I believe it was, and still is, quite common for companies to use mobile control rooms for location recording. There are two advantages which were recognized early - first it's convenient to have all of the equipment interconnected and not have to transport it into the location, and second it's useful to have a standard acoustic environment so that the engineer knows what he/she should expect to hear.

db

Sent from my iPhone

On 2012-06-28, at 10:25 AM, Don Cox <[log in to unmask]> wrote:

> On 28/06/2012, Tom Fine wrote:
>
>> Hi Don:
>>
>> This makes sense. I re-listened to the Beecham example on headphones
>> and I agree there is some stereophony to it, and the perspective you
>> suggest matches the sound quality I hear. My bet is, two relatively
>> close-spaced mics, probably not omnidirectional in the modern sense,
>> so you are getting a somewhat "binaural" effect but not what we think
>> of as modern stereophony of a symphony orchestra.
>>
> Blumlein's whole approach was to use a crossed pair of directional mics.
>
> This can be extended to four mics for Ambisonics.
>
> I'm not sure I would describe spaced omnis as more "modern" than
> crossed-pair. They are alternative techniques. The Decca Tree is a kind
> of compromise between the two.
>
> I have had people insist that it is impossible for spaced omnis to give
> "true stereo".
>
>
>> It actually sounds quite good on headphones because the groove noise
>> on the sides is easier to ignore. There are depth and height cues
>> around the orchestra, which is a mark of stereophony. To my ears, the
>> Bell Labs experiments produced symphonic stereophony more in the
>> modern sense, but Blumlein definitely achieved something akin to what
>> was called "binaural" in the early days of 2-track duped tapes.
>>
>> I wonder, did Blumlein monitor with "earphones" and did the Bell Labs
>> guys have two monitor speakers? I've seen photos of the Bell Labs guys
>> with "earphones" but I'm wondering if they also had speakers as their
>> final reference?
>>
>> By the way, speaking of monitoring symphonic recordings, in all photos
>> I've seen of Mercury, RCA, Columbia and Capitol/EMI American recording
>> sessions from the "golden era," monitoring was always done with
>> speakers, in a room isolated from the sounds of the recording venue.
>> Mercury and I think Everest monitored in 3-channel, right off the
>> 3-track tape/film. Photos I've seen of RCA and Columbia and Capitol
>> show 2 speakers, so I assume their recording boards allowed for a
>> 2-channel monitor mix. I think Mercury was unique in using a truck as
>> the "machine room" rather than just a transport vehicle.
>>
> Didn't the BBC use trucks for outside broadcasts from early on?
>
> Regards
> --
> Don Cox
> [log in to unmask]