Topic: First "matrix" recordings - dead rat effects

[Carrera2]

I was able to make my first soundboard recording -- ran the feed to my R-09 at 24/48, and ran AKG480-CK61[DEAD RATS]>UA-5busmod>H120 at 16/44.1.  I managed to kludge together, quite by accident, one of the tunes in Audacity as a matrix.

What surprised me was the visual of the two different sources in Audacity.  What is the meaning of the two different sources?  There are gaping holes in the graphical representations of the AUD recording.

Not surprisingly, the mics wearing Dead Rats (although the sound system may have contributed) had quite a haircut on the frequency response curve.

Note that the Syrinx program is free and available here: http://www.syrinxpc.com/

Thanks for any feedback.

Note: the board feed is the top pair of tracks in Audacity and the bottom pair of tracks in Syrinx.

[theSeekerr]

That's some hugely nasty waveforms you've got there....looks to me like a DC powersource fluctuating in an ugly manner.

[JackoRoses]

according to rycotes website their softies attentuate HF by about 7db at the 6kHz range
http://www.rycote.com/products/windshield/modular/documents/WindnoisereductionfiguresNov2005.pdf
more than likely depending on the material used for "dead rats" the HF attenuation would be different.

[dgodwin]

I think the big difference in the audacity waves is due to phase shifting that's caused by the wind.  It doesn't have anything to do with the dead rats.

[Carrera2]

Excellent points.  Perhaps I will simulate this at home, using the stereo, a line out and the same mic set-ups.  I'll get the quietest fan I have to simulate the wind, and check the frequency response with and without the windscreens +/- the dead rats.

+T all.

[Carrera2]

Well, I ran some living room tests and found some interesting things. 

1. Line out to R-09 to approximate sound board mentioned above
2. AKG 481 "naked"
3. AKG 481 with wind screens
4. AKG 481 with wind screens + dead rats
5. AKG 481 with wind screens + dead rats + wind

It is interesting to note that the frequency response of 2-4 is quite similar, without the degradation suggested by the Rycote paper mentioned above.

The "sound board" has a fuller frequency response curve than 2-4, but that may only point out the limitations of my stereo speakers or other variables.

The wind sample is revealing, and I think substantiates the phase explanation posited above.  The frequency response curve is limited.

Hopefully I can spread the attachments over two posts.

[Carrera2]

Wave curves mentioned above.

[baustin]

I think the big difference in the audacity waves is due to phase shifting that's caused by the wind.  It doesn't have anything to do with the dead rats.

that'd be my guess too

[atxwolfattack]

first off, when you ran these tests, how were you generating the wind? Maybe it is just fan sounds if you used a fan?

Personally, my dead rats barely cut out the high end on my recordings, but i also have different mics, so you never know.