[zmix]

Originally Posted by Nobody Special

Hmm. What's a programmer supposed to sound like on a B.B. thread?

zmix, I'm sorry you've taken such a dislike to the PCM96. There are an awful lot of very good people in the industry who've told us it's the best-sounding box we've ever made. I do a bit of classical recording on the side, and I think it's head and shoulders above our earlier boxes for that application.

Since many of the complaints seem to have something to do with modulation, let's talk about it. The purpose of modulation in Lex boxes has never been about being obvious--it's always been about breaking up room modes and improving the spectral performance. In the case of the old ConcertHall algorithm, and to a lesser extent the RandomHall algorithm, this had mixed results. While spectral performance was improved, the modulation was obvious. For a great many users, this turned out to be a plus. They loved the effect. David Griesinger, who wrote those algorithms, was never wild about that effect--especially in ConcertHall. Getting any information from him on exactly how the modulation worked was like pulling teeth. He simply wasn't interested. That's why the 96 sounds a bit different from the older boxes. Unfortunately, the original 224 and PCM70 code was lost long, long ago.

The newer algorithms like Hall and Room have a much more successful modulation, if you consider the original goal. Unless pushed to an extreme (spin anywhere past about 2, 2.5 Hz), you can't really tell it's going on.

So as I said before, sorry you don't like it. But I'll still pop in whenever I can and answer questions and comments.

N.S.

Dear N.S.

In posting my comments and various examples I intended not to simply complain, but to open up a discussion with other reverb aficionados and to share what I am hearing in these algos, what I am missing, and hopefully to inspire Lexicon for further development of the PCM96 platform.

I have been mixing records professionally since the early 1980s. Back then I used the Lexicon 224, 224x, and later, the PCM 70. I sort of "lost interest" in new Lexicons reverbs around the time the 300 / 480 were introduced.

The primary attraction to the PCM96 for me was the claim that the original "Concert Hall" algorhythm had been reintroduced. I bit hard on that lure. Imagine a 224 with instant recall! When I received my PCM96 I immediately began recalling some of my favorite 224 settings (by ear, not copying parameter values... which were obviously different in the PCM96). I could not get it happening and instantly buyers remorse set in. I felt cheated. OK, I calmed down and went through every algorhythm trying to program some useful starting points for future mixes.

Each algo shared a similar characteristic that I had never heard in my favorite Lexicons of the past. I can pinpoint the characteristic of the PCM96 as having excessive ringing in the lower frequency modes and an overly "tonal" quality to the reverb, certain notes would simply linger unnaturally and the end result was a muddy track with altered chord voicings. Using the modulation to break up these modes lead to a lumpy response and odd image shifts. I found that my programming became focused on taming artifacts rather than pursuing the sound I heard in my head. I have an associate who offered to send me his 224 as a reference, which should prove interesting. In the meantime I hooked up a PCM-70 and started tweaking the concert hall algo. I felt completely satisfied by this version of the algo. I went back to the PCM96 and again it sounded dark, ringy and the tail just sounded weird and out of phase (polarity). I experimented with the 'tail width' parameter and discovered a bug: The parameter is offset by 45˚... at 45˚ the output is mono (and the display reads "narrow stereo"), at 90˚ the output is stereo (the display reads "mono"), and at 135˚ the tail is mono with the L/R in inverse polarity. At no setting could I match the width or depth of the PCM-70... Also the modulation in the PCM96 is unable to produce the subtle magic of the 224 / 70 it always sounds obvious and cyclical.

I can appreciate that the original 224, 224x and PCM-70 code was lost "long, long ago", but 224s and PCM 70s are readily available and a serious effort to discern the operative mechanisms by listening seems not to have taken place. I have managed to create reverb algorhythms which do produce the sort of subtle yet musical modulation, as have many others here. The PCM96 version of the Concert Hall seems to be modulating the wrong places in the algo. Also, in the description of the PCM96 algos here on Gearslutz the "Concert Hall" description reads like a data sheet on an obsolete electronic part (not recommended for new designs) and the "Random Hall" is described as being "...more responsible for the term "Lexicon Sound" than any other reverb." I say that this is an outrageous statement. Lexicon's reputation and subsequent fame was built on the back of the venerable "Concert Hall" algo (and the CD plate). If it were not for the ubiquity of that algo in the early 1980s there simply would not have been a 480 etc. You would think it deserves a bit more care than It got in the PCM96...


Not happy to simply opine, I decided to measure the differences in the basic modulation LFO. First of all the PCM-70 modulation oscillator is a mixture of a 2.3hz triangle wave and a much slower random waveform (around 0.5hz). The chorusing LFO in the PCM96 has a maximum rate of 1.5hz, and is not randomized.

I am delighted that Casey has offered to discuss the 224 Concert Hall modulation with you. I think the PCM96 as a platform has tremendous potential and I'd love to see that realized.

I hope that Lexicon take these efforts to illustrate and educate seriously and don't rest on the "Other People like it" argument.

-Chuck Zwicky