Some time ago I wrote and published 56 Mix Tips for the Small Recording Studio. It turned out to be my best-selling book, to date. The feedback I got from my readers was that they liked the ‘practical-ness’ of it. They liked the way that the tips were written succinctly and included an explanation of how to apply them in their mixes. And that was the focus of this book; quick and practical tips for busy folks who don’t want to read an entire thesis before they can get down to the business of applying the tips into their mixing workflow.
Every recording engineer, regardless of their experience and stature, will surely have been disappointed by a flat-sounding, one-dimensional recording, at least once in their career. And for those boys and girls who don’t have the benefit of being mentored by the world’s best (AKA most of us), you may have been suffering the unquenchable pain of listening to your own one-dimensional mixes for years - I know I have! It’s like you did everything by the book; followed the best mixing methods you know, and your mixes still lack depth and dimension. What the heck is going on?
Have you ever recorded an acoustic guitar or miked-up electric guitar and been blistering with enthusiasm over how great it sounded in the live environment? You’re so excited that there’s a glistening rivulet of dribble running out of the corner of your mouth because you’re grinning so hard. You feel so good, you want to bake scones for your neighbours and buy everyone a present, and even though it’s raining outside, you just know it’s gorgeous and sunny somewhere in the world. Right? That’s how good that guitar sound is!
And then you listen to the recording and the smile peels off your face. You wipe the saliva off your chin, and a veil of mild depression settles over you because your incredible guitar now sounds like shit. It's flat, boring, and has none of the original vibe you heard earlier. Maybe you used the wrong microphone? How come the pros can casually jam a ’57 up against the grill-cloth of a guitar amp and make it sound like a thing of beauty? Is it because they used a vintage Vox AC30 and you’ve only got a cheap Fender amp? So, you think to yourself, “alright, maybe I can fix it in the mix.” Then you move on and start recording an acoustic guitar, and lead vocals, and percussion. And it’s the same problem over and over again; the instruments sounded great in the room, but the recordings have this flat sound to them. There’s no depth. They seem like cardboard cut-outs of the real thing.
During recording, the sound of the space around the instrument is just as important as the sound of the instrument
The reason all of these instruments sound flat in the mix is due to a fundamentally flawed recording technique where you are close-miking instruments without recording the space around them. To put it simply, you need to capture the room as well! It’s that simple! (You can reproduce this effect in the mix - more on this later).
During the recording when you’re standing near the instrument or amp, and you’re salivating over your fantastic guitar sound, your ears are hearing something entirely different to what the close-mic is capturing. At your standing position (pretend somebody else is playing the guitar) you’re probably 3-6 feet (1-2 metres) away from the instrument. At that standing position, you hear the guitar at a distance PLUS the space that the guitar is in. That’s a very different listening experience to putting your ear up against the grill of a guitar amp or one foot away from the 12th fret on your acoustic, which is precisely what your microphone is hearing. So why on earth would you be disappointed that your guitar sounds exactly the way you recorded it: close-up and super-focussed?
Don’t underestimate the importance of the sound of the space that the instrument is in during recording; the sound of the space is just as important as the sound of the instrument. If you record both the instrument and the space around it and then listen to it in the mix, you will hear the depth and richness that you’ve been missing in your recordings.
If you record both the instrument and the space around it and then listen to it in the mix, you will hear the depth and richness that you’ve been missing in your recordings
You can get great results capturing the room with a single LDC or using industry-standard stereo microphone techniques (XY, spaced pair, Blumlien, ORTF, etc.). It comes down to personal preference. I use both mono and stereo miking techniques. My usual approach is to be thinking about where all the elements sit in the mix before I start recording. In other words, if the song is a solo acoustic guitar, I’ll use stereo miking techniques to record the room. Alternatively, if I’ve got a few things in the mix, like a vocal, guitar, and percussion, I’ll record the room with a single LDC (large diaphragm condenser). If I’m not sure, I’ll record in stereo knowing that, during mixing, I can always trash one of the mic tracks and use the other as a mono track. I’ve found that recording the room in stereo often gives a better sense of space. However, beware that a stereo room recording positions the instrument within the space and, in the mix, you can run into trouble if you pan your close-miked instrument to a different position than where the stereo mics have positioned it!
During mixing when I’m only working with close-mic/mono room mic combinations, I will usually pan the close-mic guitar track to the left, and the room mic to the right. Similarly, I could pan the percussion close-mic to the right and the room to the left. But I’m careful not to pan the room mics in the same position as a close-mic since the louder close-mic will almost always mask the room-mic and severely inhibit the effect I’m aiming for. See the image below.
Haas Delays or the Precedence Effect
There are buckets of stuff written about Haas delays and the Precedence Effect - do a web search and read about it - so I’ll summarise the relevant bits rather than bore you with a drawn-out regurgitation of all this.
In essence, if the delay time of a signal is between 0 - 20ms, your ear won’t hear the delay as a discreet repetition of the original sound, but instead, your brain will fuse it with direct sound. It’s this fusing effect that gives essential spatial location information to your brain. The big point here is that the human ear identifies the position of a sound source by its volume level AND these short delays. Many noobs ignore this Precedence Effect and position musical elements in the mix solely by using their pan pots. Once you start positioning elements using panning AND short delays, the instruments in your mixes will take on a whole new level of depth and dimension.
Other sources on the internet will quote Haas delays as being in the 5ms - 40ms range. This is where it gets a bit murky. You can find the Haas effect is still working on sustained sounds like strings, synths and guitar strums, right up to 40 - 50ms. However, elements with pronounced transients, like percussion and drums, can begin to separate (you can hear the discreet delay repetitions) after around 20ms. But let’s not get hung up on the detail.
If you happen to have recorded instruments without the room, for a mix you’re currently working on, there’s a reasonably convincing workaround, and these are two options I use regularly. Firstly, you can apply a very small room reverb or delay effect with the delay setting set between 0.1ms and 10ms (yes, even very short delays work). The other option is to solo each instrument and play it back in mono over your control room speakers and record it. I have a pair of mics set up at the rear of my control room for this one purpose. This second option is very effective, but it does rely on having decent monitors and a good sounding room.
OK, there you have it. That’s the big kahuna and in-depth version of Tip #10 from my book 56 Mix Tips for the Small Recording Studio. Incidentally, if you do grab the book, you get access to a bunch of other free stuff to help you with your music production.
We’ve covered quite a bit in this blog, so here’s a list of the takeaways.
Takeaways
- Learn the sound of your room
Just like you need to know the sound of your guitars, amps, and drumkits, etc., you need to know the sound of your room. Start thinking about the space that you record in as an extension of your instrument. Even small rooms can sound great when recording the ambience. The trick is to experiment and find microphone positions in your room that sound great to record. My own tracking room is about 4m x 4m, and I have a couple of sweet spots that I discovered through trial and error. The first position is a single LDC one inch from, and pointing at the control room window, which is located about 1.2m in front of where I position a guitar player (yes, I’m miking the boundary!). The second position is behind the guitarist, one inch from and pointing at the unpainted plasterboard wall. You can probably tell I’m into boundary miking (I’ve got another blog post planned for this topic). If I locate my acoustic guitarist a little further back in the room, I often use a spaced-pair of SDCs with the artist centred between. This captures the room in stereo with the artist spatially centred in the room capture. Remember that the positions I’ve just described would be in addition to a close-mic on the guitar.
- Observe the 3:1 rule
Observing this rule reduces the chances of microphone phasing between the close-mic and the room microphones. To do it, ensure that the distance from your guitar to your room mics is at least three times the distance of that from the guitar to the close mic. And then during recording, check the phase by flipping the entire mix into mono to see if the signal collapses (drops in volume significantly and/or the tone changes, which will indicate comb filtering). If the signal collapses, then stroll casually into your room and move the room mics and try again. So much of this is trial and error, or suck-it-and-see, but it’s worth the effort.
- The human ear uses both volume and short delays (0 - 20ms) for spatial positioning of a sound source
Recording both the instrument and the room will improve the spatial positioning, richness, depth, and dimension of your recordings.
- Other ways to get ambience if you didn’t record it:a) Re-amp the close-miked recording with a pedal or hardware unit. I regularly use a TC Electronic Hall Of Fame 2 guitar reverb pedal.
b) Apply effect plugins of small rooms, ensuring that the delay time is set between 0.1ms and 10ms. Delay times up to 20ms are also usable, but the success of this is often dependant on the quality of the plugin.
c) Re-record your close-miked instruments and vocals by playing back soloed and in mono and recording them in your control room or another good sounding room.
- Haas delays can be applied to all instrumentation in the mix Don’t limit yourself to just guitars; Haas delays work on all instruments and vocals.
- Using Haas delays does two important things
It improves the panoramic position of elements in the mix (far better than panning alone) AND adds a sense of spaciousness to the element.
- Watch the level of the room-mic in your mixIf the room recording is too high in level in your mix, then comb-filtering can occur, which will undo all the excellent work you’ve just done. You don’t need much room level to get the benefits.
- Highly dense recordings will minimise the advantages of the Haas Delays
If your music mixes are very dense (heavy rock, walls of distorted guitars and drums, etc.) the advantage of using Haas delays gets severely diminished, since the volume, variety, and denseness of song can mask the room-mic sound.
- Applying big reverb effects in the mix won’t replicate Haas DelaysRecording a flat-sounding close-miked instrument and just adding your favourite hall reverb will not achieve the sense of space and positioning that Haas delays can give you.
- You can still add longer reverbs to your close-mic and room-mic tracksAdding larger reverbs to your tracks can further enhance them. It really depends on your end goals for the mix. If you’re looking for a dry, ‘tight’ character to the overall mix, then you might only add a hint of large room reverb to the stereo buss. Alternatively, adding big, lush hall reverbs can add a big, gorgeous ambience. If I go for the big-and-spacious approach, I’m careful to minimise the ‘early reflections’ on the reverb because these can sometimes fight with the short Haas delays in the room-mic. As is usual, experiment to taste.
Thanks for reading and feel free to offer constructive feedback or share your own experience using Haas Delays.
You can get a copy of my book, 56 Mix Tips for the Small Recording Studio in print or Kindle format on Amazon.com.
Talk to you soon
Amos
