Introduction

When I first saw the press release for the Integra DTR 7.8 receiver, I thought that it had a major typo. THX Ultra2 certified, 130 watts x 7 amplification, HDMI 1.3a, Dolby TrueHD decoding, Audyssey MultEQ XT, three zone operation . . . at $1,300 list price? $2,300 sounded more in the ballpark, knowing Integra’s reputation for producing fine products at incredible prices. When I confirmed that Integra was indeed offering the DTR 7.8 at $1,300 MSRP, to say I was curious would be an understatement.

The Design

I’d spent quality time with the DTR 7.8’s predecessors, the THX Select certified DTR 7.6 and 7.7 receivers. And while both were fine products, the DTR 7.8 does far more than make incremental tweaks. The staring point is THX Ultra2 certification. For those unfamiliar with the THX hierarchy, THX Select AVRs are intended for “small home theaters,” where the viewer is seated 10-12 feet from the display. By contrast, THX Ultra2 products are designed for “large” rooms, where the main viewing area is more than 12 feet away. Although most of the THX specs are closely guarded trade secrets, we know that that a THX Ultra2 receiver will have higher power ratings than Select-certified products.

According to Integra’s specs, the DTR 7.8 is rated at 130 watts of continuous power across the entire spectrum (20Hz-20kHz) into two channels, with THD at 0.05% (FTC). And as our resident THX expert Brian Florian likes to point out, a THX-certified receiver means that both the amplifier and pre/pro sections meet THX specifications. So, the DTR 7.8 includes a pre/pro and amplifier that both are THX Ultra2 certified. Did I mention that it lists for $1,300?

The DTR 7.8 uses top-of-the-line Burr-Brown 192k/24 Bit DACs for all seven channels (previous models used different DACs). New to the Integra line are Dolby TrueHD and DTS-HD Master Audio decoding for use with Blu-ray, courtesy of three HDMI v.1.3a inputs.

Few of the new high-def DVD players actually send a raw bitstream; most convert to LPCM in the player.

Similarly, the Integra is capable of supporting HDMI Deep Color video, although there are currently no compatible displays or software on the market that support Deep Color. So the Integra has a fair amount of future-proofing built into the design.

The other benefit of HDMI v. 1.3a is that it will send a raw DSD bitstream to the receiver, allowing the Integra’s three high-quality Texas Instruments DSPs to decode SACD in the receiver if the DVD player is similarly equipped. My Oppo 980HD will send a raw digital bitstream for both DVD-A and SACD, allowing the digital-to-analog conversion to occur in the Integra. This is actually a big deal to me, since I am a fan of hi-rez music formats.

Another nice touch is the layout of the speaker binding posts on the back panel. Most comparable receivers cluster the binding posts in several closely packed rows. The Integra’s binding posts are laid out in a single line, with ample spacing between the channels, which is especially helpful if connecting spade lugs or bare wire. Even better, the binding posts are organized in a manner usually found only on high-end separates, with the left channels on the left side of the panel, the right channels on the right side of the panel, and the center channel at the center of the panel. This layout seriously reduces the spaghetti wire tangles behind the unit, and makes dressing the cables much easier.

The DTR 7.8 incorporates Audyssey’s MultEQ XT room correction software, which computes speaker distance, size, and sophisticated equalization in one package. The GUI appears different than I’ve seen on other Audyssey implementations. For example, once the equalization procedure is complete, the Integra does not display any graphical representation of the adjustments made by the software. While I understand that a simple slider view, showing EQ adjustments, oversimplifies the correction process, it serves several purposes. First, it provides a rough visual representation of what Audyssey is doing. More importantly, it provides a baseline for consumers who wish to tailor the Audyssey settings to fit their own preferences.

As an example, some users enjoy the mid- to high-frequency adjustments made by Audyssey, but prefer to boost the LF somewhat. Without knowing what Audyssey did in the high-frequency bands, the user is unable to adjust the Audyssey’s parameters. However, you can still manually configure separate 15-band graphic equalizers (one each that controls the L/R, center, surround, and surround-back channels), plus a five-band graphic equalizer for the subwoofer channel. Or you can simply set EQ to Off.

Audyssey setup is basically idiot-proof, consisting of plugging in the supplied microphone, and following the instructions on the On-Screen Display. For the review, Audyssey detected all seven channels plus subwoofer, set crossovers, speaker distance, then equalization. Audyssey wasn’t perfect, as it incorrectly identified my rear surround channels as full-range, with a 50 Hz crossover point. I manually adjusted the crossover back to 80 Hz, but no other changes were necessary. Speaker distances and level calibrations were properly set in the Audyssey’s automatic program. Since my room has acoustic wall treatments, and subwoofers already run through a Velodyne SMS-1 equalizer, the Audyssey’s adjustments were more subtle than dramatic.

The Integra supports a powered Zone 2 and unpowered Zone 3 for audio, but the HDMI output is not assignable to these zones. It also offers a Direct mode, which turns off the video processing and front panel lights, but does not bypass digital processing. Conversely, the analog multi-channel inputs do not go through an A/D/A conversion, so if you’re playing hi-rez music through the analog inputs, you won’t get any crossover or speaker distance adjustments through the receiver. I don’t consider that a big issue, since one of the major benefits of the DTR 7.8 is its ability to decode and play all hi-rez audio through its HDMI inputs. In fact, I suspect most (if not) all buyers will mate the Integra with a compatible source (Blu-ray) or a universal DVD player with HDMI v1.2 or higher, such as my Oppo 980HD.

I found that the Integra had no problem identifying and locking onto audio signals, including the multi-channel PCM bitstream from DVD-Audio discs and DSD bitstream from SACD discs. There were occasional communication issues between the Integra and my Motorola/Comcast cable box through the HDMI connection. Fast-forwarding recorded material from the DVR would result in a 3-5 second lag before the audio signal kicked in, and certain recorded programs demonstrated a lip sync error. Strangely, the delay was in the audio signal, so I couldn’t use the Integra’s lip sync delay utility to fix the glitch. However, I didn’t have the issue when watching live TV, or when watching DVDs through my Oppo or Toshiba HD DVD player, so the issue appeared to originate in the cable box.

Because the Integra was designed with custom installers in mind, it includes an Ethernet port for integration with Network-based control systems such as Crestron E-Control™ and AMX Device Discovery™. It also includes bi-directional RS-232, RIHD (Remote Interactive over HDMI) system control integration over HDMI, three programmable 12-volt triggers, dual IR inputs, and three unique assignable IR code sets. The DTR-7.8 also features compatibility with both XM and Sirius satellite radio, and onboard Neural THX processing for reception of multichannel XM HD surround programming.

The Sound

It’s no secret that SECRETS is impressed with the sound quality produced by Integra/Onkyo products. As we’ve said before, it’s mostly a matter of what DACs are used, and how they are implemented. The DTR 7.8 uses Burr-Brown’s top of the line 192kHz/24bit DACs in all channels, and as usual the Integra puts out neutral, uncolored music.

So, I spent most of my time listening to hi-rez music through the Oppo’s HDMI connection, allowing the player to output a raw bitstream to the Integra and letting the DTR 7.8 do all the heavy lifting of decoding and processing the signal.

The Beatles Love album (DVD-Audio) is a topic of vigorous debate among die-hard fans, due to its mash-ups of classic songs (as Giles Martin admitted in the liner notes, he felt like he was painting a moustache on the Mona Lisa). My 11 year-old daughter and I, both originalists, came down on the side of wishing the songs had been reproduced without the embellishments. Either way, this is the first hi-rez release of the Fab Four’s work, and hearing George Martin’s impeccable production spread over five channels with a fidelity never heard before is a beautiful thing. “I am the Walrus” is a mélange of keyboards, percussion, strings, vocals, and chanting (you can win a bar bet by asking what Beatles song contains the phrase “oompa, loompa, stick it up your jumper.”). The Integra’s ability to reproduce detail and imaging let me enjoy each piece of the composition.

Switching to movies, I popped in Transformers (HD DVD). Describing the plot is beside the point; the film is a smorgasbord of eye-candy (special effects and Meaghan Fox) with an amazing soundtrack. Although it’s “only” a Dolby Digital+ mix, the audio quality is one of the best I’ve ever heard, with the DTR 7.8 rendering a huge soundstage filled with sweeping pans and flying ‘bots.

As good as the Integra sounds by itself, folks with upgrade-itis will figure out that if they buy a separate multi-channel amplifier, and use the pre-outs of the DTR 7.8, presto! Where else are you going to find a $1,300 THX Ultra2 pre-pro (SSP)? Since I happened to have the Halcro MC 70 seven-channel amplifier sitting in the rack (review in progress), I hooked up the Integra to the Halcro’s unbalanced inputs (the Integra doesn’t have balanced XLR pre-outs) and ran the DTR 7.8 as a pre-pro.

Wow!

Pairing the Halcro with the Integra resulted in an entirely different level of detail and transparency. It was the classic “bringing out previously unknown details in a recordings” cliché come to life. I didn’t look at it as a knock against the Integra’s amp section; after all, one cannot really compare a mid-priced receiver’s amp against a $7,000 dedicated amplifier. To the contrary, it was a major compliment to the Integra’s pre-pro. The Halcro would have magnified any deficiencies in the pre-amp/processor; yet the sound quality from the Integra/Halcro combination was fantastic.

On the Bench

At 1 kHz and 2 volts at the pre-out, THD+N was 0.007%. Clipping (1% THD+N) was reached at 5.65 volts output.

At 1 kHz and 5 volts at the speaker output (two channels driven into 8 ohms), distortion was about the same, but the noise floor was quite a bit higher.

Now, we present a new type of analysis. We asked SpectraPlus to develop a script that will let us calculate the ratio of odd-ordered harmonic distortion to even-ordered distortion. This takes the absolute number (THD+N in percent) one step further and tells us how much of it is odd-ordered (very irritating to the ears) and how much is even-ordered (pleasant to the ears).

So, here is the analysis of the graph shown above for 1 kHz at the pre-out. It shows the amplitude, in dB, of all the harmonics through the 11th, and down at the bottom, the relative amounts of the odd vs. the even-ordered. In this case, the odd-ordered harmonics are 16.64 dB higher in amount than the even-ordered harmonics. Since these are the first analyses that we have performed, we can't say much about the result for now. But, as we test more receivers, SSPs, preamplfiers, and power amplifiers, there will be much more to talk about.

And, here is the harmonic analysis for the speaker output, 1 kHz, 5 volts. In this case, the odd-ordered harmonics are 13.62 dB higher. Keep in mind that one also has to take into account any absolute distortion value differences, but in this case, THD+N was about the same for the pre-out and the speaker output. So, what this particular comparison says is that the speaker output has a better ratio, as a lower value means less odd-ordered harmonics in relation to the even-ordered harmonics.

At 10 kHz and 2 volts, pre-out, THD+N was, again, about 0.007%.

But at the speaker output, it had risen to 0.01%.

Frequency

As to IMD, it was about the same at the pre-out as at the speaker output, i.e., 0.03%.

THD+N vs. Frequency remained at acceptable levels from 10 Hz to 20 kHz, at the pre-out and at the speaker output for both 8 ohms and 4 ohms. At 4 ohms, distortion is a bit higher than at 8 ohms, which is to be expected. This is a new test script for the software (SpectraPlus) that we requested to be developed, and the results depend on the quality of the soundcard. The distortion curve here is approaching the limits of the card. Our Audio Precision test instrument is accurate to a much higher level, but we can't ship that around to the various writers.

The measured frequency response was within 3 dB, 20 Hz - 20 kHz. Obviously, there is a built-in steep roll-off above 23 kHz.

Conclusions

The Integra DTR 7.8 seven-channel A/V receiver has cutting edge features such as HDMI 1.3a, and internal processing of the latest hi-resolution audio codecs. It offers THX Ultra2 certification at an amazingly low price, and most importantly, produces the clean, neutral sound that we’ve come to expect from Integra products. Integra has produced another winner here.

Tags: 7.1 | Dolby TrueHD | DTS HD Master Audio | Receivers | THX Ultra2

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