Combining Inputs

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Halon451

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Hello all... new to the forum, brand new to the world of recording so I have lots to learn yet. Hoping I could get some advice on an issue that has been bugging my efforts thus far.

To give some background, I have a strong engineering background, and have worked in industrial electrical and electronic applications for a number of years, so technical jargon doesn't frighten me, if someone has any in-depth insight into my issue, please feel free.

My humble equipment list is in my sig, I'm also running the Cubase on a laptop with just over 2G of RAM, a 1.8 GHz processor, Windows XP Professional (SP3), and my audio files are being recorded to an external 7200 RPM 750 GB hard drive.

The Firestudio Project of course has 8 inputs. Mics in use are Digital Reference DRM-7's on the drums, an SM-57 on Guitar 2, and another Digital Reference dynamic mic on Guitar 1. My band has been recording live utilizing all eight inputs in the following order:

Input 1: Kick drum
Input 2: Snare
Input 3: Rack tom
Input 4: Lower Toms (Shared mic between the two)
Input 5: Mixing board** (a mix of my two condenser overhead mics) via line input.
Input 6: Guitar 1
Input 7: Guitar 2
Input 8: Bass via direct input from bass amp pre-amp output.

As of yet we do not have a vocalist, but have figured on tracking him/her separately once we get one.

My issue is in Input #5. I want to be able to maximize the mic placement on my drums (I am the band's drummer incidentally), and capture the ambience/cymbal/hi-hat sounds, but am limited by the number of available inputs on the Firestudio - hence the use of the mixing board, which has its own +48V Phantom power supply to those mics.

Problem is, the sound comes through a bit fuzzy, even though no clipping indications anywhere in the signal path. I am wondering how best to eliminate this issue, or perhaps gain insight into a different direction I should be taking to get what I need?

My thought so far is possible issue with cascading/multiple gain stages by using the mixing board as a "mic combiner" essentially? Could introduce distortion that may not register on the meters as clipping? If so, how best to avoid this?

I have to say, as a noob - the mic placement and instrument arrangement thus far has provided adequate isolation to minimize bleed, and I've been using a shelving EQ approach on Input 5 to eliminate the unwanted/unnecessary bleed through sounds from the condensers - yet they are still fuzzy in the upper frequency ranges as well.

I would appreciate any help, thoughts, insights, or amusing anecdotes on this!! Thanks in advance.
 
I would be wondering about the connection between the mixer and the firestudio. Are you taking an XLR line out of the mixer and connecting it to an XLR in on the firepod? Should this be the case, it would seem that you are taking a line level output and feeding it to a mike level input.

However, were I in your shoes, I would skip the mikes on the toms, and use these inputs instead for the two overhead condensors and let them deal with the toms. The benefits are that all mikes go straight into the firepod, minimising the signal path, you get a full stereo sound on the kit, and you free up a channel for another use (e.g. vocals).
 
i'm with the gecko for the most part... or only one overhead... is the weirdness your getting now sound phasey to you??
 
When you say fuzzy, is it like a low level distortion? You could have an earth loop between the firestudio and the mixer, fuzzy sound in digital signals are often earth loops.

If the mixer has a balanced out and the firestudio balanced ins, Lift the earth on the cable at the firestudio end and see if the problem goes away. Or you could try one of these between the mixer and the firestudio.

Cheers
Alan.
 
I appreciate the replies guys - I should have added that I am not using XLR as the connection between the mixer and the Firestudio. I'm using an unbalanced 1/4" patch cable from the 'main out' (line level) to Input 5's line level 1/4" input, versus the mic level XLR. The Firestudio has those XLR+1/4" jacks for either/or of course (forget what the actual name of them).

I tried eliminating the close mics on the toms and going with the overhead idea originally, but the problem I ran into was, since we are playing live and not tracking separately, they would get a LOT of bleed from the guitar/bass amps which would muddy up the drum sound below - tried to EQ that out, but then lost the drums in the process, therefore purpose defeated.

Also, another clarification - it's not a constant hum or buzz, not like a ground loop kind of thing. That's a problem I could easily fix - it only happens when the mic is collecting a strong signal (i.e., cymbal crashes, etc.) - it "fuzzies" up the sound.

I should note that last night during practice I played around with the levels on the mixer some - brought the master output up to near 0db full strength, dialed back the input gains on each channel strip, and matched the levels between the two mics. From there I adjusted the input trim on the Firestudio to blend nicely with the rest of the kit, and (fingers crossed).. seemed to work somewhat at making those condensers a little more crisp and "un-fuzzy". But we didn't have a chance to record much material for me to really get an idea if it cleared the problem up or not - plus one of our guitarists was absent, so the SPL in the room was a bit lower than usual.

By the way I love learning this stuff - still very new to it, but something I've always wanted to get into! Whatever wisdom anyone imparts, it surely is most appreciated!
 
Halon451,
It could very well be the microphones are overloading.
I bought some omni small diaphram condensors that sounded wonderful until I started hitting hard or crashing and then they would crap out.
you never saw it on the meters because the mixer or converters were fine...just the mics themselves were farting.(technical term...)

To eliminate the possibility of your mixer set up swap the overheads with the close toms and go direct with the overheads to the interface and go with the toms to the mixer and see if you still get the fuzzies.

Incidently I have a a slightly larger model of the same mixer and it handles close miced toms fine with ample headroom so I doubt it is the mixer unless there is something wrong with it.
I am a drummer as well so I am ultra picky on my sound. i would not use the mixer if it was cheezy sounding.
 
Tom, I will try swapping them out next chance I get, good suggestion! As for the mics "farting" :D - understandably there are of the 'budget' variety but what I could afford at the time of purchase. Since I'm brand new at this I had nothing to go on, other than a handful of reviews on the web and what the guy in the store was telling me (of course he's trying to sell me the damn things, so...)

IF I were to upgrade at some point in the future - what would be a good way to go for drum mics? I'm sure there's probably a few threads on this very thing, so this may not be the best place to ask, but it came to mind.
 
You know...there are many good budget solutions for overheads that won't break the bank.

But before I get ahead of myself see if it is indeed the mics or not, I hate to send you down the road of mic research...it can be a slippery slope!

I also had a situation come up once where the mic cables I had were really cheapo and the solder joints were badly done. In addition, a few places the shield was pinched almost through the casing. I dont know if it was just a bad connection leaning out the phantom power or just crappy wires that would not stand up to the signal trying to go through them , but as the signal strength increased they started...(lets see...farting is for mics..and...whats the technical for cables)...crapping...yeah...(has a little more substance than farting)..I switched out the cables and all was well.
 
What Gecko said- ditch the mixer. mic the drums with fewer mics, and then improve your overheads. Good luck
 
I tried eliminating the close mics on the toms and going with the overhead idea originally, but the problem I ran into was, since we are playing live and not tracking separately, they would get a LOT of bleed from the guitar/bass amps which would muddy up the drum sound below - tried to EQ that out, but then lost the drums in the process, therefore purpose defeated.

Bleeding is a fact of life with live mixing. There's nothing inherently wrong with it. By spending some time on amp and mike placement, you can control it to a certain extent.

Here's a short sample of a live mix:http://www.box.net/shared/ggi08h0122

On kit: kick, snare and two overheads.
 
Thanks for the continued responses guys - I tried Tom's suggestion and what I ended up with was the same buzzing on the toms with each strike, sooooo... swapped back to the way it was. I did reduce the number of mics to basically kick, snare and the two overheads, which worked somewhat well if the drums were the only instrument playing, but as before - the guitars and bass came in and overwhelmed the condensers (apparently), so that I could not really let the toms stand out in the mix. Many of our songs are written in a way that I (as the drummer) really play some heavy, almost tribal beats on the toms alone, therefore I NEED those to have a big, powerful sound in the mix.

But... I played around with the levels on the mixer again - got a good level set that didn't introduce the annoying artifacts as before, and now the drums sound pretty clean. Following that, I got a bit giddy and went out and upgraded some of the mics. From the DR-DRM7 kit, the kick drum mic from that set is now on the floor toms (larger diaphragm mic, figured better low end response which is what I am going for), and picked up a Shure Beta 52 to use as the kick drum mic. That REALLY made a difference - now with the mixer levels set in a way that keeps the signal clean, the drums sound incredible, and those toms pound like thunder!

Of course, this is all from recording just the drums themselves to test out the new mics - tonight the band practices together, so I may have a different story coming back from that... ? Hopefully not! :D
 
Oh and on bleeding: I do understand some amount of bleed through is going to happen, and in many cases desired. What I was getting at was the primary signal simply being overwhelmed by bleed from the guitar and bass amps - to a level I could not control. I am experimenting at this time with changes in amp placements relative to the drums, but since we recording live, probably need to compromise to some extent - can't exactly stash the amps in another room, or what have you, because we all need to hear the instruments in a normal live setting obviously.
 
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