35 Years and Just Getting Started: The J. Gordon Holt Interview Page 7
Holt: No, I don't.
Stone: What are the primary reasons people feel that Home Theater's not suitable for music? Is it not high-enough fidelity for music?
Holt: That doesn't have to be the case, but all too often it is. My own experience has been, if you buy Home Theater loudspeakers, you'll end up with a system that's much worse in terms of fidelity than what you can get from a high-end audio source. I think it's because the people who design them don't really have much respect for the people who buy them. I think they figure, "Ah, these are movie people. What do they know?"
Stone: Do you listen to a lot of music on your Home Theater system?
Holt: Laziness. [laughs] No, I have a Home Theater system right now that I think does a very good job of straddling the line between music and Home Theater. But the loudspeakers I'm using currently---Tannoy 10DMT-IIs [reviewed by Gordon in Stereophile Guide to Home Theater, Vol.3 No.1, Spring 1997---Ed.]---weren't made either for Home Theater use or for high-end audio use. They were designed to be recording-studio monitors. It's important to have high-resolution speakers. In fact, that's one of the first steps toward getting a system that will satisfy both the high-end audiophile and the Home Theater buff. Most Home Theater speakers don't meet that requirement. Most studio monitors do.
Stone: Do you feel that the main shortcoming in most people's systems is still their speakers?
Holt: Yeah. Most high-end audio speakers currently used for straight stereo are designed to exaggerate image depth because they have no other way of producing real depth.
Stone: How do they do that?
Holt: Usually by dishing down the whole midrange by a few dB, and tipping up the low end and the high end. And another problem is that high-end speaker systems generally can't handle anywhere near the volume that's required of a THX-level soundtrack.
Stone: Do you think horn speakers represent a solution?
Holt: One solution, yes. I've been very impressed with some recent horn systems I've heard, mainly because they have immense speed and dynamic range. They don't seem to compress things at all, and they're absolutely effortless at very high volume levels. You have the feeling that they're just breezing along. There are still a lot of god-awful horn speakers out there, but there are some others I've heard that I'd go to bed with any day.
Stone: So, obviously, it seems like part of the trend of horn speaker systems is also using single-ended triode amplifiers. How do you feel about those?
Holt: I would say single-ended triodes are practical only with horns---full-range horns. This is one reason why horns are currently so popular in Japan. It goes along with their liking for the sound of single-ended tube amplifiers---only horns can get decent volume levels with amps like that.
Stone: What do you think is the sound of single-ended amplifiers?
Holt: Most of them sound what I would call "tubey." They're very pleasant, a little warm. They're sweet in the high end, but unless you have horns, they overload every time somebody hits a piano keyboard.
Stone: Do you feel the loudspeaker is still the weak link in most music systems.
Holt: Yeah, I think so. Face it, they're the only thing in the system that's still mechanical, except for the CD transport. As soon as you get into mechanical stuff, you've got resonances and the problems of how to get rid of them. Add to that the fact that they're acoustical---they have to move air.
Stone: Do you think there's ever going to be any ideal design for speaker systems---one particular method that will solve everybody's problems?
Holt: I'm certainly never going to say "never." But if it happens, it won't be from any technology that exists now.
Stone: It seems like now there are so many different ways of making a speaker that the average consumer must be rather confused. I know the average reviewer is.
Holt: They all basically come down to one thing: they're just devices to push air. There shouldn't be anything confusing about it. And the thing is, the bigger the surface, the more air it can push, which means the deeper the bass. But the other thing is, the bigger the surface, the heavier it is and the worse it is at reproducing treble. This is why I'm kind of intrigued by the idea that Linaeum is pursuing, or at least have started messing around with---their so-called true line-source thing. The interesting thing about it is that, theoretically at least, it could, if the thing was made big enough, perform very much like an ideal line source. Which is to say, it would have very wide dispersion at very high frequencies. It wouldn't be frequency-selective in terms of its dispersion.
Stone: That's a ribbon system.
Holt: Sort of. It's a soft ribbon---and that's a very important distinction. A regular ribbon is attached at both ends, the center is free to vibrate, and the whole surface is sitting in a magnetic field. When it moves, all of it moves at once. In the Linaeum, the ribbons are actually nothing more than wave carriers. You have these two semicircular loops of soft ribbon, and when the voice-coil moves them, they're too soft for the whole ribbon surface to move at once. So what happens is, the ribbon flexes at the point where it's been moved, then that flexure travels along the length of the ribbon like a wave. At small amplitudes, which also happen to be high frequencies, the little wave motions die out very soon. In other words, they only go a short distance along the ribbon loops before they die out. So the radiating surface is very small, which means wide dispersion.
With higher-amplitude stuff---lower frequencies---the waves travel all the way along the ribbons to their fixed ends, giving a much larger radiating area that has about the same dispersion as the treble. Which, right there, is almost a definition of a perfect loudspeaker. I don't know how practical it would be to make a really big, wide-range system with this technology; all they're doing with it now is using it for tweeters. But my recollection was they had some earlier systems that had a multiple-driver array of larger size.
Stone: But those still used traditional woofer columns for low-frequency transmission.
Holt: As far as I know, Linaeum's soft ribbon is the first new kind of tweeter radiator that's come along in, what, 40 years?
Stone: Unless you want to consider the original Apogee, which used a loose ribbon hanging in a field.
Holt: Well, again, the Apogee was the same kind of uniform-motion ribbon that's been in use for years and years.
Stone: Recording classical music has been another hobby of yours. How has that changed over the years?
Holt: It's never really changed that much. And we're not yet at the point where it makes sense beyond just experimenting to record with more than two mikes---you know, more than two channels. Very few people are set up for discrete surround-sound. And most of the surround decoders in consumers' homes are just not suitable for ambience extraction.
Stone: Doesn't a good stereo recording have all the ambience information within it?
Holt: Yes, it has a lot in it. But if you try to use Dolby Pro-Logic, which is the only surround mode that most decoders offer, the surround information confuses the decoder because it isn't mono. It sort of varies continually from semi-mono to largely uncorrelated, because reverb is random. The decoder is looking for a correlated difference signal to lock onto, so if it finds a mono signal there for a moment, it will steer it to the rear. When it loses that, it steers back to the front. And because the reverb is random, it just jumps all over the place. So you get pumping and all sorts of things---very weird effects.
Stone: But you listen to most of your recordings in surround-sound, correct? How do you get around that problem?
Holt: Most of the higher-priced decoders have a straight "Hafler matrix" for music surround, which is a left-minus-right subtraction thing like Dolby Surround except that there's no steering. So you get the surround effects but not the pumping.
Stone: Most of your recordings are done with just two mikes?
Holt: You're asking me?! [laughs] Yes. Most of our recordings [JGH and SS regularly record their local symphony orchestra together---Ed.] are done with two mikes, unless there's an obvious situation where we can't do it with two. Like a stage layout where there's a great deal of front-to-back distance---chorus at the back, orchestra in the middle, soloists at the front. In that case, a single pair of microphones is going to be a bad compromise at best. For that we borrow a mixer and use additional mikes.