LISTSERV mailing list manager LISTSERV 16.0

Help for ARSCLIST Archives


ARSCLIST Archives

ARSCLIST Archives


[email protected]


View:

Message:

[

First

|

Previous

|

Next

|

Last

]

By Topic:

[

First

|

Previous

|

Next

|

Last

]

By Author:

[

First

|

Previous

|

Next

|

Last

]

Font:

Proportional Font

LISTSERV Archives

LISTSERV Archives

ARSCLIST Home

ARSCLIST Home

ARSCLIST  September 2014

ARSCLIST September 2014

Subject:

Re: AZIMUTH (was recording "cleanup" plugins and 192/24)

From:

Tom Fine <[log in to unmask]>

Reply-To:

Association for Recorded Sound Discussion List <[log in to unmask]>

Date:

Wed, 10 Sep 2014 16:28:20 -0400

Content-Type:

text/plain

Parts/Attachments:

Parts/Attachments

text/plain (171 lines)

Hi Richard:

Your description of the Judy Collins tape is similar to what the Abbey Road folks were up against 
with the Beatles tapes. A master like Sgt. Pepper contains master mixes completed over several 
weeks. The early albums can contain sections cut at sessions months apart, and mixed to mono masters 
at those sessions. All of this made for azimuth variences within single tapes, and hence the details 
adjustment notes that had to be followed on the fly while LPs were being cut. I don't think azimuth 
fine-tuning was as much a concern back in the day, so I doubt this was done very much in the LP 
heyday. I think gross and highly audible azimuth problems were what worried engineers back in the 
day.

The azimuth article you said you're working on may be of great interest to ARSC Journal readers. 
This is right up the alley of a lot of work being done by ARSC members. I would love to know more 
about actual field experiences regarding azimuth and cassettes, keeping in mind that very few of us 
have playback decks with easy azimuth adjustment available.

-- Tom Fine

----- Original Message ----- 
From: "Richard L. Hess" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Wednesday, September 10, 2014 2:18 PM
Subject: Re: [ARSCLIST] AZIMUTH (was recording "cleanup" plugins and 192/24)


> Hi, Jim,
>
> I do, too. StereoTool is the best assistant in that regard. In fact, it is the only support 
> software I have found useful for azimuth alignment on program. Tones are a different story and a 
> scope (generally a software variant--specifically RME DigiCheck) is very useful.
>
> What have you found to assist in azimuth adjustment and how do you use it?
>
> The "crutch" remark was meant in context to purposely downgrade the ultimate repro performance by 
> intentionally using a two-channel head for a full-track tape to enable azimuth alignment via 
> instrumentation tools and then sum the channels.
>
> It is a tough decision to decide whether to go with the full-track head and risk being out of 
> azimuth because there is no accurate instrumentation or use the sub-optimum two-track playback to 
> get better azimuth but suffer from the losses created by mis-matching between repro channels and 
> other effects. I found that especially with the early full-track tapes, the sound was richer with 
> a full-track head than with a summed NAB stereo head, even though azimuth was easier to adjust 
> with the NAB stereo head.
>
> Other people I know and I have been able to obtain pleasing and presumably accurate results with 
> full-track play heads.
>
> Anyway, with a mono signal, what software tools help you align azimuth on program?
>
> As an aside, when Judy Collins's #3 album was being remastered, the project was done and Alan 
> Silverman checked the mono sum and found that the azimuth was off despite the fact he had aligned 
> to the tones at the head of the tape. It was somewhat common practice to record a series of tones 
> at once and then splice them into the individual album tapes. He went back and started over. I had 
> given Alan a good CD-R copy of a pristine vinyl copy I had found and he indicated that was not 
> what he thought the album sounded like, so I'm happy to say he pretty much matched the LP sound. 
> This was about a dozen years ago.
>
> Cheers,
>
> Richard
>
>
>
> On 2014-09-10 12:49 PM, Jim Sam wrote:
>> I use software to help me align azimuth on cassette transfers all the
>> time in conjunction with my ears.  You can call it a "crutch" or you
>> can call it being thorough and professional.
>>
>> Consider that you could theoretically calibrate a reel machine by ear,
>> too, but I wouldn't hire anyone that didn't use a voltmeter or DAW
>> meters.
>>
>> On Wed, Sep 10, 2014 at 9:01 AM, Richard L. Hess
>> <[log in to unmask]> wrote:
>>> I probably should clarify...
>>>
>>> Think of the azimuth error situation as a right triangle.
>>>
>>> The "perfect" azimuth is one leg that is vertical. The actual recorded
>>> azimuth is the hypotenuse. The azimuth error is the leg which is horizontal.
>>>
>>> The length of the horizontal leg of the triangle can be translated into the
>>> time delay and the phase shift between the two channels.
>>>
>>> When the two channels are summed, even small errors which CAN be equalized
>>> out, grow into huge errors and cannot be recovered, so the re-timing between
>>> stereo channels prior to summing will produce far better results than not
>>> using it and summing the two channels will reduce the noise taken from
>>> either channel.
>>>
>>> For high-quality music work, using a full-track head is superior, but for
>>> oral history production work (especially from cassettes) there is merit to
>>> summing the two tracks, especially because mono cassette machines are hard
>>> to find and few (if any) were made with the quality of the top stereo
>>> machines.
>>>
>>> Here is an example using a cassette:
>>>
>>> 15 arc minutes (1/4 of a degree) azimuth error.
>>>
>>> Single channel  -3 dB point ~  9 000 Hz
>>> Summed channels -3 dB point ~  3 400 Hz
>>> Single channel  -6 dB point ~ 12 000 Hz
>>> Summed channels -6 dB point ~  4 600 Hz
>>>
>>> Sliding the second channel in time to be in alignment with the first
>>> provides a huge improvement in the high-frequency response.
>>>
>>> I contend that, if desired, losses of up to approximately 6 dB can be
>>> equalized out as long as there is no additional boost and a rolloff after
>>> the - 6 dB point (to avoid increasing noise).
>>>
>>> Cheers,
>>>
>>> Richard
>>>
>>>
>>>
>>>
>>> On 2014-09-10 10:25 AM, Richard L. Hess wrote:
>>>>
>>>> Hi, Andrew and Tom,
>>>>
>>>> I am (very) slowly working towards a paper on azimuth.
>>>>
>>>> The full-track mono tape is, of course, the hardest to play from an
>>>> azimuth perspective (of the common formats)--I hate to think about the
>>>> 1-inch two-track!
>>>>
>>>> Transport guidance is a huge issue and I have found that the Studer A80
>>>> is magical in that regard--and the Studer A810, not so much. The Sony
>>>> APR-5000 is between the two.
>>>>
>>>> For those of us who have taught ourselves how to adjust azimuth by ear
>>>> (sort of the same thing as focusing a camera lens in many ways), we do
>>>> not need crutches, but I have come to realize that using a two-track
>>>> head for "factory workers" might be beneficial.
>>>>
>>>> For one project I proposed (but we chose not to implement) a wide/narrow
>>>> head for full track mono. We batted around a few different
>>>> configurations--including a long discussion with Greg Orton. I was
>>>> thinking of something like 0.120 and 0.04. The nice thing is even if
>>>> things go south, you still have a good percentage of the highs on the
>>>> 0.04 track, albeit noisy.
>>>>
>>>> With that said, for oral history cassettes, I use, in addition to manual
>>>> azimuth adjustment, the azimuth compensation feature of
>>>> www.stereotool.com. This allows excellent channel summing for improved
>>>> noise, assuming both channels were recorded.
>>>>
>>>> There is a similar feature in iZotope RX Advanced.
>>>>
>>>> Cheers,
>>>>
>>>> Richard
>>>>
>>>
>>> --
>>> Richard L. Hess                   email: [log in to unmask]
>>> Aurora, Ontario, Canada                             647 479 2800
>>> http://www.richardhess.com/tape/contact.htm
>>> Quality tape transfers -- even from hard-to-play tapes.
>>
> -- 
> Richard L. Hess                   email: [log in to unmask]
> Aurora, Ontario, Canada                             647 479 2800
> http://www.richardhess.com/tape/contact.htm
> Quality tape transfers -- even from hard-to-play tapes.
>
> 

Top of Message | Previous Page | Permalink

Advanced Options


Options

Log In

Log In

Get Password

Get Password


Search Archives

Search Archives


Subscribe or Unsubscribe

Subscribe or Unsubscribe


Archives

March 2024
February 2024
January 2024
December 2023
November 2023
October 2023
September 2023
August 2023
July 2023
June 2023
May 2023
April 2023
March 2023
February 2023
January 2023
December 2022
November 2022
October 2022
September 2022
August 2022
July 2022
June 2022
May 2022
April 2022
March 2022
February 2022
January 2022
December 2021
November 2021
October 2021
September 2021
August 2021
July 2021
June 2021
May 2021
April 2021
March 2021
February 2021
January 2021
December 2020
November 2020
October 2020
September 2020
August 2020
July 2020
June 2020
May 2020
April 2020
March 2020
February 2020
January 2020
December 2019
November 2019
October 2019
September 2019
August 2019
July 2019
June 2019
May 2019
April 2019
March 2019
February 2019
January 2019
December 2018
November 2018
October 2018
September 2018
August 2018
July 2018
June 2018
May 2018
April 2018
March 2018
February 2018
January 2018
December 2017
November 2017
October 2017
September 2017
August 2017
July 2017
June 2017
May 2017
April 2017
March 2017
February 2017
January 2017
December 2016
November 2016
October 2016
September 2016
August 2016
July 2016
June 2016
May 2016
April 2016
March 2016
February 2016
January 2016
December 2015
November 2015
October 2015
September 2015
August 2015
July 2015
June 2015
May 2015
April 2015
March 2015
February 2015
January 2015
December 2014
November 2014
October 2014
September 2014
August 2014
July 2014
June 2014
May 2014
April 2014
March 2014
February 2014
January 2014
December 2013
November 2013
October 2013
September 2013
August 2013
July 2013
June 2013
May 2013
April 2013
March 2013
February 2013
January 2013
December 2012
November 2012
October 2012
September 2012
August 2012
July 2012
June 2012
May 2012
April 2012
March 2012
February 2012
January 2012
December 2011
November 2011
October 2011
September 2011
August 2011
July 2011
June 2011
May 2011
April 2011
March 2011
February 2011
January 2011
December 2010
November 2010
October 2010
September 2010
August 2010
July 2010
June 2010
May 2010
April 2010
March 2010
February 2010
January 2010
December 2009
November 2009
October 2009
September 2009
August 2009
July 2009
June 2009
May 2009
April 2009
March 2009
February 2009
January 2009
December 2008
November 2008
October 2008
September 2008
August 2008
July 2008
June 2008
May 2008
April 2008
March 2008
February 2008
January 2008
December 2007
November 2007
October 2007
September 2007
August 2007
July 2007
June 2007
May 2007
April 2007
March 2007
February 2007
January 2007
December 2006
November 2006
October 2006
September 2006
August 2006
July 2006
June 2006
May 2006
April 2006
March 2006
February 2006
January 2006
December 2005
November 2005
October 2005
September 2005
August 2005
July 2005
June 2005
May 2005
April 2005
March 2005
February 2005
January 2005
December 2004
November 2004
October 2004
September 2004
August 2004
July 2004
June 2004
May 2004
April 2004
March 2004
February 2004
January 2004
December 2003
November 2003
October 2003
September 2003
August 2003
July 2003
June 2003
May 2003
April 2003
March 2003
February 2003
January 2003

ATOM RSS1 RSS2



LISTSERV.LOC.GOV

CataList Email List Search Powered by the LISTSERV Email List Manager