There are lots of pro's and con's to dbx. The plus is obvious. There is a gain of around 30db in the signal to noise ratio or dynamic range of recordings encoded with dbx. This allows for an increase in headroom. That means the risk of any peak overloading is minimized and in fact I don't notice any instances of it in any of my live recordings. The downsides of dbx are several. First of all, some people hear artifacts with tapes processed with dbx. These are usually in the form of signal pumping and gating. When there is virtually no signal present the noise seems to disappear. When a small signal is present the gate is opened and there can be modulation noise present on that signal. Some will recognize this as similar to the artifacts left behind with the 'no noise' system. It is different but similar. Secondly, there is a lot of electronics in the dbx processing units including many vca's. These also have an effect on the signal. I think most of us once they know what to listen for, can usually tell whether a recording used Dolby A or DBX. There is almost a veiled sound of sorts. That said, many have found that the benefits of DBX outweigh the downsides. I personally used to use DBX-157 to make a series of live recordings in the 70's, including many jazz and classical acts. I can hear artifacts when listening to these tapes, but OTOH, there is hardly any tape hiss. This means that these recordings from the mid-70's sound much like digital recordings as far as hiss is concerned. Of course there were no digital recordings in this era. If I could go back, would I have not used dbx on these recordings? Hard to say, but I'd probably say no. In my case my recordings were made on a 1/4 track Revox at 7.5 ips. The benefits of DBX would be more significant in those cases than had I used a 15 ips 2 track pro recorder. There is one other phenomena I should discuss. The live tapes I made with the DBX system are harder to play than tapes I made without them. This is because of the larger dynamic range of those recordings. If I play them at a reasonable playback level the peaks can be too high and the low level sounds too soft. Recording on analog tape has a sort of built in compression as the tape starts to saturate, assuming the signal is recorded high enough. In most studio recordings this is not an issue because engineers can use compression to smooth things out. In a live recording without dynamic control this can become an issue. Of course the same thing applies to live digital recordings. You can't really blame the medium for allowing too much dynamic range. I always have been able to recognize DBX processing in a recording. It is my opinion that I'd much prefer a well made DBX encoded recording than an early digital recording which also had artifacts which I find more disturbing. As digital improved that distinction blurred. I guess we're now at the point where digital will sound better to most than DBX. Of course DBX encoded recordings still use analog tape and many people like the sound that analog tape contributes to recordings.
Hi Doug, What an awesome post. On a similar thread concerning NR I mentioned that I worked for dbx in the 80's. I also used dbx NR to record my country band and some of the things you mentioned are dead on. Fortunately, I have maybe 25 dbx-encoded LP's that all sound amazing. Some are live recordings, many are early digital, lots of classical....the pumping sound noticable on my homemade live tapes is not heard on these discs. All are dead quiet, even very quiet piano passages don't betray any noisy artifacts. Of course, we had lots of calibration issues with the various decoder models, but I found the Model 21 best. Thanks for sharing your story, Ron
Ron--was the Model 21 a model that used discreet components, or a newer one that had dbx on an integrated circuit? I have one of the latter, a rare dbx decoder for automobile use. It had only line level inputs and outputs, and also had bass and treble controls since using the same controls on your head unit would abnormally boost the bass or treble going to the decoder. I think my home model is a dbx 228...
Not to speak for Steve, but if I recall correctly, he hates it. If he has a project and finds that the master was encoded with DBX, he'll cancel the project. Period. Why? because it is next to impossible to get the tapes to play correctly. I mixed a big project for a friend several years ago with multis made with DBX. Even though I used the same deck the tapes were made on, there was still mistracking and mis-calibration.
Model 21 was the first unit made for the consumer. The 120 series also offered reliable service, but there were some maufacturing issues that should have been resolved with the 220 series, that clearly were not. The 228 was a later model, again, supposedly improved upon, but I remember many being sent back for service...the 21 required little service from what I recall. The car unit is quite rare actually, does it still work? As far as Steve hating masters that used dbx NR...I can't say I blame him. There are huge compatability issues with differing machines using this NR system. To Grant: I must admit I'm surprised you had such issues with tapes recorded on and played back through the SAME deck. My opinion, is that the recording itself is the culprit...not some inherent issues via playback. Many noted mastering engineers, producers and conductors have high praise indeed for the way sound could be duplicated using the dbx process...but I certainly understand that many issues prevented dbx from being more widely used. Haha, undoubtably hastening my departure when they moved to San Diego, CA from Newton, MA. Ahh, the good old days
I know at the consumer level that if you made a dbx cassette that you had to play it back on the same machine. I had two of those decks, now both long gone and i am sitting on the unplayable tapes. Guess when i get home I should chuck them out. Realinging the heads on the 2nd machine did not make the tapes form the 1st machine playable.
IIRC, wasn't dbx II the consumer version (which had treble preemphasis on recording, and deemphasis on playback), where the pro version was just dbx (or dbx I)? Not the noise reduction, but I bought a 118 over a dozen years ago, still in a sealed box. I use the compressor mostly for late-night movie watching. I like the look of that series--the glossy black front panel with the large knob and round pushbuttons on it. My 228 still works well to this day, although I don't use it much. The pushbuttons are a bit touchy, but I've had it for over 20 years. Still works! Or, at least it did 20 years ago when I took it out of one of my cars but never reinstalled it in another. The controls are probably scratchy but I'm sure it still works today.
The way I understood it, dbx tapes made on one machine should play back on any other. (Supposedly that was one of its benefits...?) It's a simple 1:2 ratio expansion, with a treble cut. Only thing I'd advise is that the deck have a good head alignment first. And I'm sure you could pick up a cheap decoder on eBay if you just wanted to make copies of any tapes you wanted to save.
From a novice's point of view REally interesting discussion! I have a Technics cassette deck with B,C and dbx. Really nice machine. I also had a Panasonic walkman that had dbx playback. It was sweet and expensive, but it was stolen unfortunately. dbx recorded cassettes sounded great, but they tended only to sound great with Metal tapes or the pumping and/or high end would sound poor. The deck did not have a bias adjust, so unless the tape was spot on for the bias calibration, dbx tapes would sound overly bright or dull and pump. A good example was that the deck appeared to be calibrated to TDK tapes (AD,SA,MA) and the Normal and High bias did not have enough high end for the compression/expansion to work evenly on the playback. As a result ,only TDK MAs and the like sounded great. One tape I used from Japan (a friend got it for me) was a metal evaporated National Panasonic "angrom" tape that was incredible with dbx. It could be recorded to +18 on the VU with dbx. Granted the calibration of the VU was obviously on the high side, but it blew away any regular metal tape. Unfortunately, I only had one and it cost $10 in 1985 in Japan for a C-54! I have never seen these tapes outside of Japan. Still I went back to Dolby B, after the dbx walkman was stolen, as dbx also was not compatible with any other tape player I had. I still have a couple TDK MAs and JVC ME-PII metal tapes with dbx that still sound great after 20 years.
Thanks Ron, I though about one other thing I should add. One of the main reasons my tapes were hard to play was because I used close microphones. I was usually sharing the microphones with the PA which prefers them close. In audio, the inverse square law applies to sound as it leaves a source. When a sound source can move relatively close to the microphone, unnatural dynamics can occur. When somebody 'eats' a mic there can be a 20 db or more jump in level. My dbx recordings were able to capture most all of that without overload due to the tremendous amount of headroom. Of course, overloading of the microphone or mixer input was still possible but was rare. I did do one live classical recording with dbx 157 and it has no close mics so none of the dynamic problems of my closer miced recordings. It sounds great except it was outdoors in Balboa Park and jets and buses were doing their things. Plus there was occasional wind noise and some of the condenser mics were at times crackling in the misty conditions. The bottom line is that distance is compression of sorts.
Well that may be. In my case I used 157 to encode. In 1996 I rented the latest dbx system which was modular and there was a 'plug in' which was designed to decode that correctly. In my case I had dozens of tapes and worked for a few weeks transferring them. I wasn't that concerned with how accurately they tracked because this seemed like the only way I'd ever get to hear what was on them. For the most part they seem to be ok. Artifacts are present but I know how to spot them. Many would not. They are mainly noticeable only when there is a very low signal. As the signal hovers around the gating threshold of the expander, the noise (yes there is still noise) rides up and down with the signal. This is unnatural sounding and is somewhat similar to the no-noise gating effect. Remember at the time I was only doing the best practical job mainly for the purpose of listening to my old tapes. Were I to go back and remaster them today I'd take a whole different approach. I actually had one of these recordings released a few years ago and they worked off a demo cd I had made from my 1996 transfers. They had no interest whatsoever in the master tapes. Interestingly, the mastering was done by Les Paul's son.
Any where there's a list of officially released dbx albums? I've got a couple when I bought a dbx encoder/decoder from drew at DAK back in the eighties. Worth anything? TIM
I got a Gort to reopen this one. I've developed a little interest in DBX since I acquired a Teac X-10M reel-to-reel deck recently. Basically, this deck sounds so good to me I got all excited about tweaks, DBX being one of them. This deck has DBX inputs and outputs, and both Teac and Tascam DBX encoder/decoders are compatible with it. What has me excited is the purported extra 30db signal-to-noise you're supposed to get with DBX. On the other hand, the cons, namely the "pumping" or "breathing" that's been reported getting through onto recordings as artifacts has me concerned. I don't want that. I don't want any "life" shaved off the top end, either. I've never used nor heard any DBX recordings that I know of, but with regard to cassette I've never been a fan of nor used any Dolby. I guess the kind of blank cassettes I've generally used and the decks I've used (and still use) reduced hiss to the point that it never bothered me much. In any case, if there are any people expert in this I'd love to hear some input. Basically -- if you were me, would you plug in a Tascam DX-2D or Tascam DX-4D into my Teac X-10M or just leave it be? I know Teac made units to go into this deck, but I've read the Tascams are more stable and long-lived than the Teac units. Thanks in advance...Interested in what any tapeheads have to say about this.
I’ve now got 5 dbx records in the collection since starting with them this year: Neil Diamond’s GH, Pramlatas’s Hips, Brother to Brother, Even in the Quietest Moments, and Frampton Comes Alive. Each one is superior to the regular release and a real pleasure to listen to. I just found the Neil D one in a used shop this week for 10 bucks. The guy working in the store had no idea what dbx was. No one does, really.
Interesting. That's a pretty rare niche though. I've never seen more than a small handful of dbx records over the years.
Talkin' 'bout cassette decks - I have two with dbx - Yamaha K960 (circa 1982) and a later K1000. Both have bias adjust, and while the tapes sound reasonably OK on either deck, they all sound better on the deck they were recorded on, the K1000 being the better deck overall. Later on I also purchased a 2nd hand KX-720 - I suspect the heads were a little worn - never recorded on this, though I observed that this gave the worse sound of the three. Not as clean. I'd have no hesitation recommending a K1000 or the K2000. The difference is the K2000 has separate dbx for recording and playback and the bias is auto, whereas on the K1000 it's manual. Both are 3-head decks.
I have Feels So Good by Chuck Mangione, Just One Night by Eric Clapton, Who Are You, and a few others. I even have a cassette, .38 Special's Wide Eyed Southern Boys. Dan
I have a Teac cassette deck with dbx. At first I thought it sounded great, specially when I taped very dynamic live records. I then I started to notice that hiss went and came in vocal passages. I stoped using dbx
I enjoy them. Your mileage may vary, but in the case of the Clapton title, I have the MFSL CD. Two great sources! Titles I might like to obtain if they're affordable would be J.Geils's Love Stinks, Duran Duran Seven and the Ragged Tiger, and Police Zenyatta Mondatta. Dan
