Jump to content



Sign up for a free account to remove the pop-up ads

Signing up for an account is fast and free. As a member you can join in the conversation, enter contests and remove the pop-up ads that guests get. Click here to create your free account.

Photo
- - - - -

spl corection for non radio shack meters


  • You cannot start a new topic
  • Please log in to reply
6 replies to this topic

#1 of 7 OFFLINE   rob hoinsky

rob hoinsky

    Auditioning



  • 14 posts
  • Join Date: Dec 02 2003

Posted December 09 2004 - 09:44 AM

i bought an American Recorder spl-8800 a while back thinking it was more accurate than the radio shack model that everyone uses, but i can't find any corrections for it. does anyone know where i might find them? thanx

#2 of 7 OFFLINE   Edward J M

Edward J M

    Screenwriter



  • 2,031 posts
  • Join Date: Sep 22 2002

Posted December 09 2004 - 10:45 AM

Is the meter c-weighted?
Ed Mullen
Director - Technology and Customer Relations

SVS

www.svsound.com

"What we do in life, echoes in eternity."


#3 of 7 OFFLINE   rob hoinsky

rob hoinsky

    Auditioning



  • 14 posts
  • Join Date: Dec 02 2003

Posted December 09 2004 - 01:02 PM

it can be a weighted or c weighted although i'm not sure where you're going with this...

#4 of 7 OFFLINE   Edward J M

Edward J M

    Screenwriter



  • 2,031 posts
  • Join Date: Sep 22 2002

Posted December 09 2004 - 11:57 PM

Set the meter to C-weighted for FR sweeps or peak SPL monitoring. The A-weighted scale rolls off the response starting up around 500 Hz and is not useful for HT applications, only industrial noise monitoring. In the absence of specific correction factors for this particular meter, use the following CFs. They are the theoretical CFs for the C-weighted filter in your meter and will be quite sufficient for informal FR sweeps to identify and correct response anomalies, etc. Thank DougBW (Trilogy over at HT-SPOT) for these; he gave them to me about two years ago for my B&K SPL meter, which is also C-weighted. Regards, Ed FrequencyC-Weight 10-14.33259693 10.59463094-13.52968703 11.22462048-12.74595335 11.89207115-11.98268094 12.5992105-11.24113838 13.34839854-10.52255777 14.14213562-9.828113197 14.98307077-9.158898305 15.87401052-8.515903684 16.81792831-7.899994991 17.81797436-7.311892737 18.87748625-6.752154684 20-6.221161728 21.18926189-5.719108023 22.44924097-5.24599587 23.7841423-4.801635653 25.198421-4.38565084 26.69679708-3.997487754 28.28427125-3.6364296 29.96614154-3.30161399 31.74802104-2.992053117 33.63585661-2.706655603 35.63594873-2.444249093 37.75497251-2.203602722 40-1.983448665 42.37852377-1.782502185 44.89848193-1.599479687 47.5682846-1.43311451 50.396842-1.282170279 53.39359417-1.145451828 56.56854249-1.021813749 59.93228308-0.910166743 63.49604208-0.809481987 67.27171322-0.718793751 71.27189745-0.63720053 75.50994501-0.563864932 80-0.498012574 84.75704755-0.438930194 89.79696386-0.385963182 95.1365692-0.338512687 100.793684-0.296032457 106.7871883-0.258025523 113.137085-0.224040813 119.8645662-0.193669799 126.9920842-0.1665432 134.5434264-0.142327811 142.5437949-0.12072348 151.01989-0.101460247 160-0.08429567
Ed Mullen
Director - Technology and Customer Relations

SVS

www.svsound.com

"What we do in life, echoes in eternity."


#5 of 7 OFFLINE   rob hoinsky

rob hoinsky

    Auditioning



  • 14 posts
  • Join Date: Dec 02 2003

Posted December 10 2004 - 03:09 AM

thank you and thank you doug a little confusion, are those all subtraction?

#6 of 7 OFFLINE   Craig Morris

Craig Morris

    Stunt Coordinator



  • 198 posts
  • Join Date: Oct 10 1998

Posted December 10 2004 - 03:32 AM

This is from my Revel B15 LFO Software .ini file. It includes the corrections for Radio Shack Analog and Digital... and also lists the following for "other". [Other "C-Weighted" Sound Level Meter] 20=6.2 21=5.7 22=5.3 24=4.9 25=4.4 27=4.0 28=3.7 30=3.3 32=3.0 34=2.8 36=2.5 38=2.2 40=2.0 43=1.8 45=1.6 48=1.4 50=1.3 53=1.2 56=1.0 60=0.9 63=0.8 67=0.7 71=0.6 75=0.6 80=0.5 95=0.4 90=0.4 95=0.3 100=0.3

#7 of 7 OFFLINE   Edward J M

Edward J M

    Screenwriter



  • 2,031 posts
  • Join Date: Sep 22 2002

Posted December 10 2004 - 06:42 AM

Yes, that's how far low (hence the negative) the meter will read at a given frequency. So you ADD that amount to the meter reading to obtain the actual SPL. So at 20 cycles, a c-weighted SPL meter will be reading about 6.2 dB low. So if the meter reads 80 dB, the actual sound pressure is 86 dB. And so forth for all the other frequencies listed above. Regards, Ed Regards, Ed
Ed Mullen
Director - Technology and Customer Relations

SVS

www.svsound.com

"What we do in life, echoes in eternity."





0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users