Recording db question

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www.witchsmark.com
Member Since: Aug 13, 2006

Howdy again all. I was wondering... when I am recording tracks I am doing so at 32-bit 44.1Khz using Adobe Audition 2.0. I read somewhere once that if using 32-bit then I should set levels to around -12db to give myself plenty of headroom later. This level is so low when it comes to monitoring... is this a common practice for others, or should I set the recording levels a little higher. Will I be able to get my overall volume up eventually in the final mixdown when all is said and done?? I also invested in a Behringer Composer ProXL Compressor/Limiter... isn't this to prevent clipping for the most part, and if so I definitely don't see why I need it I am far from ever clipping recording all at -12db, so do I really need this device?? In reference to the Compressor... Does anyone else here use the Composer ProXL and can you give me some sample settings that you would use for recording Vocals, I am very confused about this device?? Also, would this Compressor benefit running into my Behringer PMH3000 powered mixer for live performances or practices?? Also, I have seen where some run there compressor into their recording or mixer device via an alternative input rather than their recording devices Mic-input... What is the alternative input?? Thanks.

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Eat Spam before it eats YOU!!!
Member
Since: May 11, 2002


Aug 28, 2006 10:00 am

There was a good thread at homerecording.com mentioning this isue... bassically 24bit audio has a 144dB dynamic range which is well past what is necessary for recording... 32bit recording has 192db of dynamic range...and that sound level will probably kill you... actually according to OSHA 180db will cause "immeadiate death of tissue"... 194db is the loudest possible sound at 1 atmosphere... before becomiong a shockwave.

The discussion went to "set up a proper gain structure" which generally just happens to put you around -18db to -10db ... this reduced preamp noise and allows for a crisper cleaner signal.


If the monitoring volume is too soft, the solution is to turn up the monitors :)

Prince CZAR-ming
Member
Since: Apr 08, 2004


Aug 28, 2006 10:50 am

i agree with zek here, 24bit is certainly enough for anything we do. Plus the file size probably gets atrocious, let alone the tax on the processor, doing 32bit.

If you're using a compressor, you can bring up your rec level some, sometimes referred to as trim, or gain. You're right, you wouldn't need to stay quite as low on your levels, but I wouldn't go crazy either. Experience will tell you what's best. Expirement some, and it's become clear.

The compressor will squash down some of the higher signal, thereby protecting you somewhat from digital clipping. Useing a limiter would keep the clips from occuring, but probably not be too great for the signal integrity, and niceness. I'd stick to a compressor, and proper gain staging, to keep the level in a good area.

On most mixers, there is an insert point. This connection jack is 1/4" trs. The compressor connects to this jack by a 'insert cable' or a 'Y' cable. this cable has one 1/4" TRS (stereo) jack on one end, and two 1/4" TS (mono) jacks on the other end. The TRS jack connects to the mixer insert point, and the two TS jacks connect to the compressor's input, and output. This puts the compressor into the signal path.

You should be able to increase the volume at the end of the process. I use a plug-in compressor, and a plug-in limiter (both from khaerjus) when I'm increasing overall volume.


www.witchsmark.com
Member
Since: Aug 13, 2006


Aug 28, 2006 12:16 pm

Ok, so let me make sure were on the same page. When I record into my DAW(Adobe Audition)it's OK that the tracks I record in Multi-track view show up as little 1/4" high squiggles because the highest peak they are reaching is -12db?? (Sorry for all the questions I just want to make sure I am stating this correctly.)

Prince CZAR-ming
Member
Since: Apr 08, 2004


Aug 28, 2006 12:46 pm

Well, size is kind of irrelevant, as I don't know how big the track view is.

But, i'll guess that if the track pane is 1 inch, and the signal is showing up as 1/4", then yes, that's kinda low. Not impossible to work with, but it's low. If you have, say 2 inch track pane, 1 inch is above the center line, and 1 inch below the center line, then your signal should be in around the 1.5 inch area. .75" above, and .75" below. None of the peaks should be at the top, as that will introduce clipping, which is very bad.

It sounds like you may need to adjust the gain on the firepod (or the trim). This is the amount of preamp gain on your channel.

On a mixer, this is kind of easy, as the parts are visible, right there on the mixer. You may have to do this in software.

Set preamp gain, so that loudest parts reach around -3db to -10db or so. I don't know the steadfast rule on this, I'm just throwing those numbers out as a guestimate.

If you use the compressor inline, then you have a little more protection, and can push a little harder.

No problem on the questions, that's why we're here. But you probably will learn more and faster by expirementing along the way (which you probably already are).

hth

Eat Spam before it eats YOU!!!
Member
Since: May 11, 2002


Aug 29, 2006 06:38 am

a lot of it depends on the voolume of the source signal... basically it' my understanding that if the source is a 100db guitar amp and you record at 24bit which has 144db of dynamic range you can peak at -44db and still capture the entire sound. Then when you mix you bring up the volume of the entire mix closer to 0db.


here's the link to the thread.
www.homerecording.com/bbs...light=pros+loud

..so basically -12db is just fine...

www.witchsmark.com
Member
Since: Aug 13, 2006


Aug 29, 2006 10:21 am

Great link, thank you. I am realizing that I may even want to go beneath -12db as I am watching my Master track that is giving me my overall Output from the 10 tracks and it clips out about 5 different times within the song. According to the discussion from the link sent in the above post, it's actually recommended to record at -18 to -20db and that will still leave you a quality track and good headroom. Does anyone else here use Adobe Audition, as I am seeing where most peoples posting record using 24-bit, but Adobe Audition seems to only support 16 and 32-bit?? Am I missing something here?? Thanks.
Also, if I am able to get a complete mix without clipping, is there a need for a Compressor??


Czar of Midi
Administrator
Since: Apr 04, 2002


Aug 29, 2006 04:47 pm

The 16 and 32 bit are just the limitations of the software. In Sonar I can do 8, 16, 24, 32 and 48. But Adobe is just a smaller type program and they choose to use 16 and 32. Nothing limiting about it or anything. In the end you will dither down to 16 bit for Cd anyway. But working in 32 will give you a little more headroom and less degradation as you make edits and add FX and such.

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