[evlatests] sub-band to sub-band changes

[Rick Perley]

    ... and these power differences are visible in the BPASS spectra...  
Some are quite striking!

    I'll also be looking at the autocorrelation spectra -- these are 
more representative of what the requantizers are seeing ...

Ken Sowinski wrote:
> On Wed, 7 Dec 2011, Michael Rupen wrote:
>
>> We claim to be setting the requantizer gains such that the Psum for
>> all basebands and all subbands should be ~14.2  This seems to be
>> mostly working for the 8-bit, but not for the 3-bit side.
>> This suggests we're not setting the requantizer gains at the right time
>> in the script -- e.g., we may be adjusting the requantizer gains and the
>> attenuators/gain slope equalizers at the same time, which would 
>> primarily
>> affect the 3-bit paths.  This would not explain the other 3-bit Psys
>> oddities of course.
>
> Right.  I plan to check for this later today.  Another
> (unlikely) possibility is that the 3-bit system is not
> as stable as the 8-bit.