I've been intrigued by Elysia's line of products for some time now. After a few encounters with their stuff at various studios, I became impressed with the sonics and innovative features of their processors, particularly their compressors. When I saw that they were releasing a line of 500-series boxes with significantly lower price tags than the norm for their 19'' rack gear, I took the cue to fill a stereo EQ-shaped hole in my Radial Workhorse SixPack.
The xfilter 500 takes up two spaces in a 500-series rack and is operated with a single set of controls for both channels. The design is sleek and classy, with the signature Elysia silver/blue color scheme and long-shaft knobs. All eight of the potentiometers have small detents for "easier" recall (see below). There are two bands of semi-parametric EQ for the midrange, as well as high and low shelves. The high and low bands can each be switched to become variable cut-off filters, and when in this mode, the gain control determines the filter's resonance curve. The two mid bands are always in peak mode, but each has a switch that can narrow the Q factor for more precise cuts and boosts. All four bands overlap quite a bit, and the overall range is from 20 Hz to 28 kHz! The final feature of the xfilter is called the "Passive Massage," and it's a passive LC filter that, when switched on, gives a fixed resonance peak around 12 kHz and then rolls off slowly starting at 17 kHz.
One of the hardest things to get right in any ganged-stereo device is the maintenance of the stereo image. The variance of the components has to be extremely low, and many things have to be carefully aligned to make one set of controls work over both channels. Well, the Germans over at Elysia have nailed it with the xfilter. I detected no discernible phase shifts or level discrepancies between the two channels, even when cranked to extremes. Having a single set of controls is not a trivial fact, which I know well since I've been using two mono Empirical Labs Lil FrEQ EQs [Tape Op #49] on my stereo bus for the past year or so. I love their sound, but attempting to set them precisely the same is an imperfect art. Not so with the xfilter. The small steps and large knobs allow for very precise frequency and gain selections, so getting a good stereo bus EQ setting going is remarkably painless. The Class A filters are smooth and open, and they do a lot of work even at relatively small gain values.
Of course, the xfilter 500 also works great as a mono processor if you use only one of the channels. I had lots of luck tracking bass drum, snare, bass guitar, and vocals through it. I would sometimes set it for one instrument, and then run another instrument through the other channel just to see if they could share the same EQ settings. A few times, this worked quite well, especially when I was just bumping up at 28 kHz a bit and/or using the Passive Massage to give some sheen to a thing.
Yeah, so overall I would say I quite fancy the xfilter 500. It has done what I've asked of it on every occasion - make what I run through it sound better. Whether I'm looking for sheen, warmth, bottom, midrange, sparkle, or what-have-you, the xfilter has performed dutifully and happily. The Passive Massage really is a treat. It's kind of like a one-button enhancer that doesn't affect the dynamics at all; it just opens up your material beautifully.
My only problem with the xfilter is that recall is more difficult than it should be. Given the fact that the pots are stepped, you'd think it would be extremely easy to call up previous settings, but the lack of detailed markings around the base of the pots, together with the length of the shaft of the knobs and the somewhat wide notch on the base of the knob itself, make photographing the settings a little cumbersome, perspective-wise. Taking four or five photos for eight knobs just doesn't seem right.
That functional quibble notwithstanding, there is absolutely no doubt that the xfilter 500 will be staying in my rack - and on my stereo bus - for the foreseeable future. I absolutely love the way it sounds on a mix, and the extra features (particularly the cutoff filters) make it a versatile mono or stereo tracking tool as well. At just under five hundred dollars a channel, the price is right, too. I love it!