compression

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  • Updated 2 years ago
Normally run an inexpensive electret condenser mike for SSB DX on my 6500. I just connected the Heil PR40, and while the reports are excellent, I noticed that the compression level is barely kicking up. The mic level is fine. I suspect that the compression is driven by the frequencies where talk power is developed from. Any suggestion as to what I might be able to increase slightly with the EQ? Merry Christmas to all!
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WA2SQQ

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Posted 2 years ago

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Barry N1EU

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Good question Bob!  I use a Rode Procaster so the topic interests me as well.

If I could offer a suggestion to gather some initial data.  Do the SSDR FDX trick - put 6500 in FDX, open a 2nd slice on same frequency, route tx to transverter output (instead of antenna), and record the signal coming into the other slice receiver.  Use DAX RX 1 to route the audio to Audacity.  Make recordings of transmissions using both microphones and the same spoken phrase and use the Audacity - Analyze - Plot Spectrum function to compare the audio spectrum being transmitted through both mics.

73 & Happy Holidays to all,
Barry N1EU
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Barry N1EU

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Here's a data point, with PROC on "DX", I see Compression deflections of 25-33% of full scale (-25dB) speaking "test  test  test" into the microphone with audio level peak indications between 0 and -5dB and Low Cut at 50Hz.
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Walt - KZ1F

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And that's a good point that Barry just made. Where do you have the processor set to, 0, 1, or 2?
I have the Heil HM-PRO and I generally have the equalizer set to where Ken advertised he set it to back a year or so ago. As I recall at the time he, too, had a Heil PR-40. I don't know what the difference between those two are but, like you, I always get great audio reports. At 0, slider full left, there is no compression. At 1, proc slider centered I see a little bit. At 2, full right, I get about upwards of 50% compression. That's what leads me to ask about your proc setting.

73, Happy Holidays to all.

Walt - kz1f
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WA2SQQ

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I just connected an audio generator to try and identify what freq would produce more compression. Nothing that is obvious. So wit my PR40 in the DX position I can achieve peaks up to the "n' in "Compression". With my Radio Shack condenser mic I see peaks up to the "m". Mic level is adjusted so as to produce peaks that occasionally hit "0" on the level scale. One difference - PR40 is fed to the balaced input, while the RS is plugged imto the front panel. PR40 definitely sounds better, but I'm just curious what the RS mic has more of?
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WX7Y

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Here is a starting point that fits MY voice really well on my PR40 for the mid range communications.
If your interested in my settings for the Rag Chew and DX settings let me know.

Merry Christmas to everyone

Bret
WX7Y
(Edited)
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Peter K1PGV, Elmer

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I'm always interested to see other people's EQ settings. Also, you tx bandwidth would be interesting as well, to put the setting into perspective.

Peter
K1PGV
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WX7Y

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Here are all 3 of my settings Peter not a lot of change between them but enough to make things sound the way I like it with MY voice anyway.
73's and Merry Christmas

Bret WX7Y

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Barry N1EU

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The Flex compression seems to be frequency independent.  Here are spectral plots speaking the same phrase with increasing level of compression.  The amplitude increases uniformly across the spectrum:



73 & Merry Christmas,
Barry N1EU
(Edited)
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Ken - NM9P, Elmer

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See my YouTube tutorial about adjusting audio. Search my call.
When using DX and DX+ processing, it is best to cut the lower frequencies because they will add artifacts and distortion that mush up your audio. Boost the highs on the EQ a little. Give the spectrum response a slight rise from 1k to 3k. This will improve readability for weak signals and in pileup a.

Ken - NM9P
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EA4GLI - 8P9EH - Salvador

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Hi guys,

Have you seen any difference in the way PROC works with v.1.6? 
Any more tests with different mics?

I still get the best audio out a yamaha CM500 electret capsule headset, but i want an alternative for time where I might not want to have the headphones on. 

The procaster from RODE sounded great when I heard Barry on the air.

Any alternatives? Other opinions?

Thanks!
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Dan -- KC4GO

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Yes and a Heil foot switch or hand switch for PTT ( Some times when I'm lazy VOX) 
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Ken - NM9P, Elmer

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Yes, if you have a 6500/6700 the XLR/BAL input is the the best way to go.  It gives you the best balance and isolation from noise and RF feedback.  I am using the 1/4" TRS plug, but the XLR would be a bit more sturdy.  It is nice that the jack will accept both types of connectors.

I also use a footswitch that I got from a commercial/industrial supplier on eBay.  It is very solid, rugged, and gives a good tactile feedback when I press it.

http://www.ebay.com/itm/TEMCo-Aluminum-Foot-Switch-10A-SPDT-NO-NC-Electric-Power-Pedal-Momentary-New... 

I got two of them when they had a special deal for for a pair.  I have been using this one for almost three years with no problems.  I still have a spare in the box!

Ken - NM9P
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Barry N1EU

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Yikes, avoid the Heil foot switch like the plague!  I've had so many of them fall apart, very flimsy construction.  Like Ken, I use a commercial foot switch and it's a dream.
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KY6LA - Howard, Elmer

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I agree 100%. The Heil Footswitches and Handswitches are far too flimsy for serious use. Had a lot of them fail before we gave up on Heil
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Ken ve7kwa

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Same here... switch quality & price don't jive.  About the only Heil piece I'm impressed with is my PL2T boom.