Home Theater Equipment

The ideal equipment to drive Martin Logan speakers is the right mix of front end processor quality and back end amplifier muscle balanced by tools for room correction and time alignment.

Since no one really makes a processor that meets all my criteria, I have a somewhat complex system.

Processor

After many years of pleasure with my trusty Meridian 568, I've moved up to a really great all-inclusive statement preamp from Denon, the new in 2008 AVP-A1HDci

AVP-A1HD

This massive Preamp, weighing in at 65 Lbs., is nothing short of amazing at what it does.

Handling all modern sound formats with extremely high quality processing, this has become the reference unit to beat.

It also is an incredibly capable video processor as well, taking in all formats up to an including 1080p with 'DeepColor' using its SiliconOptix Realta T2 HQV processor.

Read the rave reviews of the benchmark processor: At AudioHolics

More details on my setup of this preamp are on my System thread over at the MartinLogan owners Club.

Highlights of this processor are:

Reference grade audio processing
Fully differential balanced audio topology
Reference class video scaler based on the Realta HQV processor
File and Network audio playback within the box
THX2 Ultra certified with all the latest THX, Dolby Digital and DTS HD modes
Twelve channel output - Fully Balanced
Native Dolby TrueHD and DTS-MA decoding
Audyssey MultEQ XT-Pro room correction
Audyssey Dynamic EQ volume compensation
DenonLink4 for high-rez digital audio playback from Denon Players
More inputs than you can count

Since its such a complex, statement piece, I co-founded a Wiki on this incredible processor: AVP/POA Owners
I've posted articles and info there on how to setup and extract the most from this unit.

More details on Denon's High-end line can be found in this document.

Sunfire Driving all those speakers is a ton (well not quite, just about 324 pounds and 15 channels worth) of amplifiers. Driving the panels of the Monoliths, the panel of the SL3XC center channel and the rear Sequels is the powerhouse Sunfire Cinema Grand Signature amp. This five channel amp delivers 810w/ch into the ~4 Ohm MartinLogans. Featuring a Load invariant design, the Sunfire can (and does) deliver as much as 1,620 w/ch into the demanding impedance load of the MartinLogans. However, more important than watts is the Sunfires ability to deliver up to 120 amps of current to speaker loads. And since electrostats are current driven, the Sunfire is a great match.

The woofers of the main speakers are bi-amped and driven by a stereo Sunfire amplifier. This stereo amp delivers 300w/ch into the upgraded Monolith woofers.

In preparation for the upcoming 8.1 configuration I'm expanding towards, there is also a Sunfire Cinema Grand 5ch 200wpc unit. This currently drives the side speakers, the mid-bass Line Array and eventually will drive the rear woofers along with the Z channel, a ceiling mounted height channel.

For the couch mounted 'tactile feedback' transducer, there's the ever awesome ButtKicker unit and associated 1,000w amplifier.

The Infinite Baffle subwoofer is powered by a 1,200 watt Crown XLS602 pro-sound amp, with inputs from the mixer and active external crossovers as described by the bass management page.

Signal Processors

The best crossover for any speaker is an active crossover. After playing with a few active pro-gear analog crossovers with decent results, I went for the best speaker manager unit out there (in early '03). This is the DBX DriveRack 260. Then in 2008, I upgraded the front channels to the new DriveRack 4800, a 4 input 8 output unit that does near-everything.

DriveRack 4800

In my rig, I use it to replace the factory passive 2-way crossover in the Monoliths. Use of speaker processors has made a huge difference in the soundstage presentation from the Monoliths. I attribute this to the (better) phase coherence of an electronic crossover and the steeper slopes achievable in this unit. Additionally, the ability to fine tune the crossover points, filter types, phase, timing and individual gain for each output is a winner. Oh, and it's a gangbusters EQ as well, with several parametrics to play with. Bonus is a Sub-harmonic synthesizer for those old bass-shy recordings.
Using the balanced outputs to feed the Sunfire also helps further lower noise floors.
This has been one of the best tweaks I've ever done, probably the best bang for the buck in a while.

A very, very cool feature is the 'Auto Warmth' equal loudness contour adjustment. This highly dynamic EQ let's one enjoy the system at lower volumes, yet retain all the low-frequency impact and tonal balance of a louder playback. Very, very effective and a must have, now that I have it. (although now superseded by Audyssey DynamicEQ in my AVP preamp)

When I added DVD-Audio playback back in 2001, I had to deal with the fact that one really needs external bass management solutions, as few DVD-A players integrate good solutions. The link takes you to a comprehensive write up on the topic.
But since I got the A1, all bass management is done in the main processor and the 4800.

Since the nastiest room modes are those created by low frequencies, I use a multiple parametric EQ's for the subwoofer signal within the 4800. This allows extremely fine grain control over the inevitable humps and dips in the low frequencies.

The rest of the audio range is ably handled by the AVP's Audyssey MultEQ XT-Pro room correction. Using phase-correct FIR filters, it compensates for any remaining room anomalies.

Just to prove I can go totally overboard on processing, I also use one channel of the DriveRack4800 to provide discreet time delay signals and EQ to the tactile transducers. This is required due to the time differential between speed of sound and direct transduction. So I add an 13 millisecond delay to the transducers so they 'synch-up' with the sound waves arriving from the speakers.

To adjust all of the above, one needs to use real pro-level tool, such as the ETF 5 product, which generates the appropriate test tones, and using a calibrated Mic, analyses the results. The ability to sit in the room and do real-time measurement and adjustments of EQ's, crossovers and delay's is awesome. Highly recommended for really getting it right.

AudysseyPro calibration To get the absolute maximum for this system, I obtained the Pro-grade installer kit for the Denon AVP . This allows many more sampling points for measurements and higher resolution corrections to be applied.