Wayne A. Pflughaupt· Super Moderator
Discussion Starter · #1 ·
Yamaha’s Stunning YDP2006 Digital Parametric Equalizer
Back in the summer of 2007, I was ready to call it quits after a year-and-a-half with the ubiquitous Behringer DSP1124 Feedback Destroyer I was using to equalize my subwoofers.
It had always been a love/hate relationship with the BFD. Certainly, I loved the fabulous sound I was able to achieve by accurately smoothing my subwoofer’s response. But I wasn’t particularly fond of the way it looked, especially since everything else in my system is black.
Being a fan of analog parametric equalizers, I was accustomed to their easy-access controls for frequency, gain, and bandwidth. By comparison, I found the BFD’s interface to be ridiculous and cumbersome. Another irritation was that once the BFD is set, you can’t tell what your filter parameters are without a lot of button pushing and wheel turning, and then referring to a secondary source to translate bizarre designations like “40 Hz +10” to an actual numeric frequency. With an analog parametric you have all filter settings available at a glance.
On the other hand, the BFD’s ability to save settings to memory was a decided advantage over analog equalizers. And there was an upside to the aggravation of accessing filter settings – it also meant they were safe from accidental changes or intentional tampering (filter settings on an analog parametric are all-to-easily altered – just twist a knob). So, I could certainly see the benefit in staying with a digital equalizer. Just not this garish and unintuitive one.
So, I embarked on a search-and-destroy internet search to see if I could find some obscure black-faced digital parametric equalizer from the pro audio world that had escaped the notice of the home theater set. Eventually I came across a vintage model from Yamaha that fit the visual requirements. A review of the on-line manual showed the YDP2006 fit the functional requirements as well: A two-channel model with six parametric filters per channel that could also be configured for twelve-filter mono operation. All filters could be assigned anywhere in the audio spectrum, a critical feature for any parametric equalizer dedicated to a subwoofer. And to my delight, the manual showed that filter adjustments were accomplished with digital encoder knobs for frequency, bandwidth, and gain that mimicked analog operation.
It looked like I had a winner. Now, to find one. I did a "saved search" on ebay and in a week or so one appeared for auction. It didn’t escape my notice that the seller, who had been using it in his recording studio, extolled the YDP2006’s sonic capabilities with much enthusiasm, as well as its processing power.
Although I acquired this equalizer simply because it was easier to use and a better visual match with the rest of my system, the Yamaha proved to be an absolutely stunning piece, with features and flexibility unmatched by the Behringer DSP1124 (currently designated as FBQ1000), and performance unmatched even by the superb AudioControl C-131 1/3-octave equalizers I had been using in my system for the previous twelve years.
The YDP2006 is a compact 1 rack-space package (compact in that most stereo analog parametrics are 2-space units) that, as best as I can tell, was in production from about 1996 to 2002. It was an expensive equalizer, with a list price in the neighborhood of $2300. The price at least got you an impressive pedigree: Yamaha was the first company to offer a digital parametric equalizer to the pro audio market, way back in 1987 when they introduced the model DEQ7 that featured 16-bit A/D-D/A converters. The YDP2006 was a third-generation product, benefiting from more advanced 20-bit A/D-D/A converters and an improved user interface, among other things. Yamaha concurrently offered a digital 1/3-octave equalizer, the YDG2030. Following an industry trend, Yamaha has offered no successor for these equalizers since they went out of production (although strangely they continue to offer a mediocre analog 1/3-octave equalizer that’s been in their product line for over 20 years). Other companies also offered digital equalizers during that era, many with additional features such as limiters and compression, which have also been discontinued. With the exception of Behringer and perhaps a few others, the trend in the pro-audio industry has been to roll EQ functions into digital speaker-management processors and more lately, directly into digital mixing consoles.
As the steep list price would indicate, the YDP2006 is professional-grade piece whose build quality makes the BFD look and feel like a toy by comparison. Cabinet construction is medium-gauge steel and it weighs a substantial 10 lbs., which is more than twice the BFD’s weight. The YDP is physically large as well, fully 13” in depth compared to the BFD’s trim 7-1/2”. On the back panel are heavy-duty, cast-metal XLR connectors with locking mechanisms, instead of the BFD’s plastic non-locking fare. Even the Yamaha’s power switch has a more substantial feel and sound than the BFD’s when engaged. This is not to disparage the Behringer; at more than twenty times the price, we would certainly expect the Yamaha to be a more robust product. The YDP’s appearance is a bit “industrial” compared to most consumer home audio components, but nevertheless it is much better looking than the BFD, in my opinion.
The YDP2006’s front panel features three banks of buttons. One bank provides selection of the left or right channels for filter adjustments, a bypass switch, and access to the equalizer’s menu (which Yamaha calls “Utilitiy”) to set various operating parameters and features. Another bank is dedicated to accessing and storing the equalizer’s memory settings. The third bank independently turns each of the six filters off and on, subject to the main bypass button. LEDs indicate which filters are engaged, a nice feature that many analog parametric EQs have.
And probably my favorite feature, three knobs Yamaha calls “rotary encoders” for setting filter parameters. They are logically labeled “F” (frequency), “G” (gain) and “Q” (bandwidth), in traditional analog-parametric fashion. The same encoder knobs are also used to set other programmable parameters as well.
A large dual-mode LCD screen shows the status and parameters of any filters in use. The screen’s default mode is a graphic display that shows the electronic frequency response of all filters that are engaged (i.e., deviation from flat response). An optional screen mode, accessed by pressing the “PEQ” button, offers an itemized list of all filters, showing numeric values for frequency, gain and Q settings. With either mode, it’s certainly nice to be able to review filter settings quickly and easily. In addition, twin level meters feature green, orange and red (clip) elements, and a numeric read-out indicates the programmable memory position in use.
Rounding out the front panel controls is a concentric analog knob that sets the input level for both channels. Current-production pro-audio digital processors, which feature 24-bit A/D-D/A converters, have so much dynamic range in the digital realm that manufacturers have all but done away with input level controls. However, with the YDP’s less-capable 20-bit converters, such a control can be useful to insure the best signal level and quietest operation. In theory at least. In practicality, considering the YDP’s stellar noise characteristics, input levels shouldn’t ever be a concern. I just leave mine in the “0” position.
In addition to the aforementioned heavy-duty XLR audio connectors (there are no 1/4” or RCA connections), the YDP 2006’s rear panel carries other XLR and MIDI connectors that are most likely of no use for domestic applications. Switches for -20 dB or +4 dB operation are functionally identical to the -10 dBV and +4 dBu switches on the BFD’s back panel; however, the Yamaha assigns the switches to the inputs and outputs, instead of the left and right channels as the BFD does. A potential benefit of this arrangement is that with the switches in the proper configuration the equalizer can function as a line driver, substantially boosting the signal level to a downstream pro-audio amplifier. Alternately, the analog input control can give a +10 dB signal boost beyond its “0” setting. However, a noise penalty can be expected with either approach.
A common complaint with the BFD is the high intensity of the indicator LEDs. Most will probably agree that the Yamaha’s LED lighting is not as garish as the BFD. Both the input meters and LEDS for the function buttons and memory number muted in brightness compared to the BFD. The only glaringly bright LEDs are the ones indicating that the individual filters are on.
Being digital, the YDP2006 has a lot of features that you would not find with an analog parametric EQ, or the BFD for that matter. Naturally some features are more relevant to professional users and applications; I won’t belabor the reader with a discussion on those.
As mentioned, the YDP is a stereo equalizer with six filters per channel. However, an option in the Utility menu can program the unit for mono 12-filter operation. Any filter can be set virtually anywhere in the 20 Hz – 20 kHz audio spectrum.
In addition: This is mentioned nowhere in the manual (!), but in stereo mode, filters #1 and #6 respectively can be switched to low- and high-shelving (in mono mode, this would be filters #1 and #12). This is accomplished by turning the “Q” encoder knob all the way to its widest bandwidth (i.e. smallest numerical Q). The display will show HSH (high shelving) or LSH (low shelving) when the filter has switched to shelving. As with regular parametric filters, the shelving filters can be set for virtually any turnover frequency desired.
The YDP2006 also has a bank of notch filters that can operate simultaneously with the parametric filters, which can (logically) be accessed via the “Notch” button. Those probably won’t be terribly useful to most home theater enthusiasts, but filters #5 and #6 are high and low pass filters, which certainly can be. Once again, either can be set virtually anywhere in the 20 Hz – 20 kHz audio spectrum. Yamaha doesn’t give any specs on these filters, and erroneously refers to them in the manual as “shelving HP [high pass] and LP [low pass] filters.” However, my crude measurements with sine waves and SPL meter indicate that they do not shelve but are constant-slope 24 dB/octave filters, most likely Butterworth alignments.
For those desiring absolute minimal background noise, the equalizer has a digital “Emphasis” noise reduction feature that can be accessed in the Utility menu. According to the specs, the Emphasis system will give a 4 dB noise reduction. However, Yamaha claims the equalizer has sufficient dynamic range so that the noise reduction should not be needed in most cases. I would agree. I did note a slight improvement in background noise with the Emphasis engaged, but not enough to make me want the additional processing added to the signal chain.
A delay function is also available that can be set in the Utilitiy menu to read in milliseconds, feet or meters. The delay increments are especially fine and can be set for fractions of an inch or millisecond. For instance, there are no less than 44 settings between 0 and 1 milliseconds, 1 and 2 milliseconds, etc. This is an especially useful feature that can serve to precisely time-align a subwoofer with the main speakers or the individual drivers in a bi- or tri-amped speaker system. It can also be useful in a home theater system if multiple YDP2006s are used for the main channels, delaying the center channel in relation to the mains (as it is often a bit closer to the main seating position than the side speakers), or if you have a problematic room that requires either the left or right speaker to be closer to the listening position than the other.
In addition to the front-panel input-level knob that operates in the analog realm, the YDP2006 features a digital attenuator. The manual is rather vague as to its purpose and use, but Yamaha describes it as a compensation for equalizer settings that result in an increase in “the overall gain of the sound,” which may result in “internal clipping... even if the level meters do not indicate clipping.” (If you’re getting the idea that the manual is rather poor, you would be right. It’s as bad or worse as the BFD’s manual.) Basically the situation is that (unlike the BFD) the YDP2006’s level meters are in front of the processing section and as such show only input level (as seen in the block diagram below). So, using a filter with say, +7 dB gain can make the equalizer clip before the input level meters hit red. A digital-domain attenuator is a really useful feature for this particular equalizer, since its 20-bit converters have 25 dB less digital-realm dynamic range than modern 24-bit processors. The attenuator can be set in 1/10 dB increments.
True to form, the manual’s explanation for actual use of the attenuator is maddeningly opaque, noting that it should be adjusted so that “the output level is the same as when the equalizer is bypassed.” In other words, match the bypassed and filters-engaged output levels by ear, or acoustically. It makes more sense to me to just dial in a value equal to that of your maximum boosted filter. In other words, in the example of the above-mentioned +7 dB filter (assuming you have no other filters with more boost than that) simply adjust the digital attenuator for -7dB. The input meters do seem to be calibrated conservatively, as I’ve pushed levels into the red and noticed no audible distortion. However, better safe than sorry.
The delay and digital attenuator features are accessed by pushing the “PEQ” button twice if you are in PEQ mode, or three times if you are in some other mode.
All equalizer, delay, attenuation etc. settings can be saved to any of 40 available memories, and they can manually be assigned names in the Utility menu – “Music,” “Action Movie,” “Mocha Latte,” or anything else that strikes your fancy. Also in the Utilitiy menu is a “Protect” function that can be engaged to lock down all settings to prevent accidental changes.
In addition, when the unit is turned off any settings currently in use are automatically saved and recalled when the power is cycled back on – like if you decided to make an adjustment on the fly to the memory preset you’re using. However, such adjustments are lost if you call up a different stored memory setting. In other words, if you wish to make your on-the-fly adjustments permanent, the memory setting you’re using must be re-saved.
Memory retention is made possible by a replaceable long-life lithium battery that is easily accessed with the top cover removed. Yamaha claims the battery is good for five years, which is a conservative estimate. I bought my first YDP2006 in 2007 – used, mind you – and have yet to replace a battery. Nevertheless, it would be a good idea to document your settings for the inevitable day that the battery does fail. The manual claims the display will give a low battery indicator when it’s on its last legs. Maybe someday I’ll actually see it.