Silly calibration techniques of the technologically insane!

[cyonkers]

Today someone - let's call him Phil (not his real name) - attempted to explain a calibration technique that he claims is regularly used by ?all the best engineers?. As I am having difficulty following the logic behind this technique, I present it to you Tape-Opians for discussion. The technique he conveyed is as follows:

As an engineer would set up a session, he would calibrate the trim on the console for each channel of each mic to be used by sending tones from a tone generator, through a speaker placed a specific distance from the mic. The engineer would then, using the meter for that channel adjust the trim until it reads 0db. ?Phil? claims that this is an accurate way of adjusting the trim on each channel to optimize the gain and headroom of that particular mic and to ensure the the mic will produce optimum signal without clipping. When I asked what the specific output level and/or distance from speaker-to-mic was, and if it is adjusted based on each microphone's specs, such as max SPL or impedance, ?Phil? said ?no it is the same for all mics, you send a 0db signal from the tone generator and adjust to 0db using the trim?. He also could not provide information as to which frequencies and waveform types would commonly be used.

Though I am familiar with methods using a signal generator plugged into various devices as a calibration and gain structuring technique, I have never heard of using this method that ?Phil? describes, nor does it make any sense to me as an accurate way of adjusting a mic channel's input gain based on the information he provided. I have alway been under the impression that the mic's channel trim is adjusted according to the sound pressure level of the instrument/voice being recorded. And that the trim adjustment was made to get best signal-to-noise ratio without clipping - unless of course you like the sound of your console channel clipping (see: Trent Reznor).

While ?Phil? is a ?nice guy?, appears to be somewhat knowledgeable about recording techniques and claims to have recorded in ?high-end? studios, I question the validity of this calibration technique that he purports is so often used. Moreover, ?Phil? has convinced a friend of mine and his band mates that this is the ?proper way? of setting up a mic. As they are recording their current album at home and are new to the recording process, I would hate to see them led astray by ?junk science? that could diminish the quality of their recordings.

I was wondering if any of the kind folks here could substantiate ?Phil's? claim regarding this technique, and if so please shed some insight as to the proper technique and theory behind it. If it is, as I suspect, misinformation please reveal it as such so that I may pass this new information along to friends who are recording.

Clement

[red cross]

Haha. What happens after you "optimize" each mic channel to read zero? A drummer starts hammering the snare and your mic starts clipping the channel again. Oops. Yeah that's right, moron. There goes your "gain structure."

Some people are so unbelievably clueless it's frightening.

[drumsound]

Your friend is full of shit.

[Mark Alan Miller]

Have Phil name a substantiated list of 10 of "the best engineers" who do this and I'll start to consider this not a bunch of horse-hockey. No, even then maybe I won't.

I can kinda understand how one might arrive at that idea, as it sounds a little like what one might have done back in the day of recording engineers dressing like lab techs, but there is so much wrong with it that it's implausible. "Every mic is the same" is the best place to start there...

There is a shred of an interesting idea to be had there, though. If one knew the approximate SPL of each instrument to be recorded ahead of time, one could set up all the mic pres to a relative starting point before the band even arrived by sending spectrally approriate pink noise to a speaker in the room and measuring and setting the appropriate SPL at the capsule, then tweakng the pre for an 'optimal' gain setting... hmm. Again, very lab-coat-y. Don't think I'll even bother talking it past... now.

Reminds me a little of the time, when I was a pretty green engineer, that a "producer" for the band I was recording came in and insisted on a gate on every drum. Set to chop off the decay pretty radpidly. Then required a reverb to be inserted after the gate, one for each drum, to create a "natural decay". He also, while staring into a RTA, shouted frequencies at me to boost and cut for each drum and instrument. And did everything to make me feel like I had no clue whatsoever about what I was doing. I didn't simply sit back and take it (got the chance a few times to point out to his reluctant admittance, for example, "no, i think the cut on the kick sounds better at 325 Hz, not 300" (his RTA was only something like 12 band, and the better frequencies usually fell between bands on it)) but generally had to defer to his "choices". I complained to the studio owner that evening that something seemed out of line with this guy, and felt the band was being done a disservice, even though they had "hired" him. The next day we arrived and I was told that we were to unpatch everything and get tones again. He, rather sheepishly, said "let's start with how you usually do it here..."

Sorry if I've told that one here before.


EDITed for grammarness and to try and be less wordy at saying things. Don't think I did very well...

[RodC]

No guys this is the perfect setup! How can you not see it! Now all you have to do is make sure that every piece of equipment - Drums, amps, vox ect has an output close to 0db! And perfect sine waves at the same frequencies.

Man this could eliminate that whole market for unique gear. We will never have to worry about mic placement/selection again.

[ckeene]

maybe his only experience has been recording The Zero DB Tone Generator Orchestra?

[Mark Alan Miller]

maybe his only experience has been recording The Zero DB Tone Generator Orchestra?

Where can I get the ZDBTGO stuff?

[LewKellogg]

I have only seen this work when all of the cables are connected in the right direction. Make sure the little arrows are pointing with the flow before calibrating.

[Fletcher]

?Phil? said ?no it is the same for all mics, you send a 0db signal from the tone generator and adjust to 0db using the trim?.

This is the best technique for recording "one hand clapping"... all other signals will require some source level above "0db"... like say a 110db signal created by a snare drum will require less gain than the 0db signal created by one hand clapping.

[stuntbutt]

I have set up a speaker in the room before the band arrived and played a tone as a way to check continuity on the mics without an assistant. Maybe "Phil" has seen something like this and read more into it?

[JASIII]

Funny, there's a photo in the Recording the Beatles book that shows Abbey Road enginees in white lab coats a aiming gun-like device at mics, to blast them with sound to help adjust levels on the console.......

[drumsound]

Funny, there's a photo in the Recording the Beatles book that shows Abbey Road enginees in white lab coats a aiming gun-like device at mics, to blast them with sound to help adjust levels on the console.......

That could be a Phase Clicker.

[philbo]

Well, at least you pointed out that Phil isn't his real name... That would make all the other Phil's out here ashamed to be associated with this guy...
________
Toys Dildo

[bobbydj]

Today someone - let's call him Phil

Lookin good Anka, lookin *real* good.

[joeysimms]

*shoulders, people!*