Speaker Asylum: REVIEW: Avantgarde Duo Speakers by Kurt Strain

Bottom line: The Avantgarde Duos have every attribute I ever wanted from a pair of speakers. It shattered my notion that I had something big to sacrifice even in speakers costing well over $10K. And they do it so well that I sometimes forget that I'm listening to a stereo system. Any form of music is reproduced like it sounds virtually like live, from the softest to the loudest, the lowest note to the highest, and done so as if it were just so damn easy. I've had good speakers, I've heard great speakers, but this I had never heard before and it's like moving into another league, a large jump closer to live music from my previous best DIY speaker effort (these DIY speakers were better than my previously owned Avalon Eclipse and ProAc Response 3's overall, but still a low efficiency box speaker). On a scale from 0 to 100, 100 being live acoustic music, I felt an increase in getting there from a score of about 60 to closing in on 90. Subjectively, that's about the best "measure" of how good it got for me. Uh, you figure it out because I can not fully express it.

I had a list of things to look for in a pair of speakers, and I came out better than I ever thought I could. My wish list included:

* High sensitivity so I could use it with any amp of my choosing - I like to build tube amps as a hobby.
* High power handling so I could still use it with any amp of my choosing (not killing it with 50W of power).
* Enough bass - flat to 40 Hz will do.
* No harshness.
* Unnoticeable coloration - no honking, no boxiness, no obvious flaw.
* All the dynamics of "they are here" with all the imaging and soundstaging of "you are there".
* Small enough to fit in a room 14' by 16'.
* Have little room interaction. and be easy to set up.
* Be insensitive to the flaws of the source and upstream components.
* Exploit the strengths of high quality source and upstream components. - i.e. "electrostatic transparency"
* "Affordable", meaning to me well under $20K for a purchase of a lifetime.
* Have some intangible magic to them, and if not, make it possible to be created by upstream components.

The Duos met all the above, amazingly. This review will not go into how it sounded listening to the third cut on the LP "Famous Blue Raincoat". It sounds good playing anything that isn't what you hate. It plays it all well, from cheap CDs to top vinyl, the better the source the better the sound, but always seemingly there to accentuate the positive and downplay the negative. How does it do this amazing trick I wondered. I decided it was mainly due to superior execution in two critical areas: very low distortion at any sound pressure level and low coloration of its own. It delivers everything full force, uncompressed and as loud as you need it, given sufficient amplification power - 10W. The speaker's high sensitivity of 103 dB using drivers that can handle 150W means you are virtually always operating in the linear uncompressed region of the horn driver's operating range, and that is going to make it very low in distortion provided the horns don't do something to screw it all up like horns tend to do. These are not folded horns nor exponential horns that have odd frequency responses with resonances. They are spherical, and the drivers themselves are domed to launch a spherical wavefront right from the start. They provide a smooth +-2.5 dB (approx. from my measurements) response from bass to treble. The spherical horns produce little turbulence against the sound waves traveling through it. It sounds uncolored and it sounds wide open and free to deliver the music as it was.

My wife listens to these speakers and her comment about them was "They don't have a wow factor for me . I think it just sounds like it sounds at a symphony, and I never sit there at the symphony and go 'wow, what a sound'. It's just music I hear." For me, it was a big wow. Yeah, it's all there to hear and if you set them up right they throw a tremendously deep and delineated soundstage, allowing you to hear all the cues of the recording venue, and then while doing so here comes a huge trumpet blare and without even flinching the speakers deliver it in its precise location with the power of live sound. This is when you understand the remarkable achievement of these speakers, and then you realize you only used less than 10W of amp juice to do it.

The finesse of a 2W 45 single-ended amp is played out in full glory, squeezing every minute detail and every rich harmonic from the recording. It even plays this micro amp to disturbingly loud levels.

The awesome control and power of a 25W 845 push-pull amp can reproduce the full weight of a large symphony or make a complete drum set come alive and still let you hear delicate bells and whistles, sounding like delicate bells and whistles. You can feel the impact of a bass drum and still hear the sound of the drum skin rolling along and hear its pitch and its imaged location all simultaneously and believably. Play any system-buster CD you want because not only won't it break, it won't even bend. These speakers even have a warning in the operating instructions: "Excessive sound pressure levels might cause serious damage to your health. Do not turn the speaker system too loud." And yet, when sanely used, these speakers are about the gentlest on your ears you can have. My advice to Duo owners - get a Radio Shack SPL meter and see how loud you are operating them. You can easily get carried away, annoy all the neighbors, and damage your hearing. They are capable of SPL's over 120 dB, above the threshold of pain and a level that can easily cause permanent tinnitus in short order and over time hearing loss. Or just use common sense - whatever.

Do you need more details on how they sound? You have to hear them yourself to know them. I can't verbally do it justice with terms like microdynamics and macrodynamics and detail, timbre, rhythm and pace, soundstaging, imaging, dynamic range, low distortion, ad nauseum. It's all done well. "You had to be there", as the saying goes. It makes me wonder why the Trio is even necessary. Luckily I have not heard those, helping me achieve my retirement goals.

Some tricks I have learned that helps the Duos in some small but nice ways (as I described them you wouldn't think I'd have touched a thing - well it's not a 100 yet): Try flipping the woofer to inverted phase and its level down to the 12:00 position. You might find this to flatten the overall response in bass region up to the low mids. It just so happens the midrange horn, which crosses over at 200 Hz, is about a half wavelength away from the woofer and when I inverted the phase the nulling of the response disappeared and you don't have to compensate for it with the level being so high. Also, I found I could angle the midrange horn so it fires down exactly toward the listener positioned 8 feet back. This also moves the midrange horn closer to the tweeter horn without overlap and the image height is much more normal and more focused. You can listen at 7' to 8' back instead of 9' with this arrangement, although not really designed for it but the rack that holds the horns is pretty adjustable. Speaker spikes under the subs with rack feet removed entirely and the full weight of the system on the sub's spikes is the way to go - for carpets that is.

The Duo 2.0 has many improvements over the 1.0 version: better subwoofer and the midrange is now run without electronic crossover - a direct connection to the amp (crossover is done by mechanical means - the horn design itself - no box speaker can do this I assure you). The tweeter has a simple first order crossover plus its horn cutoffs. The midrange covers the 200 Hz-2000 Hz range and the other drivers do the rest. Complaints about the 1.0 version should now be discarded. The new subwoofer is very clear and fast and produces a great deal of SPLs itself, although I'm sure if pressed the subs will run out before the horns do. I never bottomed them out at my loudest levels, however. I have heard both the 1.0 and 2.0 versions and unquestionably the 2.0 is a major improvement, in both the bass and in the overall integration of the sound. Even midrange to tweeter integration is more seamless, and when angled as I made them I can hear only one voice between them with pinpoint imaging and super deep soudstaging, nothing I ever expected from horns.

I enjoyed demo'ing these speakers to a Vandersteen model 4 owner who had about a horsepower of amplifiers on those and he likes it loud. With 25W/ch it knocked his socks off with the incredible dynamics, clarity, dynamic range, sharper imaging, and about all he could say was "that sure raises the bar." I though so too before I bought them.

REVIEW: Avantgarde Duo Speakers Review by Kurt Strain at Audio Asylum