Product Review - Meridian 568 Surround Sound Processor - December, 2001

David Wurtz



Digital - 4 x Coaxial and 1 x Optical
Analogue – 2 x Unbalanced (RCA)

Digital – 4 x SPDIF (24 bit)
Analog – 8 x Unbalanced for Mains, Center, Sides, Rears and Subwoofer
3 x Balanced (XLR) for Mains and Center

Sensitivity: 0 – 3.5 Volts
Distortion: <0.01%
Noise and Hum: <-95dB CCIR

1 x with Onscreen Display, RCA 1.5V p-p, PAL/NTSC/SECAM Compatible

1 x with Onscreen Display, Y/C on Minidin 1.5V p-p, PAL/NTSC/SECAM Compatible

All Internal Processing Done with 4 x Motorola 24 bit Chips
Formats: DD, DTS, MPEG Surround, THX, MLP, Pro Logic and PLII

Control: 2 x Meridian Comms
1 x 9 Pin “D shell” for RS232 PC (Serial) for Set-Up and Control

Dimensions (H x W x D): 88mm x 321mm x 332mm

Weight: 12 Pounds

MSRP:   $6,495 USA


Meridian Audio Ltd., Stonehill, Stukeley Meadows, Huntingdon, Cambridgeshire, PE18 6ED, England; Phone [44] 1480 52144; Fax [44] 1480 459934; Web


I was in the market for a new home theatre processor and having to choose from several units (including the Meridian 568, Theta Casablanca II, Acurus ACT-3, Sunfire Theater Grand II, Golden Theater, etc.) is a real nightmare. They are all very worthy options. Like you, I must do plenty of research when choosing such an integral component for marriage into my reference system (believe it or not, we don't have all the answers all of the time). Living where I do makes it very difficult to try to get a “full feel” for all of these options. I really would have preferred having all of them at my home for testing/evaluation (reviewers are spoiled brats aren't they!!!), but this is virtually impossible. I must do a lot of reading, and speaking with owners, and more reading, and discussion with other reviewers, and then even more reading. Really, the processor is the heart and soul of any home theater system, and it is a critical decision to make.

I decided to try out the new Meridian 568 processor first. As it turned out, this was as far as I would need to go.

Physical Properties

The 568 is physically smaller than a standard rack mount unit width by 10cm (4"). An adaptor is available from Middle Atlantic Products that will allow it to fit into a standard rack. The front of the unit is split horizontally with the top half having a glossy plastic strip. The left hand side shows the Meridian logo, and the right hand side has the unit's display. The display is limited to 12 characters. The last two characters are for the volume level (between 1 and 99). The bottom half of the front panel has the buttons that control the unit, 8 of them in all. From left to right they are:

Source – Turns the unit on and selects the source, e.g., DVD, CD, DAC, VCR, etc.
Store – Sets the DSP mode for a given source.
Preset – Changes the preset or setting menu.
Mute – Mute.
Display – Changes the information displayed on the display panel.
Decrease – Reduces the volume level in 1dB steps.
Increase – Increases the volume level in 1dB steps.
Off – Turns the unit into standby mode.

The rear of the unit is quite crowded and has:

8 x analog output RCA sockets (Front Left, Center and Right – Side Left and Right, Rear Left and Right and a Sub) Stereo subs are available out of the Side Left and Right output (software configurable).
3 x XLR (or balanced) analog outputs (Front Left, Center, and Right).
2 pairs of analog input RCA sockets.
1 x RCA video (composite) input.
1 x RCA video (composite) output.
1 x S-VHS (4 pin mini-din) input.
1 x S-VHS (4 pin mini-din) output.
4 x digital signal outputs. For connection to Meridian digital loudspeakers.
4 x digital inputs (coaxial).
1 x optical input.
2 x 4 pin din for Meridian Communications.
IEC power socket with built in fuse.
9 pin D-shell Expansion connector (connects to other Meridian 500 series products).
9 pin D shell RS232 socket.

The top of the unit is finished in a high gloss Perspex, and the bottom of the 568 has four very soft rubber feet.

The remote control (shown above) is full-featured, very stylish, and you can access all the internal 568 settings from this. It is a little awkwardly shaped (you have to use two hands) in my opinion, but I have gotten used to it. Gee, I'm lazy.

The 568's Processing Power Plant

For starters, the Meridian 568 is a 100% digital processor. That means the 568 converts all incoming analog signals into a digital format through high quality ADCs. The digital signals from CD players, DVD, etc. are left in the original state. All signals are processed in the digital domain and finally converted back only at the last output stage to be sent to the amplifiers. But, it does not have to happen this way. The 568 also has digital outputs for direct connection to Meridian DSP loudspeakers so the signal can stay in the digital stage until the absolute final stage before reproduction. By processing in the digital domain, the 568 allows sophisticated modification techniques to be performed without any degradation by the introduction of cumulative noise or phase relationships (which are inherent even in high quality analog circuits) to occur. With the added bonus of being able to remove timing variation from any incoming digital signals and resample and expand incoming analog signals to the highest available range (24 bit) and highest rate (96 kHz), the concept is a winner in my opinion. 44.1 kHz is up-sampled to 88.2 kHz, and 48 kHz is up-sampled to 96 kHz.

There is a setting called HS (High Speed). It is a feature (part of the algorithm) used in DSP modes (Music and Trifield) for improving dynamics and can only be accomplished because of the digital signal processing. In the HS settings, Y (for Yes) gives high data rate audio to the front speakers (Left, Right, Center and Sub) upsampled to match all speakers (if necessary). N (for No) gives a standard (or native) data rate to all speakers, downsampled to match all speakers (if necessary). All PCM signals are up-sampled if you have HS set to Y. You also must have HS set to Y if you want to receive a 96 kHz DVD and have it output in that format. If you want things done at native rate, then you must set HS to N. I advise that you set HS to Y.

Early next year the 568 will get a major DSP upgrade. This will allow it to upsample all eight channels instead of just the front four.

568 Preset Modes

DSP Presets

Dolby Digital, DTS, MPEG Surround, THX, MLP.

Multi-channel sources encoded on two channels

Pro Logic and PLII
TV Logic – For use where Pro Logic gives a reduced intelligibility.
THX Cinema – Enhances Pro Logic to replicate a theater situation.
Ambisonic – A format similar to Pro Logic coding and available on some CD labels.

Two Channel sources

Music – Uses Left, Right and Center speakers and a processing technique to give a wide soundstage - especially useful for orchestral and choral music.
Trifield – Gives a precise 3 dimensional image for use with solo chamber and vocal music.
Super Stereo – Recommended for multi-miked or multi-channel music. e.g., pop and rock music
Music Logic – User adjustable for giving an exciting sound for music without a natural sound field.

Special DSP Presets

Mono - especially designed for mono recording.
Direct - Uses the Left and Right speakers only.
Stereo – Uses the Left and Right speakers + Subwoofer.

Note: If you want more detail on the PC setup interface, this is fully explained in a review written on the Meridian 861 by Stacey Spears.

The Sound

After reading the manual front to back and setting up the parameters in the software configuration file and uploading it, I was ready. This took about 2 hours of “fun filled fiddling” (say that 5 times quickly). I let the unit burn in for about 6 weeks before writing anything down in my notepad. There was a noticeable improvement in sound quality over this time.

For VHS Movies and/or 2 channel sources . . .

Firstly, I just love the 568's surround fields for the 2-channel stuff. This must be partially due to the advanced set-up options that Meridian offers, being able to set the actual distance of the speakers, no worries about delays, etc. Being a 2-channel man from way back, as I guess many of us are, I was never really a fan of surround sound. The popular Yamaha DSPA1 sound modes are excellent for the mass-market receiver line, but I found myself only really using the “Jazz Club”, “Sci-Fi” and “Movie Adventure” modes when listening to CDs. The otherd just did not sound quite right to me. The Meridian defiantly leaves these for dead. “PLII THX” quickly became a favorite for my older VHS tape collection. The "Star Wars" Trilogy (+ "The Phantom Menace") is decoded and reproduced better than I have ever heard, full stop. My James Bond collection was also treated very well in this domain.

I have found, and I am sure most of you will agree, that since the introduction of DVD with DD and DTS, most video tapes are now collecting dust. Not for me now though! This feature alone is almost worth the price of the product. Even in plain old Pro Logic mode (and I mean that in the nicest possible way), the 568 brought VHS movies back to life (in a lesser way to PLII), but it was hard to leave it there for long, as PLII was so much better. My favorite music video, Pink Floyd's “Delicate Sounds of Thunder” live show is a spectacular event, and the Meridian, mixed with the PLII surround mode and this tape, were as best as I have ever heard it. It would be much nicer in DD or DTS 5.1 (Hint, Hint to any of the BMG Group out there who are reading this), but now that I have the 568 and PLII, I can live with it till it is released on DVD.

For DVD movies and DVD music . . .

On the DVD side of things, the standard array of decodings (DD and DTS) were a treat. Dolby Digital was treated to an accuracy that I could only marvel at. Most notably was the bass section, and the accuracy was so obvious. Movies like “The Matrix” and “U571” sounded completely different in their bass reproduction from what they were previously. In the past, there were times in the movies that bass seemed to be a constant rumble, but the 568 showed me detail in the bass section I never thought possible. What was a rumble now has several pulses of bass as well. The articulation of the 568's incredibly solid and detailed 0.1 action had my jaw on the floor and the hairs on the back of my neck having a party with everyone invited. At the other end of the scale, voices in movies that appeared quiet in the past were now forward and very precise. Softer detailed midrange and high frequency were also amazingly accurate. Every little whisper was now far more audible than I have ever experienced. The THX re-equalization only made it better. The entire sonic image within any DVD that I played was truly something to behold.

My 2-year-old son and I watch “The Tigger Movie” quite often, and this movie was mixed very dynamically and can be very hard to understand when some characters are talking. The Meridian's ability to separate and articulate is incredible. No longer was I turning my head to one side thinking, “What did Pooh-Bear say?”

“Toy Story 2” is another example of an incredibly dynamic movie with lots of surround sound action. Of note, the opening sequence with Buzz flying around in space was so amazingly real, I almost forgot I was in a cartoon flick. Micro detail was superbly accurate, voices crystal clear, effects dynamic, loads of well defined bass, what else could I ask for? A good story line, well it has one of those too . . . .

"The Fifth Element" has a wonderful DD soundtrack, and the 568 seemed to make it even better. The overall mood in different sequences of the movie noticeably changed. I felt more so drawn into the movie instead of just sitting, watching, and having “a Coke and a smile . . . .” Then the explosions and gun fire . . . . Pick me up off the floor please . . . . The crystal clear dynamic effects reproduced by the 568 are amazing.

The release of “The Phantom Menace” on DVD has been a long awaited one for me. I am astounded at the clarity of the DD soundtrack through the 568. This is a reference quality production and when played through a reference quality piece of hardware like the 568, it is nothing short of stunning. The soundstage, the voices, the front to back and side to side effects, the bass performance, are all unquestionably fantastic with a real feel of involvement. But that's what we spend good money for isn't it? Recreating a theater in our homes. In fact, I would say that my home theater, with the inclusion of the Meridian, is now better than any commercial theater within 500 Km of me. And that is what makes spending big dollars so worthwhile. You end up with a theater better than the one in town. And, no sticky floors, the popcorn is cheaper, and you can put the movie in pause when you need to whatever.

Music DVDs were treated with similar sparkle and sonic attention. Fleetwood Mac's live performance has some excellent examples of a fine all round surround music event. The 568 just made it better with better drum sounds, better bass guitar reproduction, better vocal sound, and better intricate percussion sounds.

As a Stereo Preamp

And now to the bit you have all been waiting for - well some of you anyway: the Meridian 568 as a plain old vanilla stereo hi-fi preamp. Let me say that vanilla is a wonderful flavor, and so is the 568. To me, this unit is the proverbial “20-foot piece of copper wire with 20 dB of gain”. Whether feeding the Meridian an average sounding Sony CD player's analog output, or the output of the Perpetual Technologies P1A and P3A combo DCE & DAC, or even the super sounding Audio Aero Prima CD player, the 568 took on the source's true characteristics. In real terms, the 568 is essentially a DAC, and that's the way it acted. This is of particular advantage if you really enjoy the sound of a particular source you own, for example, a favorite old Nakamichi cassette deck, or indeed a newer “valve driven output” CD player. The 568 will give you back almost exactly what it is being fed, including all that fine detail.

Regarding the 2-channel modes, I found that I preferred either “Direct” or “Trifield” mode in which I made most of my listening notes.

All of my reference discs were given a full workout, and every single one of them sounded better than almost nearly all solid state preamps I have heard so far. You may have noted that I purposely left out valves in this statement. Tubes have a unique sound that is all their own, and if you like tubes as I do, and listen just to stereo CDs, the Class A triode tube preamp is still king in that arena.

In any case, I still found the 568 gave me noticeable increases in the soundstage's width, breadth, and depth, and with the 568's “DAC like” fine detail to boot, I was suitably impressed. The Meridian has the ability to bring to life almost any piece of music. It delivered better sounds by actually defining the micro-detail available from all different types of instruments. Most of the time I was hearing the detail I knew was there, being picked out, sharpened up, and lovingly given back in spades. Trumpets had definite start and finish points. The natural decay from notes played by a piano proved to me the 568's ability to “code and decode” naturally. French horns were noticeably sweet and sonically correct. I feel that the French horn is one of those instruments, that when played and reproduced well, gives me the most satisfaction during my listening sessions, and through the 568, it was excellent. Selected vocal and choral tracks were just as exciting, full and dynamic, with the added bonus of almost being able to pick out individual choir members and imagining their actual position in the soundstage.

Australian vocalist, Monica Traparga, from the album “Too Darn Hot” has a voice of pure gold, and was perfectly presented and positioned exactly in the middle of the soundstage. The album is full of jazz tracks that are perfect examples of modern jazz done well. The production on the disc is superb. The double bass was presented crisply, tonally perfect, and mixed very well with the piano guitar and drums. The 568 again, gave me everything and left out nothing.

Popular classics from the likes of Michael Jackson and Madonna are mostly over-processed but none-the-less are excellent examples of typical material played by the masses. These discs were very detailed through the 568, making it easier to pick out individual instruments and backing vocalists, whereas previously they could have appeared a bit “mushy”.

In popular music I use drum sounds to judge several facets of a unit's reproduction qualities. The 568's ability to isolate dynamic bass and snare drums while maintaining the overall clarity and sweetness of hi-hats and ride cymbals, combined with the attack of crash and splash cymbals, was outstanding. But that's high quality digital processing for you and the 568 is spot on accurate! Not as sweet as a high quality valve preamp, but still definitely up there with the best of them.


I am truly in awe of the 568 Surround Processor. The unit is a perfect extension of the source with no real coloration to speak of, just wonderful detail. The configurability is second to none. The surround modes are superb, and this comes from someone who is not a big fan of these types of things. The only fitting thing I have left to say is that I have no hesitation in fully endorsing this fine product.


- David Wurtz - 

© Copyright 2001 Secrets of Home Theater & High Fidelity
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