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TC Electronic Finalizer Express

Mastering Processor By Hugh Robjohns
Published February 1999

TC Electronic Finalizer Express

Taking the essence of the highly regarded Finalizer Plus, TC Electronic have repackaged their multi‑band compressor in a new easy‑to‑use format. Hugh Robjohns puts it through its paces.

I remember reviewing the original Finalizer for Sound On Sound back in December 1996 and being extremely impressed with its awesome capabilities — both in terms of what it could do, and how well it worked. It was, and remains (in Plus form now), a very serious post‑production tool ideally suited to its professional mastering duties.

However, it could be dauntingly complex to set up and use, requiring the operator to have a good understanding of the underlying technology to make best use of the process. I don't mean that to sound patronising — it's just that the Finalizer was designed as a professional tool. Letting a musician with perhaps just cassette multitracker experience loose on a Finalizer would be like putting someone who had just passed their driving test in a Metro into a Maclaren F1 on the Nürburgring!

For readers who may be unfamiliar with the Finalizer, it provides an elaborate 3‑band dynamics suite comprising a compressor, expander and limiter; a 5‑band equaliser; level normaliser; de‑esser; an 'analogue warmth' feature; stereo width and balance adjustment; and a digital format‑converter with SCMS control, word‑length reduction and re‑dithering. These are precisely the kind of processing tools which professional mastering engineers need, but they also require shiny gold‑coloured ears to operate effectively!

However, given the effectiveness of the Finalizer and the high level of current interest in home mastering, TC Electronic have taken the initiative and come up with the Finalizer Express — a direct descendant of the original Finalizer, retaining its 3‑band dynamics section and digital format‑conversion facilities. To simplify the machine and broaden its appeal, though, the new version has a much simpler user interface, and most of the frills and twiddly bits of the original machine have been omitted. That's not to say that the Finalizer Express is of limited use — it has one of the best‑sounding multi‑band compressors currently available and remains ideally suited to beefing up any mix and really adding some punch or clarity, depending on how you set it up.

Structure

The signal path through the Express is fixed and relatively simple compared to the flagship Finalizer Plus. Analogue line‑level signals are passed to the 24‑bit, 128x oversampling delta‑sigma A‑D through a gain control, to optimise the conversion level. An input selection switch then routes either the digitised analogue or any of the three (24‑bit capable) digital sources (AES‑EBU, S/PDIF, or TOSlink) on to the DSP chip.

Now in the digital domain, the first step in the processing chain involves optimising the audio level with the Normaliser and the first of two 'soft‑clip' stages. This clipper is intended to reduce brief transient overshoots and thus allow the overall level to be raised higher than it could otherwise have been. Controlled transients acquire a mild analogue‑like distortion rather than a nasty aliasing type of digital noise.

If you're mastering your own material and want a more commercial sound, this machine is well worth a closer look and listen.

Following this static level‑optimisation, the next step involves splitting the signal into three separate frequency bands and the application of a 3‑band compression stage derived from the original Finalizer. The compressors are each followed by a limiter, and between them special level controls (one for each band) determine how hard the limiters have to work — more drive equals more limiting.

Following the limiters, the three signals are recombined and passed through the second soft‑clip stage before arriving at a master fader control. A full DSP bypass is provided, to allow comparison between the original and processed audio before the signal is re‑dithered (if required) to the digital outputs. All three digital outputs are available simultaneously at 24‑, 20‑ or 16‑bit resolution, in either professional or consumer format. Finally, a 24‑bit delta‑sigma converter with its own level control provides a separate analogue output.

Around The Box

Like its senior relation, the Express is housed in a traditional 1U rackmount box, and its build quality, both inside and out, is certainly up to TC's usual high standards.

Rear panel of the TC Electronic Finalizer Express.Rear panel of the TC Electronic Finalizer Express.

The rear panel carries all the interfacing, which includes balanced stereo analogue inputs and outputs on XLRs and all three common flavours of stereo digital I/O on XLRs (AES‑EBU), phono sockets (S/PDIF), and opticals (TOSlink). There are also the ubiquitous three MIDI connectors and a quarter‑inch jack socket for an external fader. Mains power is connected through a standard IEC inlet with integral power‑isolating switch.

The front panel is dominated by a large array of bargraph meters very similar to those featured on the Finalizer Plus. Other than that, though, this new machine has little in common with its sibling — no intimidating matrix of control buttons, or LCD screen with layered menus, for example!

On the left‑hand side of the Express, the on‑off button is strictly a 'standby' facility, as it doesn't disconnect the electronics from the mains supply. Beneath this button is a PCMCIA slot which accepts standard memory cards intended to allow software updates — there is no provision for storing user settings on cards.

The bulk of the front panel is divided into seven clear sections, starting with an input selector (cycling around the analogue and three digital inputs) and a gain control. The latter only affects the analogue input and is provided to allow optimisation of the conversion level in the 24‑bit delta‑sigma ADC. The control ranges between +6 and ‑26dB, and is aligned (strangely) with 0dBu equating to ‑16dBFS.

Next is the metering module, consisting of two stereo bargraphs, three‑gain reduction meters, a soft‑clip meter, and an assortment of status indicators. The input meter is relatively crude, covering a 40dB range in only eight steps (with 3dB steps at the top end), but it does include clip indicators for the A‑D, and a warning LED to show if the Normaliser section is being overloaded.

The output metering is far more detailed — which is exactly where you need the best resolution, of course — covering a 60dB range in 22 steps (the critical top six in 1dB increments). Just above the output metering is a short bar of four LEDs indicating the activity of the soft‑clip stages, and below are status indicators for sample rate, digital input source, and MIDI activity. The remaining portion of the meter panel is given over to three gain‑reduction meters (one for each band) together with separate indicators showing when the associated limiters are active.

Next along is the Normalise gain control (+/‑18dB) with a button to activate the first soft‑clipper. The Normalise knob is used to optimise the static signal level and set the drive into the compressor — the higher the setting, the more compression will occur. The soft‑clipper starts to work on signals above ‑6dBFS, emulating the kind of non‑linearity that might be expected from an overloaded magnetic tape recorder, and consequently imposes increasing amounts of harmonic distortion as the level rises.

TC Electronic Finalizer ExpressThe Finalizer Express front panel is divided into seven main sections.

Multi‑Banded

Moving swiftly along to the right, the next section is labelled 'Finalise', and this is where the multi‑band compression characteristics are adjusted. The second soft‑clip function is also included here, this time working on signals above ‑3dBFS; the soft‑clip button pressed simultaneously with the up cursor allows the MIDI channel over which the Express sends and receives data to be altered.

Rather than specifying attack, release, threshold, ratio and make‑up gain settings for each of the three bands of the compressor, TC have made the whole thing far easier and more intuitive with an array of 25 LEDs. This is the 'Finalise Matrix', in which any LED can be illuminated by the adjacent four cursor keys. In broad terms, moving the illuminated lamp upwards reduces the attack and release time constants (making the compressor work faster and sound louder), and moving it to the right simultaneously increases the ratio, whilst reducing the threshold (making it work harder and sound more forceful). So the bottom‑left LED represents the most subtle setting and the one in the top right the most aggressive! The 25 different settings provide a useful variety of characteristics and, to make things even easier, you don't have to worry about readjusting the make‑up gain either, as the machine does that automatically.

The next control block along is the Spectral Balance section, and this simply allows the level of each of the different compressed bands to be adjusted independently prior to the limiters. Increasing the level at this stage causes the subsequent limiter to work harder, allowing the user to optimise the relative amounts of compression and limiting. Each band also has an Emphasis button which boosts the amount of compression in that band, for extra 'punch'! The limiters all have fixed infinity:1 ratios, with relatively slow attack times of 1.4mS. The release times are 1.4 seconds for the lower two sections and 1.0 second for the high‑frequency band.

The digital master fader knob is intended, believe it or not, for performing master fades, and is accompanied by a button to enable external control either over MIDI (controller 7) or via a 50kΩ analogue fader through the dedicated rear‑panel socket. LEDs confirm which system is currently active, and the front‑panel fader always transmits its position as Controller 7 information over the selected MIDI channel. This, usefully, allows an attempted fade to be recorded on a MIDI sequencer, edited, and replayed in sync with MIDI‑controlled music.

The final section of the front panel is the Output block, featuring the analogue output level control (ranging between +6 and ‑26dB), a DSP bypass switch, and three digital configuration buttons. The Bypass button allows comparison between the original and processed signals, although the manual wisely advises matching levels carefully first. This is easily achieved, however, by turning the digital master fader down a little — the amount of reduction needed indicates the extra gain made possible by the processing.

The first digital configuration button selects either an internal word clock (at 44.1 or 48kHz), or allows the DSP to synchronise to the selected digital input. This last feature allows an external wordclock to be used even if the machine is processing an analogue input, and according to TC, the PLL circuitry rejects incoming clock jitter. The second button determines whether the professional (AES‑EBU) or consumer (S/PDIF) data format is transmitted over all three digital outputs. The last button sets the output dithering to 16‑bit, 20‑bit or off ( all 24 bits assumed to carry meaningful data). Even when set to the lower resolutions, the machine actually still sends out 24 bits of data per sample (albeit with the least significant bits carrying only dither noise), and assumes that the receiving device will truncate as necessary.

Mastering The Masterer

When using compression on a complete mix, the most useful advice is to keep it subtle — modest gain reduction is usually far more effective than squashing the music to death! The Express provides an 18dB range on each of the three gain‑reduction meters, and while it might be tempting to find a setting which illuminates all of the lights, I found compression over about 6dB in any band tended to sound pretty hard and aggressive, whatever the settings of the Finalizer Matrix. However, when used with a degree of restraint, the Express was certainly capable of boosting the energy and perceived volume of a track without any detrimental side‑effects.

The manual recommends operating the Express with both soft‑clippers in circuit all the time, and doing this certainly reduces the number of 'clip' indications shown on transient peaks in the programme material. However, I found that the soft‑clippers added a kind of coarseness to the sound which, although highly effective with the right source material, was often inappropriate and actually reduced fidelity rather than improving it. Switching the Normaliser and Finaliser soft‑clippers out of circuit resulted in a lot more 'clip' indications on the Normaliser and Output meters respectively, but gave a much cleaner sound. On tests with a pure tone source, it was clear that both soft‑clippers generated pretty severe odd‑harmonic distortion artifacts which became audible at much lower levels than the actual Normaliser and Output overload points. In fact, even with the signal levels boosted to the point when the 'clip' lights were virtually permanently illuminated on the input and/or output meters, the machine sounded considerably cleaner than when the soft‑clippers were activated! I found I kept them both switched off with most material.

I also found that the limiters could sound quite harsh if overdriven, and I often turned the spectral controls down slightly to reduce limiter activity. The ability to adjust the post‑compression 'Spectral Balance' of the three frequency bands was very useful, however, as were the Emphasis buttons, which allow extra 'bite' or 'punch' to be introduced. I found the Finalizer Matrix a very quick and easy method of setting up and experimenting with alternative compression settings, which could then be fine‑tuned with small adjustments of the Normaliser control and the three Spectral Balance controls.

The digital I/O worked very well for audio inputs and external clock feeds, and my only comment here is that I was caught out once or twice by the fact that the status indicators in the metering block only show the sample rate of a connected and selected digital source — which may not be the same as the sample rate of the machine itself (shown by the indicators adjacent to the clock‑select button on the right‑hand side)!

Conclusion

The Express is a powerful multi‑band compressor which is relatively simple to operate and, if used judiciously, bestows worthwhile improvements on most raw mixes. It will also add a hard, aggressive edge to your tracks if you want it to, and allow the overall spectral balance to be altered more effectively than with EQ alone. If you're mastering your own material and want a more commercial sound, this machine is well worth a closer look and listen, but ideally borrow one for a while, as making the best use of it requires a little familiarity.

Psychic Compression?

One of the inherent problems with compression is that the gain‑controlling element can only react after the signal has exceeded the threshold, which means that brief transient peaks can often slip through before the compressor has had time to react. This is not really an issue in analogue systems with a large headroom capability, but it becomes a serious problem in a digital machine which is already working close to the maximum quantisation level. A common solution is a 'look‑ahead delay' allowing the DSP a 'sneak preview' of what the signal is going to do before it has to perform the necessary level adjustment in the compressor. This is not a new idea — there are several analogue broadcast limiters that make use of the technique, for example — but in the Finalizer Express, an unusually long 3mS delay is (optionally) employed in the signal path to substantially improve the accuracy of the compressor (and limiter) on brief transient signals.

Pros

  • Very intuitive user interface.
  • Superb multi‑band compression algorithms.
  • Flexible interfacing.

Cons

  • Soft‑clippers add a hard edge to the sound quality.
  • Pre‑programmed compression characteristics reduce flexibility to a small degree.

Summary

A powerful processor with high‑quality 24‑bit converters and flexible digital interfacing. Innovative and user‑friendly controls allow fast setting up, and comprehensive metering is extremely informative.