Recorded sweeps using both of the Tascam US-122L and the Sound Devices
USBPre audio interfaces today. The Earthworks M30 mic remained in
exactly the same spot. The Octave plots MRFDWSmoothed.jpg and
PRFDWSmoothed-1-6.jpg are shown below.
Chinanico;231329 Wrote:
I might try that. Actually I was thinking, as more and more people get
their ECM8000 calibrated, but others don't... (or can't, for me in
Shanghai I wouldn't know where to go), would it be possible to build so
kind of database of the calibration files and compare
Here is muski's calibrations file (vertical axis in dB, horizontal is
log base 10 of frequency). The second plot is smoothed by averaging
over each consecutive set of 10 values.
It looks very roughly like the plot Behringer gives here, in the
specs:
Then the ECM8k correction file isn't good.
For example it has 10.5dB attenuation in the 10khz area while your new
graphs show that 6 is enough.
Maybe it would be better if you use strong correction, maybe there was
some approximation by the normalization.
If you find the time please try this
nuhi;231129 Wrote:
If you find the time please try this (attached), I made it by looking at
the difference in your graphs between the m30 and ecm.
I might try that. Actually I was thinking, as more and more people get
their ECM8000 calibrated, but others don't... (or can't, for me in
Shanghai
muski;230687 Wrote:
It's interesting to see that the ECM8000 does mostly OK in the lower
freq, but not so well above 1KHz.
muski
Very interesting! Thanks for sharing. Not a good news for ECM8000 users
like me (and like most here I guess). I assume that the response in the
treble would be
I took measurements today with both of the mics, using a Sound Devices
USBPre audio interface. Very interesting results!
The first chart shows the freq response of the left channel
measurements (Due to differing sensitivities the sweeps were at
slightly different levels. So I shifted the ECM8000
nuhi;230770 Wrote:
Tell me one thing please, in the first pic, which calibration file for
the ECM did you use?
The first graph is just the Impulse_Response_Measured, so there is no
mic calibration applied (ie zeros). In fact, I can't figure out how to
generate mic-cal adjusted graphs of the
Chinanico;230693 Wrote:
I assume that the response in the treble would be more sensitive to the
exact position of the mike than in the bass. Do you think this could
account for some of the differences or did you manage to position them
the very same?
I used a mic stand and was very careful
muski, oh ok.
While adjusting the curve to your new comparison I was wondering are
those dBs on the phase response actually degrees or it's more like
divided somehow?
I'm asking because in the default ecm8000 there is a huge difference,
like 3 times stronger correction in phase (they use 20,
nuhi;230770 Wrote:
muski, so it is confirmed, without a calibration the ECM8k is almost
useless :(
This gets more and more interesting. I sent my ECM8000 out as well to
get calibrated. I'll post my cal curve as soon as I get it back.
--
tonyptony
muski, so it is confirmed, without a calibration the ECM8k is almost
useless :(
Tell me one thing please, in the first pic, which calibration file for
the ECM did you use?
I hope it was none (zeros) so that I can adjust mine.
Very helpful indeed, so we do have hi freq issue. I say we because I
Here are the same first three graphs for the right channel -- just to
double check things.
Freq response is very similar, though the phase plot is slightly
different. Maybe the ECM8000 is actually ok in terms of capturing
phase information.
nuhi;230850 Wrote:
muski, oh ok.
While adjusting the curve to your new comparison I was wondering are
those dBs on the phase response actually degrees or it's more like
divided somehow
No, it's degrees (-180-0-180). (BTW, I have no phase information in
either of my mic cal files). It
I used the Sweep (with EQ in L channel) test tone and, using the M30
microphone recorded sweeps for both the M30_normal_flat and
ECM8000_normal_flat filters. Below are the plots of
Impulse_Response_Measured and phase response (1/6 octave smoothing).
Since the M30 is pretty close to flat even
muski;231024 Wrote:
I am surprised by the phase behavior of both filters in the low freqs.
That phase response may not be as bad as it looks. The point is that
if a filter is linear phase it's perfect (just as good as 0 phase
shift), because linear phase is simply a time delay. That's
muski;231024 Wrote:
It is interesting that the ECM8000 plot, though not without some
issues, does looks flat-ish (ie at least it doesn't have the huge hump
like the ECM8000's mic freq reponse plot).
There are 6dB jumps all over the high frequencies, that's too much (3dB
is 2 times
Sorry what do you mean by that, didn't you say that the mic cal files
weren't applied?
The mic cal files were indeed applied to create the two filters. The
M30 mic cal file was not applied to the measured results shown above,
but as the M30 is reasonably flat it shouldn't make much
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