Product Review -
Velodyne F-1800R Subwoofer - September, 1996 (Now called the FSR-18 - 1998)
By John E. Johnson, Jr.
|Velodyne Acoustics, Inc. , 1070 Commercial Street, Suite 101|
|San Jose, California 95112|
|Phone 408-436-7270; Fax 408-436-7276.|
Velodyne F-1800R Subwoofer; Servo-feedback sealed enclosure subwoofer; One 18" front firing driver; Built-in 600 watt amplifier; Two RCA line-level inputs, two RCA line-level outputs, two speaker-level inputs, two speaker-level outputs, two line-level balanced inputs; Variable low-pass 40 Hz - 120 Hz; Variable high-pass 80 Hz - 100 Hz; Crossover (second order initially, fourth order ultimately) defeatable; External remote trigger; Phase inversion; Auto-on; Remote control for standby and volume; Size 23 1/2"H x 21"W x 18 1/2"D; Weight 105 pounds; $1,999. (This model has been replaced with the FSR-18 which has a 1,250 watt amplifier and is $2,600 in 1998.)
The Velodyne ULD-18 Subwoofer has been the big sub to beat for some time. Well, if anyone could do it, Velodyne could, and they have. The F-1800R is the latest entry into the world of 18" subs, with the F-1500R being its little ("little"?) brother [click here to see review]. However, this bass machine is not simply the F-1500R with a larger driver. The amplifier is more powerful (600 watts), and it is also Class D instead of B. This is sometimes called a "switching amplifier" because the rail voltage switches as the demand (input signal) increases. This way, the output transistors are not required to dissipate so much heat. In fact, the F-1800R does not have an external heat sink, it runs so cool. The driver itself has been completely redesigned, although on the surface, it appears quite similar to the driver in the ULD-18. The cone is still made of heavy paper, but the dust cap is constructed of a plastic foam . . . sort of reminds me of the stuff I use to seal the edges of my door for the winter. The voice coil is dual wound, and large excursion is allowed (we measured just more than an inch at 20 Hz, so Xmax = + or - 13mm). That is a lot of air being moved! We would estimate, based on the formula for the volume of a cone (truncated in this case), plus the increased excursion capability, that the volume of air moved by this driver is about twice what it is for the F-1500. The nominal impedance of the driver is 2.5 Ohms, its free air resonant frequency is 18 Hz, and the weight of the magnet assembly is 20 pounds.
The enclosure is sealed, finished in black wood-grained vinyl, with 1" MDF front baffle - 3/4" MDF sides and rear, and looks very much like the others in the F series (see photo). The driver is controlled by a servo-feedback 600 watt amplifier that phase inverts electrical signals fed to it by a solid state motion detector attached near the voice coil. The feedback signal occurs 3,500 times per second, and the difference between the input signal and the feedback signal, after inversion, passes through the amplifier to the driver, canceling distortion (movement of the driver that is not from the original signal).
We tested the F-1800R with several laserdisc movie sound tracks, including "Jurassic Park", "Cliffhanger", "Return of the Jedi", as well as CDs that have a lot of deep bass, such as those with film scores. This subwoofer shook everything in the room, in fact, so much so that we started putting all of our sensitive components under AudioQuest Sorbothane Big Feet and Little Feet (we will talk about these at another time). Whether it was Starcruisers or kettle drums, the Velodyne did not blink. Clean, deep, no boominess (we like the 50 Hz low-pass setting). The balanced inputs are VERY handy if you require long cable runs (in fact, that is exactly what they are for). So, this sub can be placed on the other side of the home theater from the preamp/processor . . . no problem (as long as you have a balanced output to drive it). Even with just the standard RCA inputs, we noticed no hum. The hiss that can be heard with the F-1500R (the servo-feedback circuit) is not present in the F-1800R (but it is present in the FSR-18), even with the preamp volume control turned all the way up (no music playing of course). A phase inversion switch allows more flexibility in placement, and an auto-on switch, as well as remote trigger socket, along with the remote control handset, allow turning the sub on or off without having to reach behind the enclosure to flip the rocker switch.
Frequency Response Test Results (These data represent tests in a real room with furniture, not anechoic tests or simulations, and thus, may be somewhat different than you might experience in your own listening room of other dimensions and contents):
F-1800R, 1 meter, on-axis, grille off, low-pass set to 120 Hz, 10 Hz volume set just below clipping:
10 Hz - 97.0 dB 12.5 Hz - 100.2 dB 16 Hz - 97.8 dB 20 Hz - 93.0 dB 25 Hz - 95.0 dB 31.5 Hz - 97.6 dB 40 Hz - 93.4 dB 50 Hz - 88.4 dB 63 Hz - 96.7 dB 80 Hz - 89.7 dB 100 Hz - 83.7 dB 125 Hz - 83.6 dB
F-1800R, 13 feet, on-axis, grille off, low-pass set to 120 Hz, 10 Hz volume set just below clipping:
10 Hz - 96.6 dB 12.5 Hz - 100.3 dB 16 Hz - 99.5 dB 20 Hz - 95.6 dB 25 Hz - 97.0 dB 31.5 Hz - 91.4 dB 40 Hz - 90.0 dB 50 Hz - 74.8 dB 63 Hz - 89.8 dB 80 Hz - 87.3 dB 100 Hz - 80.2 dB 125 Hz - 75.0 dB
(We should note here that our microphone is only calibrated to 0.1 dB down to 15 Hz.)
The 50Hz dip is a room effect. As you can see, the F-1800R has very usable response down to 10 Hz. We could not hear anything at this frequency, indicating that no audible harmonics are produced, even at full output. I could feel the wind from these low frequencies. My pants leg shook, and fern leaves on the other side of the room fluttered. This is an incredible audio instrument, and it brings up the question of what a subwoofer really is. The woofer is the low frequency driver on a speaker system, but these drivers do not reproduce frequencies down to the lower limits (20 Hz) of human audibility, in most cases. This is where the "subwoofer" comes in. It reproduces the frequencies that the woofer cannot. Even if the subwoofer does not go down to 20 Hz, as long as it fills in some of the frequencies left out by the woofer, it is still a sub. If we can hear, on average, down to a limit of 20 Hz, why bother with frequencies below that? Because of vibrational sensors that we have throughout the largest organ in our bodies (the skin). Someone said that the sound is 50% of the home theater experience. Well, I believe it may be even more than 50%, and the subwoofer may account for the lion's share of the sound experience. Recently, I watched "Broken Arrow" on a TV in a hotel room. Then, when I returned to work, I reviewed the laserdisc version of this movie, using our home theater lab equipment. To me, there was more than a doubling of the sensory experience, and I believe it was due to the surround sound, particularly to the extraordinary feelings produced by the subwoofers. There is more than "hearing" the low frequencies; there is the "feeling" as well.
More and more, movie sound tracks are including very low frequency material. Whether it is produced by natural sounds, or digitally synthesized, is irrelevant. The fact is that it is there, and it should be heard or felt. So, it comes down to this: there are subwoofers that simply augment the home theater experience, and there are subwoofers that complete the home theater experience. The F-1800R is in the latter category. This sub is easily the finest product that Velodyne has ever produced. If you are familiar with the Velodyne sound, and you want a sub that will do it all . . . and I mean ALL the way down . . . place your order now, because they won't be sitting around in the audio shop stockrooms, that is for sure.
John E. Johnson, Jr.
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