barry@jtids.UUCP (04/22/86)
This past weekend I bought the MacNifty Audio Digitizer with the software called SoundCap for the MacIntosh. Absolutly a fantasic purchase for only a list of $130. Here are the features and my review. The application needs 512K or >. SoundCap comes with and A/D converter which they call the BOX which can be hooked to either the modem or printer port. The input to the BOX is a standard RCA connector. The sampling rate is fixed at 22KHz but the software does filtering to allow 1/2,1/3,1/4 the rate to allow samples up to ~60 secs on a 512K. Output rate is continuously variable. An oscilloscope is included to allow you to see the input waveform in real time. This can be used to set the input level as to not allow clipping. The echo box command acts like a Digital Delay Lne unit. The delay time can be entered in milliseconds from, as they claim, 0.0001 seconds to 15 seconds! The echo level and regen level amounts can take values from 0 to 2.0. Using the Mac's external sound port, you can put this in your amplification system as a great effect. The feature that impressed me the most was the spectrum command which is a real time updating bar chart that displays amplitudes for many sample frequency ranges (ie. spectrum analyzer). This is accomplished using FFT (fast fourier transform) and as the resolutions increase the time between updates increases, but is fast none the less (what do you want for $130?). Once a waveform is sampled into memory, much digital signal processing can be used. The following is a summary of their 'Sound Effects'. 1. Silence - allows you to zero any selected part of the waveform. 2. Backwards - allows you to reverse the selected wave. 3. Amplify - increases volume (amplitude) by any amount. 4. Reverb - Digital delay like the echo effect (as mentioned above). 5. Ramp Up - Fade into sound. 6. Ramp Down - Fade out of sound. 7. Scratch Bar - pitch shift of sound. 8. Flange - add flanging effect to sound (programmable). 9. Noise - makes psuedo white noise. 10. Mix - Mixes sounds for overdub effect. 11. LowPass - high frequencies above the Nyquist limit for the selected sample ratio are eliminated. 12. DownSample - reduce the amt of space that a sound takes up in memory. To make the work easier, you can zoom in and out of the waveform display. You can also cut and paste (in normal Mac fashion) sections of the waveform. Because of the memory limitations, the Undo command is unimplemented in all of the functions so save good copies. These samples are very large so the biggest problem is disk limitations. To save to disk, there is an option to compress the data files. They have included a few "Goodies" all in the public domain! 1. SOUNDINIT - makes your sounds play on boot up. 2. BEEPINIT - replaces the system beep with any small digitized sound. 3. Type Writer - Install digitized old fashioned type writer key sounds so that when you type, you here key clicks, space key and return (shhhhhhhhhhhk bell). 4. Sound Play - allows you to play digitized sounds without needing SoundCap program. 5. Sound->Video - put digitized sounds into Video Works. I would have liked to have had the capability of drawing in sections of the wave to change or add to the existing wave. I don't really see the difficulty of adding this options since programs like the public domain program Sound Lab and Concertware etc. have this ability. SUMMARY- ALLOWS DIGITZATION OF EXTERNAL AUDIO SIGNAL AT 22KHZ. ABLILITY TO PLAY BACK SOUNDS ON MAC OR EXT SOUND PORT. OSCILLOSCOPE IMPLEMENTED TO SEE REAL TIME AUDIO SIGNALS. DIGITAL DELAY WITH DELAYS OF 0.0001 TO 15 SEC. USE AS EFFECT BOX! REAL TIME AUDIO SPECTRUM ANALYZER. I have probably missed a lot of clever uses for the program, but as they say in the docs----experiment! If you have any questions about this system, please e-mail. Tell me about uses and utilities that you have written or used, I am very interested. I know you're out there, I hear you aliasing! | || || | || || || | || || | || || || | || || | | || || | || || || | || || | || || || | || || | Barry "fingers" Kirsch | -- -- | -- -- -- | -- -- | -- -- -- | -- -- | |__|_|__|__|__|__|_|__|_|__|__|__|__|_|__|_|__| !burdvax!jtids!barry (Disclaimer- I have no connection to MacNifty or Fractal Software except as a satisfied customer. My opinions are solely mine etc.....)