Dear Mr. Rich.

I greatly enjoy your articles greatly, despite not being able to follow all the byways of electrical engineering. But, I have a couple of comments:

1: You seem very much against toe-ing speakers because it emphasizes high frequencies at the listening position and limits the soundstage. Yet you note that DVD-A/SACD surround mixes are usually done on setups conforming to ITU standards--which, as far as I can tell from diagrams, always show toe-ed in speakers all around, pointing directly at the listener.

ITU toe-in is very large indeed ... that was my point. If EQ cut is used I can understand how that might compensate for the effect you cite. But actually in my own 5.1 setup I use a large toe-in (NHT Superones all around, tweeters at or near ear level) and enjoy the sound--perhaps because I have lost much hearing above 16 kHz; I haven't noticed a hit to the soundstage, which can extend beyond the speakers (perhaps a fortuitous interaction with my room) and 'imaging' tends to be better than when I point them straight out (as one might expect).

(I also use my Pioneer AVR's room compensation EQ, which probably cuts highs in at least some of the channels)

I don't think I'm particularly uncommon in these regards, as audio hobbyists go.

2: You make reference to "USB 1.1, 1.2, 1.3" as allowing passage of DVD-A, DSD, and newer high-def A/V formats respectively, but there is no USB 1.2 or 1.3, as far as I know--it skipped directly from 1.1 to 2.0. I suspect you meant HDMI, not USB.

Steven Sullivan

via e-mail

You are correct; I meant HDMI, not USB.

--DAR