Here's a picture of a recording session I just ran on a bassist playing through my Mesa Walkabout. In the red, we have the waveform of the miked cab (with an SM57, touching the grillcloth, on-axis). In the green, we have the DI signal from the Walkabout.
The gain was at noon, the instrument was a passive P with flats, and the EQ knobs were all straight noon.
It strikes me that there is a very strange signal DI coming out from the Walkabout. It made a delay of about 84 samples required to get the DI signal from imparting a considerable amount of phase cancellation on the initial miked signal. But, even then, the two signals suffered a noteworthy phase incoherence.
Moreover, the DI signal is highly asymmetrical in a way that the miked cabinet is not, leading me to wonder how phase coherent the DI signal is. I know that Radial makes a big deal over the importance of phase coherence in a DI box, and this is my first hand experience seeing why.
While I could eventually bump up the summed miked and DI signal with delay, the character of the blended tone became sounded a little foreign to me -- something different in kind from either of the two signals, as opposed to 'the attack emphasized by the DI, and the tone emphasized by the cab', which we're told in recording classes is the benefit of summing the signals.
Does this matter on a daily basis? No. The DI sounds good. But this is a not inconsiderable problem with blending a direct signal with a miked signal in a recording setting. Live rock show? I can't imagine it would be a problem. But a quiet jazz recital, with top-shelf reinforcement gear? Maybe.
I really, really wish I had some comparison data from my different recording sessions, but I don't. All I can say is that I've never had this kind of issue with my Glockenklang or Aguilar gear. (The Glockenklang DI was something especially godly.)
PS - If you're curious, I posted an article on the sample delay technique in blending bass signals on a college radio website. Click [Invalid or Expired Link Removed].
