Thanks guys. > Yes, I agree that Alan is doing way too much cut on the low end.
I should have mentioned that the microphone is a computer-type headset with a boom mic, which probably has no frequency shaping at all. Plus I have a rather deep voice so, between those two factors, I no doubt need more bass suppression than most. > Also a response to Alan's suggestion of tuning for flat spectrum on the > display. IF, and ONLY IF, the spectrum display is providing a VERY FAST > and very reliable peak and hold response, that is a potentally useful > way to START. The problem is that most displays are averaging, I was using the peak mode on the P3 with averaging turned off. The peak is basically instantaneous, limited only by the bandpass filter in front of the FFT, about 4 kHz (+/- 2 kHz from the RF center frequency) at the narrowest spans. The hold time is infinite until you manually reset it. > But it is NEVER wise to depend > only on any form of spectral response display to set EQ. The final test > instrument must always be our ears and the grey matter between them. I should use the K3's DVR to send a test signal and listen on my TR7. The thing is, listening is so highly subjective that I figured that I'd get better accuracy using a spectrum display. Alan On Tue, 2010-11-16 at 23:00 -0800, Jim Brown wrote: > On 11/16/2010 10:19 PM, Joe Subich, W4TV wrote: > > > I ended up with: > > > > > > 50 Hz -16 dB > > > 100 Hz -16 dB > > > 200 Hz -16 dB > > > 400 Hz -10 dB > > > 800 Hz -16 dB > > > 1.6 kHz 0 dB > > > 2.4 kHz +3 dB > > > 3.2 kHz +6 dB > > > > I think that is doing too much cutting at the low end and not > > enough boost at the high end. Adding 6 dB at each band from > > 200 Hz to 3.2 KHz would make me more comfortable. Like, Jim > > I prefer to leave 50/100 at -16 regardless as they contribute > > nothing to communication. > > Joe, > > Yes, I agree that Alan is doing way too much cut on the low end. > > I meant to respond earlier to your recommendation of high boost. I've > helped a LOT of K3 users adjust their TX audio using a CM500, and I've > NEVER heard a CM500 that needed ANY boost EQ. I've also gotten a lot of > very positive reports on my CM500s (I own two) and I've never used any > boost. > > So I started thinking about why you might like boost -- after all, > you're a pretty sharp engineer. I can only come up with three scenarios > where you might prefer that. The first scenario is IF bandwidth on the > listening station. I always listen to the other station with my IF > bandwidth at about 2.7 - 3 kHz, because I don't want what MY RX is doing > to color my judgment of what the other guy is transmitting. So I get him > sounding good that way, and THEN I narrow up my IF to 1.8 kHz and listen > again. > > IF you listen at 1.8 kHz bandwidth with the high end of the IF cutting > around 2.4 kHz or below, you certainly ARE going to want a bit of boost > on the high end, because the RX IF is rolling it off.. But if you center > that IF a bit higher, you won't want that HF boost. > > The second scenario is that since CM500s are pretty inexpensive > products, there may be a fairly wide tolerance on the response of the > capsules. I've seen some anecdotal observations that suggest this might > be true. I DO believe, however, that the CM500s I own, and those I've > helped set up on the air, do NOT need HF boost. > > The third scenario is hearing loss. We old farts have put a lot of > mileage on our ears, I know that I've got some hearing loss, and so do > many of my friends my age, especially those of us who work with audio or > radio professionally, or even as active hams. The nature of MOST > hearing loss is that we lose the high end first, so we want more high > end boost. I find that I need to do that with many news magazine and > interview programs that have poorly produced audio. I find it > professionally disgusting that the technicians who produce these > programs have the balls to call themselves engineers when they obviously > don't know what an equalizer is for or when to use it. But don't get me > started. :) > > The reason I'm going through this is that I hear so much badly distorted > audio and splatter during contests, and the LAST thing that we need is > HF boost to produce more of it when the mic is already providing that > boost, and the CM500s I've heard DO have that HF boost built in. > > Also a response to Alan's suggestion of tuning for flat spectrum on the > display. IF, and ONLY IF, the spectrum display is providing a VERY FAST > and very reliable peak and hold response, that is a potentally useful > way to START. The problem is that most displays are averaging, and the > average power of human speech is greatest in the lower octaves, so an > averaging display should NOT look flat. But it is NEVER wise to depend > only on any form of spectral response display to set EQ. The final test > instrument must always be our ears and the grey matter between them. > > 73, Jim Brown K9YC > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
