Lexicon reverbs: a brief bestiary
About Lexicon reverbs
I often see lots of comments about the naturalness or effect-y-ness of Lexicon reverbs. I think it's worth taking a few minutes to point out the differences in reverbs and how you can use them for either natural or effect-y applications. After all, there are more than 30 years of history in Lexicon reverbs and they're not all the same. As we go through them, you'll see me mention two parameters named 'Spin' and 'Wander'. These are often the source of great confusion, and it doesn't help that they're a little different in each of the 'verbs. In general, their intent is to provide a smoother frequency response for complex material. In some of the algorithms, they're not really even noticeable as modulation effects. They can often be turned off with no harm, depending on material.
You'll find variants of these algorithms in lots of our verbs, but my descriptions apply most closely to the PCM96.
Concert Hall
This is the granddaddy of Lexicon reverbs and it dates back to the 224. It was the definitive 80's reverberator. It is prone to coloration and is best used with very large room sizes. This is the only algorithm without Spin and Wander. Instead, it has a pair of chorus controls. It's a nifty effect for the right material, but you can hear strong pitch effects. While I like the sound, I can't ever imagine using it for any natural sort of mix.
Plate
There've been a few minor tweaks on this, but the PCM96 has a version that close to the 480L, although much cleaner. In this algorithm, Spin and Wander can be used to smooth the frequency response. They're not really intended for chorus-type effects. Even with large amounts, pitch should be quite stable. If you find that you still hear modulation effects you don't want, simple turn Spin down or off. It will sound fine.
Chamber
Extremely high reflection density and rapid onset--just like you'd expect from a live chamber. Once again, spin and wander are present and available to smooth out problem material. I generally like Chamber with spin turned all the way off. Alternatively, moderate Spin with a low Wander value ( under 3 milliseconds) will be effective at smoothing frequency response without creating noticeable modulation.
Random Hall
This algorithm dates back the the 480L and you'll find versions in every one of our high-end reverbs after that. This algorithm is the basis of a lot of good mixes, and is more responsible for the term "Lexicon Sound" than any other reverb. But it has quite noticeable modulation, especially with smaller room sizes. I wouldn't suggest messing too much with Spin and Wander for this algorithm. It is what it is, and that's nice.
Hall
This algorithm was introduced with the PCM96. It has many of the characteristics of the 480L, without the strong sense of modulation. If you have material that's strongly colored, then high values for Spin and Wander will help smooth out the material with very little sense of modulation. At the same time, for many applications you can turn Spin down completely and have a stable, natural tail.
Room
This one is also new with the PCM96 (there are some old boxes with an algorithm called Room, but those were much closer to a Hall). While the primary focus of this is post-production, careful programming can give some very nice hall sounds as well. The early reflections are quite stable and and possible modulation occurs at low levels in the tail where it's helpful in reducing coloration. If I ever have time, there are a great many presets I'd like to do with this one. It can be made to sound quite clean and natural.
One other thing
There are a couple of other parameters call Shape and Spread. They're used to delay injection of energy into the reverb--giving something of an envelope to the early stages of verb. In some cases, they may appear to cause some late motion in the tail. That's not really what's happening, but it can sound that way. Reducing either or both of those parameters may be helpful.
Finally
So let me encourage you to spend some time playing with presets based on our different algorithms. Presets often represent the mindset of the person doing the presets, and a given series of presets may explore only one facet of the algorithm. You might find that a bit of editing time will open up new possibilities. We used to throw around a phrase at Lex "We give you the rope...". I think it still applies.
It appears that many people identify with the Lexicon sound that was available in the decade they entered the business. With the PCM96, we've tried to incorporate the sounds from all four of those decades.