I've found that you have to click the Lowpass frequency setting once click at a time to reach the desired setting. Will have to do this in several sessions otherwise I may end up with Carpal Tunnel Syndrome.
Good to know that you can set the high end a bit lower than 10k and still achieve satisfactory sound. I will have to do some on air tests once I receive my new transmitter to see what the best high end level will be.
Surprised to hear that by tinkering with a FM preset you were able to get a more desirable sound on AM. I may try that myself then.
Do you think that the Basic version is adequate for a music station playing Smooth Jazz or AC Oldies provided that the files are either a 16 bitrate for mp3's or .wav files with at least FM quality sound? Or will I need to purchase the Declipper or Delossifier? These seem essential for FM broadcasting but I have had a couple of people tell me they are probably not needed for AM especially the Delossifier provided the recordings are decent.
Also, I take it you are using stereo recordings for the files but then use the Stereo to Mono for AM downmix feature for OTA playback?
You should be able to move the lowpass slider byholding the left mouse key and dragging the slider where you need it. I just checked and it works fine.
On using FM presets: They are a good place to start. You might find you need (want) so move bandwidth sliders around, and change things like attack/release constants, equalizer and clip settings. In any case, I've found a good sounding FM preset seems to be a better place to start than an AM one. It seems the Europeans use 5kHz bandwidth far more than in the US, and the presets in ST tend to reflect it. Also, timing constants are pretty subjective. I have my own criteriae, which doesn't always match up with the stock offerings. Such is the beauty of this software. Unlike some hardware boxes, made by the legacy manufacturers, ST gives you full rein to sound great, or awful. It may take you a while to be really satisfied with your sound. Be diligent in saving your work whenever you make a change. If you do, you can always go back to a previous setting.
What you license depends on what you'll need. For AM, you don't need all of the FM features. If you're playing hot CD material, you may want the declipper. The delossifier may not matter if you don't feed low-grade audio or MP3s to the processor. In any case, none of the features in the system are locked out. Though you may get an occasional nag recording, you can test any part of the software and decide for yourself what you want.
On processing in stereo: Very few of the stations I care for run monaural audio chains. I tend to like that ST can process left/right separately, to the degree you wish. I think the final result sounds better that way. The AM transmitter window has a "downmix to mono" flag, which sends the same mixdown out both left and right sides. If you put ST at the end of a monaural feed however, it will still work well. I'd still tend to feed both the left and right inputs however, as ST seems happier when it's not working with an unused channel.
By doing mono mixdowns and using the USB Matchbox, I'm able to feed (for example) the left output to a main transmitter and the right to an aux. That saves on the cost of a separate distribution amplifier.