At 10:39 AM -0800 12/15/06, Dan Dugan wrote:
> >Hi-- Thanks to Tom Bamberger who loaned me his new unit, I was able
>>to run this test:
>>
>>QuickTime Movie (IMA:4 compressed sound)
>>http://www.uwm.edu/~type/audio-art-tech-gallery/mediafiles/H4_744_NH700_C=
ompare_Sm.mov
>>(8mb)
>>Caution, the recording is loud. Adjust sound level to a comfortable level
>>
>>QuickTime Movie (uncompressed 16/48K sound)
> >http://www.uwm.edu/~type/audio-art-tech-gallery/mediafiles/H4_744_NH700=
_CompareLrg.mov
>>(12.5mb)
>
>Thanks a lot, Rob. The first thing that jumped out was that the ART
>power supply made a significant high-pass filter. Perhaps it has
>series DC-blocking caps in the output that aren't big enough. That's
>something that would be easy to modify.
>
>-Dan Dugan
Hi Dan--
I'm not positive there isn't something awry with the Art->722 segment
of the test, for example, I hear a shift in the stereo balance which
I couldn't explain. I lost the other examples of this test due to the
corruption events so I couldn't duplicate it/affirm it. No test is
perfect. I left that segment in there because I couldn't resolve the
stereo balance shift. I had to return the H4 and the main goal of the
test was to compare the recorders. Perhaps the Hi-MD combo could
sound better, but not the H4, that's for sure.
My guess is the change in the low Hz response is most likely the
result of a wind gust in the first 722 segment. I was fighting wind
and local traffic. The 722 files get boosted 12 dB and then the
whole test gets another 6-8dB boost to preserve quality when its
compressed. I can't study that moment on the orig 722 take nor go on
line at the moment to check because I'm out of town. I saw the
pronounced lows in the 722 segment, but I didn't seeing the same
dramatic change when the Art was removed in the NT1-A -> to H4 chain,
so I let it go. If a high pass change happens in the H4 section of
the test too, then something could be screwy with the Art.
I've subjected the Rolls to the NT1-A ->722/Internal Phantom test
many times and its consistently very transparent. Here's a test that
have access to on my laptop that compares the Rolls to the Art
(NT1-A->Rolls->Hi-MD and NT1-A->Art->Hi-MD) about midway through.
http://www.uwm.edu/~type/audio-art-tech-gallery/mediafiles/PortPhantomHiMDR=
eprtv01SorIMA.mov
I made a sonogram of that segment and no high Pass filtering with the
Art is evident to me. I'll be on the outlook for a performance issue
with the (my) Art PhantomII, but the evidence as a whole suggests to
me its very transparent. You can hear a subtle whine when the Art is
used with the H4 (internal phantom off) but I've not encountered this
interaction with the other inputs/recorders I tested.
I'm not sure when this post will be added to the list. Sorry if its
untimely by then. Rob D.
>
>
>"Microphones are not ears,
>Loudspeakers are not birds,
>A listening room is not nature."
>Klas Strandberg
>Yahoo! Groups Links
>
>
>
--
Rob Danielson
Peck School of the Arts
University of Wisconsin-Milwaukee
http://www.uwm.edu/~type/audio-art-tech-gallery/
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