Film-Tech Forum ARCHIVE: GOLDLINE DSP30 MIC

This is topic GOLDLINE DSP30 MIC in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=010605

Posted by V.V.Tushit Vijay (Member # 5455) on 09-14-2010, 03:00 PM:

Hi friends. I am Using Gold line DSP30 Real time analyzer With MK8C. But i had a problem with my mic. I am replace it with BEHRINGER ECM8000 i heard that it is also an omnidirectional mic. Can i Use it Will it measure the frequency in correct way.

Posted by Tony Bandiera Jr (Member # 2365) on 09-14-2010, 04:02 PM:

No you cannot, it will NOT be accurate. ANY mic used with an RTA MUST be calibrated to that specific RTA so that it will give the proper readings.

Posted by Gordon McLeod (Member # 33) on 09-14-2010, 05:57 PM:

actually that is not completely true
the mic input of a RTA is flat response and a calibrated mic will normally have a flat response usually measured against a BK reference
When the choice is made to use non calibrated microphones such as countryman then offset files are used to correct for them

Posted by Tony Bandiera Jr (Member # 2365) on 09-14-2010, 06:04 PM:

Thank you Gordon.

But would it not be true that a given "flat" mic's impedance must be matched to the input impedance (or input's impedance range) to ensure flat response?

Otherwise I would think that RTA manufacturers would simply give a range of model #s for all mics that will work with a given RTA.

In any event I do know that when I sent my RTA to be calibrated I had to send the mic too.

Posted by Gordon McLeod (Member # 33) on 09-14-2010, 08:33 PM:

it is best to send the mic
the standard for years was a capsule by AKG and one by B&K as was listed in Dolbys older manuals
Also electret condensor mics typically have very similar impedences

Posted by Sam D. Chavez (Member # 1841) on 09-15-2010, 09:00 AM:

The AKG was the standard only becuase Dolby picked it as an "affordable" mic. with good and known characteristics.

It's best to send the mic. back with the RTA so it can be checked for accuracy of response and so the SPL display can be set to be accurate.

Posted by Steve Guttag (Member # 268) on 09-15-2010, 07:42 PM:

AKG would also send a printout of the response of your mic too.

I know with the R2 and D2 we send out mics back annually for calibration. Then again, we also send our light/color meters back for calibration too (not to THX [Wink]

)