Here are the pics I promised. The global state is good for a paper that has over 30 years saved in a book. Observe the switch labeled spatial and a second switch ganged with the play/record control. It mixes partially both chanels. Again, it was a cassette player/recorder.
Attachments
Thanks for sending. That's interesting I would have like to listen to that cassette player. Did you ever hear it? I had a coworker who wrote code to simulate vinyl playback, it was more involved than I thought. Wondering if vinyl playback has the same spatial effect because higher frequencies will crossover more and that seems like an enjoyable effect.
As the mix is essentialy resistive, it is independent of frequency. However, as the phase of the signals on two stereo signals are more easily encountered in higher frequencies (low freq are more similar in both channels) the effect tends to upgrade medium and higher notes.
In my homebrewed audio amp never finished, I added a 3rd chanel obtained from the substraction of the signals on both L & R and amplifiying this difference and is applied to a loudspeaker placed at the back of the listening chair. L is ~ 45 deg in front, and R idem. The third channel has its own volume control. Excepting mp3 under 128kbps, the best mp3, ogg, aac3, etc performs excellent given a sensation to be in the middle of the recording scenario. I have several CD's or MP3 from my prefered singer songwriters Joaquín Sabina and Joan.Manuel Serrat recorded live and it amazing. However, too much 3rd channel gain creates an antinatural listening, and each recording needs it exact dosis.
In my homebrewed audio amp never finished, I added a 3rd chanel obtained from the substraction of the signals on both L & R and amplifiying this difference and is applied to a loudspeaker placed at the back of the listening chair. L is ~ 45 deg in front, and R idem. The third channel has its own volume control. Excepting mp3 under 128kbps, the best mp3, ogg, aac3, etc performs excellent given a sensation to be in the middle of the recording scenario. I have several CD's or MP3 from my prefered singer songwriters Joaquín Sabina and Joan.Manuel Serrat recorded live and it amazing. However, too much 3rd channel gain creates an antinatural listening, and each recording needs it exact dosis.
Last edited: