Monitors

My main monitors, at present, are custom units built by Manny LaCarrubba, chief engineer at The Plant Recording Studios in Sausalito, CA. These are three-way acoustic suspension designs that are reasonably flat down to about 30 Hertz, with essentially flat power response to 17 KHz. The wrinkle that makes them really special is that the high-frequency output, is widely dispersed, at 140 degrees as opposed to the 30-60 degrees dispersion yielded by normal dome tweeters.

Now, I personally believe that such dispersion yields significant benefits in terms of stereo image and impact, particularly in a reverberant room. One of my goals to find out if this is in fact so, as part of a more general study of the theory of phantom localization and stereophony. Before beginning reconstruction of the room, I have placed these speakers about 5' away from the wall, and find the stereo illusion, in the untreated space, to be very effective. I expect it to get even better with the treatment of the room. I will be interested to hear more conventional, directional systems as I get into this study.

I plan to develop a sizable collection of speakers for study, starting with Auratones, JBL 4313s (as a generic ported 3-way system) and some bookshelf 2-ways equivalent to Yamaha NS-10s. For headphones, I have a set of Etymotic Research ER-4 (Binaural) Canal Phones® plus some standard Sony and Yamaha headphones, driven by a HeadRoom headphone image processor/amplifier. The Etymotics, being flat-response transducers placed at the eardrum, are a useful lab tool (equivalent in quality to B&K microphones on the recording end of things) for detailed study and evaluation of recordings.

Control of Monitors

An essential feature of my set-up includes a fairly well-developed monitor control system with supporting instrumentation and displays. Using a TEF Analyzer, I plan to have Maximum Length Sequence Analysis and Time Delay Spectrometry available, plus oscilloscope and RTA displays. Typically, monitor control is included in the master section of the console, but for both research and client accommodation, I'm planning on custom-building one that does a little more. This means a remote unit (probably wired, and a good bit bigger than your basic TV Zapper) that includes selection of stereo, summed mono, summed mono to a 3rd (center) speaker, Polarity Reversal of Right Channel, and A-B modes. Speaker selection will be via ABCDX switching, with a Variable Level stereo pot and switch selected Reference Level, -10 dB Dim, -20 dB Dim, -3 dB Dim, -6 dB Dim and Mute. Depending on the console I end up with, I may also fit a fairly comprehensive capability for selecting different audio sources at the remote.

The ABCDX switcher is worth a little extra comment. This is a box that allows you to switch between four sets of channels, with control of the time between options and the fade-out, off, and fade-in times. Each channel pair has level controls, and switches between inputs, inserts and high-level outputs. So, along with doing the usual job of selecting between main monitors, Auratones, NS10s, and clients' speakers, this switcher can conduct some pretty rigorous subjective listening trials easily and effectively. In addition, the X capability allows me (or any listener) to randomly select one of the four options available without knowing which, so we can test our ability to differentiate between options. By using acoustically transparent screens to block speakers from view, it should be possible to easily compare loudspeakers this way. Hardware and cables will also be easy to measure, while microphone comparisons, a little harder, will still be possible. One final benefit of this system is that it permits me to use a single power amp for all of the speakers, because the switching occurs at both line and speaker levels, with gain corrections. At present I am using a Dynaco Stereo 400 left over from the Jurassic Period, but expect to replace that with a Bryston or something similar.

At some point, I hope to get a large screen projection video installed so that I can put all of the computer displays, including RTA, oscilloscope and meters, plus Macintosh and PC computer editing and sequencing screens, on the front wall where everybody can easily see them while also listening on the median plane. An infrared remote keyboard/mouse setup would then become ultra-cool. And then a . . . . See what I mean about dreams? They can get away from you, but boy are they fun! And sometimes they really lead to neat stuff!!