Taperssection.com
Gear / Technical Help => Recording Gear => Topic started by: Mr.Fantasy on August 03, 2007, 12:12:31 PM
-
Well, a week or so ago I discovered that one of the attorney's who used to work for the firm that I clerk for is a complete recording head!
This comes as a great suprise due to the lack of tapers in the Tulsa area.
Anyway....I was talking to him about my upcoming deck purchase and he said that you really only need to record to 16bit due to the fact that everyone listens to CDs and you would have to dither it down anyway.....he also said that I should look for something that records to wav files....
.....he also said that I should look for a deck with some sort of buffer or a hard limiter....or something... ???
What is this? And do any decks have these sorts devices?
Otherwise, he said, I would need to use some sort of compressor to act as a hard limiter.....
Can someone tell me what is up with all this?
-
Sounds like someone you should NOT be taking advice from.
-
I hope he is a better lawyer than gear head.
Check the threads on this board for good advice on hardware, recording modes and so on. I record at 24/48. The added bit depth gives me a bit more dynamic range. Yes, it does get dithered down to 16/44.1.
As they say in the law business, "Get another opinion."
Cheers 8)
-
Sounds like someone you should NOT be taking advice from.
Can you expand on that any?
Why is this poor advice?
-
He is right about suggesting a recorder that uses .wav format, but that is about it.
A couple points:
1) capturing in 24bit vs. 16bit provides at lot more accuracy in the analog->digital conversion, and considerably lowers the noise floor, which helps with later editing/fixing of issues with a raw recording (EQ/compression/limiting/adding gain or normalizing) and simply preserves a much larger amount of data and acoustical detail.
While 24 bit is of arguable utility for large venue/live PA recording if you intend to do nothing more transfer raw to a CD, once you do anything in the digital realm in post to a recording, even just to normalize or add a couple db of gain, that extra data at 24 vs. 16bit becomes much more important in minimizing any artifacts/noise/distortion that may be introduced by the post-editing. (many folks here could elaborate on these points in much more detail than myself).
2) typically, it misses the point of capturing the dynamics of the experience to apply a hard limiter or compression to a live 2 track recording at the show. While compression and limiting have their purpose, and are very useful editing tools for multitrack and matrix (SBD + AUD) recordings, there is a greater ability in the realm of digital recording today to do this much more accurately in post-production vs. trying to do it live at a show.
With respect to 'hard' limiters, imagine the .wav to be like a person jumping up and down in a closed room where the ceiling of the room (or subflooring since .wavs go up AND down ;) ) respresents a threshold of Odb - above that equals clipping. A limiter, whether 'hard' or 'soft-knee,' would set an artificial ceiling (threshold) beneath the real ceiling to stop the person jumping from hitting the actual ceiling (limit the signal level/amplitude before it reaches the clipping level). To extend the analogy, a 'hard' limiter would be like making that artificial sub-ceiling out of concrete or brick...above which nothing can pass. A 'soft-knee' limiter, on the other hand, would be like making that artificial sub-ceiling out of thatched wood trellis work, where the person jumping could quickly push his hand through a hole before the rest of the trellis arrests his ascent. So, a rapid transient like a snare hit (hand pushing through a hole in the trellis) will be less affected by a soft-knee limiter than a loud bass thump (person jumping's head being too big to fit through a hole). A hard limiter will smack down both the hand and the head equally.
Graphically, a hard limiter will look like an ascending line that abruptly goes flat (horizontal) at the threshold, while a soft-knee limiter will look like the ascending line curves to horizontal around the threshold level.
Why is hard-limiting less than ideal for live PA recording? primarily because it sets an artificial maximum to the dynamic levels captured on the recorder, but also secondarily because many 'hard' limiters do not sound very musical and may degrade the sound.
Hard limiters have a tendency to invite the person recording to set their levels too high b/c of the known 'safety' of having the limiter engaged, which in turn results in 'squashed' sounding recordings where there is little audible difference in volume between what should be 'quiet' and what should be the 'louder' parts of the music/performance.
---------------------------------------------
Where the two points fit together: recording in 24 bit considerably lowers the noise floor when recording, thus enabling one to set levels more conservatively and then add gain later in post-processing. The use of hard limiting is overkill in this context unless the signal is too hot for the recording device, and you cannot turn it down on the front end. It is more of a multitracking tool when setting a final output level on a stereo mix, or to be used for EFP(electronic field production)/ENG(electrnoic news gathering) work where you only have once chance to get it right for a live broadcast. If you actually need some kind of limiting or compression to control a sudden dynamic spike that is out of proportion with the rest of the music, you may make it sound a lot more pleasing when you do this processing after the fact.
--------------------------------------
A couple other responses:
-many decks, some pre-amps, and most portable mixers will have a built in limiter, although it is not a function upon which you should base a choice in buying a recording device for live PA recording with a microphone pair. As long as you can leave the limiter off, you'll be fine with whatever you chose.
-I have no idea what he means by buffer, because it could mean two totally different things: (1) a 'true' threshold before clipping on a recorder that is __db above the clipping level according to the deck's metering, or (2) a cache to preserve a rolling memory of a data stream from the A->D converter of the recorder to reduce or eliminate the possibility of write-errors in the event that vibrations or other issues cause an interruption in the normal writing of data to a medium like a CF card or a hard drive.
-I believe the attorney's knowledge and/or experience with recording is from the studio/multitracking perspective, or audio production for video, and not with respect to throwing up a stereo pair of mics to capture 'what goes down.'
*edited for spelling/grammar
-
Sounds like someone you should NOT be taking advice from.
Can you expand on that any?
Why is this poor advice?
As others have said using a limiter is overkill.. At best most offer no adjustment * ones built into recorders* thus making it impossible to set correctly. A real limiter can do great things when used properly. But for a source material in a live situation its never a good idea. Because you are not familiar enough with the content of the recorded music. In post ( when you dump it down to your computer ) you can use a plug in * software add on * that will allow you to limit * if its necessary * and they can be had for free! and downloaded on the interweb. I would stay away from any recording device that had a built in limiter in the signal chain that was meant for live recording.. I think things nowadays are way to heavily compressed and limited as it is. Everything I hear now has no dynamics at all, and have the living crap squished out of it. Not cool IMO. When you are just starting out in the studio young engineers * like your friend * squash everything I guess its better then having to move a fader lol.. heaven forbid you should have to ride a signal... Anyways good luck it sounds like your friend needs to learn a few things about how good audio is really recorded.
Chris
-
Great explanation Jim! I'll plustee ya as soon as I stop laughing at the visual... ;D
-
:yack: back at ya' Dirk.
-
Ahhhh....
Much more makes sense now about all that....
I do think that I will limit my limiter use to post production....I agree with the points presented and I think that recording in 24 bit is also a good idea.....in hind sight I think "the attorney" meant that he just liked the fact that 16 bit presented less steps, and less corruption due to multiple conversions....but I think having more captured sound is a great idea, and I like the sound of it too......captured sound......
Thanks to all for this recording 101 lesson.......I am still learning and I am just trying to get a good grasp on everything....
Thanks again...
-
Wow. DAMN good explanation Jim. +T for that my friend.