Critical Listening for Studio Production

A FREE ONLINE COURSE – Critical Listening for Studio Production

Just joined this course – described as a ‘technical ear training programme designed to improve critical listening in a music studio context’. Run through Queen’s University, Belfast and futurelearn.com it starts 12 September for 6 weeks with a 3 hour per week demand on one’s time.

Very keen to find out what’s being taught.

Proof of concept

The thought of moving away from streamers to a Mac+DAC gets stronger. As proof of concept I’ve quickly tried an old copy of Audirvana 2.2.5 under Mac OS 10.6.8 on a Mac Book Pro (2008) not wanting to lug my iMac with 2.5.3 into the music room. ‘USB out’ into the ‘digital USB in’ on the Cambridge Stream Magic 6 directly accesses the oversampling DAC. I tired transferring a more up-to-date Audirvana database from the iMac but no deal. So rather than wait for endless indexing I pointed the newly installed copy on the Mac Book Pro to my Test files folder on the NAS drive.

Impressed is not the word. What an improvement! Image focus and stability massively improved; bass more cleanly resolved and real dynamic changes from within the stereo image (i.e. not moving when the get loud). What a treat to hear the string sections so discretely imaged from the old Hi-Fi News test disc Dvorak Serenade for Strings with the Chamber Orchestra of Europe – and my chum Ivor’s flute playing in the Gluck Dance of the Blessed Spirits.

Raw DSD files were startlingly natural – thanks to Oppo’s website for Rodeo on a Ridge a pure DSD64 recording from David Elias’s Acoustic Trio – DSD Sessions download (and thanks to the techs who sorted out the proper CD Red Book camparison file download on the Oppo site for me too.)

Sadly, all put away at the end of the day but this points the way to go. Mac Mini or iMac? Touch screen or headless? Still plenty to think about…especially the issue of manual syncing to network drives. How’s that going to happend with a headless setup?

Ancient history II – Mastering

There is a handful or articles I feel truly proud of having written. My research into the mastering of vinyl and early CDs published in 1983 in Hi-Fi News is one of those. The original publication of ‘All Records Are Made Equal…But Some Are Made More Equalised Than Others Part I’ suffered from repro problems on the magazine page that obscured much of the data – though of course my text and analysis was fine. I’ve now rescanned the original Genrad traces and remade the pages to bring Part 1 into line with Part 2.

Both are available to download here: All_records_1 and All_records_2. Interesting how much is still relevant, primitive though the tools were.

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SAMPLE GRAPH – ‘Lime House Blues’ from the Proprius double album ‘Jazz at the Pawnshop’ (PROP 7778/9); this is the dashed spectrum. The solid bar spectrum is taken from the single disc recut of highlights issued by ATR (ATR 300). Though average levels are the same (A and F bars) there is more ‘push’ in the 1k to 3.15kHz bands on the ATR recut; the pressings of the ATR issue seem quieter than the Proprius presssing. Difference in low end could be due to different tape machines being used for reply.

Citations:

Präkel, David. “All Records Are Made Equal…But Some Are Made More Equalised Than Others. Part 1.” Hi-Fi News & Record Review 28, no. 7 (1983): 30-3, 36-7.

Präkel, David. “All Records Are Made Equal…But Some Are Made More Equalised Than Others. Part 2.” Hi-Fi News & Record Review 28, no. 8 (1983): 20-1, 24-5.

Vinyl Studio III – de-click and noise reduction

I’ve been far less productive than expected digitising my vinyl. In part that’s due to the great de-click and noise-reduction capabilities of Vinyl Studio.

Just as recording and track splitting have their windows, clicking Cleanup Audio opens a two-track view of the recorded waveform.

Alpine Soft recommends a ball mouse to get around the Cleanup Audio window quickly as you move a lot from overview to high magnification. An Apple trackpad and Magic mouse proved a confusing combination and while I downgraded to an older Apple mouse to try a ball I didn’t stick with it. Zooming with the keyboard + and – keys and replaying with the spacebar worked fine for me.

Clicks first.Vinyl Studio can automatically detect and correct vinyl clicks and pops. Thresholds can be adjusted and both percussion strikes and brass ‘rasps’ excluded from erroneous correction. Too much correction and the sound is lifeless. I chose a light-handed approach – once I’d learned to visually spot clicks I started editing digitised LPs by replay and eye combined. This takes considerable time but I have to say the results so far have been worth it.

This is how to see a click. In the waveform view you know roughly where the click appears but may not be able to track it down and spot it for correction.Vinyl Studio gives you an spectral view which instantly identifies the energy spectrum of the click. The fast rise time of the click waveform contains all frequencies (rather like a square wave) so it becomes easy to spot.

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You can hear a nasty click but can’t spot it in the complex waveform

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Spectral view on the V key shows just where the click is hiding

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Using a highly magnified view, the click waveform can be edited out (original waveform grey, corrected green). The area over which the correction is applied can be adjusted – see cyan correction ‘slice’ with drag handles

Click detection and editing is very flexible. With some serious headphone time you can produce click-free transfers that are musically satisfying, airy and thoroughly listenable. Just beginning to wish I was doing this at 24/96.

Hiss and hum reduction is also possible. A sample of vinyl surface noise (or tape hiss) can be used to create a noise filter. I’ve used this sparingly to reduce surface noise between tracks or with single instruments or voices. I’ve only cleaned up one whole  album – a very noisy Polydor pressing of Burt Alcantara’s synthesiser classic Zygoat. The hum filter with 50 and 60Hz mains filters has proved useful on one unexpected occasion.

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Custom EQ curve used to gently boost ‘presence’. This can be saved for later use on a whole album side or part of a track

Equalisation is also possible – again this is something to use sparingly. I have used all the click, hiss and EQ tools on one old favourite – a poor quality pressing of Richard Blackford’s Sir Gawain and the Green Knight. This was compulsory Chirstmas morning listening in our household but we began to learn every click and vinyl swoosh – not next holidays!

The more you explore the filtering capabilities of Vinyl Studio the more you are rewarded with clean, musically satisifying tranfers but as my productivity shows you have to work hard to get the best results.

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That header picture

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In response to people who have asked…my header picture is a collection of gramophone horns at the fantastic  Johnson Victrola Museum at 375 S. New St, Dover, Delaware, 19904.

I visited the musuem in 2009 and could not have been made more welcome by the knowledgeable and enthusiastic volunteers. Theirs is a fascinating collection of phonographs and gramophones chronicling the development of the sound-recording industry, in particular the contribution and achievements of E.R. (Eldridge Reeves) Johnson founder of the Victor Talking Machine Co.

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Demonstrating the origins of the phrase ‘put a sock in it’

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VinylStudio II – track splitting

Track splitting. With each LP side recorded into a single file it is necessary to mark each track before they can be written out to disc as individual files. I’m using VinylStudio to record at the NAD preamp’s maximum quality of 16bit/48kHz WAV and to split the files for saving as individual FLAC files.

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Ideally, during recording you can enter track titles, and lengths in minutes and seconds. Opening the track splitting window each track is approximately marked out with a green ‘start’ and a red ‘end’ marker. These can then be dragged into place to perfect each track length.VinylStudio uses a single combined waveform to make things easy.

Alternatively, if you are monitoring the music during recording you can add a track break at any time by pressing the B key.VinylStudio can scan for track breaks after recording but this requires some tinkering with threshold and duration settings to accurately find the tracks and not insert markers during quiet passages. Not surprisingly, it is less than accurate with classical music, solo voice or single instrument recordings.

Once split, the track title appears above the music waveform to indicate which track you are currently working with; the selected waveform/current track is blue rather than green.

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There are some clever touches. Tracks can be faded in and out independently with a simple draggable fade up or down triangle added to the track markers. This helps remove some run-in groove noise and gently lets you into the vinyl sound once your are replaying in the digital domain. I have chosen a light touch approach to editing clicks and surface noise and this flexibility to fade tracks is very welcome. Track gaps can also be adjusted by pulling the back-to-back markers apart with a drag and a shift-drag.

What could have been a chore is made easy in the VinylStudio track splitting window. Next, cleaning up LP sound…

VinylStudio I – recording

VinylStudio recording software is part of the NAD USB phono/preamp package. It was part of the attraction of the unit as it came with a reputation of being easy to use yet fully featured. I thought I’d get a few recordings under my belt before reporting.

VinylStudio comes from the UK software producer AlpineSoft. It is supplied in both Windows and Mac flavours – I bought a license for the latter. The interface is not exactly Apple ‘skinned’ and is very word heavy with layers of genuinely helpful tips and prompts – a Marmite interface in other words.

You are presented with a simple choice when you first load VinylSoft – do you want to record a new album or do you want to work with one you have previously recorded? Hang on. This is exciting. I must say this is the best thing about Vinyl Studio – it works like a digital photography RAW image processor. There is no destructive editing and any filtering, de-clicking, repairs, de-humming and de-hissing is only applied when you write an output file. The original recording is never touched. So if you didn’t cock-up the levels on recording you’ve a capture to return to and create new ‘instances’ that you can burn to CD or write to your music vault. I’ll come back to filtering and de-clicking in a later blog.

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One great feature is the speed conversion, which will be a boon for reel-to-reel recordists who no longer have that 15ips deck, but all the tapes recorded on it. Dance-mix single but no 45rpm on your audiophile deck? Play it at 33rpm and convert. There are quality compromises but what a feature!

Recording: you must enter an Artist and Title to begin and VinylStudio insists you Create an Album to proceed with level checking. This is critical to avoid clipping. A similar window opens with the two peak hold meters plus CLIP indicator. Level setting has been the only bane in what has been an otherwise enjoyable process. The software encourages you to Edit your Track Listing while recording but opens a window on top of the recording window thus obscuring those all-important meters.

Time-after-time I’ve gone back to find the CLIP indicator has gone off. But was it a music peak or a scratch or disc defect? As a perfectionist I’ve now got to go back and discover what caused the clip, waste the recording and start over. If I could watch the meters with one eye while I was entering metadata I’d be in a better placed to judge. I must say I’ve lost the knack of spotting the loudest part of an LP from just looking at the grooves!

Track splitting is easiest if you have the track times from the sleeve or a service like MusicBrainz or Discogs but if you are monitoring you can press the B (for Break) key every time you want a new track – works well even if you are a few seconds adrift as you can fine tune your results in the Split Tracks Tab. More next time…