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Gear / Technical Help => Ask The Tapers => Topic started by: yltfan on September 01, 2009, 07:49:40 PM

Title: Use the 24 bit on mics or SBD?
Post by: yltfan on September 01, 2009, 07:49:40 PM
If I have to use two different recorders, what do folks think is more important for the 24 bit: the soundboard patch, or the mics? I guess I lean towards the mics as the more dynamic source. If it matters, I'm talking mics or board straight into an r44 vs iriver. Ideally, I'll be running both into the r44, but I have a show next week where I think I will have to set up my mics in one spot, while the board is off in a weird corner, so would rather run two recorders.

Thoughts?
Title: Re: Use the 24 bit on mics or SBD?
Post by: willndmb on September 01, 2009, 11:36:06 PM
mics
Title: Re: Use the 24 bit on mics or SBD?
Post by: boojum on September 02, 2009, 01:18:53 AM
I'd say a lot depends on the mics themselves and what is being fed the SBD.  There can be no hard and fast rule on this.
Title: Re: Use the 24 bit on mics or SBD?
Post by: notlance on September 02, 2009, 08:59:42 AM
It probably does not matter whether mics or SBD is recorded at 16 bits.  I doubt the venue will be quiet enough for you to hear the difference between 16 and 24 bits.

I'd be MUCH more concerned about being able to keep in sync the files recorded by two different recorders.  If at all possible use the r44 and run cables from the SBD and mics, even if it means running long cables.  I'm assuming your mics have low-Z balanced outputs.  If the SBD does NOT have a balanced output you can use, locate the r44 near the SBD and run long cables to the mics.  If the SBD DOES have balanced outputs, keep the r44 near the mics and run long cables to the SBD.
Title: Re: Use the 24 bit on mics or SBD?
Post by: OFOTD on September 02, 2009, 09:44:29 AM
mics
Title: Re: Use the 24 bit on mics or SBD?
Post by: nic on September 02, 2009, 10:00:24 AM
I'm gong to opposite of everyone and say SBD.
assuming this is for a "matrix" and that the SBD is having every instrument/vocal run through it, the SBD is going to be the higher percentage of the resulting mix.

that said, I echo the statements about it being better to record everything on 1 recorder for ease of mixing in post to reduce clock drift.
Title: Re: Use the 24 bit on mics or SBD?
Post by: yltfan on September 02, 2009, 02:01:25 PM
Interesting to see the different opinions on this.
Last night, I ran both into the r44. But at next week's show, it probably won't be possible (unless I want to set up my mics in one of the crappiest spots in the room).

It seems most folks want to stray into the timeclock discussion, but I'd rather go off into the balanced/unbalanced area. I will again display my noobness by stating that I've never understood this, and it's never seemed to matter. I have been told a few times that the sbd patch I get won't work (xlr outs are unblanced, but the rca cables that I adapt to aren't) but it always does. Are most board outputs unbalanced, and most mics balanced? Is the main issue with unbalanced sources running too long a cable?

Again, thanks for the advice friendly fellow tapers!
Title: Re: Use the 24 bit on mics or SBD?
Post by: notlance on September 02, 2009, 03:24:21 PM
"It seems most folks want to stray into the timeclock discussion, but I'd rather go off into the balanced/unbalanced area."
OK, let's talk about that.

"I have been told a few times that the sbd patch I get won't work (xlr outs are unblanced, but the rca cables that I adapt to aren't) but it always does."
I think you meant to type “xlr outs are balanced” which they often are.  It is also true that almost all the time a cable connecting XLR pin 1 to RCA shield and XLR pin 2 to RCA center will work to connect a balanced XLR output to an unbalanced RCA input.  You will lose some signal compared to a balanced connection (6 dB I believe), but that’s not a big deal with these line level signals.

“Are most board outputs unbalanced, and most mics balanced?”
I’d say most boards have at least one set of balanced outputs, and many boards have both balanced and unbalanced outputs available.  I don’t have much experience with SBDs, so I’m getting outside my area.  I’m sure others will fill you in.
Most “good” mics have balanced outputs.

"Is the main issue with unbalanced sources running too long a cable?”
In a word, yes.  A long unbalanced cable often equals noise.  But it’s often not much of a problem with line level signals that you get out of a SBD since the induced noise is often at a low level compared to the signal.

Rane has a couple of papers that you might find helpful:
http://www.rane.com/note151.html (http://www.rane.com/note151.html)
http://www.rane.com/note110.html (http://www.rane.com/note110.html)
Title: Re: Use the 24 bit on mics or SBD?
Post by: SmokinJoe on September 02, 2009, 04:50:34 PM
Rather than focus on the 24bit/16bit argument, I tend to focus on "which one do I want to let fend for itself" vs "which one am I going to spend most of the night keeping an eye on".    I mean this both in terms of "worrying of if the levels are OK" and "worrying if some drunk is stepping on my gear".

I would think I would put the iRiver at the board, set the AGC to auto ratchet down as required, and hope for the best.  Then spend most of the evening blocking with the mics and R44 down in the pit.  (In this case SBD gets 16 bit, Mics get 24 bit)

My usual system a couple of years ago was to run SBD > R09 with levels set conservatively, left to fend for itself at the board.  Back then my recorder was mics > UA5 > H120.  (In this case SBD gets 24 bit, mics get 16 bit).

Title: Re: Use the 24 bit on mics or SBD?
Post by: yltfan on September 02, 2009, 05:20:53 PM
Again, thanks for all the advice, and notlance for the explanations and references--I'll check that balance stuff out later.

SmokinJoe brings up another crucial point about the logistics/layout of the venue. I definitely don't want my r44 and mics getting squished by some buffoon, so they will definitely not be left to fend for themselves wherever they are. Another logistical factor is the phantom power needs of some of my mics...

Maybe I'll borrow a friend's r09, go 24 bit all around. I'll also start a campaign for all soundboards to be in the sweet spot. Here in Portland, there are multiple clubs where the board is in a pretty bad place for room mics. I tend to be a fairly uptight level checker, and at one very sold out show (Sufjan Stevens at the Crystal Ballroom) I must have pushed my way through the crowd 6 or 8 times to get back to check things at the board. Now I know to just be a little more conservative and let it be...

Title: Re: Use the 24 bit on mics or SBD?
Post by: rastasean on September 02, 2009, 05:48:47 PM
I think the venue would dictate which to use but notlance makes a good point by saying you probably won't be able to hear/identify the difference in the end.
Title: Re: Use the 24 bit on mics or SBD?
Post by: dgale on September 04, 2009, 01:41:30 AM
As far as the sbd outputs go, 95%+ of the time the output offered is XLR, which is a balanced signal.  Occasionally sbds have RCA or 1/4" mono outputs, sometimes in place of the XLR output and sometimes in addition to the XLR output.  I'm not familiar with the specific recorders you are mentioning but the biggest concern I'd have running a balanced signal into a deck with unbalanced inputs is whether the deck can handle the hotter feed coming from the sbd.  Just make sure your feed is not overloading the deck and distorting (this typically is unrelated to how you set the record levels on the deck...i.e. you can lower your levels enough to not have the signal clipping but it can still be distorting as the feed is too hot for the deck).  In this case you need to have the FOH person turn the feed down for you at the sbd.

Anyway, back to the original question, I've dealt with this before and basically I make a judgement call on how good I think the sbd feed will be vs. how good I think the aud recording will come out.  Basically I give the 24bit nod to the source that I expect to be superior.  This helps when you know a venue and/or the perosn mixing the sound (since the sbd feed you get will likely be the PA mix).  Whichever recording will likely be the best as a stand-alone source would get the 24bit in my book, regardless if I plan to mix later.

As far as the question about long cables and/or having to position your mics in a location not near the sbd, one option if your mics will end up anywhere near the stage and assuming they have XLR output is to run your cables to the stage and hook them into the sbd snake (assuming you know the band and/or can talk them into letting you do this and they have some unused lines in the snake).  This will send your feed right back to the sbd, where you can run it straight into the same deck that is receiving the sbd feed.  Just a thought.