"Try these ambient stereos via ProLogic II decoding; if re-channeled stereo had been done this way back in the 60s pseudo-stereo wouldn't have received its bad rap from collectors with golden ears..."

John Sunier, editor, Audiophile Audition

Ambient Stereo XR recordings are here

Our release on 15th August 2008 marks a new era in Pristine Audio's remastering and offers new options for downloading all of our XR-remastered material. Beginning with PASC120, Toscanini's 1952 recording of Beethoven's Ninth Symphony, we wil be offering you the opportunity to choose between our superb mono remasterings, and our new "Ambient Stereo" releases.

This is the sound of Ambient Stereo:

And this is the same recording in its mono release version:

I think you'll agree that both versions sound stupendously good! However, listen out for the extra depth, dimension and space present in the Ambient Stereo recording. Try putting headphones on and comparing the two! (There's another demo track further down the page - but I'd urge you to read the notes below first, before listening to it!)

What is "Ambient Stereo"?

In the late spring of 2008 we became aware of a new development in audio processing software, which allows a mastering or remastering engineer to excert a considerable degree of control over the ambience in a recording - that is to say, the studio, room or hall echoes and reverberation contained within almost all music recordings. When working with stereo material it gives the mastering engineer precise and fine control over perceived depth and width, for example.

With mono recordings, such as the vast majority to be found at Pristine Classical, it offers something quite new - and sonically very interesting indeed. Now we have the ability to extract from a mono recording that same room ambience and spread it into the stereo field - in a very natural and neutral way. The direct signal (i.e. the original mono sound of the musicians) is preserved and is tonally unchanged. What appears to the listener is a whole new sense of place, and a degree of "air" around the performers which is entirely believeable and consistent with the recording.

Note that nothing is being added or artificially generated here - , and we're not trying to 'place' instruments in the stereo field. The effect is far more subtle than that, and as such we think it's far more effective.

(See below for more technical information on the processing used to make Ambient Stereo recordings.)

Isn't this just the notorious 'fake stereo' of the 60's in another guise?

Well, in a word, no. Just about all previous efforts at creating some kind of stereo from a mono recording involved all sorts of potentially destructive sonic manipulation. Comb filters were commonly used, sending instruments flying around the stereo soundfield as they changed notes, and screwing up any mono compatibility. Additional reverberation was added, more often than not sounding less than natural, with the risk of creating the unnatural sound of "a room within a room".

Our Ambient Stereo recordings avoid all of this. The centre image is exceptionally stable. The signal highly mono-compatible. There is no artificial generation of reverberation, as only that which is contained within the recording is heard - 'dry' recordings stay dry; reverberant recordings remain equally so. The processing is based on a US Patent which is at the cutting edge of digital audio processing research, creating in our Ambient Stereo recordings a transparent and open sound which is ideal for both headphone and loudspeaker listening.

What do the professional expert listeners say?

In the days and weeks prior to our decision to offer Ambient Stereo recordings as an alternative to our regular mono remasterings we carried out a lot of listening tests, and offered a number of experts, audiophiles and enthusiasts the opportunity to listen to the effect. Naturally some raised doubts over what they heard, but the majority response was very positive, especially given the notoriety of the so-called "fake stereo" recordings of yesteryear.

One highly respected reviewer from Fanfare magazine, Lynn Bayley, with admittedly only a 5-minute exerpt from a single, unfinished Toscanini recording to go on, was immediately impressed:

I have to admit that I was not at all prepared for what I heard. It seemed to me that by subtle spreading the tone across two channels, you have "filled in" sonic gaps that make the PERFORMANCE - for me - much more valid than any of its monophonic issues. I've often complained of what I heard as a static, station-to-station performance of the 9th in this studio recording. That static quality is, to my ears, completely eradicated by your transformation.

Yes, I think you should process the entire symphony this way and issue it [we have!]. And, if you don't mind my suggesting it, there are four other Toscanini recordings of the same vintage that would greatly benefit from this treatment as well...

 

Meanwhile Peter Joelson, who writes for a number of music publications on both sides of the Atlantic, was sent both the mono and Ambient Stereo releases of Kathleen Long's Fauré Piano Pieces release, (PAKM015). After some careful listening, he wrote back:

Listening to these through my main and active system which images tightly showed a subtle difference between the two masterings. The Mono tracks were pleasant to listen to, though switching CD to the Ambient Stereo mastering did add depth to the piano's sound. The piano itself did not seem to me to be affected at all by the process; the image remained stable and seemingly identical, though it felt more three-dimensional, and there is no more reverberation than in the Mono mastering. The piano did not wander across the soundstage, nor were the frequencies redistributed as in older electronic stereo processing with which this should not be confused. As the term makes clear, it's the work on the ambient sounds which gives the sound the effect of greater depth.

While the effect is subtle through speakers, I found the difference is more startling when listening through headphones, as would be done with a portable player. Here the ambient processing means the sound is much more comfortable for me to listen to than the straight Mono, and yet again the piano itself seems to me identical in sound.

Were I to do much of my listening by means of a portable player and headphones or earspeakers, I'd certainly be more satisfied by the Ambient Stereo mastering, as listening in this form is simply less tiring. 

Since you are offering both Mono and Ambient Stereo masterings, customers will continue to have their preferred choice. Thank you for allowing me to sample both.

So how does it actually sound?

This example is taken from an early test I made of the system - you won't find anything quite like this on any of our releases! (At the time of writing the recording under demonstration has not been issued by us - it is presented here purely for demonstration purposes of the Ambient Stereo process..)

This sample - Toscanini's 1953 RCA studio recording of Beethoven's Missa Solemnis - starts with about 28 seconds of straight mono. It then cross-fades into the Ambient Stereo recording for about 15 seconds.

We then pull back into mono (0'45") for a quieter section for roughly another 15 seconds, before returning to Ambient Stereo (0'58") for about 30 seconds. A quick pull back into mono (1'28") just to remind you is followed by a much longer Ambient Stereo section which runs from about 1'35" to the end of the recording.

If possible, listen to this on headphones for maximum effect:

Note as you listen to this clip that there's no change whatsoever in tonal quality and, as already mentioned, no impression of musicians or instruments changing position, either from side to side or forwards or backwards. What you hear is an opening out of the soundspace around the singers and orchestra using only the ambient musical information contained within the recording. This is why we feel this is a really worthwhile addition to the remasterer's toolkit, and why we've devoted so much time and effort to encoding so many of our recordings into Ambient Stereo.

Which recordings are available in Ambient Stereo?

We've encoded Ambient Stereo versions of all our mono XR releases and made these available as lossless CD-quality FLAC downloads or Premium CDs - initially this means 83 existing recordings can be heard in Ambient Stereo. We will also be releasing all new Pristine Audio XR recordings in Ambient Stereo versions, alongside the regular mono issues.

Here are some examples of Ambient Stereo in every genre of Pristine Audio recording:

Here are just some of the Ambient Stereo recordings now available as FLAC downloads:

Click here for a full listing of Ambient Stereo XR releases

Pristine Audio XR: Ambient Stereo FLAC files

We have encoded all our XR remastered releases into Ambient Stereo, and are offering these alongside other download and CD purchase options as full CD-quality 16-bit stereo FLAC downloads. The downloads cost exactly the same as our regular mono 16-bit FLAC files, which are priced according to duration. Further details about FLAC file playback and conversion can be found in our Help section.

What about Ambient Stereo CDs? Or MP3s?

For the time being we'll be offering XR recordings encoded with the Ambient Stereo process as Premium CDs only, alongside the CD-quality FLAC downloads. We currently have no plans to issue any Ambient Stereo recordings as MP3 downloads.

This is not for me - I want the pure mono sound of the originals...

No problem - we've got no plans to stop issuing mono recordings in all our currently available formats. Ambient Stereo recordings are being issued alongside the regular MP3 and FLAC downloads and CDs, and are not intended to replace them at any time in the future.

Further technical information

The software used for this Ambient Stereo processing was created by German digital audio signal processing experts Algorithmix®, using a US-patented process developed by renowned mastering engineer Bob Katz, called K-Stereo.

In their own words:

For further details you can visit the K-Stereo homepage at Algorithmix's website here.