smatchun@encore.encore.com (Scott Matchunis) (09/17/90)
I've been reading the discussions about Dolby (initially, whether Ray Dolby's possible hearing impairment might influence his engineering) and how well it works/doesn't work on cassette decks. So I'm curious, what is the consensus of opinion on DBX for home cassette decks? I have it on mine and like it much better than Dolby B. Have never compared it to Dolby C or any of the other noise reduction systems available. Anyone out there in "netland" using DBX on a cassette deck? What do you think of it? INTERNET: smatchunis@encore.com UUCP: uunet!gould!smatchunis Abstainer: A weak person who yields to the temptation of denying himself a pleasure. -- Ambrose Bierce, "The Devil's Dictionary"
eyal@echo.canberra.edu.au (Eyal Lebedinsky) (09/18/90)
In article <6354@uwm.edu> gould!infocenter!smatchun@encore.encore.com (Scott Matchunis) writes: [... intro deleted...]> >Anyone out there in "netland" using DBX on a cassette deck? What do you >think of it? I use a DBX222 on my deck (Nak580m and Nak700II). This is used on top of Dolby B and I like it very much. The 10db emphasis in the hights does tend to saturate the Dolby - so dolbyC will be much prefered. I did some A/B comparisons with CD source and TDK SA90 tape and could not pick any breathing (the most common complaint in wideband compressors). -- Regards Eyal
09nilles%cuavax.dnet@netcon.cua.edu (Fiver Toadflax) (09/19/90)
>Anyone out there in "netland" using DBX on a cassette deck? What do you >think of it? I have it both as a seperate component and as part of my tape deck. I find that if the volumes are not too high and you don't saturate the recording, that one can get very good results that are hard to distinguish from a CD. My tape deck has Dolby B, C and dbx. I have done some comparison's between the three where I don't record any signal. The backround noise is as expected noticeably less on the blank dbx encoded space. I haven't compaired my seperate with my dbx tape deck yet, and doubt I will. My opinion of dbx : I love it. Dave 09nilles@cua.bitnet
tomp@vicom.com (Tom Pohorsky) (09/20/90)
In article <6421@uwm.edu> 09nilles%cuavax.dnet@netcon.cua.edu (Fiver Toadflax) writes: >>Anyone out there in "netland" using DBX on a cassette deck? What do you >>think of it? > >I have it both as a seperate component and as part of my tape deck. What I was told a while back, and I still believe to be true is: There are basically two types or grades of DBX Noise-reduction circuitry. The better kind one finds in the 22x outboard boxes, and uses a higher voltage (9 ?). The type put inboard into cassette decks runs off a lower voltage, and the record-mode (compression) fidelity is not quite as good. Playbacks are virtually the same. Any one have any more on this ?? Allegedly the data sheet specs indicate this "lower" performance, but I don't have access to them. -- ames!vsi1!tomp tomp@vicom.com
ttak@uhura.cc.rochester.edu (Timothy Takahashi) (09/20/90)
In article <6421@uwm.edu> 09nilles%cuavax.dnet@netcon.cua.edu (Fiver Toadflax) writes: >>Anyone out there in "netland" using DBX on a cassette deck? > >I have it both as a seperate component and as part of my tape deck. I find >that if the volumes are not too high and you don't saturate the recording, >that one can get very good results that are hard to distinguish from a CD. > >My opinion of dbx : I love it. I beg to differ. I found dbx on a 1985 vintage Technics deck to be a-musical. Both dBx and Dolby C had noticable artifacts - primarily hiss "pumping" and tracking error. This was irritating : Dolby C mistracked on percussive material such as piano music, dBx pumped badly on vocal/operatic music. Despite the high hiss levels, Dolby B was relatively innocuous in operation. I've noticed the hiss pumping on stereo VCR tracks as well. My choice for recording is my old Teac X-3 open reel deck (a mere 65 db S/N ratio). This hiss is audible, but has a "soft" character. The sound quality seems more open and dynamic than cassette (w/ dolby B). tim
thurlow@convex.com (Robert Thurlow) (09/20/90)
In <6354@uwm.edu> gould!infocenter!smatchun@encore.encore.com (Scott Matchunis) writes: >So I'm curious, what is the consensus of opinion on DBX for home cassette >decks? I have it on mine and like it much better than Dolby B. Have never >compared it to Dolby C or any of the other noise reduction systems >available. I have Dolby B, C and DBX on a Teac deck. The deck sounds really good when I use DBX, except for breathing I *can* hear on some material. I use Dolby C mostly because of the compatibility with the rest of the world, but it mistracks just enough to dull the highs, and I've never got round to tweaking it. I thought I'd use DBX a lot more, but the work involved in making tapes makes me reluctant to put a lot of work into tapes that I can't use in my walkman or in my car. Rob T -- Rob Thurlow, thurlow@convex.com or thurlow%convex.com@uxc.cso.uiuc.edu ---------------------------------------------------------------------- "I was so much older then, I'm younger than that now."
strong@tc.fluke.COM (Norm Strong) (09/22/90)
In article <6354@uwm.edu> gould!infocenter!smatchun@encore.encore.com (Scott Matchunis) writes: }I've been reading the discussions about Dolby (initially, whether Ray }Dolby's possible hearing impairment might influence his engineering) and }how well it works/doesn't work on cassette decks. } }So I'm curious, what is the consensus of opinion on DBX for home cassette }decks? I have it on mine and like it much better than Dolby B. Have never }compared it to Dolby C or any of the other noise reduction systems }available. } }Anyone out there in "netland" using DBX on a cassette deck? What do you }think of it? I have dbx. I find it a definite improvement when using cheap Type I tape, such as C-120. But I use Dolby C with Type II tapes, mainly because I'm concerned with the future availability of dbx equipped decks. Another problem with dbx is inferior bass response. The quicker the aperture response of the encoder, the sooner the bass has to roll off. Not much you can do about this. -- Norm Strong (strong@tc.fluke.com) 2528 31st S. Seattle WA 98144
drm2@mvuxn.att.com (David R Moran) (09/24/90)
In article <6446@uwm.edu>, tomp@vicom.com (Tom Pohorsky) writes: > In article <6421@uwm.edu> 09nilles%cuavax.dnet@netcon.cua.edu (Fiver Toadflax) writes: > >>Anyone out there in "netland" using DBX on a cassette deck? What do you > >>think of it? > > > >I have it both as a seperate component and as part of my tape deck. > > What I was told a while back, and I still believe to be true is: > There are basically two types or grades of DBX Noise-reduction circuitry. > The better kind one finds in the 22x outboard boxes, and uses a higher > voltage (9 ?). The type put inboard into cassette decks runs off a > lower voltage, and the record-mode (compression) fidelity is not quite > as good. Playbacks are virtually the same. > > Any one have any more on this ?? Allegedly the data sheet specs indicate > this "lower" performance, but I don't have access to them. > > > -- > ames!vsi1!tomp tomp@vicom.com dbx comes in two flavors, type I and type II. The former is for better media (e.g., tape decks > 15 ips) and goes slightly lower in the bass (to the octave below 40 Hz). Type II is more forgiving and was designed for cassettes, encoded LPs, video tape (NOT with HiFi audio, though, which is similar to type II in the first place, wrapped around FM), 7.5 ips open-reel etc..... I and II are not compatible, having different preemphasis and deemphasis curves. II is highpassed at around 40-30 Hz. Type II in cassette decks is not always up to the standard of outboard dbx-manufactured II boxes, as in 228, 224, and other model numbers for that family. But it often is; the chips are good and uniform for the most part. Some cassette deck manufacturers implement things with care, some with less care, same with Dolby; there is no safe generalization. Sonically the difference with so-called inferior chip sets and noisy stages and loose-tolerance preemph/deemph is still going to be very small. So I would not sweat it much. Compared with how cassettes fail in wow and flutter, scrape noise, noise-floor modulation, azimuth consistency, plus al the bias and EQ headaches, etc. etc. etc. (it's a loathsome medium, really, requiring tremendous compensatory engineering), NR is not usually the salient problem to my ear. Although Dolby can be fussy. With dbx, just keep your levels high and hit the tape hard. One advantage with outboard dbx is that you can wrap it around cassette with Dolby B, which helps.... dbx sonically is just fine for everything but sharp events where the harmonics are not loud enough to mask successfully. Piano, especially low-level piano, bongos, wood blocks, sometimes plucked bass, baseball bats, and the like all may reproduce with noise tails that are the sound of the tape noise floor being modulated by the companding. The better the S/N the lesser the problem. With other material, from rock to choral to orchestral to flute, no prob, and usually good results. And very very very quiet.
bill@uunet.UU.NET (Bill Vermillion) (09/24/90)
In article <6537@uwm.edu-> strong@tc.fluke.COM (Norm Strong) writes: ->In article <6354@uwm.edu> gould!infocenter!smatchun@encore.encore.com (Scott Matchunis) writes: ->}I've been reading the discussions about Dolby (initially, whether Ray ->}Dolby's possible hearing impairment might influence his engineering) and ->}how well it works/doesn't work on cassette decks. ->} ->}So I'm curious, what is the consensus of opinion on DBX for home cassette ->}decks? I have it on mine and like it much better than Dolby B. Have never ->}compared it to Dolby C or any of the other noise reduction systems ->}available. ->} ->}Anyone out there in "netland" using DBX on a cassette deck? What do you ->}think of it? -> ->I have dbx. I find it a definite improvement when using cheap Type I ->tape, such as C-120. But I use Dolby C with Type II tapes, mainly because ->I'm concerned with the future availability of dbx equipped decks. -> ->Another problem with dbx is inferior bass response. The quicker the ->aperture response of the encoder, the sooner the bass has to roll off. ->Not much you can do about this. Not a comment on dbx on cassettes, as I have never used that combination, but a comment on dbx in general. We had 48 tracks of dbx encoding at our studio 24 permanently in one room , 16 in another, and 8 tracks that floated between the two studios. A room had a 16/24/32 track machine and B had a 16/24. dbx's compansion/eq routines expect a machine to be reasonably flat. Any anomolies in the rec/pb chain are exagerated. Our 32 track head-stack had a rec/pb bump of almost 2db in the 175-200Hz range, so when doing dbx on a 32 track session, we depressed that band by about 2db during the rec process so that pb was relatively smooth. Otherwise we had about 4db bump at that frequency. We weren't that worried about compatibility as there were very few 32 track 2" analog studios in existance. We were perhaps the third, and at the most the 6th in the world the day we opened our dooors. Number one and two were a Cinecitta (sp) in Rome, and Dieter Dirk's (sp) in (I think) Colgone Germany. These were both Telefunken machines, there was another Telefunken in LA, we had a Steven's. I suspect there were not more than 50 in existance, if that, and Queen's producer had a portable 32. With track width's the same as a 4 track quarter inch, noise reduction was almost a neccesity for 15 ips sessions. As for 32 track 3", I think only the pro-type I saw ever saw any service in the real world. The move to a 22.5 ips speed AND 3" tape effectively put that out of contention. -- Bill Vermillion - UUCP: uunet!tarpit!bilver!bill : bill@bilver.UUCP
tasos@bucrf13.bu.edu (Anastasios Kotsikonas) (09/25/90)
I am using a 224x with a Revox B77 MkII. It's dynamic range when recording LP's is more than adequate. I haven't tried recording from a CD, because I see no purpose. -tasos
jbulyk@twwells.com (Jerry E. Bulyk) (09/25/90)
Hi: I have been using dbx with a Nakamichi LX-5 (3 head) cassette deck for ~ eight years and absolutely swear by it. Actually, the reason I got into dbx was because of my first cassette deck (a Harmon-Kardon). It had what turned out to be a badly misaligned Dolby calibration. By throwing a dbx on top of the H-K, the faulty Dolby was bypassed, and the results were excellent. But, in disgust, I dumped the H-K and bought the Nak instead. This was circa '82-'83. Turns out, the Nak Dolby implemen- tation is excellent and with their Dolby C, I could have almost avoided dbx. dbx does provide a greater reduction in noise, without a doubt, but there exists a minor side effect which has been described as "pumping" or "breathing"; an effect of a rising/falling hiss around some notes. I have noticed this effect mostly on solo piano; since a piano is almost a percussion instrument in terms of its attack, dbx sounds a little slow in following the notes. For such, Dolby C is available with slightly increased hiss without the dbx side effects. With other forms of music, no such effect is heard. The best demo for dbx traditionally, has been the "blank tape" test: record nothing on a three head deck, first run w/o any noise reduction, then apply Dolby B, then switch to C, then to dbx. The drop in tape hiss is obvious to any non-audiophile. The dbx implementation does indeed differ between those found in outboard units made by dbx, such as the 224, and those built into decks. For some time, I used to have a luxman cassette deck (with built-in dbx) at work (as my walkman). I did not find it suitable for making dbx recordings. I recently bought a second nak, and a dbx for it; I have dbx in my car stereo, and consider dbx the only noise reduction system which does not introduce any additional tape hiss into a cassette recording. In summary, I would recommend dbx for cassette decks iff it is an outboard unit manufactured by dbx. - jerry Jerry E. Bulyk TeleSciences C.O. Systems, Inc INTERNET: jbulyk@telesci.uucp UUCP: ...!princeton!telesci!jbulyk
strong@tc.fluke.COM (Norm Strong) (09/27/90)
In article <6421@uwm.edu> 09nilles%cuavax.dnet@netcon.cua.edu (Fiver Toadflax) writes: }>Anyone out there in "netland" using DBX on a cassette deck? What do you }>think of it? } }I have it both as a seperate component and as part of my tape deck. I find }that if the volumes are not too high and you don't saturate the recording, }that one can get very good results that are hard to distinguish from a CD. } }My tape deck has Dolby B, C and dbx. I have done some comparison's between }the three where I don't record any signal. The backround noise is as expected }noticeably less on the blank dbx encoded space. I haven't compaired my }seperate with my dbx tape deck yet, and doubt I will. } }My opinion of dbx : I love it. I have all 3 on my tape deck, too. I find dbx handy for recording on C-120 tapes, or other tapes using low grade Type I oxide. On better tape I stick with Dolby C, not because it's better, but because it has better "portability". You know, it's possible that I won't be able to replace my dbx deck when it wears out. -- Norm Strong (strong@tc.fluke.com) 2528 31st S. Seattle WA 98144