As low as it gets

The last day or two I've been thinking about the Phase Vs  at the same time as  I was listening to Donald Fagan's LP, "Morph the Cat", and I noticed that some of the base lines were fairly deep.

How deep?

Well, the plot on the left, generated in Audacity, shows that on track #4, "Bright Nightgown", the fundamental of the bass note is at about 34Hz. The open E on a bass guitar is 41Hz, and the open B on a 5 string comes in a 31Hz. For what it's worth, 34.65Hz is a C#. 

Since the Phase IV Mk2s don't really render much below about 60Hz, the reproduction of this note depends almost exclusively on the harmonics (of which fortunately there are several). This low note in "Bright Nightgown" is almost an octave (10 semitones) below what the Phase IV Mk2s can reproduce! 

And Walter Becker's "Down In The Bottom" from "11 Tracks of Whack" (right) does seem to have an open B - at 31Hz!

All of which has got me wondering how different would the sound be with drivers that could really generate those low frequencies.

I haven't tested the AC250F1s and really can't do a proper job until the enclosures are built. However, if the published specs are to be believed (and there have been some comments on the web to suggest they are not as reliable as one might hope) the 250F1's should cope fairly well down to 30Hz.

Which turns out to be just as well. We shall see...