This month we tackle problems that were causing a bass-heavy mix and use coat-hangers to produce better vocal recordings!
Howard Bragen seems to have no trouble coming up with good songs, but he called Sound On Sound because he was having problems with his mixes. He said that they sounded fine in his room, but came over as very bass-heavy elsewhere. I suspected that his studio layout and general acoustics could use a bit of help, but when I asked him to describe his room and his equipment setup, he told me that he used a pair of Spirit Absolute Zero monitors. That's a model that can be rather bass light, in a large, untreated room such as Howard's, so I thought this might explain why he was mixing with too much bass end. As Howard was thinking of upgrading his monitors anyway, he went out and bought a set of KRK VXT8s (he chose these because his main musical collaborator also uses them), plus some substantial 1.14-metre stands from Studiospares, but he didn't set them up before the day of our visit.
Howard lives in a flat that is part of a large, converted country house, with very high ceilings (approximately 3.5m). The room he uses as a studio also doubles as a living room and bedroom and is almost square, at roughly 4.75m x 4.25m. Because of the way the furniture was arranged, the Absolute Zero speakers were set up on lightweight Samson stands behind the computer desk, which meant that the two computer screens sitting on the desk were partially obscuring them. This setup is undesirable because sound bounces off any solid object in its path, and in this case both the tonality and stereo imaging of playback were adversely affected. Furthermore, the computer desk was around half a metre to the left of the centre line of the room, and a tall chest of drawers immediately to the right of the desk meant that correct speaker placement was not possible.
We persuaded Howard that we should move the drawers to the left-hand-side wall between the windows, as this would give us space to set up the system more symmetrically — and with the speakers sited so that they would now be firing past the computer screens, and not into the back of them! We also felt that putting some acoustic foam on the expanse of bare wall directly behind the speakers would cut down reflections and improve the stereo imaging. The side walls were quite distant, and because of the location of the windows it would have been impractical to add further acoustic treatment there, so we decided that we would try to find a solution that wouldn't involve treating them. Likewise, the ceiling was so high that it was impractical to treat that — and probably unnecessary too.
Howard Bragen uses his studio to produce CDs of his own songs based on a whole range of influences, from blues, country and jazz to latin. He plans to spend a month in the USA in March 2008, working to place some of his material with publishers in order to get coverage from well-known artists. His latest album is near completion and will soon be at mixdown stage, ready for its release in 2008. Watch the news page at www.intermetmusic.com as well as Howard's MySpace page at www.myspace.com/howardbragen for release dates.
After an introductory coffee, we moved the drawers and decommissioned the Spirit monitors, before dragging the computer desk to a central position about 500mm from the wall. We assembled the new speaker stands (which would benefit from being filled with dry sand at a later date, in order to add mass and damping) and used a pair of Auralex MoPads, with their angle wedges in place to direct the new KRK speakers downwards towards the listening position. Normally some Blu-tak is all that's needed between a speaker and a solid stand, but if we'd placed the monitors directly on these tall stands the tweeters would have been above head height, which isn't ideal. While we were rewiring the monitors into the back of Howard's music PC, Hugh rationalised the mains wiring to ensure that we had a 'star' system, with all the audio gear fanning out from a single power point: this is a good idea, as it minimises the risk of ground-loop hum.
Howard wasn't using a separate monitor controller, which meant that level control had to be done in software. When you're working at 24-bit resolution, the drop in resolution as you turn the level down isn't serious, as long as the monitor input-gain trims are set to somewhere near the maximum level you're likely to monitor at, with the on-screen level fader most of the way up.
As this was a rented flat, we didn't feel we could go sticking Auralex acoustic foam directly to the walls, as removing it can make a bit of a mess. Instead we tried Auralex Temp Tabs, which are essentially self-adhesive Velcro fastenings. However, as self-adhesive tape doesn't stick to foam very well, Auralex also include some small plastic rectangles, the idea being that you glue these to the foam using their own adhesive, then stick the Velcro pads to these. We used the supplied Auralex caulking-gun adhesive rather than the usual spray, and though it was easy to apply, it took rather a long time to set. For the first hour or so it exhibited all the adhesive properties of Marmite on a warm day, so as time was of the essence we took a trip to the local DIY store and bought some Evo Stik contact adhesive. By the time we returned, the Auralex glue was starting to grab, but to make sure the panels stayed up, we added another plastic tab at the top centre of each sheet and fixed this in place with Evo Stik, which did the trick for us. With the Velcro pads stuck in place, and their mating halves clinging to them, we stuck four vertical panels to the wall behind the speakers, centred at roughly (seated) head height. This would cut down on sound being re-reflected from the hard wall behind the speakers, and we hoped that soft furnishings elsewhere in the room would reduce the amount of unwanted sound bouncing around the place. I've since tested the Auralex adhesive and found that although it can be slow to set compared with many instant-grab adhesives (including the excellent Auralex spray adhesive), after a few hours it goes rock solid and is extremely strong.
We weren't quite sure how the room would behave at the low end, as an open archway coupled the room to the adjacent kitchen, which was about half as wide but just as high and long as the main room. We tested the system using a Steely Dan track that we all knew, and were pleased to discover that the bass end was pretty even and the stereo imaging acceptable — so we wouldn't need to treat the side walls. To get a subjectively correct balance of bass end, we had to set the speakers in their 'full space' mode, using the rear-panel switches, as the half-space setting sounded a touch bass-light. Because the speakers weren't close to the walls, we felt this was OK.
Next, we put up one of Howard's own mixes, which was indeed a bit heavy in the low bass region, and it also sounded slightly low-mid heavy. We set up a parametric equaliser to see if I could improve on the spectral balance, and I ended up cutting the low bass slightly, dipping the lower-mid at around 350 to 400 Hz to take out a residual hint of boxiness, and adding some 12kHz 'air' by using a Q setting of around 0.5 and a gentle boost.
Though subtle, this clarified the mix and brought it into focus, which Howard liked. Though he was using Cubase as his DAW, he was mixing the outputs via his Yamaha DSP Factory PCI card, which was controlled using XPI software, as he much preferred the XPI interface over the Yamaha original. We couldn't find any way to bypass the EQ other than a section at a time, so A/B testing wasn't as quick and precise as we'd have liked, but it was generally agreed that reducing the low bass and low mid helped achieve a better tonal balance for the mix. However, we stressed to Howard that now the new monitoring system is in place he shouldn't do any overall EQ or compression to his mixes if he plans to have them professionally mastered — which is something that he's seriously considering. It can be almost impossible to undo the effects of EQ and compression, and as the mastering engineer is likely to have more sophisticated processors to do the job, as well as a far more accurate monitoring environment (not to mention years of experience!), it's best to leave everything to them.
Much of the time Howard records his own vocals while standing close to the computer keyboard, so that he is able to operate the system and sing at the same time. This meant that our usual 'duvet across a corner' trick wouldn't work, so we made up a couple of foam panels that Howard could hang up behind him when singing. These would reduce the room reflections bouncing back into the live side of his AKG C414 XLII microphone, which is normally set for cardioid pattern mode and feeds into the system via a digitally connected Focusrite Twin Trak preamp. The Twin Trak also provided latency-free input monitoring via its headphone output. I needed a simple way to hang up the two panels (a couple of two-foot squares left over from a previous job) from boom mic stands so they could be arranged in a 'V' shape, and arrived at the simple solution of glueing a wooden coat-hanger to the top of each piece, and simply hooking them over the clip adaptors on the mic stands. We had the panels finished in a few minutes and the improvised hanging system worked fine — so I'll probably use that trick again! An SE Reflexion Filter or something similar placed behind the mic would improve the isolation from the room ambience even further, so we suggested that this would be a worthwhile and cost-effective upgrade.
Howard was pleased that we'd been able to make a useful improvement to his monitoring environment without damaging the room or compromising his living environment, and he liked the idea of our hanging panels for vocal recording, as these could be stowed out of sight when not in use. He liked the sound of his new monitors, which seemed to have a well-balanced and reasonably extended low end, and he could see from the way I'd EQ'ed his earlier mixes that the combination of untreated room and the Absolute Zero monitors had been misleading him.
Howard: "Working with the new KRK VXT8 speakers that Paul and Hugh set up for me has been a massive improvement. I bought them partly because of a review in SOS of KRK's previous model, and because I've used those in the studio in Cardigan owned by Jon Turner. The whole listening experience is less tiring and I feel I can now trust the sound of my mixes to a far greater extent.
"The Auralex foam on the wall has killed some of the sonic 'nasties', and the ingenious solution of hanging the foam pads on coat-hangers from mic stands has helped too, in that I've got fewer unwanted reflections from the room getting back into the mic whilst I'm recording vocals, and I can hear this in the results. I also really liked Paul's EQ settings for the song I played to them and I intend to try mixes using those same (or similar) settings, as well as taking a flat mix to a mastering suite and making comparisons. Thanks again to Paul and Hugh!"