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Re: newbie: problem with distortion

Subject: Re: newbie: problem with distortion
From: "haughki" <>
Date: Tue, 18 Nov 2003 06:27:18 -0000
thanks very much for the reply.  this wouldn't seem to be my problem
though, since i still get the distortion when my recor levels are
coming in well below -12 db.  the link i specified below
(http://www.hadal.org/misc/distortion.zip) is artifically gained post
record (i just increased the levels to make the distortion more
audible).  take a listen to this:

www.hadal.org/misc/distortion_lowlevel_bad.zip

in this example, the levels are *very* low, but the distortion is
severe.  it's *supposed* to be a recording of the ocean.  it'd be a
piss-poor recording anyhow, heh, but the distortion is really
incredible.

the distortion seems to be connected with movement of the mic:  when
i'm walking or if i tense my arm (i'm holding the mic directly in my
hand) the distortion seems more severe.

hawkeye

--- In  "Rich Peet" <>
wrote:
> I recall a number of dat people complaining about what you describe
> but could only find one example quick:
>
>
> To quote another web site and a different author. I think sonic
> devices:
>
> "The TCD-D8 resists infrequent overloads of short duration with
good
> performance.  However, frequent constant VU REC levels above -12dB
> produces an audible 'soft' distortion (very audible above -6dB
VU).=20
> Sony still recommends that VU peak indications (during recording)
be
> best kept to -12dB to avoid momentary 'overload' distortions.=20=20
>
> It does seem that keeping the frequently occurring program peaks
at -
> 12dB produces the best sounding recording with D7/D8 DAT decks.=20
> This -12dB VU recording limit for best quality sound recording is
> apparently consequence of +4 hour penlight cell power recording
time
> and a 'consumer' design approach that still allows Real
Professional
> Quality (RPQ) in a pocket sized affordable DAT DECK if only the
> recordist allows for these known limitations.
>
> D7/8 RECORDING TIP #3:  When in MIC (H) Sensitivity position (the
> mic. preamp. Hi-Gain setting), avoid preamplifier overload
distortion
> by switching to (L) SENS (low preamplifier gain) when the manual
REC
> LEVEL knob indicates (4) or below;  meaning the input signal is too
> great.  At 1st opportunity, switch to (L) Low gain position and
> advance the REC LEVEL knob to (~7) for proper VU peaks at -12dB.
> NOTE:  MIC SENS must be set properly for all MIC inputs (not Line),
> even when in ALC position.
>
> Other notable features:  Date/Time Tape Encoding and Auto Level
> Control (ALC) with (2)two modes: Voice or Music. The music setting
is
> unprecedented as it works for some music types quite well. [NOTE:
MIC
> SENS. (H)/(L) is always manually set] This means that from Rock to
> Brazilian to Reggae you could forgo monitoring the VU level.  The
> very fast attack/very slow release music ALC setting is sufficient
to
> keep 'level-pumping' inaudible with rhythmic music only; that is, a
> quick/constant bass beat but, not for most jazz and not at all for
> classical type music. Reports of audible 'distortion type effects'
> when using the music ALC setting on the previous D7 model suggests
> caution in using any ALC for best overall recording quality.=20
> However, the Voice ALC setting is perfect for news reporters,
> interviewers, and documentary researchers who cannot allow the
> distraction to monitor VU recording levels.
>
> ALC SUMMARY: ALC reduces signal peaks to well below -12dB (as
> indicated by the VU); not at the -12dB I would manually choose for
VU
> peaks.  Also, some recordists tried music ALC setting and report
> audible 'distortion' that's not heard in manual.=20=20
>
> Remember: ALC function is strictly for the recordist's convenience
> when viewing VU levels is too distracting or impractical. "
>
>
> --- In  "haughki" <>
> wrote:
> > hi all
> >
> > i'm a musician/composer who's very new to nature recording, and
> i've
> > run into a distortion issue.  i'm using a sony d8 DAT with a
> straight
> > line in from my rhode nt4 condenser stereo mic, a dedicated XY
> > cardioid coincident pair.
> >
> > i did some recording recently with this setup, just walking
around
> > with cans on, mic in hand.  now, when i use this setup and
manually
> > increase the record levels to greatly "magnify" the ambient sound
i
> > get an odd distortion:  not clipping (the levels are clearly
fine,
> > between -24 and -12 db and it doesn't *sound* at all like
> clipping),
> > but a quick, stuttering momentary dropout.  you can find an
example
> > here:
> >
> > http://www.hadal.org/misc/distortion.zip
> >
> > it's especially pronounced when using the high sensitivity preamp
> > setting on the D8.  i'm assuming this has something to do with
> > cranking up the levels so high; i've certainly never had the
levels
> > set so high for music recording, and i've never heard this
sound.=20
> i
> > just want to confirm that my gear is not somehow defective....
> >
> > any ideas?
> >
> > thanks
> >
> > hawkeye



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