I measured these mics last year, heres some info.
The AT3032s are pointing forwards and also the MX391 omni's. Except the res=
ponse of the 391's is rather different for the front vs side.
See linked graph:-
http://urlme.net/audio/MX391O-AT3032unref.jpg
The mics are not referenced due to two different measurement times but give=
a rough idea of the response from 0 to 90 degrees in the same location. Wh=
ich in this case is pretty close.
The AT3032's have a predictable fall off as the source moves off axis.
The Shure capsules still in the housing tend to peak around 8Khz for front =
source, and eventually they are flat for side sources. Aiming them up may g=
ive a more natural impression since the frontal peak may tend to sound "up"=
unless corrected with EQ.
BR
Mike.
--- In Emanuele <> wrot=
e:
>
> On 14/02/2012 23:14, tk7859 wrote:
> >
> > Hi All
> >
> > Following comment by Emanuele and Haken in previous posts on this
> > topic I decided to compare the performance of the MX391s in the new
> > boundary rig with AT3032s in a similar rig. Another reason for the
> > test was to better asses the stereo field because the initial test
> > recording seemed to have a hole in the middle (probably due to the
> > presence of a building directly in front of the position of the rig).
> >
> Hi Tom,
>
> thanks a lot for your comparison.
> It is hard to say what's the difference between the two recordings,
> because you used two different recorders.
> If you have someone around there to borrow a four track recorder you
> could do the same test in a quieter place.
> In your actual test the AT3032 sounds deeper and and the stereo image is=
> narrower to me while the MX391 is crispier and wide.
> I think the difference in "wideness" is due by the construction itself:
> the AT3032s are pointing front, having their capsule's focus on a real
> parallel line, while the MX391 I think are facing side and thieir
> capsule's focus is 180=B0 apart (I think, we will need to double check th=
e
> construction specific of that mic) and that could be the "hole in the
> middle" issue.
> That could also cause a discrepancy in sound having some frquencies out
> of phase.
> The crispier sound of the MX391 could be just the auto self noise of the=
> mic.
> In that particular recording I do prefer the MX391, the bass frequencies=
> are less present cutting out some undesired background noise and the
> crisp sound give us more presence of the salty water.
>
> --
> Emanuele
>
> www.ecsound.net
>
>
>
>
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