Velodyne Digital Drive DD-10 subwoofer.

Manufacturer: Velodyne Acoustics, Inc., 345 Digital Drive, Morgan Hill, CA 95037; www.velodyne.com

Price: $2,499 (list); $1,999 (street)

Source: Manufacturer Loan

Reviewer: Gregory Koster

You need to do three things to be a perfect subwoofer: move a lot of air, control distortion, and blend with the satellite speakers. And do it in my room, not just in some perfect lab.

Velodyne figured out the first two back in 1983 with the High Gain Servo (HGS) series that combined stiff long-throw drivers powered by high-watt amps (to move a lot of air) with servo-controlled feedback loops (to reduce distortion). This allowed even the tiny HGS-10, which I reviewed in issue #84, to provide bass down to 20 Hz at volumes as loud as you want. But it's taken 20 years of development to get that last part.

Which brings us to the Digital Drive series, and specifically the DD-10. The cabinet has grown a tad from the HGS-10, but it's still under a foot in height and width so it fits into my bedroom corner. Frequency response is now rated down to 18 Hz with the same <1% harmonic distortion. The driver is still 10" with a 19.3 lb. magnet, but the class-D amp has increased to 1,250 watts RMS (3,000 peak) and the overall weight is up to 57 lbs. The test unit is finished in the same high-quality gloss black finish as my old HGS-10, but now there are maple and cherry wood veneer options.

The really big news, however, is the Digital Drive room management technology. Based on a Texas Instruments digital signal processing chip upgraded with a 20-bit A/D converter and extra memory, all Velodyne Digital Drive subwoofers convert the audio signal to digital and then do all EQ, phase and level manipulation in the digital domain. Even the servo control is now digital, and operates at an inaudible 15,800 cycles per second (up from the all-too-audible 3,500 in the HGS series). The result is a combination of control flexibility and simplicity that couldn't even be imagined before the Digital Drive series.

There are three levels of setup: tall, grande and venti. Oh, sorry--that's Starbucks. I mean small, medium and large. Small is "take it out of the box, plug it in, and listen." This at least let's you know that the unit is working, and might even sound fine if you're lucky. For me it proved that the unit worked, and is dead silent between tracks--but there was way too much bass on most music.

Medium is only a little harder: connect the (supplied) calibrated mic, put it in your preferred listening position, and punch a code into the remote control to do an Auto EQ that attempts to mate the subwoofer to your satellites and to correct for room anomalies between 15 and 200 Hz. This was very easy, but it didn't seem to make much difference for me. Neither did the six presets. The reason for this became clear at the next step.

Large-style setup took me a while because I had to rustle up a spare TV (and stand, of course) to see the on-screen menus. This won't be an issue if you're installing a Digital Drive subwoofer in a home theater, but even if you're using a music--only rig like me it's definitely worth the trouble because this unlocks the full potential of the Digital Drive room management technology. You connect the DD composite- (or S-) video out to the TV, and the L & R audio outs to your receiver's aux inputs. (All the cables, and the mic and mic stand, are supplied--very nice.) Put the mic in your preferred listening position, and now the Digital Drive sweep tones come from both the sub and the satellites--and a clear frequency-response graph is displayed on the TV screen.

You can easily change the low-pass frequency in increments of one Hz from 15 to 199 (I ended up lowering it from the default 80 to 41--how's that for fine control?) and the filter slope (6, 12, 18, 24, 30, 36, 42 or 48 dB/octave--I selected 36). There's also a subsonic filter, but I (like most people) had no reason to mess with that. Polarity (the usual +/-) and phase (in 15 degree increments) can be adjusted if need be, and finally subwoofer volume can to set relative to system volume.

The volume setting turned out to be the biggie for me. The default volume level is 30 (out of 99), but I got an almost flat curve with the stated low-pass frequency and slope at a volume of only 6. No wonder the tall and grande settings seemed so over-caffeinated!

Once you've zeroed in on the best curve, there's an 8-band equalizer to fine tune it. It comes up as a graphic EQ set at 20, 25, 32, 40, 50, 63, 80 & 100 Hz, with +6/-12 adjustments. I only needed a couple of very minor tweaks to achieve an almost ruler-flat curve from 25-80 Hz.

But wait, there's more! If the graphic EQ doesn't cut it, you can turn it into a parametric EQ and shift any of the bands to the exact frequency center you want (and vary the Q of that band as well). Mastering this might require a little more knowledge than the (otherwise very thorough) manual provides, but the beauty of the video display is that you can see the effects in almost-real time after a brief reboot of the software.

I also learned the wisdom of step 24 in the "Step by Step" setup instructions: listen with your own ears. Velodyne points out that flat systems often sound deficient in the bass. Since mine showed some major peaks in the lower midrange (caused by the satellites and therefore not fixable by the Velodyne adjustments), this was even more likely to be a problem. Listening tests led me to raise the saved volume setting, and to raise it even further on some selections. Happily, changing the volume is easy with the remote control, and the Reset button takes it back to the saved setting with one click--so I don't need to keep the TV hooked up all the time.

With these custom settings the Velodyne Digital Drive DD-10 subwoofer meshes perfectly with my bedroom minisystem (Denon D-M10 electronics with Mission 771 satellite speakers). The system sounds better than it ever has (and it was mighty good with the HGS-10) on jazz and chamber classical. Huge orchestral works are still a problem, but that's a midrange congestion issue with the bookshelf satellites. Pop is hugely better than ever, because I can switch from the default Jazz/Classical preset to Pop/Rock and vary the volume of the bass.

When Velodyne reads this I'm sure they'll say that I'm not getting half the potential out of the DD10. But that's the point: you don't need to crank this thing up to appreciate its virtues--and the headroom is always there. If it can provide enough bass for jazz (and even pipe organ) in my bedroom at volume 7, it should be able to fill your Great room with heavy metal and still have power to spare. But unlike other subwoofers with less control, it won't saddle you with more bass than you want. To me that's priceless.

Movies require more bass power than any genre of music, and the Digital Drive series has that covered too. There are presets for Action/ Adventure (think "things blowing up") and Movies (Foley effects) that switch from the traditional Velodyne tight bass (low distortion) music bias to a special effects-friendly loudness bias. I couldn't test these, but since Velodyne hasn't lied to me yet I figure they'll work when I want them and I know there's enough power to handle it. For a serious home theater setup I'd recommend the larger DD-15 or DD-18, which have a THX input and enough driver area to properly reproduce the end of the world. Large-scale music lovers (with large wallets) might want the top-of-the-line Digital Drive 1812 Signature Edition, which I assume was engineered for the Overture of the same name.

But as for me and my house we're content with the little Velodyne Digital Drive DD-10, which provides all the bass I want from the tiniest subwoofer cabinet. Highly recommended.--GK