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Gear / Technical Help => Ask The Tapers => Topic started by: landshark on July 25, 2007, 04:03:40 PM
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Hi all -
Just tried out some new gear this past weekend (the 463's (hypers) and the MixPre, the Shure FP24 rebranded version), and I'm wondering if I'm doing this right. Any suggestions are appreciated!
The venue was very small (call it 30' x 60', 12' ceilings) private party. In terms of gear the band was about 2 steps up from garage band, 2 Marshall amps and 2 towers of midrange speakers. For the first set, they had the volume up too loud (and it was loud - not quite ear bleeding, but borderline uncomfortable), they backed off a little for the next two sets. The 463's were clamped on a DJ rack about 3" from the ceiling to keep them out of wookie range, and they were about 25' from the speaker stacks, so relatively close.
The issue was sound levels. I ended up putting 10db pads between the mics and the MixPre, and even with the pads in, I only had the MixPre gain turned up to about 0.5 (out of 10). I swear if I even looked at the gain knobs funny, it started clipping....
I had the limiter turned on on the MixPre, all the way up / maximum limiting, which according to the instructions limits to +6 dB. Since the Korg MR1 accepts a max +6 dB line input, that seemed to make sense. With the gain set low, the limiter lights weren't on much at all so I wasn't using the limiter all that much. When I downloaded onto my computer, converted to wav, and opened up in Soundforge, the waveform looked surprisingly uniform - not a lot of highs and lows. This makes me concerned I'm losing some of the dynamic range that should be available. Of course, it could also be consequences of recording in a noisy venue.
Here's my questions:
1. Use of limiters and attenuators - where in the chain and how much? Should I be trying to get as hot a signal out of the microphones, and applying minimum gain in the preamp, or should I be attenuating the mic signal and using more gain from the preamp? I'm using almost zero gain from the preamp under the current settings, with a 10 Db pad. Should I go up to a 30 db pad and use more gain on the preamp, or is that just adding noise? Also, will my decision have an effect on the dynamic range of the signal coming out of the preamp? Are AKGs particularly "hot" mics? I'm also putting the attenuation between the mics and the pre - should I instead be between the pre and the Korg?
2. Gain settings on the Korg and use of the mixpre limiter - I'm targeting a signal at an average of -12dB on the Korg, with peaks up to -6db (and pretty much nothing over -6db). Should I be going higher, like maybe targeting -8db with peaks to -4db? Also, the MixPre has a limiter that ranges from limiting to +6 db up to +18 db (what the heck takes a +18 dB signal??). I'm planning on using the limiter more for transient spikes (caused by things like crowd clapping, etc.) so I can avoid clips without having to ride the gain on the Korg. Any suggestions on technique or settings?
All in all, I think it came out well. It was a big step up from running my AKG 391's direct into the Korg using the mic inputs. Part of the issue is that given the nature of the band's gear, I can't really distinguish flaws caused by my gear versus flaws due to their PA system. I'm more concerned that the signal is so hot coming through the recording chain. Theoretically, it seems that the less gain I'm applying at any given stage (MixPre, Korg), the less noise, but I'm not sure if I'm thinking about that right. Do I have to worry about the noise floor if I'm using little or no gain?
Thanks in advance all!
Mike
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Yes, I've used the mixpre, and it is not the same as the FP-24 (MP-2). Not used the MR-1 put have looked at the specs. Used older AKG451, 426, C33, etc.
Here is what I'd do.
My general rule is.... if you have a gain pot just cracked open and you are getting massive gain, something is wrong..... your gain stages are not correct.
Recording clubs are really loud. MP-2 developed for film sound dialog. Really good pre BTW.
I'd run at least a 20db pad between the mics and mixer.(make sure pads work with phantom power). Pad the signal down so you have your gain pot on the mixpre running about 12 to 1 o'clock and you are peaking around +12-+8 on the meters. Use the 1/8 inch tape out to go into your MR-1.
It's rated at +8 max output, and will be a better match for the MR-1. The FP-24 XLR line outs are +20 to +22 and are too hot for the MR-1 unless you pad them down too.
Set limiter at about +17
Padding down the mic will not add noise... it will reduce the noise and the signal by the same level. Same with the outputs.
Basically you have really good mics; condensers typically have high outputs compared to ribbons or dynamic mics........ a professionally mixer operating on a pro +4 level, and a consumer level recorder that operates 12 db lower (-10) than the mixer.
http://www.sounddevices.com/products/mp2master.htm
http://www.sounddevices.com/tech/mp2_or_mixpre.htm
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Hi BRH -
Thanks! I was suspecting as much on padding the mics. One question - in the web page on mixpre vs mp-2, they mention one difference is the mixpre allows 0-66db of gain, while the MP2 has 12-66db (no "zero" gain). In the manual for mine, it also lists 0-66db, not 12db-66db. Are you sure I have an MP-2?
Thanks,
Mike
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basics:
1. you are running "line in" ?
and if so, you can attenuate the input, but dont go beyond -5db or so. that will help (a lot).
2. the 48xx i've never found to be a "super hot signal", so I would expect that it will work out here.
3. if your preamp is adding a minimal gain (and maybe it is..from what i've read), then that is also a problem, and a pad between the preamp and the deck might be good
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Thanks Nick!
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Ya,
Might be dependent on your serial number.
Something about if you have the phantom on, then you have less gain.
Turn phantom off, you have more gain, presumably for dynamic mics that need more gain.
Also, says no zero gain on some of them, the first step is about 18db.......
I've only used the mixpre, so I can't really tell.
Although I still say use mic in and pad down the input so you don't overload the preamp stage (if you have pad on mic, use that too, as the electronics in the mic body will overload before the capsule distorts), and use the 1/8 mini out so it will better match your MR-1.
I think that will be fine.