5121cdd@houxm.UUCP (C.DORY) (12/27/83)
The new Beta Hi-Fi concept is truly the best thing that has happened to videophiles since color TV, melding high-quality video and audio into a single system which is, afterall, upward compatible with the standard Beta system. This is, however, not to say that Beta Hi-Fi surpasses, or even equals, other recording technologies. First, let's look at how Beta Hi-Fi does in comparison with the audio cassette deck, its nearest competitor. By itself, the Beta Hi-Fi technology boasts only 60dB of S/N (internal noise reduction, seemingly similar to dbx, is used to obtain the advertised 80dB S/N of the units on the market) so it is only fair to compare the S/N specs to a cassette deck with noise reduction -- a good cassette deck with dbx will also boast S/N of around 80dB: a tossup. As for frequency response, we also have a tossup: both machines are fairly flat to 20K Hz at -20VU, however, as recording level increases, the high frequency response of BOTH Beta Hi-Fi and cassette decks go to pot. As far as distortion goes, both systems introduce the same order of magnitude of THD into the music, however, in using the metal (type IV) formulations in cassette tape, this can be reduced somewhat. Therefore, the only significant difference between audio cassette decks and Beta Hi-Fi is the Wow & Flutter with the Beta Hi-Fi performing better. Now, for those with enough chutzpah to compare Beta Hi-Fi with a pro open-reel mastering deck. The only Beta Hi-Fi I have had direct experience with is the Sony SL-2700 -- a fine consumer machine. However, mini jacks, can you believe it, MINI JACKS are used for mic inputs and headphone outputs -- this is fine for Walkmen and the like BUT NOT RECORDING EQUIPMENT. Good quality mic cable WILL NOT fit into the mini-jack plug housing, therefore you must use an adaptor of some form, forcing extra weight to be supported by the jack itself...get my drift? As well, the mic inputs are unbalanced so if you want to use them with high-quality condenser mics (which normally require an external power supply to polarize the element and power the electronics) forget it without a line-matching transformer or external mic pre-amp. In fact, an external mic pre-amp is not a bad idea since the mic pres in the SL-2700 aren't too hot. As far as specs go, the SL-2700 can't hold a candle to a reasonable open-reel deck, much less to a Studer or Nagra. For example, my (modified) Technics RS-1500US half-track machine has a flat (+0, -3dB) frequency response from 30Hz to 32KHz!! (at 15ips, 0VU re. 250nW/m) The S/N (with pro dbx) is well in excess of 80dB, and the Wow & Flutter is 0.015%. In use, the SL-2700 seems to have been designed by Astro-Boy (busy control panel) -- I wouldn't want to have to depend on finding the correct knob in the dark. Overall, I hope I've made my point that the Beta Hi-Fi is great for watching "Raiders..." with good-quality sound or for recording a simulcast to appreciate the simule -- but if location recording is your game, spend your $1250 on an open-reel deck and a dbx unit. Craig Dory -- AT&T Bell Laboratories Holmdel, NJ
rmd@hpcnoa.UUCP (01/02/84)
#R:houxm:-65800:hpcnoa:30200007:000:458 hpcnoa!rmd Dec 30 14:25:00 1983 I disagree with the statement or implication that cassette decks are as good as Beta HiFi. dbx really increases the sensitivity of a cassette deck to misalignment and head wear. You have to spend a lot to get a cassette deck with adequate frequency response and then they never seem to match the manaufacturers specifications. Also, music passed through ANY noise reduction system never sounds quite the same as the original. Rick Dow hpfcla!rmd
5121cdd@houxm.UUCP (C.DORY) (01/04/84)
Again, the point is missed -- remember that the Beta Hi-Fi uses a companding scheme very similar to (I assume) dbx. Also, look at how dbx Type II noise reduction works -- frequencies above 10K Hz do not effect the RMS detection so mistracking (pumping) is reduced (i.e., head wear and misalignment are not a big factor). This, however, is not true with dbx Type I (professional) noise reduction, for optimum results flat frequency response is required +-1 dB. In practice, I find Dolby B (and even Dolby A - professional) much more objectionable than dbx. Dolby noise reduction is very level sensitive -- overall record and playback levels must be within 1 - 2 dB to avoid mistracking. This is why Dolby B recordings are not as transportable as advertised -- record/ playback electronics from tape deck to tape deck are not closely matched. I agree that no noise reduction is better -- for absolute sonic purity. However, as always, we are dealing with a set of compromises -- I personally hate tape hiss. dbx eliminates this problem while only paying the piper a small amount. Craig Dory -- AT&T Bell Laboratories Holmdel, NJ