Today saw the completion of another four band tracks, a Wildcard track as an extra and finally the Re-Amping of Bass. I'll provide the complete process for Bass in this post. Tomorrow will be a few alternative Guitar Solo takes then on to Lead Vocals.
Re-Amping Bass: We begin with the Bass recorded through a D.I. (direct input device), which essentially brings the instrument in at Mic level through a pre-amp. So depending upon the D.I. itself and the pre-amp there are unique opportunities to apply colour and character to the signal. The instrument is a classic Fender Precision (P Bass) and features the iconic subtle pick-up distortion around 160Hz, responsible for the wonderful 'growl' it produces. To accentuate this I chose a Valve D.I. by legendary local designer Ross Giles (Giles Audio). Pre-amp was the gorgeous AWA console, importantly with a HPF at 70Hz. This ensures a tighter low frequency response by rolling off the subsonic rumble and noise. Most miss this point by thinking a Bass needs subs, but we're talking attenuation of frequencies (HPF: 70Hz @ 12dB per Octave) which do nothing to improve the Bass tone or definition, and they devour the headroom.
After tracking we then send the recorded Bass D.I. back out of the interface, into a Bass Amp. We want to capture the 'air' that is shifted by lower frequencies, providing the Bass with warmth and a solid foundation; a bit of BOOM. Most importantly here is the gain structure of this signal, sent from ProTools in this case. The interface will hike the signal up to essentially Line level; way too hot for a Bass Amp input. This would only serve to overdrive the input of the amp resulting in immense distortion and likely damage the amp input pre-amp. I lower the level of the Bass D.I. send to -20dBFS out of the interface to better match the impedance the Bass amp usually receives.
However, we are now also sending a Balanced signal out of the interface; the Bass amp requires an Unbalanced signal such as that from a Bass or Guitar. My method to alter this is very simple, but perhaps a bit quirky: I use a Passive D.I. box in Reverse. So the XLR balanced Output becomes my input from the interface, whilst the Input now serves as the output into the Bass amp input.
Now the bass player (Stuart) pulls the sound he wants for each track from the Amp, which I record with a Microphone; a Beyer M88TG in this case (placed approx. 20cm from the 'best sounding part of the speaker cabinet' - just put your face down there and listen!). Perfect for adding the air and boom that will enhance the Valve D.I. signal. The Bass player then gets to relax whilst I re-record the parts previously performed. I brought the M88 back in through another AWA pre-amp, this time with a HPF at 45Hz. Otherwise essentially FLAT.
Final stage is then completed within ProTools, where I align the two Bass signals to ensure Phase cancellation of the lower frequency bands is avoided. Depending upon your signal path this is generally within the realm of 5-6 m/s . Calculate this by measuring the 'time' between the attack of a note on the D.I. track to that of the same note on the AMP track. The two Bass sounds will then be blended accordingly to provide both 'front' and 'definition' from the D.I. but with the all important 'body' and 'boom' from the Amp.