cb29+@andrew.cmu.edu (Chad Kavanaugh Bisk) (10/30/88)
The decisions NeXT made regarding their sound chips and overall sound quality seem quite understandable. My reasoning is as follows: 1) The 16-bit, 44.1 KHz D/A chips are useful not for playback of a voice message or anything else that you recorded on a NeXT machine, but for sound synthesis and digital playback at the de facto digital standard level (e.g. Compact Disc). 2) There is only one speaker provided in the NeXT system so playback at the machine can only be in mono. The single speaker is also probably not really good enough to handle the full range that the two D/A converters can produce. It is, however, completely suitable for the job of playing a voice mail message. This and primitive sound generation are what can be done with a bare NeXT. Note that the sound demos heard at the announcement ceremonies and elsewhere were piped through the stereo RCA jacks into external speakers, not through the internal NeXT speaker. 3) It looks as if Jobs was aiming more towards the musical workstation concept when he decided on these features. This is consistent with the concept that the NeXT machine is the computer "for the rest of academia". The external RCA plugs make this an ideal machine for incorporating into a university music studio (or a college room stereo setup). One 8-bit D/A would have been suitable for voice mail applications (any more is wasted on an internal computer speaker), but a musical workstation requires much more audio resolution. There are already some high-end systems on the market (like the Synclavier) but low-end competition is non-existant. This field seems ripe for the pickings. 4) The 8-bit codec (just what is "codec" short for anyway?) is plenty powerful for its intended purpose: voicemail. At 8-bits the quality of the sampling will be as good as, if not superior to most telephone lines. The codec is not meant for stereo CD sampling for many reasons. First, most people don't have true stereo microphones handy. When Jobs decided on a microphone input, he had to pick something basic, standard and cheap. One, mono plug was the result, thus only one codec was neccesary or even useful. Second, good sound sampling is much harder than it seems. You need a good, expensive stereo mic, good connectors, and a quiet studio quality room to do the recording in unless you want your sound samples to sound like they were recorded using an answering machine. This is not the averge setup the NeXT machine is aimed for. Anyone with needs like this will be willing to get a good, external digitizer (of which there are already several on the market) that can hook into the Mac-style serial plug on the back of the NeXT machine. One tremendous and as yet unmentioned advantage to the basic setup is that when hooked up to a fast network via NFS, any NeXT machine capable of voice mail (i.e. having a microphone or an operator headset) will also be capable of real live 2-way packet-switched voice conversations. This would require writing some software and would load down the net, but the advantage of real time communication in a networked environment is incredible. -- Chad Bisk -- cb29@andrew.cmu.edu