Review – Seventh Heaven from Liquidsonics
Seventh Heaven is the latest state-of-the-art convolution reverb offering from Liquidsonics … and it’s quite possible it will put you right where the name suggests.
by David Baer, July 2017
Liquidsonics has recently released two new convolution reverb plug-ins: Seventh Heaven and Seventh Heaven Professional (hereafter SH and SHPro for brevity). These are a natural evolution of the technology behind Liquidsonics Reverberate, also a convolution reverb, which I reviewed here:
Anyone who read that review (which was for Reverberate version 2) will have noted how very impressed I was with it. In fact, I concluded with the following:
I already had a handful of very fine convolution reverbs installed on my DAW computer, and some of those were accompanied by superbly-produced IR collections that covered the breadth of types of natural spaces. I think there’s a very good chance I will never feel inclined to use any of them again, that’s how spectacular Reverberate 2 sounds to me. In fact, if there were to be no further advances in reverb technology in my lifetime, I would feel no disappointment.
Well [spoiler alert], there has been another significant advance and I’m quite happy to be able to say I’m still around to enjoy it! Seriously, Reverberate 2 was the best convolution reverb I had ever had the pleasure of using, and SH and SHPro are even better with only one qualification. The new reverbs offer a thorough, accurate and superbly rendered experience of one particular high-end hardware unit, the M7 from Bricasti Design. You will get no real-life spaces that have been captured for convolution recreation. As you will see, the technology unique to SH and SHPro requires a programmable device from which to capture reverberation behavior in order to deliver the full dose of magic.
First let’s get a few essential details out of the way. Both plug-ins run in any mainstream DAW, PC and Mac, 32-bit and 64-bit (64-bit rather strongly recommended). Both VST 2.4 and VST 3 versions are provided. List price for SH is $69 USD and for SHPro is $299 USD. Authorization is via iLok. SH requires 469 MB of disk space for reverb IR data; SHPro requires 8.79 GB.
Let’s back up briefly and discuss what made Reverberate 2 so special. Convolution can reproduce with remarkable fidelity either the ambient characteristics of real-life spaces or hardware-generated reverb simulations. The downside is that those aural snapshots are as static as is a photograph made with a camera. In a real-life performance space, there will be subtle differences in localized pockets of air pressure and temperature that will affect sound transmission characteristics and these will be subject to continual changes. Also, the movement of people inside the performance space can also cause shifts in sound transmission that will slightly change over time. An audio snapshot of reverberation will not reflect this “living, breathing” ambience.
Algorithmic reverbs use various techniques (internal delays, all-pass filtering, chorusing, etc., etc.) to produce a reverb-like result. Real-time modulation can be applied to this internal processing to introduce some “life and breath” into the sound. Convolution reverbs cannot use this trick because to do so would be too computationally intensive for today’s DAW computers.
A solution to this limitation was Liquidsonics’ first innovative breakthrough, an approach called Fusion. Convolution-generated reverberation uses files called impulse responses (IRs) to reproduce the reverberation characteristics of a given space. Reverberate delivered the capability to juggle multiple IRs of separate individual measurements of the same space and morph between those parallel IRs in real time and do that in a way that did not overtax the computational capabilities of typical DAW computers. To deliver this capability, Liquidsonics also had to develop a custom file structure to hold the multiple impulse images and had to ship a collection of Fusion-enabled files to use with Reverberate.
The results were nothing short of amazing. Now, I have never worked with the super-expensive gear available to studio professionals, so my experience is in this area limited to what’s commonly found in the home studio domain. But I was blown away when I first heard Reverberate 2. It comes bundled with two sets of Fusion-enabled IR file collections. One reproduced typical real-life spaces (rooms, halls, etc.). The other collection was of impulses taken from a high-end hardware reverb, the M7 from Bricasti Design.
The M7 Mystique
Bricasti Design was formed by several engineers who formerly had worked for Lexicon, another manufacturer of legendary high-end studio gear best known for their reverbs. The M7 was their first product, which appeared around 2007 to considerable acclaim. It did not attempt to duplicate the Lexicon Sound but was said to most certainly have benefited from the background and experience of the engineering team.
The M7 used computer computation to accomplish its purposes, but it had under the hood a load of hardware optimized for digital signal processing (DSP) that could leave desktop computers in the dust that were attempting to do the same thing. Even in the ten intervening years, Moore’s Law has not brought us forward to the place where desktop computers can come close to competing. Of course, you would be far from pleased to have to write a spreadsheet program or a word processer using DSP processors. DSP-chip technology is narrowly focused but impressively succeeds in its specialty.
A major firmware upgrade to the M7 appeared around 2010. Its main attraction was a second internal reverb algorithm that was claimed by Bricasti to produce a somewhat more “effect-y” sound, not that the new programs using it were anywhere close to be overly showy. The upgrade also introduced a delay feedback mechanism for both the original algorithm and the new one. This is important to know only for those sufficiently curious to read both the SH/SHPro documentation and the original M7 manual, the former of which mentions the second reverb algorithm and the delay option which are not covered in the first M7 manual.
The M7 was never cheap. Today new units cost in the neighborhood of $3500 USD. At that price, a home studio producer is rarely going to get access to an M7. This is one major reason Reverberate 2 was so special. It made it possible for a home studio to have affordable access to the M7 sound, and Fusion delivered the best M7 convolution experience ever. Mission accomplished! Well done, Liquidsonics.
Knockin’ on Heaven’s Door
So, Fusion technology solved one problem with getting convolution reverbs to sound credibly non-static. But several other limitations constrain convolution reverb reproduction when compared to algorithmic reverbs. Even modestly-positioned algorithmic reverbs normally offer the capability to separately control the behavior of early reflections and the later-to-materialize reverb tail. Likewise, the decay time of an algorithmic reverb program can easily be changed without necessarily an unwanted loss of quality. On the other hand, a reverb IR is a single image with no delineation between early reflections and reverb tail. Also, it cannot be shortened or lengthened more than a little before that trick compromises authenticity of sound.
Some convolution reverbs do offer some sort of early/late differentiation, but this is crude at best. It involves something like establishing an arbitrary point in the IR to be flagged as the early-to-late border. Using cross-fades between the data on each side of this line, things like making the early reflections more prominent than the tail can be done. Such trickery can work but just how far things can be taken is usually limited. Likewise, decay times can be manipulated, but the inherent loss of authenticity limits to what extent this can be done.
This is where we arrive at the second big advancement found in SH/SHPro. Liquidsonics extended the Fusion capability to handle not only multiple parallel IRs but to juggle IRs dedicated to specific parts of a reverb, such as separate IRs for early reflections and reverb tail. But this can only be applied to reverb patterns captured from a programmable device. One cannot go into a space and say “OK, cathedral, for the next measurement I just want to hear the early reflections” or “OK, studio, please increase the decay time for this next measurement by 75%”. With a programmable reverb device, these things are often possible.
And so, welcome to Seventh Heaven where this is exactly what is happening. Liquidsonics undertook what must have been a massively painstaking capture initiative. Not only were individual M7 programs captured with early and late content segregated; for those programs, separate captures were made of a series of discreet decay time values.
In the case of the delay option, measurements were taken of the M7 programs in which delay was engaged. The M7 employs an eight-voice mechanism when including delay. But the program was also captured with the delay off. If the user chooses a delay time or level value different from the original program, SH/SHPro simulates the delay signal introduction. This simulation is not as rich or complex as the original program, but it still delivers a potentially desirable end result. As I said, the attention to detail to make this all happen is more than a little bit impressive.
Before we get into the actual software and the differences, a couple of points are worth contemplating. The first is a sage observation once made by my fellow SoundBytes writer, Dave Townsend, on a forum we both frequent. He suggested (and I paraphrase) that it seemed foolish to obsess over minute details of a reverb program when that sound was going to be 12 or 18 dB down from the main sound in the first place.
A related thought was presented in the marvelous book Mixing Secrets for the Small Studio by Mike Senior. After commenting that decay time was really the only really important setting with which the mixing engineer should normally be concerned, he wrote:
There’ll be a slew of other controls on a lot of [reverb] plug-ins, but for typical small-studio operators – and indeed a lot of professionals – there simply aren’t enough hours in the day to worry about what all of those do. (They do serve a useful social purpose, however, in distracting computer anoraks from ever getting any music finished).
My point in mentioning these notions is to suggest that if one has a lovely reverb delivering an excellent sound, perhaps the best strategy will normally be to just pick an appropriate program (hall, room, whatever), tweak the decay time to taste, set the dry-wet balance, and otherwise leave things well enough alone.
This consideration becomes most relevant when considering what features you absolutely must have (and will therefore have to pay more to get) when purchasing a reverb. From the viewpoint of the above, is an economy of features actually a feature in its own right? This is one thing to think about when trying to decide if SHPro is worth over four times the price of SH. So, with that preamble out of the way, let us now finally talk about the software.
Before anything else, let me be clear: both of these reverbs sound fabulous. SHPro has more programmability than SH, and it has more programs. But to my ears, when choosing identical presets, of which there are several, and otherwise doing no parameter tweaking, SH and SHPro are indistinguishable. Assuming both are within your budget, choosing between the two largely comes down to two things: a) is the extra programmability in SHPro something you will actually use, and/or b) do you need those extra programs? We’ll discuss the tradeoffs in both areas next.
The image above shows the full UI of SH. The bottom portion can be hidden when unneeded. When that is so, all you’ve got are four controls: dry/wet balance, output gain, program and decay time. We’ll look at programs in a moment. As to decay time, a continuous range of values is available. If the selected time matches one of the times captured, then that’s what you get. If not, SH interpolates between the captured images of the closest bracketing times. However, with SH there is no way to tell what those times are other than (we assume) a preset’s time will be as captured with the program.
When exposed, the bottom section adds controls for the following. Pre-delay can be specified and it affects only the reverb tail, not the early reflections (just try doing that with any other convolution reverb!). Delay invokes the delay function of the M7 as described earlier and uses a fixed value of -6 dB. The delay time can be adjusted but not the -6 dB level. Both Pre-delay and Delay can be synced to host tempo (a trick not available on an actual M7, of course).
The two 12 dB/octave filters act on the entire reverb signal. The VLF needs some explanation. The M7 provided for very low frequency content in the reverb and treated it separately from both the early reflections and tail. I am not exactly clear on what this is all about even after having read the M7 manual. Suffice it to say that SH claims to reproduce this content faithfully. Given how meticulously everything else was done, I have little doubt that this is so. The VLF control allows adjusting its relative presence.
Finally, the relative loudness of early reflections and tail can be controlled. That’s pretty much everything. The manual is only eight pages in length and is entirely adequate – that’s how easy programming SH will be.
The factory content is comprised of 30 programs that faithfully duplicate identical ones on the M7. The list of available programs is seen below.
SH is a closed system with respect to content. It can only work with the library bundled with the software. That library cannot be used in any other reverb and SH cannot work with other IR files. Furthermore, the library of SH and SHPro are not interchangeable. SH’s content will not work with SHPro or vice versa.
Let’s move up to SHPro. It does everything its smaller sibling does and we won’t repeat that information. The screen image above shows both tabs of the lower section of the UI. I’m not going to cover every control (the user manual does that well and can be downloaded from the Liquidsonics site – URL below).
Notable in the advanced controls is a parameter labelled Pattern. The M7 had 32 different early reflection patterns from which to select. SHPro offers these just as in the original hardware – impressive!
In SHPro, unlike its smaller sibling, a list of captured times for primary decay is made available in a menu. A continuous range is still available for selection and like SH, such a selection will result in interpolation of behavior between the nearest captured times.
Frequency-dependent decay time is part of the M7’s original repertoire, but individually sampling all such permutations for use in SHPro is clearly an impossibility given the massive number of possibilities. What SHPro does instead is to simulate what happened in the M7 by using multiband separation and individual filtering of the resultant bands.
This is not to be confused with the master filter section shown just above. The M7 did not have this, but, hey, why not include one in SHPro? The M7 was probably often followed with an EQ in the signal chain. Using SHPro, this will not be necessary.
There are around 200 supplied programs for SHPro – see just below for a listing. Eight of the banks of presets shown below come with a “1” or “2” suffix, which denotes which set of M7 programs was the source and which algorithm was used in those programs. According to the manual (16 pages in the case of SHPro and again completely adequate), the version 1 algorithm programs have static tails while those of version 2 have modulated tails. All have modulated early reflections and a VLF component.
Is SH or SHPro for You?
Do you like the reverb sound of a revered piece of outboard gear that you will probably never get your hands on due its price tag? If so, you are going to want to check out either or both of these plug-ins. Working 14-day demos of either may be downloaded from the Liquidsonics site. But don’t grab the demo unless you have the money in your budget to buy it. If you hear it, you will be impressed, you will almost certainly like it, and there’s a very good chance you will lust for it.
Of course, this is provided you are amenable to using an iLok dongle for authorization. Liquidsonics has stated that there will be no software iLok authorization option forthcoming. The reason is the value Liquidsonics places upon this intellectual property and the feeling that a hardware dongle is sufficiently more secure to justify what is accepted to be an inevitable loss of sales as a result. I cannot say I blame Liquidsonics for this attitude. They have something truly special here, so much so that I finally relented and acquired an iLok dongle myself in order to be able to run this software (admittedly, my list of software-iLok-authorized synths, FX and content was growing so large that this wasn’t really a difficult choice in the end).
One more thing about the iLok issue: if you really cannot stomach the use of a dongle-dependent title, then do consider Liquidsonic’s Reverberate 2. It doesn’t offer the advances of SH/SHPro, but it does provide a generous number of Fusion-enabled M7 sounds and has another collection of Fusion-enabled real spaces as well. It’s a most-impressive reverb solution in its own right and the availability of real space convolutions might actually tip the balance in favor of Reverberate 2.
Liquidsonics had a couple of sales last year, the Black Friday one had Reverberate 2 discounted by 50%. It’s too early to say what future discounts may be available for SH and SHPro, but past history suggests some sales will be forthcoming. That said, at a mere $69 USD, SH is one hell of a bargain. That’s not to say the $299 USD SHPro is overpriced, but it is on the high end of most home-studio budget limits.
The only criticism I have of Liquidsonics is the absence of a SH-to-SHPro upgrade discount option. I think customers who purchase SH will be so impressed they will seriously consider upgrading. Lack of a customer-loyalty benefit may end up costing Liquidsonics more than a few lost sales.
To download a demo copy of SH or SHPro, for more information, or to purchase, go here:
Liquidsonics software is also available from independent retailers, so shopping around for the best price might save a few bucks.
This just in: just a few days before the July issue is to be published, Liquidsonics has announced a summer sale with significant discounts on both Seventh Heaven versions. Check the above URL or your favorite music software retailer for details.