Integra Research RDC-7 Processor Review

Integra Research has paved the way and set the standard for audiophile products with the design and creation of the RDC-7. Recognizing that there are a number of people hoping to purchase something that will last and not become obsolete by new formats or technologies, Integra Research designed the RDC-7 for both hardware and software upgradeability. The unit has an RS-232 Port for easy software upgrades and to Communicate with AMX, PHAST, Crestron or Other Similar Control Systems. Where the RDC-7 stands apart from many other software upgradeable products is that it was designed and built with modularized electronics for hardware upgrades. When looking under the cover of the RDC-7, it's obvious that Integra Research modularized the PC boards and hardware so they can be easily removed, upgraded or replaced by an authorized technician. In fact, the inside of this unit is reminiscent of today's modular PC's.

By modularizing the RDC-7, Integra Research has increased the service life of this processor by reducing the chance of obsolescence. The first upgrade to the RDC-7 happened two years ago with the addition of DTS-ES and Dolby ProLogic II. This upgrade was provided at no charge. The second upgrade included THX Ultra2, DTS 96/24 and variable subwoofer crossover at a cost of $500. All RDC-7's currently being sold now include both upgrades. Future hardware related upgrades will be market driven and may include additional IEEE connectors.

The Front channels employ dual differential Burr Brown (now part of Texas Instruments) PCM1704, SoundPlus (TM) 24-Bit, 96kHz BiCMOS Sign-Magnitude Digital-To-Analog Converters . This is an improvement to many "high-end" processors that utilize single ended DAC's for their front channels. The PCM1704 is a precision, 24-bit digital-to-analog converter with high dynamic performance, ultra-low distortion and excellent low-level signal performance. The PCM1704 supports 8X oversampling at 96kHz.

Dual differential DAC implementation can offer quite an improvement over a single-ended configuration, especially if the entire design path is complimentary. Integra Research takes it one step further with a low jitter Apogee clock that ensures the full performance of the DAC's can be realized.

The center, surrounds, rear surrounds and subwoofer channels implement Analog Devices AD1853 24 Bit, 192 kHz, Multibit Sigma-Delta DACs in a single-ended configuration. The AD1853 is fully compatible with sample rates from 32 kHz up to and including 192 kHz. It also achieves 120 dB of dynamic range and Signal-to-Noise ratio without muting of 107 dB THD+N. The AD1853 also features a superior Digital Filter with 115 dB stop-band-attenuation. The AD1853 uses Analog Devices' exclusive Multibit Sigma-Delta Modulator with "Perfect Differential Linearity" for reduced idle tones. It also features Analog's patented Data Directed Scrambling to minimize sensitivity to jitter.

Just to note, while these are quality DAC's, Integra Research implemented them in a single-ended configuration. This single-ended configuration is similar to that found in the Integra DTC-9.4 and many other receivers and processors currently available. Even with the low jitter Apogee clock and Vector Linear Conversion described below, we wonder if including dual differential DAC implementation with full complimentary circuit topology on all channels would have offered an audible improved performance from these channels. However, our listening tests did not appear to reveal any major sonic limitations in its current configuration.

There are two 493000 series Cirrus Logic Crystal Enhanced, Dual Engine, Multi Standard Digital Audio Decoders (otherwise known as DSP chips) in the RDC-7. One DSP chip is devoted to Dolby Digital and DTS decoding, while the other is devoted to secondary functions. By implementing two DSP's, Integra Research has employed technology above that of many other processors we have reviewed in this price range. However, we wonder if their next generation platform will require more horsepower to handle new features such as room correction or digital video processing which seems to be the next evolutionary step in home theater products.

Perhaps the most notable feature within the digital topology of the Integra Research RDC-7 is the low jitter clock from Apogee. Apogee Electronics was founded in 1985 by Betty Bennett and Bruce Jackson, both veterans of the professional audio industry. They formed the company for one purpose: to deliver the highest possible quality for digital audio.

Apogee's patented low jitter clock audibly cleans up jitter by taking in erratic or jittery timing signals and putting out cleaner, lower jitter signals. This allows optimum A/D and D/A conversion for improved sonic performance.

For more information on the Digital Architecture of the RDC-7: download the following Technical Paper

Integra Research's RDC-7 implements a non-scaled circuit design so the LFE signals are added using analog circuits after the digital to analog conversion process to ensure that the music data is preserved. This also eliminates the possibility of digital domain clipping, thus the summed signal integrity is preserved by adding it in the analog domain.

For more information on Non-Scaling Configuration: download the following Technical Paper

The 36-lb, 18" x 8" x 17 ½" RDC-7 is a giant when compared to most other processors on the market. With a quick peek inside this beast, it was notable to see that components are tightly packed within the chassis. The RDC-7 is a multi-dimensional product that offers refinement not only in its digital and analog architecture, but also in its build quality, as portrayed by its sleek and formidable front and back panels and display.

There is one point of criticism that can be identified with respect to the front panel, and it concerns the mode selection and power on lights. Both are significantly brighter in their blue lighting than the blue text on the LCD display. They are so bright, in fact, that they can overshadow the display in a dimly lit room. Also, if the processor is located on a rack next to the TV monitor, as is the case in Audioholics' Reference System 2 , these lights can be seen with peripheral vision while viewing movies at night and are a bit of a distraction. These lights remain on even when you implement the dimming feature, which seems to dim only the LCD display.

The DB-25 connection used for the 6-channel input provides a simplified connection with the Integra Research RDV-1 DVD Player or other players that have matching connector. But when connecting DVD players with standard RCA's, it somewhat complicates things. Since there are no well established standards for color coding the 25-pin connector cables (except for a THX guideline that few cable companies follow let alone know about) it can become a challange to connect. The processor comes with an adapter that combines a DB-25 male connector with 6-female RCA's to allow the user to connect via standard RCA's. If you care to attempt a simplified connection, there are a few cable manufacturers that actually make a DB-25 male connector directly to 6 RCA males to allow direct input to your DVD player. But with no governing standard for the color codes, you'll need a pin-out diagram to ensure your connections are accurate. Furthermore, due to the nature of the DB-25 connector, these cables can not be easily shielded like quality RCA cables. In our opinion, a DB-25 connector for 6-channel input offers few advantages over standard RCA's, save the space savings on the rear panel.

The bottom left corner of the back panel includes an IR in Main , IR in Zone 2 and two 12-volt triggers. The two 12-volt triggers are a useful feature when tied to the Integra Research RDA-7 power amplifier, for example. This feature allows for instant power-up of an amplifier with matching trigger input. The second trigger is useful for tying into any other devices that have a 1/8" mini-jack 12-volt connection.

The OSD of the RDC-7 was self-explanatory and user-friendly. Without referring to the manual, we were able to navigate freely and set up the appropriate parameters.

The Speaker Setup section has five main menu options including speaker configuration, speaker distance, level calibration, bass peak level and LFE level setup.

Speaker Distance adjustments are a useful feature as it allows for customization based on room size between 1 to 30 feet (0.3 to 9 meters). This important feature allows adjustment of timing via a group delay and it helps to provide proper time alignment of all speakers to a reference seated position, thus ensuring the recording is heard properly. The RDC-7 also provides distance (group delay) adjustment for the subwoofer, unlike some "high-end" processors which lack this basic feature. This ensures optimal acoustical blending between the speakers and subwoofer system.

Level calibration provides speaker volume adjustments for each channel, including the subwoofer. The volume calibration level provides +/- 0.5dB accuracy, which is once again an improvement to many well known "high-end" processors that only provide +/- 1dB. For those serious home theater enthusiast who calibrate speaker level's using a SPL meter, a difference of 0.5dB when trying to obtain uniform speaker level volumes for all channels is critical.

We did notice one slight flaw in the RDC-7 test tone. We first adjusted all speaker levels with the internal pink noise generated of the processor (reference level 75dB) while carefully measuring their respective levels with a Radio Shack SPL Meter at a fixed distance. Once we were certain all channels were approximately set to the same level, we decided to double check our results by using an external source calibration disc. To accomplish this, we used Ovation Software's AVIA Guide to Home Theater DVD. Once again, we carefully measured levels for each channel. It was then that we noticed a difference in the channel to channel levels. Using the AVIA DVD as the source, the center channel measured 1dB louder than the mains and the surrounds each measured 2dB lower when compared to the test tones of the RDC-7. We were unable to verify the pink noise for the back surrounds as the AVIA Guide to Home Theater DVD did not feature pink noise for 7.1 surround. We did report this potential pink noise bug to Integra Research and are awaiting their response.

We recently discovered that the RDC-7 provided separate speaker level trim settings for multi-channel input. This was not a well advertised feature, and in our initial review, we totally missed this fact. It wasn't until we received constructive feedback from in our forum discussion by one of our members (thanks MBRiley) that we discovered this feature. Not even a tech guru at Integra Research picked up on this. Although the RDC-7 only included one storage bank for speaker level settings accessible within the OSD, it did allow speaker level trim settings to be adjusted and stored On-The-Fly when in multi-channel input. This was extremely useful when switching between SACD and/or DVD-Audio and back to DD / DTS sources. This is due to the inherent subwoofer level differences of the formats. In DVD-A / SACD, the subwoofer output is significantly lower than DD / DTS (as much as 15dB!). With this additional speaker level trim setting, we were able to change the subwoofer level and speaker level settings for DVD-A and SACD. Many other "high-end" processors do not offer this feature. In fact, it wasn't until the most recent releases of some receivers that additional speaker level trim settings even became available.

The RDC-7 also provided speaker level settings On-The-Fly for digital inputs. This too came in handy for when you wish to tweak the volume of the center, rears or surrounds while listening to a digital source. These On-The-Fly settings were stored in the memory bank found within the OSD. Although, perhaps it would be better if these settings were not permanently stored. While I found it useful to change level settings On-The-Fly, it really depends on the source you are listening to. My feeling is that the O-T-F settings should not permanently change the calibration settings that we configured with s Sound Level Meter.

For more information on Set-Up and Configuration of the RDC-7: Download the attached RDC-7 Instruction Manual.

Listening Mode Preset is perhaps the most useful feature within the On Screen Menu setup. It allows you to set a different listening mode for each signal type that comes from any input source, while providing parameter settings for the listening mode. If you take the DVD player as an example, the processor will automatically detect and default to the DTS or Dolby Digital mode. What is especially useful about this feature is its ability to detect the varying signal from satellite or cable TV digital inputs. Throughout the day, there are a few programs broadcasted in Dolby Digital 5.1, with more broadcasted in Dolby Digital 2.0 and the rest in PCM. The RDC-7 can sense the movies that are being transmitted in DD 5.1 and select the Dolby Digital setting automatically. If the movie is broadcast in DD 2.0 or PCM, the RDC-7 automatically selects the surround mode you programmed into the default. My personal preferences for DD 2.0 or PCM movies are either Pro-Logic II or DTS Neo as explained in the sections that follow.

For more information on Listening Mode Presets for the RDC-7: Download the attached RDC-7 Instruction Manual .

The RDC-7 provided another very useful feature. It allowed coarse tone control adjustments for bass and treble that can be stored for each input (for digital only). This was especially useful for boosting the bass a bit for the satellite TV input. It may also help those with inefficient speakers or poor room acoustics and are therefore looking for a little extra bass.

The Preference Menu provides settings for customizing certain functions, including Volume Setup, On Screen Display setup and tweak.

The DSP modes include 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 personal preference as to which will work for you.

For our complete listening study of Integra Research's RDC-7, we went through an exhausting variety of different formats and sources over a 5 month period. For two-channel formats we listened to a broad base of CD's in Analog bypass, stereo mode, and through several DSP modes. We also spent a considerable amount of time listening to movie and concert broadcasts from satellite. We also tested the unit with DTS CD's, SACD's and DVD-Audio so that we sampled all possible modes of operation.

For our listening pleasure, we auditioned the RDC-7 with satellite radio broadcasts and the following list of CD's.

During our time with the RDC-7, much of it was spent entrenched in a pile of CD's. The experience allowed us to better understand the performance of this processor. During playback of these CD's, the RDC-7 was able to produce a large soundstage with detailed, accurate sound without sounding bright or mechanical. The music sounded lively and natural, and vocals were not lispy, nor stale. In Direct Mode without the addition of a subwoofer, there was sufficiently deep bass coming from our large main speakers. The bass was tight and projected with authority, more so than any of the other processors placed in this setup, particularly when compared directly against the Sunfire Theater Grand III. While enjoying the music, we were able to appreciate the subtle nuances of Jewel's voice as well as the reverberation from Church Hall acoustics found on the song "Mining for Gold" on The Cowboy Junkies Trinity Sessions CD. Guitars, sax, bass, drums, vocals and all instruments were reproduced with precision and detail. Direct Mode should be the preferred setting for those embarking on a listening experience with time to sit back, relax and enjoy the delicate sounds of music. The RDC-7 demonstrated its ability to serve as an audiophile preamp during these extensive listening sessions.

The same collection of CD's listed above, was replayed using the Stereo mode to compare performance to the Analog Direct bypass. This mode allowed operation of the subwoofer with the mains set to either large or small. We initially listened with the subwoofer turned off for a direct comparison. We also switched back and forth between stereo and analog bypass (direct) to note any audible performance differences. While stereo mode does add the option for subwoofer, it theoretically cannot provide the level of detail of the Analog Direct Mode. We felt the Stereo mode was not a sonic match to the Analog direct mode. Perhaps this was due to expected losses from the digital circuitry that results in subtle reductions in details and nuances. Keep in mind that a marginal performance difference is expected when listening to music in Stereo, so it was not a fault with the RDC-7. If anything, it allowed us to appreciate how well the analog direct mode performed. This mode is generally used when added bass from a subwoofer is desired, but it's not necessarily for the audiophile who cleared the house of wife and kids (who, me?) just to sit down and listen to music. Those rare moments should be reserved for the Analog Direct mode. Alternatively, one can opt for bypassing the source DAC's in favor of the excellent DAC section of the RDC-7. We optioned to do so in our listening tests and were most pleased with the results. This allowed us the best of both worlds; a fabulous DAC section (rivaling most high end CD/DVD players) and the ability to utilize subwoofer output in 2 channel mode.

I found these modes especially useful for decoding Satellite broadcasts of concerts or music videos. These modes did not place as much of an emphasis on the center channel as their counterpart movie modes. Vocals still originated from the center channel speaker, but there were more vocals heard in the mains. The result was the recreation of a concert theater environment where most of the sound originates from the left and right front speakers. What amazed us most about these modes was the RDC-7's ability to direct the sound of the audience to the surround speakers.

In order to get a handle on how the Integra Research RDC-7 performed in Dolby Digital and DTS, we selected the following DVD's and CD's.

The performance of the Integra Research RDC-7 in Dolby Digital and DTS was stellar. What we noticed immediately, was the improved performance of the subwoofer channel when compared to other processors and receivers previously reviewed in this reference system. This was noted by the richer, deeper and even tighter bass response that emanated from the sub. Another noteworthy item was the performance of the center channel with vocals that were well pronounced and defined.

We also listened to several DVD Concerts as noted above. To me, this was the tell-all test for the processor as the Concert DVD's require a full soundstage in order to accurately recreate instruments and vocals. This was especially true for theYes Symphonic Live Concert DVD which included an orchestra. The RDC-7 did not disappoint. The instruments, orchestra and vocals were well pronounced and defined with an overall balance and no harsh or bright tones.

Perhaps the best part of the soundstage of the RDC-7 was noticed when listening to extremely quiet parts of DVDs. The low signal-to-noise ratio of this processor assured that every detail, no matter how faint, was reproduced without being masked by hiss or noise. The dynamic range of sound and low level noise that was presented by the RDC-7 affirmed that this was a formidable processor capable of audiophile performance.

The Dolby Digital EX and DTS ES Modes engaged the back surround channels. During our listening testing of the RDC-7 in Audioholics' Reference System 2, the Dolby Digital EX and DTS-ES modes helped open up the sound field of the surrounds. DVDs such as The Lord of The Rings: The Fellowship of the Ring were enriched with a heightened sense of drama that resulted from implementation of the back surrounds.

The RDC-7 included the new THX Ultra2 standard from LucasFilm. This standard is said to ensure higher quality sound and picture quality. THX Ultra2 includes both Cinema and Music modes.

When performing 7.1 channel playback of Dolby Digital, DTS or other 5.1 channel movie sources, THX Ultra2 Cinema analyzed the source signal and created a matrix for the surround back channels for improved surround sound, thereby creating a virtual 7.1 surround.

What we noticed most about the THX modes was the emphasis on the center channel and surrounds. Vocals subjectively sounded a bit more forthcoming and the surrounds more lively when implementing the THX modes.

The remote was somewhat lacking in regards to programming it for other products in our Home Theater setup. This was primarily due to it not having any pre-stored codes. Every function, from turn-on to operation, had to be manually "learned" into the unit. What was even more challenging was when we decide to use the Universal Remote's MX-700 home theater remote control as there were no codes for Integra Research found on any Universal Remote product, though there may be some independent online resources available to users.

If you are patient, and plan on having the RDC-7 for a long time, then programming this remote for your entire home theater system will not be that big of an issue. When completed, the RC-418M remote offers many useful features that will make it easy to operate your entire setup.

Audioholics found the RDC-7 to be a powerful, refined processor fully capable of satisfying the audiophile in all of us. Its sonic performance was staggering as it was able to reproduce subtle detail, along with deep, tight bass. In Analog Direct Mode, the RDC-7 we heard reverberation of room acoustics and nuances of vocals that went unnoticed on previous processors and receivers we reviewed. The RDC-7's low noise floor and premium DACs allowed it to perform notably with CD's and current high-resolution formats such as DVD-A and SACD.

With a host of DSP Modes, the RDC-7 was able to create an ambiance tailored to our listening room. The RDC-7 also boasted THX Ultra2 certification, which is only commonplace for higher-end equipment. It also meant that the processor incorporated video switching capable of handling all wide-bandwidth sources, including HDTV and progressive scan DVD, without degradation of picture quality. The unit was easy to setup and operate, and even allowed us to select preferred modes of operation that were source dependant.

The RDC-7 also allows for On-The-Fly stored speaker level trim settings for multi-channel analog inputs. Add the fact that the unit has an above average signal-to-noise ration, and you have a processor fully capable of providing optimum performance for any current high resolution format, including DVD-Audio and SACD.

As with many home theater products, there are a few areas where this processor can be improved. In the future, Integra Research would do well to consider a remote that has stored settings for other manufacturers. This will make it easier for users to program the remote to run an entire Home Theater system, instead of just the processor. Other welcomed features needed on the RDC-7 include video up-conversion to component video. This would minimize connections thus reducing signal degradation (extremely important for video, especially HDTV and DVD) while simplifying video operation by virtually eliminating the need to switch video inputs on the TV. With this would necessitate the need for On Screen Display through component video.

Audioholics created a "wish list" for future products that we submitted to Integra Research and several other manufacturers. In this wish list, you will find other features that we would love to see considered either in future upgrades to the RDC-7, or for its successor. With only a few minor shortcomings, it is Audioholics' opinion that the Integra Research RDC-7 is currently one of the best dedicated A/V Processors and we were privileged to implement it into our Reference Systems.