Originally posted by Oldghm:
I don't think proximity effect is lessened anymore with the Bose preset than it would be on any other mic / mixer / amp / speaker combination if it were optimized with a 1/3 octave EQ for close mic technique with one particular make and model of mic.
Agreed. However, to my knowledge, the only accessible way to do all of the above is with a PAS preset.
If one is used to using proximity effect as part of their artistic presentation, it is necessary to set Gain and EQ while NOT placing lips against the mic so there will be a change as you move closer.
Agreed. I assume the LF control on the remote is a shelving filter, which will give you the amount of "proximity" boost/cut you want.
I am more surprised that Bose now says that presets are made up using a 1/3 octave EQ. In the past I thought I remembered reading statements suggesting that the process was much more involved and utilized an EQ that was more sophisticated than could be achieved with 1/3 octave.
Agreed. I happen to own a TEF20 system. One of the things a TEF20 can do is generate a known swept test signal. This signal is sent through a loudspeaker and picked up by a test microphone. At the same time, a filter removes the frequencies just below and just above the swept tone. This effectively removes room reflections. Only the direct sound of the speaker remains.
Need I say that these readings are never anything like what speaker manufacturers publish for their products? Kudos to Bose for not playing the ruler flat speaker frequency response chart game.
So. Time to EQ the system for flat response. I'll just get out my trusty 1/3 octave graphic equalizer, and have at it.
What's going on here? I have a hump in the speaker response, but none of the equalizer knobs are anywhere near the middle frequency of the hump. The closest knob has a curve that is too wide to fix the shape of the hump, anyway.
The above occurs over and over and over again. You quickly learn that 1/3 octave EQs are pretty much useless for anything. The centre frequencies are in the wrong place, and the filters are either too broad or too narrow to fix any real world problems.
Solution: The parametric EQ, which allows you to set the centre frequency exactly, set the width of the filter from extremely narrow to extremely wide, and set the boost or cut at will. There are so many adjustments, however, that to be used effectively, it is pretty much necessary to use a system like TEF20, Smaart, SIM, or the soon to be released MacFOH.
Many of the current parametric EQs operate in the digital domain. It is easy to do, and easy to build a nice user interface (easy for computer hardware and software engineers - not me). They usually show you the curve you are making as you adjust. If you want to play with this, download the ffree (PC) software for the Shure DFR22 from the Shure site.
However, the really cool thing about the digital domain is that once I derive a system frequency response in the TEF (or whatever) I can click on the curve, copy it, click on the parametric window, paste, and the inverse (i.e. correcting) EQ curve will be generated in the DFR22!!
So, finally we get to the point: It seems to me that the right way to create presets, at least as a starting point, is to measure the system frequency response (microphone and speaker), copy the curve, paste into Shure DFR22 or equivalent, copy correcting curve, and paste into Bose preset #nn.
And I just bet that Ken-at-Bose has all the stuff to do that sitting on the shelf in his office. I suspect that because I just happen to know that if you ask them very nicely, Bose will tell you how to duplicate the Bose Panaray Controller curves using several parametric filters. Obviously, they know the frequency response of the speaker, the required compensating curve, and how to take that curve apart and describe it as a series of filters.
Well, that's boring enough for one post. More later.