Broad Horizon Natural Soundscapes

Contents

Introductory Notes

As from June 2012 I started using a Sony PCM-M10 recorder to make CD-quality recordings of natural soundscapes that would be healthy and harmonious to have playing at times in one's living space — indeed, more often than not, more so than music. These soundscapes would usually involve the sea along rugged parts of the Cornish coastline, but would also include wind and other weather sounds, and of course, where it suitably presents itself, birdsong and indeed even insects. I have included in this overall project a sub-project, Wind Chimes in the Wild — Symphonies of Wind Chimes and Nature.

In January 2013 I purchased a second recorder of the same model, so that I could often make concurrent pairs of recordings with different viewpoints / perspectives. That turned out to be an excellent choice, which considerably boosted the productivity of many of my recording sessions.

Then in March 2016 I took a big step forward in terms of sound quality by buying a Sony PCM-D100 recorder. The difference between an equivalent recording on old and new recorder from the listener's perspective is that between a 'great'-seeming recording and there being no recording at all but simply something like a hologram of the original sound.

I find myself repeatedly transported back to the respective recording session when I listen to the D100 recordings played on my more or less monitor-quality audio setup, while even on my little Audioengine A2+ computer speakers (with Audioengine S8 subwoofer on the floor), the D100 soundstage extends beyond the speakers and far behind them, so producing a miniature 'hologram' effect.

Why simply using a supposedly good hi-fi speaker system isn't enough for listening to natural soundscape recordings

The very notion of 'hi-fi' ('high-fidelity' and thus supposedly giving accurate reproduction) is actually FALSE as generally applied. The main problems are as follows:

• Generally speaking, what people are looking for in 'hi-fi' is NOT genuine accurate reproduction of what was recorded, but a presentation of somebody's notion of what it ought to have sounded like! — Think about that!

  Generally hi-fi systems are configured to reproduce music pleasingly. However, when a hi-fi component is described as being very 'musical' in its effect on the reproduced sound, you can be sure that that 'musicality' is actually a distortion of what had actually been recorded. Yes, it may make much music sound more pleasing, but the sound would be that little bit further away from the original. Much is made, too, of smoothness of the treble, whereas an accurate treble response would sound smooth only to the extent that the original sounded smooth in the treble! — Stands to reason, doesn't it!

• There is a category of speaker systems that are supposed to bypass that 'hi-fi' malaise and present genuinely accurate sound, having as near as can sensibly achieved to a flat frequency response — so-called 'monitor' speakers. The reality is, however, that unless you are using them in something akin to an anechoic chamber you would still be hearing something of a sonic mess. — Why?

  — Because the amazing complex of room resonances and cancellation 'nulls' in any domestic living environment screws up the sound no end — especially the bass. So, you can pay thousands of pounds for some top-of-range speaker system with a purportedly near-flat frequency response from 20 to 20,000+ Hz and still my beautiful, wonderful sea recordings can readily come out boomy and even really horrible to listen to!

• Natural soundscape recordings usually consist mainly or almost completely of 'neutral' sounds, and will sound wrong in various respects as long as they are subject to any alteration through the reproduction chain. For listening to such recordings you need a 'warm' or 'musical' overall sound like a hole in the head! Particularly, recordings with significant proportion of low bass frequencies would typically sound too bass-heavy, especially in the 'boomy' frequency range, even before room resonances have magnified the problem many-fold to create the mess that you actually hear and try to convince yourself is how the original would have sounded!

Solutions to the problem

I had a miserable and frustrating series of Internet searches for a graphic or parametric equalizer that would do the trick. Actually eventually, for use with my computer speakers, I came up with a quite tolerable software solution — the parametric equalizer Equalizer APO, using fPEQGUI-10 as an excellent front-end for it. However, setting this up requires considerable expertise and isn't the sort of thing that the average listener would make a good job of, even if they wanted to try.

On the other hand, for my main hi-fi system, taking audio from my CD player and DAB radio, and not connected to my computer at all, some sort of hardware solution was required. After a long and frustrating series of Internet searches (and return-for-refund of one cheapo Behringer graphic equalizer that got far too hot every time*) I bought an expensive BSS 31-band graphic equalizer, which I was able to set up to do what I thought was a tolerable job of cutting down the various resonance peaks, even though the sound was clearly still not fully correct in the bass region. However, I was aware that it was a very blunt instrument and would be reducing a lot of frequencies that really shouldn't be reduced, and I didn't like having such a bulky and heavy piece of equipment anyway in my small hi-fi cabinet.

Eventually I came up serendipitously with THE solution! Ditch the top-notch graphic (or parametric) equalizer, and now enter the real star of the show — the DSPeaker Anti-Mode 2.0 Dual Core. Sure, this small, unassuming-looking unit isn't cheap (it set me back £680), but this solves all the bass resonance problems at a stroke, and regardless of how much those problems are a speaker or room issue.

The Anti-Mode unit is connected between your audio source(s) and your amplifier or powered speakers. You carry out a calibration according to the simple instructions, using the included measurement microphone, and then the unit displays to you a graph of the bass frequency response of your speaker system in your particular listening environment (typically looking like the Alps!), together with a line showing the after-correction in-room frequency response (with all the peaks flattened out). It automatically applies that correction when you exit the menu.

Actually it applies other corrections too, which improve the apparent timing of bass frequencies, and there is a huge range of further adjustments you can make from the menu system on the little display — though most or all of those would be more for satisfying personal taste and would in the majority of cases make the sound less accurate!

The result of running the initial 'typical room' calibration is truly staggering. Indeed initially many music lovers would hate it, because they are so conditioned to living with sound that is heavily adulterated in ways that they find pleasing. Without all that heaviness and 'clag' of exaggerated bass, recordings can initially sound 'sterile' and 'anaemic'. In fact, if you listen carefully you would find that for the first time you're hearing the actual bass that would have been heard in the recording session — at least, provided that your speaker system, with subwoofer if necessary, is reproducing those frequencies properly in the first place.

However, that's only part of it. With the clag all dissolved, the whole soundscape sounds clearer, even in the treble, with much more detail at all levels. This isn't the normal sort of transformation that would be noticeable only to dedicated audiophiles — it's a dramatic transformation that would immediately strike even the dullest TV-watching 'sheep' who has no notion of 'high fidelity'!

With this unit, for the first time I have been hearing my sea and other natural soundscape recordings as something closely approximating to the original experience. I cannot recommend it too strongly!

One tip, though. The best way of minimizing dips in the post-calibration bass frequency response curve, if you have a subwoofer, is NOT to use any dip-filling functionality of the Anti-Mode, but, to redo the calibration with the subwoofer volume turned up a couple of notches higher than what seems to be an accurate balance against the main speakers (provided of course that that would be an easy level for the subwoofer to cope with; the aim is NOT to cause distortion or indeed damage your equipment!). The Anti-Mode would flatten down the excess, but the low points would be higher, and so the overall result would be a much flatter curve, and with smaller or even no dips, and a more gradual roll-off at the bottom end — at least, if the subwoofer is any good to start with. See below…

The MYTH of a single (mono) subwoofer being all one needs for the very low (non-locatable) frequencies in stereo recordings

The received 'wisdom' is that because of the considerable wavelength compared with the distance between our ears, we cannot locate the source of frequencies from about 80Hz downward without other cues to guide us — and because of this, supposedly, it's pointless having more than one subwoofer in an otherwise 'straight' stereo system. However, my own very careful listening to my own recordings as well as many commercial classical music recordings was causing me increasingly to doubt the validity of that widely held belief.

The point is, what you actually hear in the original 'live' soundstage is much more subtle and interesting, for you get all sorts of interactions between low frequency soundwaves coming from different directions. These give the soundstage, whether natural or a live music performance, a vibrancy and sense of breadth / depth that isn't fully re-created by the use of a single subwoofer, in which all really low frequency sound has been summed into mono.

Indeed, not only that, but I hear a sort of roughness or lumpiness in the 'monoed' very low frequency sounds, where in real life the sound was much smoother and more subtly and intricately varying. This makes perfect sense, because when you reduce all that very low frequency sound to mono, all phase differences between the channels are cancelled out, giving transient dips in the sound, where, in the original situation you would have heard beautifully subtle variations in the nature of the sound instead of many of the dips.

Also, there is another very practical and remarkably obvious factor that most people don't think about at all. Generally it's assumed that when you set your subwoofer 'crossover' point to 80Hz, that sub will then not be reproducing locatable frequencies, but actually that is seriously wrong. These 'crossover' filters are not 'brick walls' but slopes. Therefore, even if you set your subwoofer 'crossover' point to 50Hz or 40Hz, it will still be reproducing locatable frequencies (above 80Hz), but simply at reduced volume. A typical crossover slope for subwoofers is only 12dB per octave. It would be very difficult to have your subwoofer not audibly reproducing any locatable frequencies — at least, without causing problems in smooth integration of the sub's sound into the overall sound of the speaker setup.

That isn't just an academic consideration. Rather, it explains nicely why I found that very low sounds (most of which do still contain some frequencies above 80Hz) were locatable to my single subwoofer when I played a mono recording of organ music. That effect would be there too in playing stereo recordings — that situation somewhat degrading the stereo image. That was the final straw, which persuaded me that it really would be worthwhile to buy a second subwoofer (of the same model) — and I haven't regretted doing do.

I don't at all mean here to discourage anyone from using a single, mono, subwoofer in a nominally stereo system if it isn't practical for them to use two, for, if really well configured, it would still bring about a great improvement in the overall sound as compared with no subwoofer. However, I do mean to encourage awareness that you would get still more engaging and inspiring sound (indeed, perish the thought, more accurate!) if you'e able to take that further step and have two subwoofers, placed and wired for proper stereo operation.

Another sound quality advantage would be that the labour would be shared by the two subs, so that for any given sound level each sub would be reproducing close to half the sound level that it would as a single mono unit, so that you would be much less likely to have the sound audibly degraded by distortion.

For a more detailed account of the situation, please see Ken Rockwell's excellent article.

Contents (repeat, for the other pages)