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<p>thanks, as John says, makes sense to me. <br>
</p>
<p>Cheers</p>
<p>Alan<br>
</p>
<div class="moz-cite-prefix">On 2/11/2020 11:32 AM, Bill Whitlock
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:594339864.1111898.1581449551857@mail.yahoo.com">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<div style="color:black;font: 12pt Arial, Helvetica, sans-serif;">Since
it keeps the total bias fluxivity more constant, the physical
location where it no longer switches the remanent magnetic field
on the tape (the recording zone) should remain <span
style="text-decoration-line: underline;">more</span> stable,
not less. In non-HX recording, the location will move in
response to high levels at high audio frequencies.
<div><br>
</div>
<div>Bill Whitlock<br>
<br>
<br>
<div
style="font-family:arial,helvetica;font-size:10pt;color:black">-----Original
Message-----<br>
From: Alan Garren via ProAudio <a class="moz-txt-link-rfc2396E" href="mailto:proaudio@bach.pgm.com"><proaudio@bach.pgm.com></a><br>
To: Bill Whitlock <a class="moz-txt-link-rfc2396E" href="mailto:engineer_bill@verizon.net"><engineer_bill@verizon.net></a>;
proaudio <a class="moz-txt-link-rfc2396E" href="mailto:proaudio@bach.pgm.com"><proaudio@bach.pgm.com></a><br>
Sent: Tue, Feb 11, 2020 11:13 am<br>
Subject: Re: [ProAudio] HX Pro was :FeralA - Recordings
released encoded with Dolby A<br>
<br>
<div id="yiv5840493414">
<div>
<div>yes, I was casting about in my head for the
appropriate work to call HX, process seemed most
likely. <br clear="none">
</div>
<div>the point is that, as you point out, it modulates
the bias, which should then change the location of the
trailing edge? What affect does this have on the bias
signal on the tape for John and Jaime to process?</div>
<div>Cheers</div>
<div>Alan<br clear="none">
</div>
<div><br clear="none">
</div>
<div class="yiv5840493414yqt8503393163"
id="yiv5840493414yqt90603">
<div class="yiv5840493414moz-cite-prefix">On 2/11/2020
11:03 AM, Bill Whitlock wrote:<br clear="none">
</div>
<blockquote type="cite"> </blockquote>
</div>
</div>
<div class="yiv5840493414yqt8503393163"
id="yiv5840493414yqt99507">
<div>
<div style="color:black;font:12pt Arial, Helvetica,
sans-serif;">I'd hesitate to call HX Pro a
"process". All HX Pro does is to account for the
fact that HF program material tends to "bias" itself
and that this HF program content, when combined with
fixed ultrasonic bias results in significant
self-erasure and loss of HF MOL (maximum HF level
residual on the tape). So HX Pro simply modulates
the ultrasonic bias so that the combined effect of
program HF bias plus ultrasonic bias remains
constant. Depending on tape and speed, it can
improve HF "headroom" or maximum HF audio output
level by up to 6 or 8 dB. It doesn't change
frequency response of the record/play process -
except at levels where MOL/saturation is an issue. I
guess it technically is a "process" but it's record
side only, no "decoding" needed.
<div><br clear="none">
</div>
<div>Hope that made sense. Lots of folks actually
believe(d) that HX Pro was another noise reduction
system. It's not of course, it's simply a way to
get the most out of a given tape at high audio
frequencies. Not so much an issue at 15 IPS, but
really a big deal at 1-7/8 IPS - where it can make
ordinary iron oxide tape perform like chrome.</div>
<div><br clear="none">
</div>
<div>Bill Whitlock<br clear="none">
<br clear="none">
<br clear="none">
<br clear="none">
<div style="font-family:arial,
helvetica;font-size:10pt;color:black;">-----Original
Message-----<br clear="none">
From: Alan Garren via ProAudio <a rel="noopener
noreferrer" shape="rect"
class="yiv5840493414moz-txt-link-rfc2396E"
ymailto="mailto:proaudio@bach.pgm.com"
target="_blank"
href="mailto:proaudio@bach.pgm.com"
moz-do-not-send="true"><proaudio@bach.pgm.com></a><br
clear="none">
To: John Chester <a rel="noopener noreferrer"
shape="rect"
class="yiv5840493414moz-txt-link-rfc2396E"
ymailto="mailto:jkc@jkc-lab.com"
target="_blank" href="mailto:jkc@jkc-lab.com"
moz-do-not-send="true"><jkc@jkc-lab.com></a>;
proaudio <a rel="noopener noreferrer"
shape="rect"
class="yiv5840493414moz-txt-link-rfc2396E"
ymailto="mailto:proaudio@bach.pgm.com"
target="_blank"
href="mailto:proaudio@bach.pgm.com"
moz-do-not-send="true"><proaudio@bach.pgm.com></a><br
clear="none">
Sent: Tue, Feb 11, 2020 10:42 am<br clear="none">
Subject: [ProAudio] HX Pro was :FeralA -
Recordings released encoded with Dolby A<br
clear="none">
<br clear="none">
<div dir="ltr">On 2/11/2020 10:12 AM, John
Chester via ProAudio wrote:<br clear="none">
> Why does perfect azimuth adjustment
usually not produce minimum <br clear="none">
> interchannel time difference? The most
obvious answer is gap scatter <br
clear="none">
> in the record head, but there are
others. Record EQ may not be <br
clear="none">
> precisely matched, and bias setting may
be different. Recording occurs <br
clear="none">
> at a point slightly past the trailing
edge of the record head gap, and <br
clear="none">
> that distance varies as bias level
changes.<br clear="none">
<br clear="none">
<br clear="none">
This causes me to wonder if you have had to
try this on an HX processed <br clear="none">
tape. I am only aware of one pro deck with HX
Pro, the studer A820, and <br clear="none">
most people leave it turned off anyway. But it
is there on some later <br clear="none">
models. (possibly on the A827 as well, can't
remember)<br clear="none">
<br clear="none">
Seems like a horror story for your process,
chasing a HF modulated bias <br clear="none">
level.<br clear="none">
<br clear="none">
<br clear="none">
Cheers<br clear="none">
<br clear="none">
Alan
<div class="yiv5840493414yqt1448531379"
id="yiv5840493414yqtfd88679"><br
clear="none">
<br clear="none">
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