Topic: Newbie question about recording level

[Marshall7]

How about you give us some links so we can check out your greatness for ourselves?  After all, you obviously are a far better taper than everyone else here. 

[DSatz]

Hi. I would just like to present a viewpoint which I would never have thought of as controversial before I came to this board: If you can record without overloading anything, the ideal in fact is to get your signals to peak as close to 0 dB as you can get without actually reaching 0 dB--rather than the -12 dB that several people have mentioned in this thread.

It's one thing to aim for a higher peak level and end up with your peaks down at -12; that can happen, and for a hobbyist recording it's usually no tragedy. That's because at this point in the development of audio technology, our recording equipment has a considerably wider dynamic range than much of the material that many of us have the opportunity to record.

For example, if you're in a venue with a noise floor of 40 dB SPL and the peak SPL of the program material is 110 dB, then the difference is 70 dB. So it only takes 80 dB dynamic range (10 dB greater than the distance from the noise floor to the peak SPL) to capture that sound with no audible noise contribution whatsoever from the recording equipment. In that example situation, a peak level of -12 dB, even on a 16-bit recorder with a dynamic range of 90+ dB, would be adequate (and incidentally there would be no advantage whatsoever in recording 24-bit in this example, either).

But assuming that you have competently designed equipment that is appropriately chosen in terms of sensitivity and overload margins and used correctly, nothing whatsoever is gained by setting the peak recording levels low on purpose. All that's happening is that (in the example I gave) you can afford to throw away those 12 dB because the full dynamic range of 16-bit recording is enormous, and because the venue is as noisy as it is.

In other situations, however, you would not be able to afford it, i.e. some of those 12 dB will turn up as audible noise in the recording.

--best regards

[adrianf74]

I'll agree with what DSatz is saying.  In the digital world, I've always tried to go "as loud" as I can figuring peaks around -6dB and average audio around -8dB/-10dB.  I still have headroom and my levels are where they need to be.

Of course, this runs a risk if levels get cranked but I've noticed most shows have levels that are heavily compressed so the likelihood of going over is pretty close to nil (for me).  Again, this assumes pop/rock. 

[Church-Audio]

Everyone raves about these battery boxes .I used my sony m-10 with
CA-14 cards into mic in and no BB or 9100 and it sounds like i was plugged into the soundboard .
100% True ! JMHO Done the same with my tascam DR-05

The reason why you need a battery box with my mics is simple.. They are designed to work with 9volts of plug in power and not 4 voltyressure. Now unless you have a db meter and can measure how loud the show is at any given time you will never know when you will get distortion from overload until you get home and listen to the play back its for that reason I make the battery box available for $29 so that customers can at least be able to get a simple battery box to avoid this situation.

My mics are designed to have a distortion of 0.2% THD at 114db at 1k @ 9 volts. That is the spec, of all my mics. So you will never know when you are in a situation where you will get overload until its too late. When you lower the voltage to the mics that 114db at 0.2% THD goes out the window and the distortion figure goes much higher.

Please if you want to use my mics I don't care who you buy a battery box from but every time you go out, use one. Because it would be a shame to waste a perfectly good recording. Sometimes when the sound pressure levels are low its not an issue but that is not always the case and you have no way of predicting it.

Chris Church

[F.O.Bean]

Everyone raves about these battery boxes .I used my sony m-10 with
CA-14 cards into mic in and no BB or 9100 and it sounds like i was plugged into the soundboard .
100% True ! JMHO Done the same with my tascam DR-05

The reason why you need a battery box with my mics is simple.. They are designed to work with 9volts of plug in power and not 4 voltyressure. Now unless you have a db meter and can measure how loud the show is at any given time you will never know when you will get distortion from overload until you get home and listen to the play back its for that reason I make the battery box available for $29 so that customers can at least be able to get a simple battery box to avoid this situation.

My mics are designed to have a distortion of 0.2% THD at 114db at 1k @ 9 volts. That is the spec, of all my mics. So you will never know when you are in a situation where you will get overload until its too late. When you lower the voltage to the mics that 114db at 0.2% THD goes out the window and the distortion figure goes much higher.

Please if you want to use my mics I don't care who you buy a battery box from but every time you go out, use one. Because it would be a shame to waste a perfectly good recording. Sometimes when the sound pressure levels are low its not an issue but that is not always the case and you have no way of predicting it.

Chris Church

But he recorded 32 shows without one. Obviously he knows more than we do

[Gutbucket]

I've always tried to go "as loud" as I can figuring peaks around -6dB and average audio around -8dB/-10dB.  I still have headroom and my levels are where they need to be.

The relationship between peak level and average level is referred to as crest factor, and varies greatly with the type of material and the recording position.  Dense music, usually 'constantly loud' music, and the output of highly compressed and peak limited PA system will have a relatively low crest factor that may be similar to the numbers stated above.  More sparse music, acoustic music, transient-rich material like drums, and especially close microphone placement to the sources (such as recording on-stage in close proximity to a drum kit) will have a far higher crest factor and will require more headroom to accommodate that difference between peak and average level without reaching 0dBfs and clipping.

I recorded an organ trio last night with the mics about 2' in front of the centrally positioned drum kit and the difference between peak and average level while they were playing was more than 16dB, so to avoid clipping I needed to set input levels 12dB lower than what would be required for the example above with a difference of just 4dB.

To take full advantage of the dynamic range of the recording system we want to peak as close to 0dBfs as possible with out going over.   Since we don't know exactly how high the biggest peak will be, we are wise to set gain lower than it would be in the perfect case.  The real question becomes, “how much lower is safe” without setting it so low that the noise floor of the recording system becomes the bigger problem.

[TimeBandit]

now i taped lot of shows with the CA-11 straight into the DR-05 with no battery box. as long its not Heavy Metal in arena or straight in fire of the stacks - no overload. for very quiet shows i tend to uses the ca9100 preamp to get more gain.

[Church-Audio]

now i taped lot of shows with the CA-11 straight into the DR-05 with no battery box. as long its not Heavy Metal in arena or straight in fire of the stacks - no overload. for very quiet shows i tend to uses the ca9100 preamp to get more gain.

Again its all relative.. To how loud your shows actually were. And with out a db meter you will never know. So you might have been attending shows that were all under 95 db? who knows.. But thats why I recommend everyone use a battery box.