RDC-7.1 Listening Tests

Editorial Note on HDMI (High Definition Multimedia Interface)
HDMI (High Definition Multimedia Interface) is a trademark of HDMI Licensing LLC. Developed by Sony, Hitachi , Thomson (RCA), Philips, Matsushita (Panasonic), Toshiba and Silicon Image, HDMI was created as a digital interface standard for the consumer electronics market.

The HDMI protocol combines high-definition video, multi-channel audio, and inter-component control in a single digital interface. This lone interconnect has the ability to transmit uncompressed digital video and up to eight channels of audio from source to display. Even more, the HDMI connection enables audio/video components to share data and commands, thus unifying an oft-disjointed collection of "boxes" into a real, working system. Based on Silicon Image's TMDS ® technology, HDMI is also fully compatible with PCs and display devices incorporating the Digital Visual Interface (DVI) standard.

For more information on HDMI Connections check out our Audio & Video Connections - Definitive Guide

Surround Processing

The RDC-7.1 is fully armed with all the latest surround modes including PLIIx, DTS Neo, DTS 96/24, THX Ultra2 as well as their own proprietary surround modes which I found to be a cut above what is typically thrown in the mix by other manufacturers. What's really cool is you can overlay PLIIx over virtually any audio signals and formats (ie. Dolby Digital, DTS, DVD-A and SACD transported through i.link!)

All of the THX options are also present, including Ultra2 Music, Cinema, EX, and the newest THX Games mode. Read our article on the Different Levels of THX Certification

Not since my review of the Yamaha RX-Z9 have I found a processor with DSP mode enhancements worthy of consideration. In most cases, I prefer PLIIx Music over any surround mode for music and PLIIx Movie when watching old VHS tapes. However, there are occasions when the right acoustical environment cannot be conveyed in these modes and a little extra processing can help. Integra Research offers a variety of DSP modes including Theater Dimensional, Enhance 7, Orchestra, Unplugged, Studio-Mix, All Channel Stereo, Musical and Action. Each of them produce their own ambiance and can be somewhat tailored to suit the listening environment. My personal favorite includes All Channel Stereo (with the rear surrounds), and Unplugged. When listening to two-channel CD's, the All Channel Stereo mode is an excellent processing mode for filling the room with sound, especially when hosting parties. This mode assures that no matter where you stand in the room, you will be able to indulge in a complete sound field. The Unplugged mode is the perfect setting for CD's with acoustic guitar as it provides a warm, MTV Unplugged type ambience. All other DSP modes offer their own sound field that some may like and others may not. It's completely dependant on your personal preference and source material as to which mode(s) (if any) will work for you.

The Sound

What good is a feature packed receiver or any A/V gear for that matter if it cannot deliver the goods in sonic performance? Our viewpoint is sound first, features second. With that, here is my subjective impression of the RDC-7.1 for the gamut of playback modes I put it through.

Two-Channel Audio

I always begin my initial listening tests in two-channel since I am a two-channel audioholic at heart. I always tweak my system to get the front soundstage optimized prior to getting into any multi-channel listening sessions. I began my review with some familiar tunes from a CD I picked up in Canada visiting Axiom Audio called "Mediterranean Nights" by Vehkavaara & Piltch. I took note of the smooth and melodic melodies of this CD with an extremely low noise floor. The bass extension was very pronounced and controlled with the notch filter in place. Toggling it on and off I could hear just how colored and overpowering the bass was in the off position. This was clear indication to me that my measurement efforts paid off. The notch filter did a bang up job at removing my room's primary modal peek and subsequently increasing system bass linearity.

The RDA-7.1 amplifier proved to pack what seemed to be much more punch and weight than its published specifications. I was able to really crank this CD for long periods of time both in two-channel and PLIIx music without the amp even giving indications of being stressed. It remained cool to the touch, even with the RDC-7.1 stacked on top of it. So far this combo unit was proving itself worthy of the Integra Research heritage and brand.

Listening to SACD via i.LINK was a luxury missed since my review of the Yamaha RX-Z9. For those worrying about the RDC-7.1 passing subwoofer information in two-channel mode - fear not as it does handle bass management via its i.LINK interface much like it does when decoding DD/DTS. While some would argue converting DSD to PCM to enable this may result in sonic degradation, I would counter with "But can you really hear a difference?" If implemented properly, there shouldn't be any ill effects, and in my opinion, the benefits of having bass management and digital delay compensation in this case far outweigh such concerns.

SACD: Patricia Barber Cafe Blue
This, as well as the other three Patricia Barber recordings by Premonition Records, remains one of my benchmark SACD's for good reason - lumpy jazz in a smooth jazz environment free from compressive artifacts. You won't find repetitive and annoying saxophone scales, single stroke drumming, and simplistic guitar rifts. Instead you're showered with snappy jazz and provocative lyrics, slamming drums and memorable instrumental solos. The SACD layer of Track #2, "Morning Grace" sounded about as good as I've ever heard which in one word would best be summed up as "phenomenal". Oddly, listening to the RDC-7.1 via i.Link appeared a bit noisier than I remembered when using Yamaha or Denon i.Link enabled receivers. A quick listening comparison between the RDC-7.1 i.LINK and the Denon DVD-5900 analog outputs demonstrated my suspicions were correct. I detected about a 6-10dB increase in noise floor via the RDC-7.1 i.LINK connection. I suspect there is a firmware configuration issue with the RDC-7.1 and until it is resolved I recommend using the i.LINK interface for DD/DTS and DVD-Audio only and analog connections for SACD.

Some Notes About i.LINK / IEEE-1394 Firewire
1) FireWire is a balanced interface. The modern "low voltage differential serial" interfaces are *all* based on the original work done to develop Firewire back in the early '90's. The low level interface is a pair of LVDS signals (2 pair) in addition to very aggressive grounding for those systems that are not galvanically isolated (the "b" form of 1394 supports both copper and optical connections, and the copper connections can be transformer coupled if necessary).

2) The amount of jitter for audio applications is arbitrarily small. The IEC 61883-6 transport method used for 1394 allows each audio source to provide its own sample clock, and the sync can follow that clock with arbitrary accuracy and stability. It's totally up to the system cost budget how stable the PLL must be. For more information on this, suggestive reading material on this topic can be found at: http://www.1394ta.org/Press/2003Press/january/White_paper.pdf

3) The AES (audio engineering society) has been working with 1394 specs for some time, and the experts there have no problem with the quality of 1394-based transports. There are a few AES specs based on 1394 networks.

Note: IEEE-1394 / Firewire / i.LINK / Lynx are all names describing various manufacturers depiction for cables belonging to the IEEE-1394 standard. IEEE-1394 is the new, extremely fast external serial bus standard that supports data transfer rates of up to 400 Mbps (400 million bits per second). It is used primarily for multimedia devices such as camcorders, computers, video cassette recorders (VCR's), digital audio recording workstations and, in this case, a digital transport for high resolution audio.

Multi-channel Audio

DTS CD: Steely Dan Goucho
I always start off with my base DTS CDs for quick sanity check. The reason being is I intimately know how these discs should sound, and they usually provide me clear indication when I have configuration issues. Steely Dan Gaucho is one, the Alan Parsons Project On Air is the other.

When I hit play, I immediately heard the classic DTS fizzle sound that has been pretty much absent in most products for the past several years. I was surprised that the RDC-7.1 didn't include a muting function during DTS lock on and search. In addition, when I allowed this disc to play through the end on my CD changer, the RDC-7.1 remained locked in DTS mode and would only resolve through power cycle. This only occurred on two of my DTS discs in my 50+ collection. I made Integra Research aware of these issues and they are looking into a firmware fix. Aside from these issues, DTS sounded great, especially with PLIIx Music Mode overlaid to yield 7.1 surround sound!

DTS CD: Pat Metheny Speaking of Now LIVE
Overlaying PLIIx and Integra Research's very impressive DSP processing modes (Orchestra, Unplugged) over the DTS soundtrack brought about new dimensions to the stellar performance of the Pat Metheny Group: Speaking of Now Live DVD. The soundstage of "Last Train Home" was really opened up in 'Orchestra' DSP mode, without sacrificing the focus of Pat's acoustic guitar, though I ultimately preferred Unplugged or regular PLIIx Music mode for more program material. "Roots of Coincidence" rocked my house, cranking the volume up on this song, using the Integra Research combo and my RBH Sound T-2 system transported me back to the live event at Ruth Eckerd Hall in Clearwater Florida I so fondly remembered being a part of only a few years ago. This experience has primed me for the next Pat Metheny concert which is coming to my hometown in only a few short weeks!

When playing back concert DVDs or other recordings for that matter, my advice is to experiment with variety of DSP modes and configuration settings Integra Research offers. I personally enjoy using the Orchestra and Unplugged modes to bring back life in ordinarily dull or compressed sounding DVD concerts and VHS tapes. I ultimately prefer using PLIIx music for CD music in most cases, but this is entirely subjective and you must decide what works best for your listening preferences.

Home Theater

Eager to hear the RDC-7.1 in action for movies, I popped in the Extended Disc set of Lord of the Rings - Fellowship of the Ring and configured it for DTS ES. The RDC-7.1 had no problems identifying ES mode and I was quickly on my way listening to discrete 6.1 surround sound.

The RDC-7.1 performed flawlessly and the opening battle scenes sounded about as good as I have ever heard them in my set-up. The panning between channels was fluid, the noise floor so commendably low that, until the sound kicked in, I kept pumping up the volume until I was blasted with the dynamics of the first action scene and literally grasped the handles of my chair in agony while swords sliced through those nasty goblins.

Playing an assortment of DVD movies ranging from Star Trek, to Double Jeopardy, I was equally enthralled by the RDC-7.1's home theater performance capabilities. I always found it to be transparent and extremely clean sounding. I also loved the fact that I could transform standard 5.1 DD DVD's to 7.1 via PLIIx processing and felt it really added a sense of realism and envelopment to the movie watching experience. If you are contemplating on whether you wish to integrate the extra two back surround channels, just do it! Find a way to make it work as it will be worth your while.