Hi All,
This post contains a lot of technical information which may only interest a few readers, so You Have Been Warned…
In my list of things to try with the Naim CI-102 I wanted to see if I could set the CI-102 to give the same room resonance correction as the Linn DSM (that uses Space Optimisation). The Spot The Difference Challenges were in fact the two graphs from the Naim EQ software (left hand pictures) and Linn Space Optimisation (right hand pictures).
The table posted previously and repeated below summarises how similar I could make the settings:-
Product A is the Linn Klimax DSM.
Product B is the Naim CI-102.
In summary:- for the Gain and Q factors of the EQ filters I could make the settings identical. Only the centre frequency and hence the corresponding bandwidth differed very slightly. Is this significant? Probably not for most users. These EQ corrections are trying to linearise the phase perceived at the listening position - but only for sound below 100Hz (see ‘Special Notes’ comments at end). When I undertake REW measurements, I can spot if a correction filter is not properly sitting precisely on the centre frequency or if the bandwidth (and/or ‘Q’ factor) is not quite precise. But at this level we are needing to also consider compensation for air temperature and humidity.
Here are two images from the relevant control windows in the Focal-Naim Manager EQ Software where I am able to set the relevant filter parameters.
Left Channel:-
Right Channel:-
For Linn SO, the method is different - it choses the default settings for centre frequency, but control over bandwidth (‘Q’ factor) and gain for each filter is achieved collectively and indirectly by sliding the ‘Optmisation’ between ‘Flat Frequency’ and ‘Short Decay Time’.
Special Notes: Linn SO only facilitates corrections below 100Hz. There are good technical reasons for this to do with human hearing. Naim EQ facilitates corrections over the whole audio bandwidth - which is similar to many other DSP based EQ audio products. The limitations in the Naim CI-102 EQ are that a maximum of four separate filters are allowed, with an additional crossover setting if one wished to use that. The other ‘feature’ of the Focal-Naim software is that it has pre-coded corrections for all the Focal loudspeakers (see example selection window below)! Not particularly useful if one has Magico or Kudos or Neat loudspeakers etc etc…
Needless to say, I just bypassed that setting!
I could at this point demonstrate how I was able to get practically identical sets of REW measurements using the Linn Klimax DSM as the source and also using the Naim CI-102 as the source. The sound was very close too - but not quite the same. More on that later.
However I also wanted to see what the Naim CI-102 offered for Sub Bass control?..
See next posting…