Audyssey Pro EQ Listening System - Part 2

The current L/C/Rs for our home system are three Infinity Beta10 s; rear ported, 5.25" two-ways with a 1" metal-composite dome tweeter, ($150ea. SRP). Before you turn up your nose take at look at Dr. Floyd Toole's CEDIA class outline which is available online.

Check out the performance graphs. At the bottom of page 19, the $300pr. of anonymous speakers; that's the Beta 10s. And that's the type of performance envelope specifications that even non-golden eared people will favor time after time after listening double-blind versus similarly priced competitors' speakers.

Audyssey Sound Equalizer at lower left on top shelf in rack. Infinity Beta 10 L/C/Rs. Beta 10s aligned to 34" H @ midpoint on sofa. Sony 32" XBR LCD is temporary.

Surrounds consist of three pairs of JBL SP5 s; 5.25" two- way in-walls with 1" metal-dome tweeters, ($175/pair SRP). The SP5's have swiveling tweeters but I set them straight forward. I like keep the horizontal and vertical axis of woofers and tweeters the same, especially for surrounds. Speakers that are designed to a flat response with smooth but continual high frequency attenuation when moving off axis have been proven to provide a superior performance envelope. So why mess with success? Tilting a tweeter toward the listening area destroys the performance envelope with which it was designed. It also calls far off-axis attention, very high frequencies only, to an area which is supposed to be invisible, for envelopment.

For the eight stereo pairs of interconnects required going into and coming out of the Audyssey Sound Equalizer's eight inputs and eight outputs I went with seven and a half 3' pairs of Impact Audio's SonicWave interconnect. The single long-run interconnect going to the rear subwoofer is a no-name that I made up from cable I had on hand. The required Y-connector from the single subwoofer out on the Denon AVR-3806 to the two subs was also an Impact Audio SonicWave interconnect.

Each of our three pairs of surround speakers (right, rear & left) is wired in series which presents a very easy-to-drive 12 ohm load back at the amplifier (6 ohms + 6 ohms for each JBL SP5). Note from the pictures that each of the monopole surround speaker pairs points at 90° perpendicular angles to each other and toward a different wall (for reflection generation). All surrounds point away from the "acoustic bubble listening area".

I can't refer you to a set of performance graphs for the SP5's but I can tell you that all Harman (monopole) speakers are designed to the same criteria; flat on-axis frequency response with smooth and continual high frequency attenuation when moving off axis.

Looking across sofa back. Dual JBL SP5 5.25" two-way right surrounds. Dual JBL SP5 5.25" two-way left surrounds.

Wire runs from the surround speakers are 14 gauge, twisted two-conductor, off-the-roll Monster. The longest wire runs to the left and right surround rears is ~45'. For the short runs to the L/C/Rs I've used the same DH Labs Silver Sonic T-14 (twisted-pair, 14-gauge) for many years.

Terminations to the in-wall SP5s with push in spring terminals are 3/8" bare copper wire; simply twist wire ends (tin lightly if you like) and insert. Wire terminations to the L/C/Rs are gold-plated and silver-soldered spade connectors which give a tight connection when the gold-plated barrel + and - terminals of the Beta 10s are tightly snugged down. Terminations to the Outlaw Audio 7075 amp are self expanding, gold plated, spring-steel and copper alloy banana plugs which are again silver-soldered to stripped wire ends.

The power amplifier. In the days of stereo receivers many of the higher quality units had true pre-amp out, power amp in jumpers. With today's multi-channel receivers that particular feature is almost non-existent. So when I started thinking about a low-cost, well-built multi-channel power amplifier I turned to long time industry colleague Peter Tribeman of Outlaw Audio and Atlantic Technology. Back in the eighties Peter was one of the founders of NAD, a brand always known for tremendous audio performance for the dollar. A quick perusal of the Outlaw Audio 7075's specs indicated this $599, 7-channel amp looked to be out of the same low dollar, high performance mold.

The Outlaw amp's 75 watts/channel x 7, , looked to be exactly the choice to replace the 7-channel amp section in the Denon AVR-3806. The 7075 is built like a pro product. Heavy gauge steel chassis with beautifully rounded front-to-back edges, a just-under 0.5" (!) thick black anodized front panel, 12V amp-to-pre-pro trigger, and five-way binding posts on the rear. This little bad boy is only 4" H x 15.5" D x 17.2" W yet it weighs 41 lbs (due to a beefy toroidal transformer), more than the entire Denon AVR-3806 receiver.

I knew I was going to high pass all the satellite (loudspeakers set to "small") at 80Hz so the 7075's power supply section would be loafing along even when driving all "small" loudspeakers to their limits. What really sealed the deal though was a damping factor greater than 400 from 10Hz to 400Hz and a slew rate of 50V/microsecond. The 12-ohm surround speaker pairs would be extremely well controlled at their 80Hz high-pass crossover frequency. (Given the lack of an engineered back enclosure for most in-wall speakers, electronic control in the form of electronic damping applied to the speakers - voice coils aids bass damping and control at the in-walls - applied 80Hz low frequency cut-off.)

For the eight stereo pairs of interconnects required going into and coming out of the Audyssey Sound Equalizer's eight inputs and eight outputs I went with seven and a half 3' pairs of Impact Audio's SonicWave interconnect. The single long-run interconnect going to the rear subwoofer is a no-name that I made up from cable I had on hand. The required Y-connector from the single subwoofer out on the Denon AVR-3806 to the two subs was also an Impact Audio SonicWave interconnect.

With the Audyssey Sound Controller between the Outlaw Audio amp and the Denon AVR-3806, the receiver now became a preamp-processor. In preparation for putting the system through its paces immediately after running the MultEQ Pro routine I went into the Denon's menu and configured it as follows:

• Room EQ (Audyssey, Front and Flat) > Off
• Tone Defeat > In
• Left, Center, Right, Left/Right Surround > Small
• Speaker B > None
• Speakers Surround Back > 1 Speaker
• Subwoofer > LFE
• Crossovers > Subwoofers and all Satellites > 80Hz
• Important! Set "3. Input Function Level" on the AVR-3806 to +9 to +10dB for all inputs. i.e. Tuner, Phono, CD, Tape, DVD, VDP, etc. The MultEQ Pro's equalization algorithms can add a maximum of +9dB boost at selected frequencies. So inserting the Audyssey Sound Equalizer between pre-pro and amp attenuates all signals by -9dB to self-assure adequate headroom. Thus when contemplating the use of another model or brand of "pre-pro" it is imperative that the unit's pre-amp section has a true 3 to 4 VRMS gain stage to ensure adequate headroom and protection against input signal overload.

Now the Denon AVR-3806, configured as a pre-pro, can be turned off. It can remain off during the whole Audyssey Sound Equalizer set-up and calibration routine.

The final pieces of audio gear for our home theater is the main A/V source DVD player and a UPS. The DVD player is an $80 Toshiba SD-K860. That's right, a Costco special. How can you beat a player that comes with its own HDMI cable included? Simply amazing value.

One last piece of gear is a Tripp-Lite Omni (aka Smart) 1000 LCD 1000VA UPS with battery backup. Also from Costco and another bargain at $100. This unit is a basic surge and spike protector but with a beefy 1000VA transformer. Neither the subs nor the Outlaw amp is currently plugged into this unit but the amp probably could be without any current limiting. So it's adequate protection until I substitute an APC H-15 with voltage regulation, at which time I will also plug in the Outlaw Audio 7075 satellite amplifier. The two subs each are plugged into their own dedicated 15 amp circuits.