Dirty Digital [sic.]
 

Don Pearce wrote:

Eeyore wrote:
tony sayer wrote:
Eeyore scribeth thus
Please explain how MRI scanners came into this thread.
Well if its magnetic fields your after they don't usually come much
higher?..

I said they were *electro-magnetic* fields.

Then there was no need to go to the huge expense of a steel box. Any old
conductive mesh draped around the place would have done as well.

The contractors said 2mm mild steel. It's THEIR job to make it work (and it
did) so why would I complain ?

Graham

Dirty Digital [sic.]
 

Don Pearce wrote:

Eeyore wrote:
Don Pearce wrote:
Eeyore wrote:
tony sayer wrote:
Eeyore scribeth thus
tony sayer wrote:
Eeyore scribeth thus
tony sayer wrote:

Or did you mean that your friends make rooms that are screened against
magnetically induced fields?..
Is 2mm mild steel over say 10 m3 going to do that ?
So you really think that there are magnetic fields around external to a
top rate studio that are going to produce that field level?.

A NMRI scanner isn't that well screened;)..
It's Don who claims they're magnetic. Yet they don't fall off with distance
appreciably.
Theres more to the screening of an NMRI scanner .. its to do with
keeping signals -out- rather then in. Even the 1-2 odd Tesla field isn't
likely to cause a problem in the studio next door to the manky guitar
pickup coil company;)..
Please explain how MRI scanners came into this thread.

They are sources of very powerful magnetic fields, and the steel
enclosure under discussion can only have been designed to exclude
magnetic fields. MRI was a guess at a possible source powerful enough to
require such exclusion.

Do they 'hum' day in, day out at frequencies between the low hundreds Hz and mid
kHz ?

No. Just hammering away at a few Hz when they are running.

As I thought. So not THAT then.

You have the map co-ords now - why not go and measure yourself ?

Graham

Dirty Digital [sic.]
 

Phil Allison wrote:

Frankly - if ever I receive a phone call from any recording studio (even
quite famous ones), the hair on the back of my neck stands up and I and very
reluctant to continue the conversation.

Cos I just know the * ****ing arseholes * are going to try and scam me out
of my time and fail to pay me monies owed.

Yes, that would be true to form too. I won't bore you with that either other
than mention that my colleague who's the 'contact' is a born mis-negotiator.

Graham

Dirty Digital [sic.]
 

On 2008-06-25, Jim Lesurf wrote:
At dire risk of pulling this thread back onto the original topic... :-)

Alas, thread drift seems to be an irreversible phenomenon.

People might be interested in

http://www.audiomisc.co.uk/ddd/Dirty...Delusions.html

After comments about earlier communications with the author on this
topic I gave up any thought of re-reading the article and setting out
the errors. However I am glad someone has done so.

--
John Phillips

Dirty Digital [sic.]
 

In article , John Phillips
wrote:
On 2008-06-25, Jim Lesurf wrote:
At dire risk of pulling this thread back onto the original topic...
:-)

Alas, thread drift seems to be an irreversible phenomenon.

Perhaps it is related to continental drift or Hubble expansion. Bit like
the way when you try to use a wire carefuly pre-cut to fit... it turns out
to be too short. The Universe clearly expanded in the time between it
being cut and you trying to use it. :-)

People might be interested in

http://www.audiomisc.co.uk/ddd/Dirty...Delusions.html

After comments about earlier communications with the author on this
topic I gave up any thought of re-reading the article and setting out
the errors. However I am glad someone has done so.

Hope others fine it useful, also. But I don't imagine it will alter the
ideas of the author of the article which it comments upon. Shame, as I do
genuinely have a high regard for many other areas of work he has done. Just
that this seems to be a 'blind spot' he has for some reason...

Slainte,

Jim

--
Change 'noise' to 'jcgl' if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

Dirty Digital [sic.]
 

Eeyore wrote:

Don Pearce wrote:

Eeyore wrote:
tony sayer wrote:
Eeyore scribeth thus
Please explain how MRI scanners came into this thread.
Well if its magnetic fields your after they don't usually come much
higher?..
I said they were *electro-magnetic* fields.
Then there was no need to go to the huge expense of a steel box. Any old
conductive mesh draped around the place would have done as well.

The contractors said 2mm mild steel. It's THEIR job to make it work (and it
did) so why would I complain ?

Graham


I've forgotten; what was your role in the project?

d

Dirty Digital [sic.]
 

Eeyore wrote:

Don Pearce wrote:

Eeyore wrote:
Don Pearce wrote:
Eeyore wrote:
tony sayer wrote:
Eeyore scribeth thus
tony sayer wrote:
Eeyore scribeth thus
tony sayer wrote:

Or did you mean that your friends make rooms that are screened against
magnetically induced fields?..
Is 2mm mild steel over say 10 m3 going to do that ?
So you really think that there are magnetic fields around external to a
top rate studio that are going to produce that field level?.

A NMRI scanner isn't that well screened;)..
It's Don who claims they're magnetic. Yet they don't fall off with distance
appreciably.
Theres more to the screening of an NMRI scanner .. its to do with
keeping signals -out- rather then in. Even the 1-2 odd Tesla field isn't
likely to cause a problem in the studio next door to the manky guitar
pickup coil company;)..
Please explain how MRI scanners came into this thread.
They are sources of very powerful magnetic fields, and the steel
enclosure under discussion can only have been designed to exclude
magnetic fields. MRI was a guess at a possible source powerful enough to
require such exclusion.
Do they 'hum' day in, day out at frequencies between the low hundreds Hz and mid
kHz ?
No. Just hammering away at a few Hz when they are running.

As I thought. So not THAT then.

You have the map co-ords now - why not go and measure yourself ?

Graham


Might do just that.

d

Dirty Digital [sic.]
 

John Phillips wrote:

On 2008-06-25, Jim Lesurf wrote:
At dire risk of pulling this thread back onto the original topic... :-)

Alas, thread drift seems to be an irreversible phenomenon.

People might be interested in

http://www.audiomisc.co.uk/ddd/Dirty...Delusions.html

After comments about earlier communications with the author on this
topic I gave up any thought of re-reading the article and setting out
the errors. However I am glad someone has done so.

Does the ASA have any authority in such matters ?

Example ...
http://www.asa.org.uk/asa/adjudicati..._ADJ_44177.htm

Failing that, a group of audio pros ought to picket the next edition of HFN

The spread of false information and LIES has GONE TOO FAR.


Graham

Dirty Digital [sic.]
 

Don Pearce wrote:

Eeyore wrote:
Don Pearce wrote:
Eeyore wrote:
tony sayer wrote:
Eeyore scribeth thus
Please explain how MRI scanners came into this thread.
Well if its magnetic fields your after they don't usually come much
higher?..
I said they were *electro-magnetic* fields.
Then there was no need to go to the huge expense of a steel box. Any old
conductive mesh draped around the place would have done as well.

The contractors said 2mm mild steel. It's THEIR job to make it work (and it
did) so why would I complain ?

I've forgotten; what was your role in the project?

Measurement consultant. Using tools RELEVANT to audio recording not some bleeding
IEC document that doesn't start 'til 150 kHz !

Graham

Dirty Digital [sic.]
 

Don Pearce wrote:

Eeyore wrote:
Don Pearce wrote:
Eeyore wrote:
Don Pearce wrote:
Eeyore wrote:
tony sayer wrote:
Eeyore scribeth thus
tony sayer wrote:
Eeyore scribeth thus
tony sayer wrote:

Or did you mean that your friends make rooms that are screened against
magnetically induced fields?..
Is 2mm mild steel over say 10 m3 going to do that ?
So you really think that there are magnetic fields around external to a
top rate studio that are going to produce that field level?.

A NMRI scanner isn't that well screened;)..
It's Don who claims they're magnetic. Yet they don't fall off with distance
appreciably.
Theres more to the screening of an NMRI scanner .. its to do with
keeping signals -out- rather then in. Even the 1-2 odd Tesla field isn't
likely to cause a problem in the studio next door to the manky guitar
pickup coil company;)..
Please explain how MRI scanners came into this thread.
They are sources of very powerful magnetic fields, and the steel
enclosure under discussion can only have been designed to exclude
magnetic fields. MRI was a guess at a possible source powerful enough to
require such exclusion.
Do they 'hum' day in, day out at frequencies between the low hundreds Hz and mid
kHz ?
No. Just hammering away at a few Hz when they are running.

As I thought. So not THAT then.

You have the map co-ords now - why not go and measure yourself ?

Might do just that.

Please do. It'll freak you.

All you need is a few tens of turns of wire on a bog roll (or a guitar pickup in a box)
into a modestly high gain amp ( ~ 60dB) . We used a PigNose for general use and a
Radford ANM03 ? for more specific detailed measurement stuff.

Graham