Introducing the AVS Forum 2-Channel Speaker Review Reference System

AVS Forum 2-Channel Speaker Review Reference Rig

A new system for official AVS Forum 2-channel speaker reviews

Speakers and subwoofers are my two favorite types of audio products to review. That’s because the impact they have on a system is so profound, whether we’re talking 2-channel, surround-sound, or 3D immersive audio. Amps, DACs, and processors have their points of divergence—there are no absolutes to great audio—but your choice of speakers and subs make the biggest difference.

When I first suggested that product reviews be part of the editorial mix at AVS Forum, I promised to experience products as consumers do. That includes proper (i.e., obsessive) setup for 2-channel speaker systems.

In past 2-channel speaker reviews, I’ve encountered debates over whether using EQ or room correction with speakers is appropriate, and whether adding a subwoofer system to a speaker pair should be part of the review.

Today, thanks to the ubiquity of DSP processing in consumer devices, there are more options than ever to achieve the precise result you desire. You’ll find room EQ on a wide variety of devices ranging from AVRs to soundbars and even portable wireless speakers like those from Sonos.

Because EQ, DSP, and room correction are so commonly available, I will evaluate 2-channel speaker systems in several contexts: completely unassisted and un-EQ’d, with Dirac Live applied, and finally integrated with a subwoofer system that’s capable of flat and powerful output down to 16 Hz.

Because 2-channel audio enthusiasts are typically a picky bunch, I have asked the generous folks at Bowers and Wilkins, Classé, and JL Audio for assistance in putting together a reference-quality 2-channel rig.

I did not want a stack of gear like you’d typically see at a high-end audio show. This is AVS Forum, so a reference rig needs to reflect what’s possible now, not what once was. The solution we came up with is to use a combination of the Classé Sigma SSP and Amp5 (a combo I reviewed back in 2015) as the foundation. This gear, albeit very pricey, offers great specs and sounds neutral and transparent. The goal is to let the speakers shine by making sure the system driving them is as transparent and invisible as possible.

The Sigma SSP (reviewed here) features HDMI plus asynchronous USB input, and it has balanced analog circuitry for two of its channels. It’s a surround-sound system that’s also optimized for 2-channel operation.

The Amp5 can supply 200 watts per channel for five channels (into 8 ohms) and is a class-D design. It’s also capable of delivering 400 watts per channel into any two channels at once. Used as a 2-channel amp, it’s got more than enough gas in the tank to power difficult speakers. Most of the time, I’ll only use the two balanced channels, but I can also use four channels to bi-amp a pair of speakers.

While the Sigma SSP offers parametric EQ that you can program with measurements from REW (Room EQ Wizard), I prefer to use Dirac Live, so I’ve included my miniDSP DDRC-88A processor (with the BM plugin) in the stack.

JL Audio generously provided a reference subwoofer system consisting of dual F112 V2 subs and a CR-1 subwoofer crossover. Some folks may argue about the value proposition of the company’s F112 V2 sub—it’s definitely a luxury product—but the performance is top-tier. And to top it all off, there’s an SVS SB13-Ultra in the mix—I have it in a corner to maximize its infrasonic output. The SB13-Ultra works in conjunction with the JLs to bring the in-room response down to about 12 Hz (post-EQ), and using three subs smooths things out quite nicely, enough that Dirac can take care of the rest and offer flat response, or something that conforms to whatever curve I dial in.

The source for all the tunes and test tones is a Windows 10 laptop running the Tidal streaming service’s desktop application. This gives me access to tons of CD-quality audio as well as Tidal Masters that use MQA compression to offer 24-bit/96kHz quality hi-res streams.

This dedicated 2-channel stack significantly outperforms the AVR-based rig I’ve used for speaker reviews in the past. It has better processing, more power, and balanced connections. The JL Audio CR-1 crossover may seem like an extravagance to someone who is never going to change the settings, but for my purposes, being able to adjust the crossover, sub/sat balance, or bypass the subs at the touch of a button or twirl of a knob is extremely handy for reviews.

So here’s the idea: Listening impressions and measurements for 2-channel speaker reviews will feature this system, first in a “purist” approach with just the speakers. Then, I’ll do it “AVS Forum Style” with subs and Dirac room correction. I believe that employing DSP correction can transform many affordable speakers from modest performers into superstars.

Some speaker systems I review employ a sub/sat design to begin with. In these instances, I’ll test the speakers with the included sub, and then switch to the triple-sub JL/SVS system and discuss the difference.

Last but not least, I’ll still connect speakers to at least one of my AVRs (Denon X4300H or Pioneer Elite SC-85) to see if going high-end is justified, or if a good AVR on its own is enough to take care of business. This is especially true for the Denon, which supports the new Audyssey MultEQ Editor app that lets you customize and optimize the room correction profile (much like Dirac Live).

I have some exciting speakers lined up to review in a 2-channel context including the following:

B&W CM6 S2 bookshelf
Definitive Technology BP-9060 towers
Emotiva T1 towers
KEF R500 towers
KEF R100 bookshelf with dual R400b subwoofers (2.2 system)

Markaudio-SOTA Viotti One bookshelf
Power Sound Audio MT-110 with V15 subwoofer (2.1 system)
SVS Prime Bookshelf 

Of course, there are more speakers to come; these are just the speakers in the review queue at the moment.

Done right, 2-channel sound can be astonishingly holographic and immersive. One of the primary goals of my reviews going forward will be to figure out how to get a given pair of speakers to deliver that experience. What does the trick? If all it takes is hooking them up to an AVR, I’ll say so. If using a five-figure stack of rarefied electronics and top-notch DSP processing is what it takes, I’ll discuss that too.

The main thing is that future reviews will consistently use the gear I have described as the reference for what’s possible. I cannot afford Classé or JL Audio gear, so I want to thank these companies for helping make the AVS Forum 2-Channel Speaker Review Reference System possible.

Plenty of speaker reviews are coming soon! Power Sound Audio is next, and that’s gonna be a 2.1 situation with a 15V subwoofer in the mix.

Keep on rocking, folks.

AVS Forum 2-Channel Speaker Review Reference System

Classé Sigma SSP surround-sound pre/pro with 2-channel balanced XLR output
Classé Sigma Amp5 5-channel 200-watt class-D amp with 2-channel balanced XLR input
JL Audio CR-1 subwoofer crossover with balanced XLR input and ouput
miniDSP DDRC-88A with BM plugin, wired with balanced XLR connections
AC Infinity Aircom T8 cooling fan
Two JL Audio F112 V2 12″ subwoofers with balanced XLR input
One SVS Sound SB13-Ultra subwoofer with balanced XLR input

P.S. I’m keenly interested in what speakers and subs AVS Forum members most want to see reviewed, so please leave a comment with your suggestions; if I spot a trend, I’ll act on it.