This is topic weighting on "B" chain tune ups? in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.
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Posted by Greg Mueller (Member # 17) on 05-27-2001, 12:03 PM:
What weighting do you use on your RTA, when you do a "B" chain tune up? "A" "C" or none?------------------
Greg Mueller
Amateur Astronomer, Machinist, Filmnut
http://www.muellersatomics.com/
Posted by Aaron Sisemore (Member # 145) on 05-27-2001, 12:17 PM:
Usually C Weighting. Same for the SPL meter (if applicable).Aaron
Posted by Mark Gulbrandsen (Member # 72) on 05-27-2001, 05:47 PM:
Greg,
I may be up next week. Do you want me to bring my R-2 with and tune your room?
MArk @ GTS
Posted by Greg Mueller (Member # 17) on 05-27-2001, 06:16 PM:
What?
Deprive me of countless hours of fiddling?
What's an R2?
(I sure hope you plan some time to visit)------------------
Greg Mueller
Amateur Astronomer, Machinist, Filmnut http://www.muellersatomics.com/
Posted by Mark Gulbrandsen (Member # 72) on 05-27-2001, 09:03 PM:
Greg,
Its the THX spectrum analyzer.......da best in da buisness.....I'll make time this time.
Mark
Posted by Aaron Sisemore (Member # 145) on 05-27-2001, 10:51 PM:
Mark: Are you still interested in that sound equipment? Aaron
Posted by Greg Mueller (Member # 17) on 05-28-2001, 11:11 AM:
Sure Mark, bring it. It will be interesting to see how bad my tune up job is------------------
Greg Mueller
Amateur Astronomer, Machinist, Filmnut
http://www.muellersatomics.com/
Posted by Gordon McLeod (Member # 33) on 05-28-2001, 12:15 PM:
C weighting should only be used for the spl display not the rta display as you will see a change in the HF response
Certain analyzers switch both the RTA and the SPL displays togather
Posted by Steve Guttag (Member # 268) on 05-28-2001, 12:17 PM:
Wait, wait...Weighting on the analyzer? While some find it convienent to have an inverse "x" weighting impressed onto the display..C weighting make no sense for an RTA display. In some rare circumstances, "A" weighting can be used while making noise measurments but often is not needed either.
Now as to the SPL meter....they only make sense when they DO have a weighting (unless you are positive that the meter has more bandwidth than that which you are measuring. For theatres, "c" weighting on the SPL meter yields a meaningful number.
Steve
------------------
"Old projectionists never die, they just changeover!"
Posted by Greg Mueller (Member # 17) on 05-28-2001, 01:23 PM:
Hmmm
My RTA has a filter that goes between the mic and the RTA. You can select "C" or "A" or take it out for none. My RTA is an Audio Control unit.
So should I take the filter out?------------------
Greg Mueller
Amateur Astronomer, Machinist, Filmnut
http://www.muellersatomics.com/
Posted by Gordon McLeod (Member # 33) on 05-28-2001, 01:39 PM:
Filter out for RTA (ie equalization)
Filter C in for SPL measurements
Posted by Steve Guttag (Member # 268) on 05-28-2001, 05:00 PM:
As an experiment, try inserting and removing the filter...I'd be surprised if you see a difference on the RTA display though you might see a change in the SPL measurement. But Gord is correct, no weighting on RTA but "C" weighting on SPL...
Are you SURE that there is a separate switch for the RTA display to have weighting and that it isn't just for the SPL display?
Steve
------------------
"Old projectionists never die, they just changeover!"
Posted by Gordon McLeod (Member # 33) on 05-28-2001, 09:30 PM:
I know for a fact that the Goldline and the PCRTA software have a common filter for SPL and RTA functions so the RTA display switchs with the SPL on the weighting this is for OSHA testing
Some of the ABBACUS units do as well
THE audio control did on certain software revisions
see if the 1/3 octave display changes when the weighting is selected
Posted by Greg Mueller (Member # 17) on 05-28-2001, 10:53 PM:
I'll try that stuff next time. I didn't know listening to pink noise all day could be so fatiguing. I'm bushed. I took the filter out of the line and did it that way. I know there's no weighting, for sure. Thanks for all the help guyszzzzzzzzz.------------------
Greg Mueller
Amateur Astronomer, Machinist, Filmnut
http://www.muellersatomics.com/