Music and Recording Features

So what are the parameters for making these "improvements"? What are Gibson and his fellow engineers specifically looking to heighten or eliminate?

"We're listening to it with experienced ears and sort of thinking, Does it sound natural? If it's an orchestral recording, does it sound like a good orchestral recording should—does it sound balanced, high frequency, low frequency; are there particular frequencies that are a bit nasty, that are a bit harsh? Sometimes that's the case. It's those sorts of questions that you ask, and then decide to make some changes to the EQ, and that's when, yes, we might, as it were, master the sound a bit. In every case, it's not massive amounts. It's rare that we need to do an awful lot. You're talking about a few dB here and a few dB there. Our ultimate aim is to make sure that they sound as good as they've ever sounded. Because it's the best they will ever sound, really.

"Having said all that, I'm well aware that a lot of people, some collectors, would quite happily take the flat analog tape with nothing done to it. But from our experience, the reason we do intervene, to a certain extent, is because we believe that quite a lot of these tapes do have problems with them, and actually some of these problems would spill into the enjoyment of listening to [the] music if we did nothing to them. There are opinions both ways, but that's the way we do it."

For remastering, Abbey Road Studios uses the SADiE Series 5 PCM 8 Digital Audio Workstation with hardware controller (v.5.6.1), the SADiE DSD8+ Digital Audio Workstation (v.5.4.1), the SADiE Mastering Limiter, and the CEDAR Retouch plug-in tool (all 96kHz). Retouch is used every day and, according to Gibson, is a remarkable digital tool.

"It's extremely forensic and it's extremely sensitive. You can be very, very subtle with it, and sometimes you need to be because you can't afford to do something with it and find that it leaves an artifact that's just unacceptable. And we never do that. It's always down to the engineers' ears. It's not a one-button solution.

"And alongside that—and that's something which we use all the time—we've got a bigger box of tricks, which is a standalone, PC-based, 64-bit, high-resolution CEDAR Cambridge system, which has about a dozen different programs within it to deal with different types of noise in terms of general sort of crackle, broadband noise reduction, and all sorts of things as well, including harmonic buzz. We use that much more sparingly.

"I've read comments on the forums along the lines of, 'Aahh, well, they've used CEDAR on these and I can hear it. They've sucked all the life out of it.' Well, I'm sorry, but people don't know what they are talking about, because we don't do that.

"If there's a recording which has a particularly bad level of ambient hiss, for want of a better word, if that gets in the way of the music, then we would make a judgment to reduce that maybe a dB or two. But it's not across the entire frequency range. Because of the tools that we have, you take a fingerprint of the noise, and the computer will only affect the noise in whichever frequency change you choose to reduce it. It will not affect the underlying music. It's all down to our ears. We will make the judgment that we're going to reduce it enough so it's not the first thing that you hear."

But why SACDs now, when many audiophiles see the format as something that never caught on? Can the trained ears of Gibson and his Abbey Road colleagues hear the difference between DSD Super Audio Compact Disc and standard PCM ("Red Book") CDs?

"There's a whole debate there. If you make a new recording in the studio and you record it going straight to DSD, the SACD format, it just sounds fantastic. The bottom line, though, is if your engineer puts up your microphones and knows how to record something well, it doesn't really make a lot of difference as to which format it ends up in or which format it was recorded on, as long as the engineer is making a decent recording in the first place.

"You're frankly not going to hear that much difference between the two, because some of the recordings are pretty vintage. In that sense, the improvement we've got in these versions, as opposed to previous CD versions, is in making the initial analog-to-digital conversion. And we've chosen to do that in the PCM domain. We did it at 96kHz/24-bits, clearly because it's almost impossible for us to remaster and use our remastering processes in the DSD format. We can only work in the PCM format. So we produce a finished, remastered 96kHz/24-bit file, and then that gets transferred into DSD format to author the SACD. Some people will say that's pointless, that's not true SACD. Well, I'm not going to argue. It's the way we do it, and we do it for valid reasons."

Finally, there's the question of why no Signature Collection SACD contains a mix in 5.1-channel surround sound. Again, Gibson has been peeking at those rip-roaring, often insulting audio forums where flames seem to break out suddenly, with or without provocation.

"There are discussions on the forums out there about it," Gibson admits. "For a lot of fans of SACD, it's [all about] multichannel. It would be great to see some multichannel EMI recordings, etc., but the fact is that a lot of the core catalog material just has no multichannel version. It's purely and simply recorded and mixed in stereo, and that's it.

"There was a period, from the mid- to late '70s, where analog recording went up from two-track to four-track, and then eight-track. On the classical side there are plenty of recordings that were recorded and mixed to eight-track, and then that was mixed down to two-track. Generally speaking for this series, when we were mastering we used the LP stereo master tape. For some of these recordings we have actually gone back to the eight-track analog and we've remixed a new stereo master from that, but listening closely to the original LP stereo master for reference, making sure that it sounds exactly as it should.

"Now you could argue that if you've got something that's on eight-track, you could do something in surround. And yeah, you could, but that's a whole new ball game, because then you would be creating a new recording, a new mix, and it would need time and money in the studio to do something like that. And not every recording would be feasible. On paper, you think, 'Okay, we've got the tapes, we could do it,' but you're probably going to end up finding that there are issues with the tape. There's a couple channels missing from one of the [symphony] movements, which does happen. And then what are you gonna do? Some things get covered up in stereo, and when you listen to the eight channels you start to hear things, like, 'Crikey, what went on there?'

"For the Signature Collection, we don't set out to create a new recording. We have a chance to issue it in a format that enables us to make it sound better than it's ever sounded before!"