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.

Thanks NS. Most helpful.

What's the closest starting place to on the 96 to get the great Hall sound on the 480? Also, how about the small wood room (is that what it's called...??) on the 480?

Great explanations. LOVE IT!!!!


bp

If you're working from the front panel interface, look under any of the halls folders for presets with the RHall name. Those are based on the RandomHall algorithm. If you're using the plugin interface, then just load Random Hall.

I'm afraid I don't have a 480 close by, so I can't tell you about the wood room. But a good starting place for small spaces is the Rooms folder (front panel) or the Room algorithm (plugin).

This is really helpful.

Thanks. & Encore Please (Hana Hou !)

Any other hints on getting the PCM96 to get to sound specifically like some notable presets on the 200, 224, 300, or 480? Or presets in the PCM96 that were specifically designed to replace some "retro" favorites? The Rhall note for 480 types is helpful... thanks.

PCM70 "tiled room"? Anything close? 480 silica beads?

Just got the reverb today and looking forward to firing it up.

Excellent post, NS!!! Thanks.

Yes, a million kudos to you for this information.

Back to the ancient (and zero current profitability) PCM 70...what programs are like Tiled Room, Bright Plate...and any other signature PCM 70 stuff?

Masny thanks, you are very generous!

Seems like Lex should include presets on the 96 that are similar to some of the classics: obviously the PCM70 Tiled Room and 480 Hall.

They've been busy on software and other products, it seems. I wouldn't be surprised if we see some "Classic" programs released down the road. After all it's a simple enough software rev.

I kinda like the genericness of the titles, but it would be cool to see a "best of" preset category. I'd throw the 91's "Deep Blue" into that mix.

I love love love the small wood room from the 480L & have found the Altiverb versions to be really close to the real thing.


Best- Brad

Thanks NS -

It helps place many things in perspective. Very good of you to give us this info.

I can only imagine that if there were a software release resembling "Best of..."
that word would get around fast in the purchasing circles.

Thanks for a great post.

Do you know anything about Lexicon 200? I have one, like a lot especially considering it´s age! /Toby

Many good remarks here about favorite presets and such. I'd certainly be interested in getting as close as possible to some old classics. I'd also like to gather up some user-generated presets. We don't have a good way to organize such an effort just yet, but I'd think something with MIDI bulk dump might be one way to get there.

I do hope that some of you have been rolling up your sleeves and getting into programming the box (or even some of your older Lexes). One thing I've learned is that different people--with different applications, different ears, and different points of view--can come up with some unique and useful sounds. I know that we've just scratched the surface of what the box can do, and I've love to offer a folder of user favorites.

Toby, hang onto that 200. It's like your favorite old aunt. She's crotchety and a little limited for sure, but even if you found a replacement, it would never be the same.

I've been a bit busy of late, but I hope I can get back in here before too long and cover a few more areas of interest.

Hi NS, is the 96 surround shipping yet in quantities?

It started going out a few weeks ago. If your dealer doesn't have any yet, it shouldn't be too long.

Hi NS (1st time poster here):

How much consistency is there between algorithms of the same name over Lexicon history? For example, is the Rich Chamber of the 224XL similar to the PCM70 room/chamber, and how much do things change with the 480L and later reverbs?

Also, is time variation generally found on the high end Lexicons only, or does it make its way into the lower priced units as well? I remember using the 224XL, and the Mode Optimization seemed like some sort of chorusing, while I presume the 480L and later use some different type of time variation.

Thanks,

Sean Costello

Hi Sean,
Some things change, but many things remain consistent (wishy-washy answer but it's true). Back when David Griesinger was doing products like the 224, there were zillions of things he wanted to do that the hardware wouldn't allow. As hardware became more powerful, fewer corners needed to be cut. On top of that, time, thought and experimentation led to better ways to make a reverb algorithm. So there's been a continual process of improvement. Lots of times, customers may not see it that way: if you cut your first hit record with a 224, the last thing you want is to see it change. But on our side of the fence, we're always looking for some way to make things sound better. But still there are some things that make a plate a plate, and we try to respect and extend that.

In terms of specific products, the 70 was a simplified version of the 224 and the algorithms sound pretty similar. The 480 extended that with a better S/N ratio and more algorithms. The 960 was a further extension. It was a little lighter and more transparent: some people loved it and some people hated it. The PCM96 incorporates qualities of both, and can be leaned in either direction. It was also our first floating-point processor, with considerably better performance.

The chorusing sound of the 224 family was a characteristic of the ConcertHall algorithm. It's the only algorithm that works that way. You'll also find variants of that sound in the PCM91 and PCM96. As I indicated in an earlier post, it sure isn't realistic but it might just be the thing you need. Other algorithms approach time variance (we call it randomization) in other ways and for other purposes. Ideally, it's not something you should hear as chorusing. It's intended to break up room modes and improve frequency response.

Randomization has been a feature of most of our products in recent years. Ten years ago it came down as far as the PCM90/91. A few years later it came down as far as the MPX100. Now it's in everything. It's obviously a little slicker in the high-end products, but even in a product like the MX-200 it's more complex that the 480. I kinda like Moore's law.

The Decay Optimization in some of the 480L algorithms have nothing to do with chorusing. And the same is true for the 224XL.

Did you mean Mode Enhancement?

Yep. I just mixed the two terms up. Decay Optimization seems like something used to reduce certain artifacts for impulsive sounds.

Sean

This is becoming a great historic record, thanks for starting it NS.

Early on decay optimization was simply turning down the level of reverb when no input signal was present. Over time it transformed into a switch which coupled/decoupled the size parameter from the reverb time. (If I recall correctly!)

More importantly; NS I don't believe that you mentioned Davids 480 surround algorithm, which I believe he is quite proud of. I will add that it rocks, even in stereo, and makes finding a surround option cart for the 480 a requirement for 480 fans.



-Casey

Almost. Decay optimization had to do with managing allpasses (could be my memory giving out. Got a virus of some sort today). The decoupling parameter was called "Link". It 'disappeared' and hasn't been missed. David's nice surround algorithm was based on the Random Hall and was 2-in/4-out. I don't think we have any of the carts left, so you'd have to pursue them on the open market. The 480L cart format was based on the cart for the PC-Junior. In retrospect, that perhaps wasn't the best choice...

Hi NS,

The "Ambience" program in the 300 is probably my fave of all Lex verbs.
Any background or info you can give on that would be greatly appreciated.

TW

It always comes back to Symphony Hall. Do you know the story?

Long before convolution reverbs were possible, there was a statement put forth that you could identify a specific seat in Symphony Hall by collecting the stereo sound energy of the Hall over each 10 millisecond interval and then play that energy back in the form of ambience. This is the 300 Ambience program, with a best attempt reverb following the early ambience.

In a private conversation with David about 5 years ago he told me that he thought the whole notion was rather silly, but there it is.

The forerunner to todays convolution reverbs.

I agree, it is really very nice.



-Casey

So is that why there are so many reverb people in Boston? I always thought it was due to having so many local tech schools that were good, but maybe having a good local hall as a reference inspired people to create better sounding algorithms. I have never been to a concert in Symphony Hall, and I don't know if Seattle has any particularly inspiring acoustical areas, apart from that huge cistern at Fort Warden with the 45 second RT60. Not many people out here were trying to model the Kingdome back in the 1970's and 1980's...

Since we are on the subject of Lexicon reverbs, here's a question: Can you break down the different Lexicon units by the original origins of their algorithms, or are the algorithms constantly evolving by increments? For example, the 224XL (by reading the manuals) seems to have algorithms that weren't in the original 224. The PCM60, PCM70, and M200 all seem to be based upon the 224XL algorithms to some degree, with varying amounts of control. The 480L seems like it was a big leap forward in algorithm design, with the introduction of some new type of randomization, many new algorithms, and the Shape and Spread controls. The PCM90/91 and M300 are obviously descended from the 480L, but many of the lower end Lexicons that followed (PCM80/81, LXP1/5/15) seem like they were based on the 224XL algorithms, at least by the descriptions of the parameters. The current Lexicons all seem to be based solely on the 480L and the 960L style algorithms, with the exception of the PCM96 which brings back the original 224 Concert Hall (and adds a few new algorithms). Is this a correct interpretation of things ("punctuated equilibrium" in evolution terms) or are the algorithms constantly evolving, even when they keep the older parameters and algorithm names?

Sean

Thank you very much for the description of the different algorithms inside the PCM96. I already own the 480L (incl. classic card & surround/HD card), 224XL and the PCM91, so I would appreciate if you could pinpoint the benefits of buying the PCM96 in terms of algorithms/quality.

I don't think that my 480L have a dedicated plate algorithm (excluding the Rich Plate in the Classic card), but it does use the dense algorithm for both plates and rooms - that algorithm doesn't have any modulation i.e. spin, wander or chorus. When you mentioned the plate version from the 480L, did you refer to the dense algorithm with additional modulation? If thats the case, I presume that you could recreate most of the room and plate programs from the 480L, including the previous mentioned small/large wood room.

Regarding the Concert Hall - The PCM96 version have shape and spread parameters, whereas the 224XL, the Classic card and the PCM91 have the depth parameter - those sets of parameters works differently - is it possible to mimic the behaviour of the depth parameter with shape and spread?

Do you have any plans for additional algorithms, like Random Ambience and Constant Density Plate B? Or the bandwidth limitation of the 224XL?

Also, the pre-480L boxes had Inverse Room programs. Is it safe to assume that the Shape and Spread parameters allow for this behavior to be emulated, or did the Inverse Room algorithm reappear in later units?

Sean

There's an Inverse/non linear algorithm in the PCM91.

Hi. Yes, I believe you could cover most or all of the older plate sounds. We've probably already gotten there with more generic names for the presets. As I've said elsewhere, time and personnel allowing, we might try to do some closer name-for-name matches.


As far as ConcertHall goes, Shape and Spread are in the original (although perhaps by a different name--I don't have a 224) as well as the new version. The chorus/depth parameters are in the new one as well.

Do I have plans for additional algorithms? Yes. I can't say anything about them until we release them, but the DSP has the power to do many interesting things.

Hi Sean. Believe it or not, we always thought that the Inverse algorithm was a half-assed way to do what we really wanted. The new Room algorithm has about 4 dozen reflection patterns. There's a reverse parameter that allows you to flip any of those patterns backwards. You can also scale them and do a few other things. It's a much better way to get that reversed sound. The best way to learn how that works is to go into one of the Playroom presets and fiddle around.

Having said that, you can get something very much like Inverse out of any of the reverbs. Here's how:

Room Size: pretty big
Reverb Time: All the way down (very important)
Shape and Spread: High values
Tap Slope: +10

You can doodle around with the Size/Shape/Spread and get some interesting effects that are pretty similar to Inverse. The Diffusion parameter will also have an important effect.