Comment to Pls1, 031701
Re: Measurement with TacT 2.0 versus MLSSA.
It is absolutely true that the measurement performed and displayed by the 2.0 does not match the response when you measure with other measurement systems. In fact no two measurement systems will concur unless you set all the parameters for the measurements to identical parameters.
When you make in-room measurements there are a number of variables that will influence the measured result:
1. Microphone – is it well calibrated and corrected
2. Gating – how long a window for the measurement
3. What kind of windowing filter, Hamming, Hanning etc.etc
4. What kind of smoothing is applied
The TacT measurement system is designed to be used with the TacT correction system. The measurement uses proprietary frequency dependant gating, windowing filter and smoothing, and the measurement also takes into account the way the sound decays in the room.
It stands to reason that at very low frequencies – where the wavelength is long, it is desirable to correct for all the variation in frequency response imposed by the room while at higher frequencies it can be total nonsense to correct for small variations, simply because the measured results can be completely different if you move the microphone 1”. So the TacT measurement will surely differ a lot from measurements that are designed for steady state response measurements with no regard for what the measurement will be used for.
It fact a lot of the research leading to the TacT Correction systems have gone into the design of a suitable measurement system.
It would have been much easier just to adopt an existing measurement system and use it for correction, and in fact that was what we did in the early trials of RCS, sometimes with reasonable results but more often with rather terrible results.
Re: The comment on number of chips. Yes TacT 2.0 uses 3 very fast 48 Bit DSP’s while the Sigtech uses many more. However the DSP’s used in the Sigtech are ancient designs so it is really irrelevant to compare.
