Copland DRC205 digital room correction


Hi, has anybody known or used this new "equalizer"?
It seems a really good product, useful and extremely simple to understand, designed build around a Lyngdorf/Dynaton logic process.I've not found many informations about it, could you tell me how does it work really? Is 205 at the level of TACT or is it sloser to a Behringer DEQ2496???
I would like to try it in my listening room (a square plant room...) but in Italy it is very difficult to find and testing.
Thanks in advance for your support, sorry for my english but I've studied another language at school (and now I have to pay private lessons :-((( , I prefer buying CDs)

Massimo
massimobar

Showing 8 responses by wazmoh

That is frustrating! I have a busy schedule for the next few days but I will try to repeat the installation and take some notes. I'll also get in touch with my local rep and see whether he has any ideas.
Hi,

Based in large part on the TAS review and on a demonstration by the retailer here in Denver, I purchased a DRC-205 this weekend. I am using it with the following equipment:

Speakers: Magnepan MG-12
Amplifier: PS Audio GCC-100
CD Player: Marantz SA-11 S1
Conditioner: Equi=Tech Son of Q. Jr.

With the unit "engaged," tonal balance in my 22' D X 17' W X 12' H listening room is dramatically changed. String bass is far more prominent and forceful, as are the lower registers of male and female voices and acoustic guitars. An audiophile friend who owns a very expensive set of Krell Speakers and an equally expensive Krell amplifier was very impressed.

I also hear much more ambient information. This has been especially true for my classical recordings, which are now rendered with much more information about the performance venue. Image specificity is significantly improved as well.

I was very nervous about digital artifacts, since this is something to which I am fairly sensitive. To date, I have not heard anything I would attribute to the D/A or A/D conversion. Of course the 24/96 word length/sampling rate offers considerably more resolution that the 16/44 redbook format. It is also worth noting that in spite of the addition of another analog stage, this unit has not increased my noise floor perceptibly.

I chose this unit in preference to the Lyngdorf because it allows the user to define custom response curves, a feature I might use if I decide that the current presentation is too warm or romantic. That said, the Lyngdorf an outstanding product which may use a more sophisticated room correction algorithm.

I can't account for the divergent reviews. It's possible that the unit receiving the "MidFi" rating was defective or that the reviewer is especially sensitive to the signal components modified by the room correction process. It's also possible that when the novelty of what the Copland does wears off, I'll hear more flaws.

That said, it's worth pointing out that a lot of hi end equipment is rendered functionally MidFi or worse by room interactions. That might explain some of the truly dissapointing exhibits I saw this year at RMAF. If room correction provides a net gain, it's worth considering. No amount of room treatment will render smooth frequency response to this extent. If anyone is interested I can provide updates as I continue listening.
Hi Downunder,

I am using the flat setting. I found the BBC curve a little warm for my tastes. I'll report back as soon as I've tried creating a custom setting.
Update: PC Interface

Working with the Copland PC interface was both intriguing and instructive. The display consists of a logarithmic graph of frequency (X) and amplitude (Y) overlaid with three sets (left and right channel) of curves: The first set represents room response, the second represents room correction applied and the third represents the net (corrected) response. A line through 0 db represents the target.

In my system, the display showed a room having very uneven response. Above 1 kHz, there were several broad excursions having peaks and troughs of ~6 db above and below center. These the DRC corrected easily, yielding a net response that was within +/- 2 db.

Below 1000 Hz, there were two severe but narrow dips, the first being –10 db at a center frequency of 170 HZ and the second being –15 db (!) at a center frequency of 65 Hz. Since Copland does not recommend filters with a gain above 6db, I spent some time experimenting with speaker placement to see whether I could ameliorate the problem before adding more compensation.

Based on my reading, the likely culprit was either floor reflections or reflections from the rear wall. Tipping the speakers back ~5 degrees from vertical helped slightly, Toeing the speakers in smoothed response above 1000 HZ but aggravated both of the lower modes. Toeing the speakers out had the opposite effect.

Moving the speakers further from the front wall reduced the mode at 65 HZ but made the mode at 170 Hz worse, suggesting that much of the room interaction was coming from the wall behind my listening position. Some basic math suggested that reflections at both frequencies would be out of phase by nearly 150 degrees at my speakers. Given the wavelengths involved, the speakers would need to have been 6’ or more into the room before the effects were reduced significantly. I settled on a position slightly inboard and forward of the original location with ~ 10 degrees of toe-in.

I now had 2 narrow, 10-12 db modes to remove. Copland allows the user to define 5 filters of varying configurations and Quality (Q) factors. Beginning with the default (A1) curve, I created a pair of peak filters having higher than recommended Q and gain that were centered at each mode. Although the contours of the response curve were very similar between channels, the amplitude was not. Because adjustments are applied to both channels, I had to settle for a final curve in which the right and left channels straddled center.

The PC interface permits the user to try curves before committing them. It also allows the user to switch among each of the filters. That said, if a filter is not saved before switching, it is lost. Configuring the filters was very easy, and the results were very audible. At the end of the session, I preferred my “custom” settings to the default by a slight margin.
Hi,

I bought mine from Dave Tyree at Heirloom Audio in Denver. You can reach him at:

303-333-1504
[email protected]

Because of noise/distortion concerns, Copland does not recommend placement between the amplifier and preamplifier. You can use the tape loop or insert it between a source and input (clumsy, I know). I am using the latter configuration until I find a suitable integrated amplifier having a tape loop.

This is one of the reasons Copland does not want the unit connected between the amplifier and preamplifier. It is equivalent to a line level device (such as a CD player) and does not have the voltage swing of an active preamplifier.

The input/output voltage of 1 volt nominal indicates unity gain. Input/output impedance is not given, although it would not be difficult to determine. Typical values are 47 K ohm or more at the input and 1 K ohm or less at the output. My manual states maximum output as being 2.4 volts.

Unless your passive preamplifier uses an autoformer, it does not have voltage gain, meaning that whatever voltage is produced by your line source must be sufficient to drive the power amplifier. Typical line level sources, such as CD players, have outputs that fall between 1 and 2 volts.

Is it possible that your power amplifier is unusually sensitive? If so, you might be able to insert the DRC between your passive preamplifier and amplifier (assuming suitable impedances). Hope this helps!
Inputs, Mic. Position and Filter Configuration

Hi Oscar44 and rhljazz,

The Copland has only a single input. However, you could use an input switch such as you might find in an inexpensive passive preamplifier. The volume control would be easy to bypass. I feel your pain. Now that I've decided to keep the Copland, I'm replacing my otherwise satisfactory PS Audio GCC-100.

When I first saw the DRC205 a RMAF, I asked whether the unit limited listeners to a single position. The representative answered that the improvement was audible over a wide area. This has certainly been my experience.

The maximum gain/attenuation for any filter is +/- 6db. That said, this can be applied in addition to the automatic setting which forms the basis for custom curves. I am using two filters (see earlier post) which have more than the recommended gain and Q without ill effect. Of course, since this falls outside the manufacturer's specifications, the usual caveats apply.
The installation was somewhat clunky and counterintuitive. As I recall, the software needed a USB driver and some sort of serial port emulator. I was able to install the program on an older Dell XP Pro-based laptop without undue difficulty.

I am not terribly surprised that it does not work on a Windows 98 platform. Was the DRC connected when you installed the software? The manual is very emphatic on this point. It may be worth uninstalling the utility and trying again.