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Low audio INRAD M650 microphone

Phil N3ZPPhil N3ZP Member ✭✭
edited February 2019 in FLEX-6000 Signature Series
I purchased an INRAD M650 desk microphone and base directly from INRAD at Dayton after learning they were being sold and recommended by Flex. I used it first with a 6300 and now have a 6400 and in both cases it appears that this mic has low output. I know it's a dynamic mic so I don't have bias on but have checked +20 db. I always have to run the processor and run the audio as high 60 to 70 but still appear to have low power output on a peak reading watt meter even on voice peaks both when running 100 watts or driving a KPA500 amp at about 20 to 22 watts drive. I have the mic stand set so I can speak pretty close it it. I am running V2.4.9 and using the M650 mic profile. I am using the RJ-45 adapter cable, plugged into Maestro MIC-1. I have tweaked the equalizer a bit but haven't seen much change. I do see modulation if I view the VU meter display but never gets close to the red end. I don't want to keep raising the mic gain. I have been licensed for 57 years but mostly worked CW. I have been wanting to work more SSB now that I own a Flex.

My 6400 came with an FHM-2 mic and when using this mic with it's profile, the output looks significantly better. Although this works I would prefer to use a desk mic or headset I haven't looked at the Heil or Radiosport mics, which can get pretty pricey.

Have others experienced this problem with an M650 or M629 mic? Any suggestions for improvement are appreciated. I would prefer not to have to get a different mic. I considered getting a headset mic and see INRAD has the W-1 but expect I would have similar result, since it's also a dynamic mic.


Phil N3ZP


  • Larry _ W8LLLLarry _ W8LLL Member ✭✭
    edited February 2019
    My Electra voice RE-20 needs near 100% mic gain and DX or +DX with 20DB Boost in order to achieve between -10 and 0 db on the level meter. If your only at 60 or 70 % on the mic gain turn it up to what you need.

  • Ora SmithOra Smith Member
    edited February 2019
    I have the same problem, and just turned up the mic gain.  I find I like the  hand mic better than the very nice looking Inrad desk mic.   Ora W9DJ
  • KF4HRKF4HR Member ✭✭
    edited February 2019
    I've found that even with the +20db gain activated and mic gain set to max, my Flex-6700 doesn't have enough audio drive for certain microphones.  This was the case with my Electro Voice RE-27nd.  Thanks to some great advice I added a StudioProjects VTB1 preamp which solved the problem.
  • Phil N3ZPPhil N3ZP Member ✭✭
    edited February 2019
    Thanks. I didn't think I should have to run the gain that high. I'll have to try that.

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