Logitek Ultra-VU 71 Metering System

Logitek has several different metering packages for surround monitoring. The eight-channel, Ultra-VU 7.1 ($3,900), reviewed here, is available in both an analog and digital input versions. I reviewed the digital version.
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Logitek has several different metering packages for surround monitoring. The eight-channel, Ultra-VU 7.1 ($3,900), reviewed here, is available in both an analog and digital input versions. I reviewed the digital version.
Product PointsApplications: Studio post production, mastering production/location audio

Key Features: Accurate level metering in two-channel, six-channel (up to 5.1) and eight-channel (up to 7.1) configurations; analog versions include trim controls, digital versions setup for AES/EBU in and thru via XLR connectors

Price: $3,900

Contact: Logitek at 800-231-5870 713-664-4470; Web Site

Plus

+ Many metering configurations

+ Simultaneous VU and PPM displays per bargraph

+ Excellent metering resolution

Minus

- None

The Score: An essential metering tool with enough customizable settings for all types of users.
Features

The differences between the digital and analog versions are simple and logical. The analog units have trim controls to adjust to specific console and monitor path calibration levels. The digital versions have calibration adjustments via mode setting switches on the back panel.

I chose the digital input model Ultra-VU 7.1 for review, as most 5.1 and 7.1 mixing is done on digital consoles feeding a digital mixdown recording platform. This fit seamlessly into my mixdown arrangement because the Logitek Ultra-VU 7.1 has four AES/EBU pairs that pass through the unit.

Using four female XLR ins and four male XLR outs, the Logitek just looks at the digital signals passing through these four AES/EBU pairs and displays levels accordingly. The Ultra-VU 7.1 can be inserted in the bus path to any digital recording platform being used for 5.1 or 7.1 mixdown, that accommodates AES/EBU.

The unit features an extensive list of operational mode displays that can be changed using the included two-button remote. The remote uses a 9-pin D-sub connector and is supplied with a short, easily extended cable. All display modes are visible on the front panel with orange LEDs indicating the current mode.

Each channel's vertical bar display provides 51 individual, dual-colored (red/green) LED segments, plus a red clip LED. The top 40 dB range is displayed with 40 LED segments (1 dB per segment). The first indication is -70 dB FS, followed by 5 dB steps at -65, and -60, 2.5 dB steps to -50, 2 dB steps to -40, then 1 dB indication on all 40 LEDs up to 0 dB FS. The clip LED is programmable for either one or four samples in a row.

A cleverly implemented orange LED remains lit at a reference point adjustable between -10 to -20 dB below full scale; factory preset is -20 dB FS (SMPTE standard reference).

The "Fine" mode changes the display to indicate plus or minus 10 dB in 0.2 dB increments above and below the chosen reference point. Variations of display modes are possible: simultaneous VU and Peak, just VU or just Peak. On the Ultra-VU 7.1 the eight channels are labeled, from left to right: L, LC, C, RC, R, LS, RS and Sub.

The operation and service manual provided includes a complete set of schematics, part numbers and even part manufacturers.

In use

The four display pairs (eight channels of monitoring) follow whatever AES/EBU pair is connected, making this unit handy for providing accurate level indication on whatever is being routed through my eight-bus digital console. This was so useful I highly recommend getting the eight-channel unit, even if you are not doing 7.1 mixing.

Loudness filter options and stereo image phase displays are selectable. Even eight levels of brightness are selectable for comfortable viewing in dimly lit rooms.

Many transfers in the post production realm use DA-88 tapes to deliver a 5.1 mix on the first six tracks, and an L/R (Dolby Stereo) mix on the last two. Having the 7.1 model in their scenario allows accurate monitoring of all eight tracks/busses. Also, by having the Logitek monitor all eight busses of my console, whether in 5.1 mixing, overdubbing, recording, etc., I enjoyed a high degree of accuracy.

When calibrating my system, I found the Logitek unit consistently accurate for all frequencies between 20 Hz and 20 kHz.

One of the first things I did was cover up the factory channel labeling with board tape. I just wrote 1 through 8, indicating which bus channel was which. On the bottom of the unit, I put another strip of board tape and wrote L, R, LS, RS, C, Sub, when using the Yamaha/DTS track numbering scheme; and L, R, C, Sub, LS, RS, when using the SMPTE track numbering format.

Logitek should just leave the factory-printed label off or provide some stick-on or clip-on track labeling. There is, however, plenty of room at the top and bottom of the meter for pieces of board tape to write current track schemes/names, without interfering at all with the display. (Custom legends are available from the manufacturer-Ed.)

Although I have used other meters in my post production work, I immediately became spoiled by the Logitek. The use of the bicolored LED segments provides concurrent displays of a solid green bargraph indicating VU ballistics, with Peak Program Meter (PPM) indications displayed in red. The PPM indications fall at a rate of 2.8 seconds per 24 dB, and a red telltale can be programmed to stick for 2 seconds, 5 seconds or hold until cleared. It is easy to find an option that seems natural to your own viewing preference or to the task at hand, such as switching to peak-hold mode while transferring.

I used the Logitek Ultra-VU on several projects - recording, overdubbing and mastering. Since I had the eight-channel unit for review, whatever was sent to any bus of my eight-bus digital console was displayed. The peak levels are red, with enough display persistence to catch your eye, so level adjustments for recording and overdubbing were easy, and allowed good levels without clipping.

I also used the Ultra-VU on two 5.1 projects that were being remastered for DVD-Audio release. The peak-holding monitor allowed me to play each song, and monitor the busses to the destination platform without having to stare at the meter the whole time.

The Logitek can hold the loudest peak indication for each channel, thereby allowing me to generate a final master right at digital zero without clipping! In other words, if on the trial pass, I saw that, say the left front incurred the loudest peak of all channels at -5 dB FS, I could adjust the whole mix up 5 dB. Channel balance and dynamics were preserved with the final mix being as "hot" as possible without clipping. Please remember that the peak-hold feature is very easy to toggle in and out, with clear indication of display modes (via orange display LEDs) on the front.

Logitek took great care and attention to the solid green bargraph that underlies the red peaks. All of Logitek's Ultra-VU meters conform to the ballistic standards described in IEEE document G.2.1.2/13, IEC document 268 and EBU document 3205-E.

With the -20 dB FS (SMPTE and THX reference for dialogue normalization; dial-norm) clearly displayed with solid orange, dialogue levels are much easier to get right than with other metering systems I've used.

The solid green bar display of the Ultra-VU hitting this reference level was very useful for a concert video soundtrack we had in-house during this writing. We provided location recording for The Phoenix Rising Choir, one of the study programs offered by the Institute for Harmonic Science. Dr. Harold Moses, conductor for the choir and managing director of the institute was onstage many times during the performance talking to, and providing narration for, the audience. With the Logitek meter, during post production, I was able to maintain consistent -20 dB FS levels for his dialogue, while allowing dynamic peaks of the orchestral and chorale performance to be transferred to VHS tape with excellent results.

When I received the Ultra-VU 7.1 for review, the Universal release U-571 had just come out on DVD with a DTS soundtrack. In my 5.1 room at Porcupine Studios (Chandler, Ariz.) I was having a blast playing quite a bit of Chapter 15 for clients and visitors. This is where the Germans start pelting the stolen submarine with depth charges.

Sincere compliments to Steve Maslow, Gregg Landaker and Rick Kline, the Universal Studios rerecording team for U-571! I found that dialogue levels were consistently at -20 dB FS, the reference level for the center channel. Also, just as Matthew McConaughey says, "Step away from that bulkhead, Mr. Hirsh. The shockwave from one of these explosions can crush a man's spine...," the soundtrack gets amazingly quiet. Just a few creaks and groans of submarine sound effects indicated at -50 to -60 dB FS on the Logitek meters. Of course, several frames later ... KA BOOM!! All six channels indicating -2 dB FS instantaneously displaying the peaks of the depth charge explosions.

Summary

Incredible dynamics are now possible (and implemented with stunning effectiveness in U-571) with 20- and 24-bit resolution equipment. The expense of having multichannel metering the caliber of the Logitek should not be viewed as a luxury, but as a necessity. I was impressed that a commercially produced soundtrack exhibited more than 60 dB of dynamics, with the noise floor well below -70 dB FS and the Logitek Ultra-VU displaying it all clearly and accurately.