Requests for Version DC8 Product Inputs

[Craig Maier]

Quoting Jos:

"Another useful application of separate M-S processing is reducing hiss in FM radio stereo recordings, which is present in the S-channel only."

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You can get some pretty good hiss reduction of stereo FM signals right now with the channel blender. Check out some of the presets that involve summing to mono signals above a certain frequency (like 3000 Hz or 5000 Hz).

Craig

[Dan McDonald]

A feature that would be most welcome is an automatic speed adjustment to the 50 or 60 Hz mains frequency (present in recorded hum around 50/100 or 60/120 Hz).
Jos

I think we talked about something like this a few years ago. I'd vote for this also if it's possible. I think there were some issues with it, though.

Dan

[weskola]

Unless these functions are already there and I just haven't found them, how about the following?

Suggestion 1 for DC8: Ability to "open append". Example 1; select 2 or more files which would then append each other to one file when opened. Example 2; open one file and then "open append" a second file which would append itself to the first file.

You currently have to 1) open 2 or more files, 2) copy one of them, 3) select the other file and then select Edit/Paste/Append to End. And then repeat for more files.

Suggestion 2 for DC8: A shortcut to repeat the last command (perhaps a function key such as F3, F4, etc.).

[Dan McDonald]

Hey Weskola -

You can run the batch process of concatenate files. Just list them in the order you want them.

Dan

[Dan McDonald]

Presets for Spectrum Analyzer

I'd like to have the ability to save presets for the spectrum analyzer if that's possible. Everytime you stop it and change a parameter, you have to put the start and stop values back, etc. It would be nice to select a preset for whatever you need it to do on a regular basis.

Dan

[James]

Perhaps there is something like this already, but I believe it might be helpful if one could open the spectrum analyzer and, once a file is playing, have the ability to highlight a section of the SA and only that section would be heard. That way you could hear what you are seeing. I envision left clicking and dragging to define the range on the spectrum you want to listen to. I think this might be helpful in defining what the frequency range is of a record so one can set the band pass filter more effectively. It is one thing to 'see' it on the SA, but for me, it would be a whole lot better to actually hear what that bouncing line is telling me. Does my description make any sense?

[Craig Maier]

Hi James,


Try bringing up the Spectrogram found under the Forensics menu; I think that you will find that provides you with what you want. The spectrogram will follow your zoom level so that you can see what you re hearing. Let me know if you agree.

Craig

[James]

Well, never checked that out before! Frankly, I am not sure what I am seeing with that. Before I run the band pass filter, I like to play a file with the Spectrum Analyzer open and see if I can pin point where the high frequency goes from music to noise and then run my band pass filter accordingly. I understand the basics in regards to frequency response for 78's, but that is just a rule of thumb so I like to try and confirm via the SA. That being said, it is not always that clear to me where that transition really is. If I could listen to a selected section as highlighted on the SA, that could help confirm my search I would think. Plus, if there were other peaks, etc., I could check those out as well and see what is driving them.

[Dan McDonald]

It sounds like James is asking for something that would restrict what is played to a specific frequency range.. So, for example, if you see a particularly loud sound on the spectrum analyzer, you could highlight it and all you would hear is the range you have highlighted.

I think Craig is talking about selecting a given time period but hearing everything in that time period, right?

So, for example, selecting a frequency range in the spectral filter rather than selecting a certain section of time in the spectrogram.

Maybe I have it wrong. But that's what it sounds like to me.

Dan

[Craig Maier]

James,

I do that all the time with the Spectrogram. The horizontal axis is time, the vertical axis is frequency (you can set up your preferences for the Spectrogram in the Edit/Preferences Menu. The Z axis (brightness and/or color) represents the amplitude of the signal.

The controls on the right effect the intensity and the contrast of the display (more detail can be found in the help file or users guide.)

If you want to use the spectrum analyzer, you can simply highlight a sector of the audio file of interest and put the system in looped play while viewing the spectrum analyzer.

Or, am I not understanding the problem?

Craig

[James]

Dan is right on the mark. I think it would be helpful if we were able to select a frequency range on the Spectrum Analyzer and then only hear that frequency range being played back. I am sorry I am so clumsy in trying to make my point, but Dan summed it up nicely. I would like something that helps me understand aurally what I am seeing with the Spectrum Analyzer specifically. I want to zero in on a specific frequency range as defined by me, not something that plays or shows all the frequencies in a specific period of time.

[Craig Maier]

Oh, I see. Well, we could do that, but here is how I do that now:

I bring up the IIR bandpass filters in conjunction with the spectrum analyzer. I adjust the lower and upper frequency controls until I come to an understanding of what range of frequencies are useful in the signal. I usually use steep slopes when doing this like 24 dB/Oct.

Does that recommendation help any? But, I do understand what you are asking for. We have the feature that you describe in the Forensics version (the spectral filter which is a combination of a spectrum analyzer and an fft based filter) but that is a very costly feature because of the environment in which it is used (government work).

[James]

Yes, I can see how you can set the band pass sliders so as to limit the frequency range you are hearing, but then the Spectrum Analyzer reflects that adjustment. The idea I had allows one to select the frequency you want to hear and see how what you hear relates to the rest of the spectrum. If you note a spike or a dropping off at a given frequency, you could highlight that area only and hear what is going on while using the SA to guide your investigation. I like the idea of being able to do this sort of thing on the fly so to speak.....

[Craig Maier]

I understand. I think that it is a lot like the Spectral Filter in the Forensics version. Maybe you can download the demo version of v.7.5 and see if that is true. It will be fully functional for around 10 days for experimentation. Otherwise, we will look into something simpler that we might be able to put into DC8.

[James]

Another thing that I have always thought would be helpful is if one could have manual control of the playback speed when viewing a file. This is most often an issue when trying to locate a click in a file. You can hear it, and as the file plays, you can follow the tracking line and see about where it is, but it moves so fast as to not allow you to really pinpoint where the click is. If you could somehow manually control the playback speed, you could zero in on the item with greater control. I envision something like setting a marker on the file that is locked to your mouse/trackball cursor. You then move the mouse/trackball left or right and and the file plays at the speed and in the direction you move. You could set the sensitivity in the options menu, much like you would for gaming applications. You could slide the marker back and forth, zeroing in on the click. Once you are right over the spot, you could perhaps release the left mouse button, leaving the marker in place, then you could highlight the area around the marker and zoom in as per normal for a closer view. Then, you could remove the marker by right clicking it or by some other user defined action.

I don't know, it would seem helpful to me