Conference napalm::commusic_v1

    
    	I have a 10 band Soundcraftsman (sound impressive, eh?) that
    I use for recording, to set the overall EQ of the sound as it goes
    on the tape. I havent had the chance to use it "live" yet.
    
    	I'm aware of two types of EQ's. There's the multiband type;
    perhaps if you have 30 odd bands or so - you might hit the exact
    frequency, or close enough - to the "ringing" you described to be
    able to cancell it. The other type of EQ is the parametric, which
    has less bands, but these can be "slid around" in the spectrum so
    you can "tune" out the offending frequency.
    
    	WJB taught me how. You boost the frequency band up, then tune
    it around looking for "potential" squeels - then cut.
    
    	Joe Jas 

    
    I think that if you can only afford one eq, then it should be a
    1/3 octave graphic. The para's and quasi-para's are more flexible
    but you have to have the time to futz with them. The graphic is
    easier to use and 27+ bands should get you pretty close to your
    problem areas.
    
    The DOD is a good match for your system Dan; although the small
    format (some companies call them micrographic) will give you less
    resolution than a full size 2 space unit, if you don't have the
    rack space, you don't have the rack space.
    
    I'm a Rane fan, and have 2 GE27's. They're quiet, clean, and have
    gobs of headroom, but are expensive. The Yamahas are great units,
    and as Mr Crowley can tell ya, can be had cheep at Steve's.
    
    I think a 15db problem at 120Hz is not a fault of the room, but
    of your system itself.
    
    CdH
    

    FWIW - I use a home-stereo type graphic equalizer (about 8 bands
    per channel) that I picked up somewhere for about $50.  I don't
    think it has a name on it - don't remember.  Got it on sale from
    a store going out of business.  Does about +/- 12 dB.  I have yet
    to notice any noise.  The case is all metal and the thing is tiny.
    Had I known what a good deal it was, I probably would have gotten
    a second.

    I took a look at what Radio Shack has to offer.  I don't think I'd
    get a unit there - at least not from what I've seen.  My little
    mule does just fine.
    
    
    Steve
    

RE < Note 1173.2 by TWIN4::DEHAHN >

>    The DOD is a good match for your system Dan; although the small
>    format (some companies call them micrographic) will give you less
>    resolution than a full size 2 space unit, ...

	This is what I suspected.  Little area to slide means a finer touch to
get the right cut/boost...

>    I think a 15db problem at 120Hz is not a fault of the room, but
>    of your system itself.

	Yeah, we're trying to work that out, though I admit I'm not sure where 
to start...  The sound was fine in my basement and it was fine before the people
started arriving in the hall, too.  Maybe it only shows up when you need to 
boost the volume above a certain level?
    
	Dan

    
    One interesting unit to look at is from Ibanez.  It is a combination
    unit containing a compressor, a 2/3 octave (15 band) graphic EQ
    and a two band notch filter.  I forget the name, MSP-1000 or something
    like that.
    
    The unit can be used either with the three effects in series, or
    you can patch in and out of each section individually.
    
    The notch filter has a very narrow notch band, and you sweep across
    with maximum cut until you notch out the ringing.  Then you decrease
    the amount of cut until you hear the ringing coming back, then back
    off a little bit.
    
    It only has 1/4" jacks.
    
    It sells new for around $150 or so.
                     
    For fine manipulation of the graphic, you can select the range,
    either full (+/- 15 db??) or half (+/- 7.5 dB?) to give you more
    "play" when making fine adjustments.
    
    A pair of these (one for mains, one for monitors) give you compression
    (for driver protection), graphic EQ for matching the room, and notch
    filters for feedback control, in only two rack spaces. 
    
    I would guess it is a little noisier than other EQs;  I have used
    it and it seemed OK to me, but I have no comparison with other (more
    expensive) units.
    
    BTW, at home I use a Rat Shack 7-band graphic that I bought when
    they closed it out for $30.  At that price, it is great.  I wouldn't
    use it for live work, though, it's all RCA jacks and not enough bands.
    
                                                     Brian

RE < Note 1173.5 by AQUA::ROST "A peach, a pear or a coconut, please" >

>    One interesting unit to look at is from Ibanez.  It is a combination
>    unit containing a compressor, a 2/3 octave (15 band) graphic EQ
>    and a two band notch filter.  I forget the name, MSP-1000 or something
>    like that.

	This sounds like a great product!  Has anyone 'round here used one over
the long haul?  How well does it perform?
    

    I've got eq's all over the place... 10 bands per side on the board
    plus 3 shelves per channel, 12 bands per on the stereo, single 7
    band in the car.
    
    I've seen lots of people make the same mistake that I'm guilty of,
    "I paid for all that bass and treble response and dammit I'm gonna
    get it!". The eq's end up looking like lots of smiley faces with
    over accentuated bass and treble curves. 
    
    Aural fatigue will also cause an otherwise sane person to boost
    the bass into hyperspace and add enough honk to the midrange to
    make the vocalist sound like a goose.
    
    When looking for an eq, add enough to the budget for some sort
    of spectrum analyzer. Some consumer grade eq's have a small one
    built in; it's better than nothing. Feed some pink noise through
    it and then make judicious adjustments.
    
    Edd
    

    re .4, 'and then the people walked in'..
    
    I bet the room got real dull in the back, the human body absorbs
    hi freq.
    
    karl

    re: .7
    
    FMI, what's the difference between pink noise and white noise. Is
    pink noise "skewed" in terms of the frequency distribution?
    
    Rodney M.
    

    Pink noise be weighted to more closely approximate the human ear's
    response curve.
    
    Edd

    pink noise has equal energy distribution per octave.
    white noise has equal energy distribution per equal interval.
    
    So a white noise audio source (like the one from Heathkit for $80
    or $60) should put out the same energy from 100 to 200Hz as from
    200Hz to 300Hz, but twice as much from 200Hz to 400Hz.
    Pink noise should put out the same amount of energy from
    100Hz to 200Hz as from 200Hz to 400Hz.  So pink noise sounds lower.
    White is higher, and hissier.
    Tom

	I have a couple of options open to me.  O.K., maybe three...

	1)  There's a parametric someone's selling - it's a Furman PQ-3.

	Now tell me something about parametrics.  When you set a band-width,
does it have a straight slope or does it angle itself in toward the center.

Picture:

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	Or perhaps some of both or some parametrics do one, some do the other?
Is the 'straight-slope' example something more like a notch filter?  Are 
parametric EQ's a good alternative to a 1/3rd octave graphic?

	2)  I could go for the DOD 1/3rd octave EQ for a good price used (about
the same as the parametric mentioned above).

	3)  This is a long-shot, but...  I've seen the PAIA parametric EQ in the
catalog for some time.  Now before you tell me how poor a reputation PAIA has, I
understand that.  But I'm wondering if it can be added in series with my stereo
10-band EQ to deal with feedback as a notch filter.  There are four independant
sections of this EQ, and the cost is only $60.  I realize I may be adding 
significant noise...  But I wouldn't be using it for recording, only for stage.
I know... wait until you can get something good...

	4)  O.K., four options...  Not an option, really, just wondering...  Has
anyone ever used one of those cute little hand-held sound analyzers?  How are 
they for de-bugging a sound system?  There's a cheepo Rat Shack one for $29...
Would that give me any aid in finding out where that major 120Hz hum came from?

	Dan

    The $29 Rat Shack device is a sound LEVEL meter.  
    
    I have one and I use it a lot, simply because ears get fatigued
    over a long session and fail to notice that the speakers are
    putting out 110 dB and it's 11:30 PM and that's not very neighborly.
    
                                        
    Except for the A/C (OSHA versus CONSTANT (flat) ) frequency weighting
    switch, the device doesn't do frequency analysis.

    
    
    re .12
    
    The second diagram with the sloped sides is more accurate of a
    parametric.  A true parametric will also have an adjustable
    'Q' which simply put, is the width of frequencies you're cutting
    or boosting.
    
    Ralph
    
    

    The 31 band EQ is very effective at eliminating ringing.  Most
    professionals use one for every monitor mix they send to the stage.
    
    The tricky part is figuring out exactly which frequency is causing
    the problem.  I can usually identify the octave (1K versus 500 hz)
    but have to diddle around to figure exactly which of the three silders
    to tweak.
    
    I personally don't care for parametric EQs on the whole mix in a
    live situation.  Having a paramteric EQ for each channel in either
    a live or recording board is wonderful, however.
    
    I would vote for the third octave (31 band) EQ for live use.
    
    		Derek
    

    re .15 - the standard way to identify the troublesome frequency
    is to *boost* the gain on each slider successively until you find
    the one that boosted makes things howl.  Then you cut that one back.
    WJB (I think) pointed this out somewhere else recently, but it's
    pretty common practice.  Just be careful when you do it - 18 db
    of boost at a feedback frequency could be just what it takes to
    burn out a driver.
    
    len.
     

    Per the Cameo Dictionary of creative audio terms:
    
    Pink Noise - Random Noise which is modified to have an equal amount
    of energy in each octave. The octave from 10000hz to 20000hz occupies
    10000hz of bandwidth, whereas the octave from 5000hz to 10000hz
    occupies only 5000hz of bandwidth, but due to a 6db/octave roll-off,
    both octaves would contain equal pink noise energy.
    
    White Noise - Random noise which contains equal energy for any equal
    bandwidths. That is , the 5000hz badwidth from 5000hz to 10000hz
    and 10000hz to 15000hz would have equal white noise energy. The
    total energy per octave increases 6db/octave as you go up in frequency.
    
    .10 and .11 described pink noise accurately. Just thought you might
    like to hear the textbook definitions.
    
    Mark Jacques.
    

    
    The best way, if you have the hardware, is to use an RTA set at
    minimum gain. The LED that lights up is the band that's oscillating.
    Very quick and effective, you don't have to dip the volume at all.
    
    Re: Derek
    
    Nice picture in the Worcester Telegram. That's my memory in that
    system, BTW.
    
    CdH_ex_8300_memory_designer
    
    

    I just demo'd a real nice EQ this weekend made by DBX. This is a
    pro audio model with both balanced and unbalanced ins and outs.
    It is a single rack space model with one very unique feature.
    It doubles as a Stereo 10 band/Mono 21 band graphic equalizer
    at the flick of a switch . The asking price at Wurlitzers was $350 but 
    I would shoot a little lower if I was looking to buy. The dual 
    function makes it extremely flexible. Sounded excellant as well
    with plenty of headroom. 
    
    Check it out !!!
    
    Mark Jacques
    

    correction, the dbx equalizer mentioned  in .19 is actually
    15 bands/side in stereo mode, or 31 bands in mono. It does +-15db
    cut/boost. Single space rack unit.
    
    Mark

    
    
      Dan...
    
      Which EQ did you end up getting?.
    
    
    
    
    
    RichC
    

    	Well, it's been some time, but I ended up selling my ten band and
    picking up a 15 band (both stereo).  I'm waiting to see Alesis' new
    dual 1/3rd octave for $199 for a possible addition to my system.
    
    	Dan