDA" to see what I've done with my X5 Advanced for audio recordings using external audio sources other than the built-in X5 microphone!
Good luck! :approve:
quovadis7
Thanks for the input. Wonder if one could get a rough idea of the microphone frequency response by plotting the microphone response
vs the response from a "good" external microphone?
I have a half-decent sould level meter.
I might have to lug the thing outside and do
some open field comparisons...unless someone
has already done that.
It would just be handy to be able
to do an impromptu frequency response test without having to plan ahead and lug around a bunch of extra stuff.
The hardware mod looks intersting, but would
seriously limit my abiltiy to plug in the
CF network card.
Couple of comments on your desire for higher frequency response from the X5 and a spectrum analyzer running on it:
1) the microphone itself is almost certainly limited to less than 20 KHz (it is merely an audio device after all), so you won't pick up any ultrasonic "audio" above that anyway (unless it is REALLY high intensity), and
2) the maximum sampling rate of the X5's internal Analog to Digital converter is 44 KHz, so with the maximum usable signal having to be 1/2 of that or less (Nyquist criteria from information theory) you can't possibly use the X5 for anything above 22 KHz anyway.
As far as my X5 mod and using the CF slot goes, just read the details of my modification documentation. I can use my CF memory cards and all of my CF accessories (WiFi, Bluetooth, etc.) even with the modification. I can even make a recording with an external microphone while I'm connected via a WiFi CF card!
In a nutshell, there is a 1.5mm gap on the top part of the CF slot that the CF cards don't use (look for that gap when you have a card inserted) and all of my connectors and wires reside in that gap area - thus, they don't impede any of the CF accessories I own. The only thing my mod does impede is the red plastic CF cover that you can use to protect the CF slot when it is not being used, but then I have never used that thing with my X5 anyway....
Let me know if you want/need to discuss my X5 mod further.
You do make a very good point that you could use a "good" quality microphone for calibration of the X5.
However, you'd also need to have the specs for that "good" microphone to be able to determine a precise response for the X5 and its built-in microphone.
With my X5 mod, you could actually USE the "good" microphone itself for recordings and measurements on the X5! Cool, eh? :approve: That's really the whole point of my X5 modification anyway....
Best of luck in your audio experiments and/or projects.
Couple of comments on your desire for higher frequency response from the X5 and a spectrum analyzer running on it:
1) the microphone itself is almost certainly limited to less than 20 KHz (it is merely an audio device after all), so you won't pick up any ultrasonic "audio" above that anyway (unless it is REALLY high intensity), and
2) the maximum sampling rate of the X5's internal Analog to Digital converter is 44 KHz, so with the maximum usable signal having to be 1/2 of that or less (Nyquist criteria from information theory) you can't possibly use the X5 for anything above 22 KHz anyway.
As far as my X5 mod and using the CF slot goes, just read the details of my modification documentation. I can use my CF memory cards and all of my CF accessories (WiFi, Bluetooth, etc.) even with the modification. I can even make a recording with an external microphone while I'm connected via a WiFi CF card!
In a nutshell, there is a 1.5mm gap on the top part of the CF slot that the CF cards don't use (look for that gap when you have a card inserted) and all of my connectors and wires reside in that gap area - thus, they don't impede any of the CF accessories I own. The only thing my mod does impede is the red plastic CF cover that you can use to protect the CF slot when it is not being used, but then I have never used that thing with my X5 anyway....
Let me know if you want/need to discuss my X5 mod further.
Good luck! :approve:
Steve B
quovadis7
The free spectrum analyzer only goes up to 5KHz. And there's no log frequency scale, so
it's not very useful at low frequencies.
no vertical calibration, but it looks like
linear.
The pay versions have all this. I just don't
want it badly enough to pay;-) If you know
of a better free one, I'm all ears...
15KHz with log scales would be much more useful.
Interesting thought about ultrasonic. I have
an ultrasonic leak detector that's a frequency
translator. I'll have to plug that in to my
laptop and see what interesting things I can learn.
As for your mod, by golly, you're right.
Never noticed that gap 'cause my wifi card overlaps it.
But I hate to modify the machine. I'll just
use my laptop and sound level meter as microphone.
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