Music in the Round #54 Page 2
With digital S/PDIF or TosLink datastreams, there was no doubt that Bryston had applied their considerable experience in D/A conversion to the SP-3. I've been out of the mainstream of the standalone DAC business for a little while, but Bryston's 24-bit/192kHz DACs drew finer detail from the music, especially in the treble, than I got from the analog outs of either the Sony or the Oppo player. This was true even when I compared the Oppo's 24/88.2 PCM output from SACDs with the analog output of the Oppo's vaunted 32-bit ESS Sabre DACs directly converting the DSD signal.
Switching to multichannel, as fed from the analog outputs of the Oppo BDP-95, meant using the Oppo's crossover and distance settings, although the external EQ of the subwoofer was retained. I found this sound utterly amazing. It retained all those characteristics that had so impressed me with two-channel signals, now enhanced and expanded into the three dimensions of surround sound. This was the first time in a very long time that I had enjoyed convincing multichannel high-resolution sound without a digital processor. Chalk it up to the excellent analog signals provided by the Oppo, but also, in no small measure, to the Bryston SP-3's utterly transparent sound.
Indeed, moving on to the more standard digital connection between the player and the SP-3, there was still something to be gained, but nothing was lost. The integration of the subwoofer's output was improved by the Bryston's use of second-order high-pass and fourth-order low-pass filters at 45Hz. (The Oppo's only relevant options were at 40 or 60Hz.) This contributed to the overall illusioneven powerful low bass had unequivocally specific imaging at all levels.
And all this in only my first two weeks with the Bryston SP-3! At this point, my preliminary verdict is clear: The SP-3 is an uncompromisedly superb analog preamp that also includes Bryston's excellent 24/192 DACs. In that sense, it can be regarded as Bryston's ultimate stereo component. I need and want to spend more time listening to the SP-3's multichannel performance via HDMI in my Manhattan system, as well as in my Connecticut system, where the supporting cast is so different. Those results, in detail, will appear in my next column. I have very high expectations.
XTZ Room Analyzer II Pro
I refer you to my report on the original XTZ Room Analyzer, in November 2008, and on its 2.0 update, in November 2009. XTZ remains the least expensive, easiest-to-use package of software and hardware providing the basic functions for acoustical analysis of a room and system and the development of correction filters. (See the report, in my March 2012 column, on setting up room EQ using XTZ with the parametric equalizer in Rotel's RSP-1572 pre-pro.) Other programs, such as REW, can be cheaper and more comprehensive, but not easier to set up and use. Still others, like Omnimic (see this column, November 2011), are comparably priced and easy to use, but do not as yet provide the most appropriate suite of functions for the nontechnical home user.
The XTZ Room Analyzer II Pro ($359.99) comes as a kit in a nice aluminum carry case. That case contains: the microphone, mike stand, and tripod adapters; a USB preamp with XLR connections for mike and sound system; two 20' XLR cables (one with RCA output); a tabletop tripod; and a USB memory stick with instructions. The software itself is downloaded from www.xtz.se.
II Pro includes everything in the Room Analyzer, with some important additions to the software: a very sophisticated SPL meter function that provides variable weighting and averaging (LCpk Hold shows the highest SPL since start/reset; LCpeak shows continuous peak levels, including short bursts; LAF Hold (footnote 1) shows the highest average level with current settings; LAF shows the current average with current settings; LAeq shows the current SPL with current settings, according to the selected frequency curve); a delay alignment function that aids in setting proper relative speaker and subwoofer distances; frequency and room-analysis functions with up to 1/12-octave display resolution (previous editions were limited to 1/6-octave resolution).
Fig.1 System low-frequency response as shown by the XTZ II Pro Room Analyzer screen before (blue) and after (red) DEQX, is in the center.
The equally important hardware improvements are a dedicated USB preamplifier and a more accurate (especially at high frequencies), small-diameter microphone that can be mounted on a standard mike stand. I found the original mike, on a gooseneck stalk affixed to a small base, somewhat unstable and susceptible to vibration if placed on, say, a cushioned couch. That alone would have justified the new model and the price hike of $40, even without software improvements.
I attached the mike to my standard stand, which can be purchased from online musical-instrument shops for under $30. It's a good investment; the provided tabletop tripod limited placement options, as had the original gooseneck mount, and leaves the mike's performance dependent on the mounting surface. It's almost self-defeating not to use a real mike stand, and I would have preferred it had XTZ omitted the miniature tripod. After all, they call this the Pro kit, don't they? (footnote 2)
Fig.2 System full-range response as shown by the XTZ II Pro Room Analyzer screen before (blue) and after (orange) DEQX on the top.
I currently have no hardware installed that will accept and test the Room Analyzer II Pro's suggested filters, but I have little doubt that this function, carried over from the earlier version, will function as well as or better. I did, however, use the II Pro in two situations.
First, I used it to set up my system with the Bryston SP-3 processor. This entailed determining the effect of room acoustics on the main speakers. For the three B&W 800 Diamonds in front, the effects all appear below 45Hz. The B&W 804 surrounds suffered from peaks that were higher in frequency, and because the SP-3 lacked any way to correct them, I used the XTZ to reposition them to get the remaining modal peaks below 80Hz. This is what led me to choose those two frequencies for the redirection of lows to the subwoofer. I then used the XTZ's room-analysis function to confirm that the DSPeaker Anti-Mode 8033 had indeed so reduced the modal behavior of the JL Audio Fathom f113 sub that the XTZ Room Analyzer no longer found any modes or suggested any corrective filters. Finally, the XTZ's delay-alignment function allowed me to calculate the effective acoustical distance of the subwoofer from the listening position in the SP-3, and to compensate for its physical displacement, as well as the latency of the subwoofer's processing and that of the 8033. So, even without being able to EQ the three front channels, I was able to get pretty close to acoustic Nirvana. Could I have adjusted all of this by ear? Probablybut it would have taken a lot longer, and even so, I'd have had lingering doubts that I'd arrived at the optimal EQ.
Fig.3 System full-range 3D time-decay spectrogram as shown by the XTZ II Pro Room Analyzer screen.
So far, the other use of XTZ's Room Analyzer II Pro has been to confirm the success of the installation in Jonathan Scull's two-channel system of DEQX's HDP-Express, a one-box speaker- and room-correction system for two-channel sound. I say "confirm" because Jonathan had hosted a listening party for John Atkinson, Steve Guttenberg, Stephen Mejias, and me, and the vote was almost unanimous. Still, just before that gathering I'd run the XTZ Room Analyzer II Pro and found that the DEQX setup had smoothed J-10's system's already excellent frequency response and evened out his room's modal behavior. True, it's a damn good-sounding setup anyway; the XTZ could detect no room modes even with the DEQX bypassed. (That the XTZ did detect the very high frequency of the steam-heat pipes chez 10 is a testament to the new mike's frequency response.) Still, the subtle but meaningful improvements were revealed by the XTZ, and to the ears of the jury. As JA said, "Just a dB or two in the right places can make all the difference."
The original XTZ Room Analyzer and the 2.0 edition were respectively nominated as Stereophile Products of the Year for 2009 and 2010. In every way, the XTZ Room Analyzer II Pro is a better and more useful product that should part of the toolkit of any serious audiophile.
Footnote 1: These three measurements are adjustable using the menu under the meter bar for Fast (125ms) or Slow (1s) average, shown as an LAF (Fast) or LAS (Slow) on the level indicators. They are also adjustable for A, C, or Z (flat) weighting using the bottom menu, shown as LAF, LCF, or LZF on the level indicators.
Footnote 2: The XTZ Room Analyzer II Standard ($229.99) includes most of the functions of the Pro, and though it carries over the gooseneck mike of the original version, the mike itself is improved and its base modified. The Standard lacks a signal generator and the ability to test the generated filters on the computer before trying them on as your EQ. However, it retains the SPL meter, the delay alignment, and the RTA modes. At $70 less than the original and $130 less than the II Pro, it will appeal to the less committed user.