Bozak Concert Grand B-410 loudspeaker Page 2
Bozak speaker crossovers are the polar opposite of the Infinite Slope designs attributed to Richard Modafferi, of McIntosh fame, and currently licensed by Joseph Audio. The crossover rate is an "easy" 6dB/octave, which results in a gradual transition from driver to driver. Bozak made available a biwire biamp model of the Concert Grand, which removes the low-to-mid dividing network from the cabinet and replaces it with an active outboard crossover box for two separate power amplifiers per side. This does not allow for adjustment of signal amplitude and is not buffered, and so is best suited to amplifiers with similar transfer functions. I have a pair of CGs configured this way using low-powered Wright Audio SETs, and the midrange clarity is extraordinary.
One school of Bozak experts believes that a flatter frequency balance can be obtained by modifying the crossover (footnote 2). The philosophy of these reviews, however, is to evaluate vintage components as they would have sounded at the time of manufacture. My sonic valuations are based on stock units, though one change I did make was to reverse the polarity of the midrange drivers—their output then seemed to better blend with that of the woofers. [See the "Measurements" sidebar.—Ed.] There is some scuttlebutt over this midrange unit polarity. It seems the factory miswired some units (also some reports have prior owners replacing drivers and miswiring them). There appears to be no rhyme or reason to it. Some Symphonies/CGs/302s have correct midrange polarity, others do not.
My first foray into Concert Grand magic was on the day I brought them home. I played the LP of Georg Solti's recording of Mahler's Symphony 4 with the Chicago Symphony (London/Decca CS-6217). I was not prepared for the size of the orchestra that the Bozaks allowed into my room, nor was I prepared for the true 28Hz low-end notes the speakers reproduced. I suspect that the sound's scope or size was a factor of the size of the baffle, and that the bass was due to the enormous cabinet. I was also shocked at how smooth the sound was while still being detailed and lifelike. You can have your cake and eat it, too. The word to describe the sound would have to be effortless.
The other night I was spinning Suzanne Vega's "Lolita," from Nine Objects of Desire (CD, A&M 31454 0583 2), and the bass transients were knocking the wind out of my chest. The Bozaks could really get my pants flapping, and without any midband distortion. The soundfield on this track is nicely layered, and Vega's voice punched through very 3-D. I heard her at Philly's TLA, a venue with great sound support, and the bass is better on the Bozaks. And did I say how much smoother the Bozaks are on top?
If you need to relax, try some of Robert Rich's or Vidna Obmana's ambient music and turn off the lights, as I did. Suddenly it was Prozac time—the Bozaks surrounded me with organic sounds and vast landscapes of relaxing atmospheres. The CG's excellent powers of transient-decay resolution made it really shine with this music. Samsa's "Long Since Gone," from the compilation disc Convergent Evolution (CD, Greenhouse GHM 99.01), has endless electronic winds that remind me of Contact. In that film, Jody Foster seems to travel in time to another planet, where she stands on a virtual beach in a new world and speaks with her long-dead father. The Bozaks reproduced the sonic equivalent of this setting, transporting me far from my listening room.
As if that weren't good enough, I could also rock my brains out with the Concert Grands. Nine Inch Nails' "All the Love in the World," from With Teeth (CD, Interscope HALO 19), starts off as a winding ballad and mounts to a growling finale that will jar your fillings loose. The Bozaks' bass was powerful and gripping—I felt it throughout my body—and Trent Reznor's vocal is repeated in a trancelike loop. He seemed to be in the room with me. This fantastic track is a great respite from the audiophile-approved rut I sometimes find myself in.
For the grand finale, and to complete my journey back to teenhood, I spun "Soldier," from Destiny's Child's Destiny Fulfilled (CD, Columbia CK 92595). A lot of money is being pumped into the production of R&B pop artists, and the influence of the urban hip-hop scene has added a beat flavor that appeals to the owners of boom cars. This gives the music a very youthful feeling—again, a refreshing change from Patricia Barber and the 30th reissue of Miles Davis' Kind of Blue. Plus, "Soldier" has a great beat and is flush with pace, rhythm, and drive—qualities the Bozak Concert Grand laid down better than any other speaker, in my opinion. The natural transients the CG reproduced were anchored by the speaker's extraordinary bass and a solid, hump-free lower midrange, giving the music a quality of forward momentum unlike anything I've heard from any other speaker, regardless of size or cost.
In my listening experience, the Bozak midrange driver delivers the most velvety sound I've ever heard. It excels at reproducing transient decay, resulting in a better reproduction of harmonic overtones than other speakers manage. Bozak's signature "house" sound was indeed smooth—no Bozak system ever sounded fatiguing. However, this "soft approach" takes a little getting used to and some listeners may find the CGs a bit too polite.
When I need more high-frequency energy, I augment the Concert Grand's top end with one RadioShack supertweeter per side, firing to the rear. This gives more snap to the sound, but increases the sibilance of vocals.
You read about speakers that perfectly image but have limited bass, or hyperdetailed speakers that, over time, fatigue the listener. But the Bozak Concert Grand does everything well while not excelling at any one sonic parameter. I believe this is its greatest strength. It is dynamic beyond belief, with gobs of musical detail and harmonic richness. A pair of them are magical in their ability to deliver space and ambience cues, but they image more like what you hear at a concert—not "pinpoint" imaging, but a more blended sound. And the speaker has extraordinary but not superfast bass. The Bozak Concert Grand is the most musically satisfying loudspeaker I've heard. It may be the best non-horn vintage speaker you can own.
All of the bigger Bozak loudspeakers have the midrange magic of the Concert Grand, but only the CG can reproduce the scale and drive of live music. Expect to pay up to $3500 for a pair of mint CGs; if you have them shipped across country, add another $500. The Symphony B-4000A ranges in price from $400 to $800/pair, and the 302A from $200 to $400/pair, depending on condition. But no matter which model you try, your ears will smile. I have found no other vintage speaker system that delivers so effortless and musical a sound.
Footnote 2: The most senior Bozak expert in the US is Pat Tobin, a helpful gentleman who is a frequent contributor to www.Audioasylum.com and is a one-man well of information about driver types, crossover modifications, and all things Bozak. He can be reached at firstname.lastname@example.org.