Frequencies and your mixer

So. . .Since we've been on the lines of audio information sharing I thought I would post one that has helped me a lot.

So, understanding the frequency ranges of your instruments helps when you are cleaning your mix of unwanted sounds and making the instrument speak more clearly through amplification. Even more so when you are out doors and there are many environmental things  going. (I.E. frame noise, wind noise, and other various other unwanted sounds) So checking out the frequency ranges of your instruments is a start.

I've attached a picture that gives you an idea of where these ranges start between the octaves. These numbers correlate to the Mid low and high range settings on the various channels of your mixer.

I will not go into the full details of what you can do, but I am sure any smart person can figure out the ranges are of their own instruments.

One of the first and easiest things you can do is figure out what particular frequencies your instruments use and start by ELIMINATING the frequency ranges on that channel that the instrument DOES NOT use. This typically will help in eliminating frame noise and many other environmental elements that tend to find their way to your speakers.

The other possibility is either boosting or diminishing the certain frequencies of the instrument to create more bite, warmth, or body to the sound as you so desire. I do not recommend doing this a lot but it has helped me create the sound I am looking for in certain musical situations. It takes LOTS OF TIME and LISTENING to do this effectively. If you do not have a stadium like rehearsal facility or at least proper distance from the set-up to hear the end result you can really screw things up. (Trust me I know this from experience) :)

Hope this helps you guys out in some way.
Thanks Robbie! I have a little program that does that for me, but a chart is always nice to have.

It really is about making sure you're not boosting anything you don't need, so cutting especially low frequencies (I usually start low-cutting around 40-80 Hz, depending on the marimba, and most of the lows on vibraphone) Frame noise I've found is best solved with the shock mounts (Shure makes a great cheap one!)

And definitely ditto on trying to alter the keyboard sound in anyway... It can work... in small doses. What sounds pretty good up close can lose the ability to cut through an ensemble, or not be able to blend at all. Work in small doses!

And for anyone in the New Orleans area, I'll actually be doing a clinic for the LA WGI circuit on Pro-Audio/ Electronics basics (and some arranging/show design things) on September 25th with Shane Gwaltney. (Not sure of the location yet!)
Matt -- will that clinic be available online anywhere afterwards?  I would LOVE to see it, but can't make the trip.
I'm sure a YouTube posting of that clinic would get some hits :)

Good post; cutting out unwanted frequencies is definitely something that you should do when amplifying a pit.

One thing I've occasionally struggled with is minimizing the amplification of accessory instruments that are mounted on the Vibe and Marimba frames. Toms and cymbals really don't need the amplification assistance...

It's easy to figure out frequency ranges of pitched percussion instruments, but less so for non-pitched percussion, especially cymbals. This year in my pit we have a 20"; suspended cymbal mounted on a marimba, which I use carefully; it's a big, powerful cymbal. The higher overtones of this cymbal get picked up in one of the marimba mics and it sounds horrible. Killing the high-frequency EQ on that channel on our cheap analogue mixer is a big help (I think the EQ is centered at 12 kHz), but I'd like to know more about working around these sorts of issues.

Does anyone have frequency information for cymbals? If not I might be able to do some acoustical measurements if people would find it useful.

I'm not sure if they're planning to record it or not. I would gladly share it, and at the very least after I get the handouts done, I can send you one of those! It's going to cover basic PA concepts (types of mics, powered vs. unpowered speakers, analog vs. digital boards, basic set-up and EQ) as well as the basics of sampling and options for electronics usage (hardware synth vs. midi controller and computer). Anything else you think people would like to hear about?
This is a chart I put together last year that is similar to what Robbie has up here.  It shows the range in Hz of most of the popular sizes of instruments for marimbas, vibraphones, and timpani.

In my yamaha 01V96, I have built an EQ library to include settings for marimba low, marimba high, vibraphone low, and vibraphone high.  These settings have High and Low pass filters set to isolate the frequencies that the low and high microphone for each instrument is picking up.  I then set the other two bands somewhere in the middle so that I can ";bump"; the EQ curves if wanted.  Make sure to leave a little bit of room for the microphones on the top end to have room for the overtone series above the top note.  I usually leave at least 1 octave open (double the top number to get one octave).  By doing this, you will greatly reduce frame and wind noise.  I don't get much cymbal sound in the microphones, but that is largely due to the cymbal and microphone placement.  I also use 2 mallet bags per vibe and 3 per marimba to help reduce any ";sound bleed"; from behind the players.

Since this EQ is scene memory specific on the 01V96, you can have a different EQ for every scene even.  By using the library, you can get the EQ right on one instrument and then copy and paste it to the others.  This is really a time saver!  If you will get these setting ";right"; on your very first scene, or template, it will be there on all of the subsequent ones as you build from there. 

Hope these tips help!
Thanks for the more detailed specifics Tom!

Also, on a side note. . . if you don't have ANY experience in this whatsoever. . . First try to at least READ THE MANUAL! If that is complete Greek to you, it would be worth it's weight in gold to hire someone to come and set the stuff up for you and pay a little extra to have them explain how it works. Or if you are fortunate enough to go to a large size church that has an audio engineer on staff. . . he/she would be a great person to get to know. (Might even help you out for free. . . :) )

Wow - thanks guys! Totally getting schooled here by the pros :)
Hello all,

I'll ask for your forgiveness in advance, as I am just now getting into the craft of mic'ing, mixing, and mastering the please have patients.....

Side note:  I am still learning analog, but plan on making the move to digital this coming  year....but until then, here is a quick question....and hopefully I have clarified my thoughts enough to make my question coherent. 

is it possible to cut, or eliminate the frequencies of pit equipment with an analog board?  Heres what I have:  Yamaha 12 input, with compression on the first four mono ins, and digital effects.  I know you can completely boost or cut off an entire frequency range (low, mids, and highs), by just turning the knob the desired way....but is it possible to completely cut out all the frequencies in each instrument that is not needed...on an analog board?
The only true and complete cut that an analogue board typically offers is a 100-Hz high-pass filter. This is usually activated by a switch located at or near the top of each channel strip. This lets everything above 100 Hz pass through and rolls off anything below that frequency at a steep rate (usually 18 or 24 dB per octave).

The 100 Hz high-pass filter is designed for use with tripod-mounted stage microphones; it prevents boomy footfall noises from being picked up by these mics. 100 Hz is about equal to G2, which means a 100 Hz high-pass filter can be safely used on vibraphone, xylophone, 4-octave marimba, and 4.3-octave marimba. It should be avoided with anything lower than that (4.5-octave marimba, piano, electric bass, timpani, etc.).
Thanks Joe,

That makes perfect sense!  So, a digital mixer would be the way to go, in terms of versatility, and features....but are there any cons to having a digital mixer, that an analog has going for it?  All I can think of, is simplicity!
[quote author=gots2drum link=topic=3813.msg20452#msg20452 date=1291499163]
Thanks Joe,

That makes perfect sense!  So, a digital mixer would be the way to go, in terms of versatility, and features....but are there any cons to having a digital mixer, that an analog has going for it?  All I can think of, is simplicity!
[/quote]Simplicity is the main thing. Most people can grasp the basic concepts of an analogue mixer quite quickly - channel level controls and main level controls being the most important. They are just volume controls for microphones and other inputs, and there is a direct physical connection.

Once you get into digital mixers with re-assignable channel strips, that direct physical connection disappears. Any channel strip can control any channel on most digital mixers, which can make them confusing and can create trouble when a mic feeds back and the operator doesn't know what channel to pull down. In a rehearsal situation the solution is to yank the main level controls down, but in a live performance situation that may not be a good option.

Since feedback is rare outdoors except with extreme levels, this isn't that big of a concern for marching band performances. It can hamper indoor rehearsals, though, and if one plans to use a digital mixer for an indoor percussion program as well, then it can require a more experience operator to use a digital mixer.
I was recently reading an article on eq and I came across something that I thought would be useful, or at least debatable, here at tapspace.  

Basically, this article on eq stated that 2 or more instruments consuming the same eq frequencies, will ";muddy"; up the sound.  The ultimate fix would be splitting the eq's frequency range of the instruments that share the same eq, would eliminate any ";mud"; in the amplification process.....  ex.  A solution to this problem is to have one of them occupy the extremely low frequencies, say, below 80 Hz, and the other to occupy a slightly higher range, say from 100 to 220 Hz. This gives each instrument a distinct ";space"; for it to be heard in, and results in a much more pleasing overall sound than trying to get the instruments to mesh by trying to balance the volumes.

This could probably come in handy for instruments that share a lot of the same frequency range...especially those instruments that cover such a broad range of frequency's.

Can any credit this research?  Or does having more than one instrument sharing the same frequency range, aid in the clarity of amplification (in the case of front ensemble amplification)?  
[quote author=gots2drum link=topic=3813.msg20503#msg20503 date=1292798363]
Can any credit this research?  Or does having more than one instrument sharing the same frequency range, aid in the clarity of amplification (in the case of front ensemble amplification)? 

I understand the theory here and how one would apply it to the amplification of the front ensemble dependent upon your own personal concept of sound you wish to produce. I have experimented with separating each of the sounds as best I could in the mix however in amplified percussion environments there are TONS of other instruments in close range and while weeding out the noise and other various sounds it is practically chokes many of the timbrel characteristics of the instruments.

Many of the EQ and mastering manuals/guides will not give you a cut and dry answer to this situation because the environmental variables are far too vast. These manuals typically deal with instruments that are plugged directly into the board and can be manipulated to whatever end you wish. (I.E. covering up Kanye West's lack of singing skill or making a bass guitar sound like a lead guitar) We, however deal in multiple environments, implements, instrument stagings, textures and VARIOUS levels of background bleed. (I.E. 80 Brass Blowing their brains out behind you or a snare line inside of a gym) ALL of these factors will bleed into your amplified sound. The only true isolation would be to put your instruments in a sound proof box on the front sideline or if you had the Capitol to run 10-12 Xylo Synths. (I've always wanted to do this by the way it would be the most IDEAL arrangement for indoor groups, however it would take an incredible sound man, a very mature group to understand the instruments, and several MACS and sound modules, but it would be FREAKIN AWESOME and I would have hay day programming that bad boy!)

So..............Since the above factors are not practically at our disposal (or at least at mine) I would suggest you think of the FULL ENSEMBLE sound and work on mic positioning and mallet selection and mix from there. Isolate the individual sections and have them play for you at the high and low points in the music, add each group together after the isolation and listen for the QUALITY of the instruments. DO NOT HAVE A MARCHING BATTERY WITHIN 200 YARDS OF THIS SPACE! I recommend it be quite and in the environment you will be playing in most often. (I.E. indoor or outdoor) Set your master levels for each section based on CLARITY OF VOICES. I highly recommend routing the sections to separate speaker arrays (panned of course) if your equipment allows you to do so.
When you are doing all of this, You are listening for the BEST SOUND meaning the characteristic colors of each of the individual instruments of the ensemble speak effortlessly to the listener at the majority of the volume levels.

When you add the add the battery to your mix DO NOT ADJUST THE INDIVIDUAL INSTRUMENTS! (just yet) Listen to full ensemble statements and find the FULL ENSEMBLE SOUND first , both the soft and loud! Once that is defined you should be able to set your individual instruments as needed throughout the show and set your scenes based on this spectrum. SYNTHS. . . That is a completely different chapter and will not even go there right now.

On a side note. . .I personally feel that I am a novice with the amplification of electronic and acoustic percussion instruments and my advice is based solely on my last 15 years of reading, personal failures, questioning of others and self discovery. Hope that was helpful! :)
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