Send an e-Mail to: see " SSB RX Setup" and " SSB TX Setup" for more details and explanations.Īll information given on this site are the express opinions of NU9N and I assume no responsibilityįor the outcome produced by such suggestions and opinions that may cause band splatter, distortion and/or unacceptable transmitter I. If I can be of any assistance in any way with your setup, With a few fundamentals being presented, this site was designed to help you achieve a sound that would produce a graph similar to GRAPH 1 for both transmit and receive. The Cyan graph was made while listening to a 3.5kHz (N2) SSB station.Īnd the Yellow graph was made while listening to one of the prominent DX'ers on the 20 meter band which is more common for SSB than not.
The Red line was yours truly on my Kenwood TS-850S / DSP-100 with some processing. AM Broadcast (White) has about a 9.5kHz audio bandwidth (that's a 19kHz RF bandwidth) and is relativelyįlat from about 60Hz ~ 9.5kHz with roll-off occurring below and above this. Pink Noise is perfectly and perceptibly "Flat" (linear as opposed to logarithmic) descending 3dB/Oct., and spans from 20Hz ~ 20kHz. These lines look a bit confusing, but as you can see, there are some major differences in these graphs and in the sounds of each audio source that produced them. See the "eSSB" Page for a complete definition of eSSB and it's purpose. Obviously, some of this has to do with some psyco-accustic perceptions of what and how we hear.Ī sound that would produce a graph with equal amplitude across the frequency spectrum would sound very brittle! Great for DX, but not so pleasant for extended and pleasing listening! 3kHz bandwidth, being 1/3 of this, would then require less of a roll-off (by 1/3) resulting in 1dB/Oct. If we were working within a 3kHz bandwidth, I would choose a 1.5 dB/Oct roll-off since broadcasters in 9.5kHz bandwidthsĪnd above use a 3dB/Oct roll-off. I picked a 2dB/Oct slope was to make up a bit of perceived high frequency response that is lost in this bandwidth. Properties that is relatively "FLAT" within a given bandwidth of 50Hz ~ 4kHz or more with audio amplitude descending linearly by about 1dB to 2dB per Octave (depending on the bandwidth being used) as we move up in frequency. Also, "Good quality" is a very subjective term determined by several factors, such as your hearing attributes, the transceiver being used, your transceiver bandwidth, the headphones being used (ifįor our purposes here, I am going to define the medium or "Mid-Fi" threshold of "High Quality Extended SSB Audio" as being audio with very low IMD and Harmonic Distortion Of course, there are several variables that will determine
It is my desire to be of some assistance in providing some fundamentals regarding good quality SSB audio transmission and reception. Introduction to eSSB Hi-Fi Audio ProcessingĮSSB SSB Hi fi, Mid fi and Low fi audio for Amateur Radio that increases the intelligibility and reliability of communications audio is my primary focus for designing this web site.
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